[Objective]This study was to analyze the karyotypes of wild diploid strawberry species,so as to provide basis for revealing the ori- gins,evolvement and genetic breeding of strawberry. [Method] Four diploid strawberry...[Objective]This study was to analyze the karyotypes of wild diploid strawberry species,so as to provide basis for revealing the ori- gins,evolvement and genetic breeding of strawberry. [Method] Four diploid strawberry species including Fragaria gracilis A. Los,Fragaria nilgerrensis Schidl,Fragaria pentaphylla A. Los. and Fragaria vesca L. were used as experimental materials to analyze their chromosomal kary- otypes. [Result]The karyotype formula for strawberry species tested was as follows： 2n =2x =14 =10m ＋2sm ＋2m＊ for F. gracilis A. Los, belonging to type 1B; 2n =2x =14 =14m for F. nilgerrensis Schidl,belonging to type 1A; 2n =2x =14 =12m ＋2sm for F. pentaphylla A. Loz. , belonging to type 1A; 2n =2x =14 =14m for F. vesca L. ,belonging to type 1A. Karyotype analysis showed that karyotypic asymmetry degree of the four species was F. gracilis A. Los. F. pentaphylla A. Loz. F. vesca L. F. nilgerrensis Schidl. [Conclusion] The evolution order of these four species was probably F. gracilis A. Los. ,F. pentaphylla A. Loz. ,F. vesca L. ,F. nilgerrensis Schidl.展开更多
The chromosome karyotypes of Chorthippus （Megaulacobothrus） aethalinus （Zubovsky） and Ch. （M.） chinensis Tarbinsky were compared. Results show that the chromosome numbers of the two species fit 2n （♂） = 17 = ...The chromosome karyotypes of Chorthippus （Megaulacobothrus） aethalinus （Zubovsky） and Ch. （M.） chinensis Tarbinsky were compared. Results show that the chromosome numbers of the two species fit 2n （♂） = 17 = 16 ＋ XO, in which three pairs of autosomal and sex chromosomes were terminal chromosomes, and the other five pairs of autosomes were metacentric chromosomes. These are diagnosis characters for Chorthippus. However, these two species can be distinguished by the different chromosome formula （CF） and the relative length （RL）. The CF in Ch. （M.） aethalinus is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 6M ＋ 4S ＋ XO, whereas that of Ch. （M.） chinensis is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 8M ＋ 2S ＋ XO. In addition, we also found that the relative lengths of sex chromosomes in the two species were different from each other. The sex-chromosome of Ch. （M.） aethalinus is located at the fifth position and its relative length is 8.33% whereas that of Ch. （M.） chinensis is at the eighth position and its relative length is 5.53%. These results show that significantly different genetic features exist for the two species of Chorthippus.展开更多
The chromosomal number variations & structural aberrations of the MDCK cell line, primary feline or canine kidney cell(FKC or CKC) and Hela cell line were investigated and their karyotypes of conventional chromoso...The chromosomal number variations & structural aberrations of the MDCK cell line, primary feline or canine kidney cell(FKC or CKC) and Hela cell line were investigated and their karyotypes of conventional chromosome bands were analyzed. The carcinogenesis or tumorigenicity testing of these cell lines in about 232 nude mice and for colony formation in soft agarose and for haemagglutination under different concentration of plant lectins of these cells were carried out. Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0 (0/10), respectively. The incidence of the progressively-growing malignant tumor(MT) in positive-control nude mice inoculated subcutaneously with Hela cell cultures of KB, X, or NM20/X strain was 10/10, 25/25 and 5/51, respectively. The results showed that the incidence of tumor in nude mice with tetraploid YA strain of MDCK cell during 20 - 45 passages, with hy-podiploid JB strain of MDCK cell on passage 25, with di-and hypoploid JC strain of MDCK cell during 2-15 passages or with hypoploid M strain of MDCK cell during 9 - 27 passages was 28/58, 1/5, 4/18 and 0/31, respectively. The chromosomal analysis results showed that the ratio of difference in the rate of modal chromosome number between high(mcs+ n) and lowest (mcs) passages was not more than 5% - 15% and the structure aberrations was generally 0 - 3% . These results proved that the genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species-specific. MDCK line has tumorigenicity no matter what its chromosome karyotype is, at least it has very low tumorigenicity even when its modal chromosome number is hypoploid. The repeatedly frozen, thawed and split controls of tumorigenicity-positive cell lines(X strain of Hela, M strain of BHK-21, JA strain of Vero, YA strain of MDCK) have much lower tumorigenicity or are even non-carcinogenesis, and the repeatedly frozen, thawed and split controls of very low tumorigenicity cell lines (M or JC strain of MDCK) are certainly non-carcinogenic and never have increased tumorigenicity. It is thus evident that MDCK cell of M, JB or JC strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YA strain can not be approved as substrate for the preparation of attenuated viral vaccines. In summary, all strains of MDCK cell line have tunorigenicity, at least have low tumor igencity , never have non-cancinogenic MDCK, but very low tumorigenicity MDCK cell strains can certainly be used for the approval production of canine viral vaccines if the DNA content in viral cell cultures was remarkably decreased through conventional means in manufacturing process. Therefore, the master cell stock and working cell bank of MDCK line used for vaccine manufacture were established in China, which are free of infectious agents, and described with respect to cytogenetic characteristics and tumorigenicity.Tests showed that there were correlations among cell line chromosome number variations, anchorage independence in soft a-garose, haemagglutination under plant lectins, and tumor-forming ability in nude mice, thus all the in vitro tests are economic, simple and reliable means for monitoring the tumor-forming ability of MDCK line in nude mice.展开更多
[Objective] This study aimed to investigate the chromosomes and karyotypes of three seagrass species of hydrocharitaceae-Enhalus acoroides, Thalassia hemprichii and Halophila minor collected from Li’an Lagoon, Hainan...[Objective] This study aimed to investigate the chromosomes and karyotypes of three seagrass species of hydrocharitaceae-Enhalus acoroides, Thalassia hemprichii and Halophila minor collected from Li’an Lagoon, Hainan Province, China. [Method] The root-tips of E. acoroides, T. hemprichii and the axillary buds of H. minor were selected as the materials in this study. The conventional crushing method was used to prepare the slice specimens of chromosomes, and the karyotypes of the three species were analyzed. [Result] The chromosome numbers of E. acoroides, T. hemprichii and H. minor were 2n=18, 18, 28, respectively. The karyotype formulas were K （2n）=18= 12m＋6sm, K（2n）=18=12m＋6sm and K（2n）=28=16m＋8sm＋4st, respectively. According to the standard of Stebbins, the karyotypes of E. acoroides and T. hemprichii were 2A, and that of H. minor was 2B. There was no B chromosome and satellite in these three species. [Conclusion] According to the comparison on the karyotypes of this three species, E. acoroides and T. hemprichii are similar in karyotypes to each other, indicating that there is close, inter-relationship between E. acoroides and T. hemprichii.展开更多
The chromosome karyotypes of Chorthippus albomarginatus （De Geer） which represents the genus Chorthippus Fieber and Euchorthippus unicolor （Ikonnikov） which represents the genus Euchorthippus Tarbinsky were compar...The chromosome karyotypes of Chorthippus albomarginatus （De Geer） which represents the genus Chorthippus Fieber and Euchorthippus unicolor （Ikonnikov） which represents the genus Euchorthippus Tarbinsky were compared. The chromosome numbers for these two species fit 2n （♂） = 17 = 16 ＋ XO, in which five pairs of autosomal and sex chromosomes are terminal chromosomes, and the other three pairs of autosomes are metacentric chromosomes. This similarity between the two genera indicates that they have a close phylogenetic relationship. However, these two species can be distinguished by their different chromosome formula （CF） and the relative sex chromosome length （RL）. The CF in C. albomarginatus is K （2n,♂） = 6m ＋ 11t = 8L ＋ 4M ＋ 4S ＋ XO, whereas that ofE. unicolor is K （2n, ♂） = 6m ＋ 11t = 8L ＋ 6M ＋ 2S ＋ XO. The relative lengths of sex chromosomes in the two species are different. The sex-chromosome of C. albomarginatus is located at the ninth position and its relative length is 2.96% whereas that ofE. unicolor is at the eighth position and its relative length is 4.26%. These results show that significantly different genetic features exist for the two genera.展开更多
The chromosomes of three odor frogs, Luetuosae- group of Rana were analyzed by conventional, as well as Obanding and silver staining techniques. The three species here examined all had 26 chromosome karyotypes encompa...The chromosomes of three odor frogs, Luetuosae- group of Rana were analyzed by conventional, as well as Obanding and silver staining techniques. The three species here examined all had 26 chromosome karyotypes encompassing 5 large and 8 small homologous pairs. Differences among them were found in gross shapes of chromosomes and positions of secondary constrictions. Generally speaking, karyotypes of R. andersonii and R. grahami resembled each other, while the karyotype of R. tiannanensis differed from the former two in several respects.Analyses of karyotypes by C-banding technique indicated that, centromeric areas of every chromosome and interstitial parts of some chromosomes of each species were hetero-chromatinized, and differences of distribution of heterochromatin were found among species. In early metaphase plates of R. andersonii, much more heterochromatinized areas were observed, and when it reached late metaphase, the numbers of heterochromatin sections in each chromosome pair reduced to a limited level, e. g. centromeres and a few interstitial parts.The active nucleolar organizer regions (NORs) were localized in long arms of pair No. 10, in connection with secondary constrictions for R. andersonii and R. grahami as in other odor frogs previously reported, but in the long arm of pair No. 6 for R. tiannanensis.The cytogenetic and taxonomic implications of the findings were discussed based on comparisons with each other, and with published literature.展开更多
The karyotypes of three species of marine Veneroida molluscs, Solen grandis Dunker, Saxidomus purpuratus Sowerby and Mactra chinensis Philippi were studied by using the adult gill tissues. The chromosomes were-prepare...The karyotypes of three species of marine Veneroida molluscs, Solen grandis Dunker, Saxidomus purpuratus Sowerby and Mactra chinensis Philippi were studied by using the adult gill tissues. The chromosomes were-prepared through injecting phytohemagglutinin (PHA) and colchicine, hypotonic treatment, chopping air-dry, and squashing technology. The results show that the diploid chromosome numbers of the three Veneroida species are the same as 2n = 38. The karyotype of Solen grandis is 26m + 6sm + 2st + 4t, NF = 70, the karyotype of Saxidomus purpuratus is 32m + 2sm + 4st/t, NF = 72, and the karyotype of Mactra chinensis is 20m + 16sm + 2st/t, NF = 74. Satellite and sex chromosome were not found among the chromosomes of three species.展开更多
Karyotypes of four Chinese species of field mice of the genus Apodemus were examined,including Apodemus chevrieri （diploid chromosome number,2n=48,fundamental number of autosomal arms,FNa=56）,A.draco （2n=48,FNa=48...Karyotypes of four Chinese species of field mice of the genus Apodemus were examined,including Apodemus chevrieri （diploid chromosome number,2n=48,fundamental number of autosomal arms,FNa=56）,A.draco （2n=48,FNa=48）,A.ilex （2n=48,FNa=48）,and A.latronum （2n=48,FNa=48）.Karyotypes of A.chevrieri,A.draco,and A.ilex are reported here for the first time,providing useful information for their species taxonomy.Determining the karyotypes of all species of Apodemus in Asia,both in this and previous studies,provides a solid overview of the chromosome evolution and species differentiation of the genus in East Asia.In addition to allopatric speciation,chromosome rearrangements likely played an important role in the formation of the four Apodemus species groups as well as speciation within each group in East Asia.For example,increased centromeric heterochromatin in A.latronum may have contributed to the post-mating reproductive isolation from the A.draco-A.ilex-A.semotus clade.展开更多
The Hengduan Mountains region is a biodiversity hotspot. In this study, we report the karyotypes of 19 species(21 populations) of Asteraceae from this region, 14 of which are reported for the first time. We also exami...The Hengduan Mountains region is a biodiversity hotspot. In this study, we report the karyotypes of 19 species(21 populations) of Asteraceae from this region, 14 of which are reported for the first time. We also examined polyploidy in Asteraceae plants and summarized karyotype data in the literature for 69 congeneric taxa. In these genera, there were five different ploidy levels in the region, though the most dominant was diploid(73.08%). There is no direct evidence that ploidy level and karyotype asymmetry are associated with the distribution of recorded Asteraceae species from the Hengduan Mountains. This suggests that polyploidy(26.92%) may not play an important role in the evolutionary history of these plants, even though, among these genera, the ratio of paleopolyploidy was high(46.15%).展开更多
[ Objective] This study aimed at investigating the chromosomal characteristics and karyotypes of Gynura medica. [ Method ] Stem tips of G. medica seedlings were taken every 20 min from 6：30 to 10：30 am, and then wer...[ Objective] This study aimed at investigating the chromosomal characteristics and karyotypes of Gynura medica. [ Method ] Stem tips of G. medica seedlings were taken every 20 min from 6：30 to 10：30 am, and then were treated and squashed. The slices were observed under a microscope for investigating the chromosomal number and karyotypes of the cells in metaphase in which the chromosomes were well dispersed. [ Result] In the total 102 stem tip cells in meta- phase, 96.08% of cells were with 20 chromosomes, and 3.92% of cells were with 40 chromosomes. Optimal time for sampling was from 7：50 to 9：30 am, when more cells were in metaphase. [Conclusion] C. medica is the diploid plant with 20 chromosomes. Karyotype analysis gets formula 2n = 2x = 20m, and all 10 pairs of chromosomes belong to type 1A. The article reporls the chromosomes characteristics of G. rnedica firstly.展开更多
In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amoun...In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amount of transcriptionally active nucleolar organizer regions on chromosomes were analyzed by Giemsa staining and Ag-NORs. The results showed that the number of diploid chromosomes of O. potamophila was 44; the genome of O. potamophila was composed of 44 telocentric chromosomes; the karyotype formula was 2 n = 44 t,NF = 44; Ag-NORs were found in the paracentromeric region of chromosome. The results may lay the foundation for revealing the genetic pattern and chromosomal evolution of O. potamophila and contribute to further genetic breeding of O. potamophila.展开更多
By adopting the method based on colchicine-hypotonic-air drying technique with bone marrow cells, the paper presents the chromosome of four egg-type fowl breeds. The diploid chromosome 2n=78, chromosomal morphology ar...By adopting the method based on colchicine-hypotonic-air drying technique with bone marrow cells, the paper presents the chromosome of four egg-type fowl breeds. The diploid chromosome 2n=78, chromosomal morphology are very similar and sex chromosome type are ZZ (♂) and ZW(♀) in four egg-type fowl breeds. According to standard of Leven in 1964, the euchromosome and sex chromosome of four breeds are measured and compared in relative length arm ratio and centromere index of each chromosome including all the microchromosome. The morphology of these chromosome is described as follows: pair1, 2, 8 and ZW are metacentric, pair 4 and 6 are submetacentric, and the rest is telocentric.展开更多
The karyotypes and meiotic behaviors of three Carbula species( Carbula obtusangula Reuter, C.putoni (Jakovlev)and C. sinica Hsiao et Cheng)were studied.Karyotype analyses using specific software were m...The karyotypes and meiotic behaviors of three Carbula species( Carbula obtusangula Reuter, C.putoni (Jakovlev)and C. sinica Hsiao et Cheng)were studied.Karyotype analyses using specific software were made and model karyotype chart was presented.All three species have the typical diploid chromosome number of 14 for the family Pentatomidae and X Y sex chromosomal mechanism,but the behavior of autosomes and sex chromosomes during meiosis among three species are different,and one or two supernumerary chromosomes were detected in C.putoni. These characteristics may provide some useful clues on the study of pentatomid taxonomy and phylogeny.展开更多
Haploid chromosome numbers （n） of parasitic Hymenoptera （= traditional Parasitica ＋ Chrysidoidea） vary from 2 to 23. However, this range can be subdivided into three intervals with n = 14-23 （less derived parasi...Haploid chromosome numbers （n） of parasitic Hymenoptera （= traditional Parasitica ＋ Chrysidoidea） vary from 2 to 23. However, this range can be subdivided into three intervals with n = 14-23 （less derived parasitic wasps, e.g., some Ichneumonidae and Braconidae as well as Gasteruptiidae）, 8-13 （many other parasitic Hymenoptera） and 2-7 （Dryinidae, the majority of Chalcidoidea and some advanced Braconidae, e.g. Aphidiinae）. The symmetric karyotype with a relatively high chromosome number （n -- 14-17） and the prevalence of biarmed chromosomes must be considered as a groundplan feature of parasitic Hymenoptera. Independent reductions of chromosome numbers （n ≤ 10-11） occurred in some groups of the superfamily Ichneumonoidea as well as in the common ancestor of the Proctotrupoidea sensu lato, Ceraphronoidea, Cynipoidea and Chalcidoidea. Further mul- tiple decreases in chromosome numbers （n ≤ 4-6） took place in some Braconidae, various lineages of the superfamily Chalcidoidea as well as in the family Dryinidae. Two main trends prevailed in the karyotype evolution of parasitic wasps： the reduction of chromosome numbers （mainly due to tandem fusions and less frequently due to centric ones） and karyotypic dissymmetrization （through an increase in size differentiation of chromosomes and/or in the share of acrocentrics in a chromosome set）. Although karyotypic features of parasitic Hymenoptera can be used for solving taxonomic problems at various levels, this method is the most effective at the species level.展开更多
Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.T...Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.This study evaluates the efficacy of multiple genetic technologies-including karyotyping,fluorescence in situ hybridization(FISH),chromosomal microarray analysis(CMA),and next-generation sequencing(NGS)-in detecting and characterizing derivative chromosomes in prenatal samples.methodology:We analyzed 150 cases of suspected chromosomal abnormalities,comparing detection rates,resolution,and clinical utility across these methods.Results:Our findings demonstrate that integrated multi-technology approaches significantly improve diagnostic accuracy,with NGS-based structural variation analysis achieving the highest detection sensitivity(99.2%)for cryptic rearrangements.Conclusions:Additionally,long-read sequencing(PacBio/Oxford Nanopore)enabled precise breakpoint mapping in 92%of cases,facilitating more accurate genetic counseling.Clinically,this approach enhances risk assessment for fetal anomalies,guides pregnancy management,and improves parental counseling for recurrence risks.展开更多
This study conducted karyotype analysis on 56 Chinese kale varieties from Guangdong and Fujian provinces using conventional chromosome analysis methods.The varieties were categorized into four groups based on their or...This study conducted karyotype analysis on 56 Chinese kale varieties from Guangdong and Fujian provinces using conventional chromosome analysis methods.The varieties were categorized into four groups based on their origin and flower color:white-flower Chinese kale originating from Guangdong(GW),yellow-flower Chinese kale originating from Guangdong(GY),white-flower Chinese kale originating from Fujian(FW),and yellow-flower Chinese kale originating from Fujian(FY).Karyotype differences among the four groups of Chinese kale were analyzed,and the evolutionary relationship between yellow-flower and white-flower Chinese kale from the two regions was inferred based on karyotype parameters.The results indicated that all Chinese kale varieties were diploid with 2n=2x=18,including a pair of satellites.The chromosome types included median-centromere(m)and sub-median-centromere(sm),and the karyotypes were 1A and 2A,a sper karyotype asymmetry index.The karyotype 1A of Chinese kale was identified for the first time.Partial least squares discriminant analysis(PLS-DA)identified nine karyotypic indicators that differentiated the four groups,and these differences were further visualized using heatmaps and box plots.Based on the evolution trends in the four groups and PLS-DA analysis,it was speculated that white-flower Chinese kale originated from Guangdong,yellow-flower Chinese kale originated from Fujian,and GY and FW were derived from the cross of GW and FY.This study provides a reference for understanding the genetic relationships between Chinese kale in Guangdong and Fujian,and offers a cytological basis for the evolution,hybridization,and phylogenetic relationships of Chinese kale.展开更多
Hibiscus Linn.,an angiosperm genus belonging to Malvaceae,Malvales,is mainly distributed in tropic and subtropic regions.Numerous species within the Hibiscus genus exhibit large and visually appealing flowers that are...Hibiscus Linn.,an angiosperm genus belonging to Malvaceae,Malvales,is mainly distributed in tropic and subtropic regions.Numerous species within the Hibiscus genus exhibit large and visually appealing flowers that are highly prized for their ornamental beauty and enjoy widespread admiration.For instance,H.syriacus serves as the national flower of South Korea,H.rosa-sinensis is favored as the floral emblem of Malaysia,and Chengdu city has earned the moniker"City of H.mutabilis"owing to its substantial cultivation.展开更多
Established allopolyploid species often contain specific gene(s)dedicated to suppressing the pairing of homoeologous chromosomes during meiosis.A longstanding question is whether such genes in allopolyploids with lowe...Established allopolyploid species often contain specific gene(s)dedicated to suppressing the pairing of homoeologous chromosomes during meiosis.A longstanding question is whether such genes in allopolyploids with lower ploidy levels can retain full functionality when the ploidy level rises following the addition of a new subgenome during outcrossing.Here,we addressed this question by generating a synthetic allohexaploid wheat species,Triticum kiharae(GGAADD),by crossing the allotetraploid Triticum timopheevii(GGAA)to the diploid Aegilops tauschii(DD),followed by colchicine-induced chromosomal doubling.The gene Pairing homoeologous 1(Ph1)inherited from T.timopheevii was likely hypofunctional in nascent T.kiharae,as evidenced by irregularities during meiotic chromosome pairing and organismal numerical and structural chromosome variation in selfed progeny populations.The allohexaploidization event also induced substantial rewiring of gene expression among homoeologs and nonadditive gene expression,leading to distinct predicted biological functions for differentially expressed genes(DEGs)when they were partitioned into the subgenomes.F1hybrids from a cross between T.kiharae and bread wheat(T.aestivum,BBAADD)were male-sterile but female-fertile,confirming intrinsic postzygotic reproductive isolation between the two species while enabling backcrossing of these sterile F1hybrids to bread wheat.These features provide a feasible route to simultaneously introgress standing congeneric genetic variations from both T.timopheevii and Ae.tauschii,as well as heritable de novo variations that have arisen in T.kiharae into bread wheat.展开更多
The Malvaceae family,the most diverse family in the order Malvales,consists of nine subfamilies.Within the Firmiana genus of the Sterculioideae subfamily,most species are considered globally vulnerable,yet their genom...The Malvaceae family,the most diverse family in the order Malvales,consists of nine subfamilies.Within the Firmiana genus of the Sterculioideae subfamily,most species are considered globally vulnerable,yet their genomes remain unexplored.Here,we present a chromosome-level genome assembly for a representative Firmiana species,F.hainanensis,2n=40,totaling 1536 Mb.Phylogenomic analysis shows that F.hainanensis and Durio zibethinus have the closest evolutionary relationship,with an estimated divergence time of approximately 21 millions of years ago(MYA)and distinct polyploidization events in their histories.Evolutionary trajectory analyses indicate that fissions and fusions may play a crucial role in chromosome number variation(2n=14 to 2n=96).Analysis of repetitive elements among Malvaceae reveals that the Tekay subfamily(belonging to the Gypsy group)contributes to variation in genome size(ranging from 324 Mb to 1620 Mb).Additionally,genes associated with P450,peroxidase,and microtubules,and thereby related to cell wall biosynthesis,are significantly contracted in F.hainanensis,potentially leading to its lower wood density relative to Hopea hainanensis.Overall,our study provides insights into the evolution of chromosome number,genome size,and the genetic basis of cell wall biosynthesis in Malvaceae species.展开更多
基金Supported by Program for Excellent Scholars Returned from Overseas~~
文摘[Objective]This study was to analyze the karyotypes of wild diploid strawberry species,so as to provide basis for revealing the ori- gins,evolvement and genetic breeding of strawberry. [Method] Four diploid strawberry species including Fragaria gracilis A. Los,Fragaria nilgerrensis Schidl,Fragaria pentaphylla A. Los. and Fragaria vesca L. were used as experimental materials to analyze their chromosomal kary- otypes. [Result]The karyotype formula for strawberry species tested was as follows： 2n =2x =14 =10m ＋2sm ＋2m＊ for F. gracilis A. Los, belonging to type 1B; 2n =2x =14 =14m for F. nilgerrensis Schidl,belonging to type 1A; 2n =2x =14 =12m ＋2sm for F. pentaphylla A. Loz. , belonging to type 1A; 2n =2x =14 =14m for F. vesca L. ,belonging to type 1A. Karyotype analysis showed that karyotypic asymmetry degree of the four species was F. gracilis A. Los. F. pentaphylla A. Loz. F. vesca L. F. nilgerrensis Schidl. [Conclusion] The evolution order of these four species was probably F. gracilis A. Los. ,F. pentaphylla A. Loz. ,F. vesca L. ,F. nilgerrensis Schidl.
基金supported by the Special fund for basic scientific research project in the central scientific research institutes (Institute of Grassland Research of CAAS)(1610332012007)
文摘The chromosome karyotypes of Chorthippus （Megaulacobothrus） aethalinus （Zubovsky） and Ch. （M.） chinensis Tarbinsky were compared. Results show that the chromosome numbers of the two species fit 2n （♂） = 17 = 16 ＋ XO, in which three pairs of autosomal and sex chromosomes were terminal chromosomes, and the other five pairs of autosomes were metacentric chromosomes. These are diagnosis characters for Chorthippus. However, these two species can be distinguished by the different chromosome formula （CF） and the relative length （RL）. The CF in Ch. （M.） aethalinus is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 6M ＋ 4S ＋ XO, whereas that of Ch. （M.） chinensis is K （2n, ♂） = 6m ＋ 11t = 6L ＋ 8M ＋ 2S ＋ XO. In addition, we also found that the relative lengths of sex chromosomes in the two species were different from each other. The sex-chromosome of Ch. （M.） aethalinus is located at the fifth position and its relative length is 8.33% whereas that of Ch. （M.） chinensis is at the eighth position and its relative length is 5.53%. These results show that significantly different genetic features exist for the two species of Chorthippus.
文摘The chromosomal number variations & structural aberrations of the MDCK cell line, primary feline or canine kidney cell(FKC or CKC) and Hela cell line were investigated and their karyotypes of conventional chromosome bands were analyzed. The carcinogenesis or tumorigenicity testing of these cell lines in about 232 nude mice and for colony formation in soft agarose and for haemagglutination under different concentration of plant lectins of these cells were carried out. Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0 (0/10), respectively. The incidence of the progressively-growing malignant tumor(MT) in positive-control nude mice inoculated subcutaneously with Hela cell cultures of KB, X, or NM20/X strain was 10/10, 25/25 and 5/51, respectively. The results showed that the incidence of tumor in nude mice with tetraploid YA strain of MDCK cell during 20 - 45 passages, with hy-podiploid JB strain of MDCK cell on passage 25, with di-and hypoploid JC strain of MDCK cell during 2-15 passages or with hypoploid M strain of MDCK cell during 9 - 27 passages was 28/58, 1/5, 4/18 and 0/31, respectively. The chromosomal analysis results showed that the ratio of difference in the rate of modal chromosome number between high(mcs+ n) and lowest (mcs) passages was not more than 5% - 15% and the structure aberrations was generally 0 - 3% . These results proved that the genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species-specific. MDCK line has tumorigenicity no matter what its chromosome karyotype is, at least it has very low tumorigenicity even when its modal chromosome number is hypoploid. The repeatedly frozen, thawed and split controls of tumorigenicity-positive cell lines(X strain of Hela, M strain of BHK-21, JA strain of Vero, YA strain of MDCK) have much lower tumorigenicity or are even non-carcinogenesis, and the repeatedly frozen, thawed and split controls of very low tumorigenicity cell lines (M or JC strain of MDCK) are certainly non-carcinogenic and never have increased tumorigenicity. It is thus evident that MDCK cell of M, JB or JC strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YA strain can not be approved as substrate for the preparation of attenuated viral vaccines. In summary, all strains of MDCK cell line have tunorigenicity, at least have low tumor igencity , never have non-cancinogenic MDCK, but very low tumorigenicity MDCK cell strains can certainly be used for the approval production of canine viral vaccines if the DNA content in viral cell cultures was remarkably decreased through conventional means in manufacturing process. Therefore, the master cell stock and working cell bank of MDCK line used for vaccine manufacture were established in China, which are free of infectious agents, and described with respect to cytogenetic characteristics and tumorigenicity.Tests showed that there were correlations among cell line chromosome number variations, anchorage independence in soft a-garose, haemagglutination under plant lectins, and tumor-forming ability in nude mice, thus all the in vitro tests are economic, simple and reliable means for monitoring the tumor-forming ability of MDCK line in nude mice.
基金Supported by the State key Subjecet of Botany at Hainan University (071001)the Malor Scientific Research Protect of Hainan Province, China(20080137)~~
文摘[Objective] This study aimed to investigate the chromosomes and karyotypes of three seagrass species of hydrocharitaceae-Enhalus acoroides, Thalassia hemprichii and Halophila minor collected from Li’an Lagoon, Hainan Province, China. [Method] The root-tips of E. acoroides, T. hemprichii and the axillary buds of H. minor were selected as the materials in this study. The conventional crushing method was used to prepare the slice specimens of chromosomes, and the karyotypes of the three species were analyzed. [Result] The chromosome numbers of E. acoroides, T. hemprichii and H. minor were 2n=18, 18, 28, respectively. The karyotype formulas were K （2n）=18= 12m＋6sm, K（2n）=18=12m＋6sm and K（2n）=28=16m＋8sm＋4st, respectively. According to the standard of Stebbins, the karyotypes of E. acoroides and T. hemprichii were 2A, and that of H. minor was 2B. There was no B chromosome and satellite in these three species. [Conclusion] According to the comparison on the karyotypes of this three species, E. acoroides and T. hemprichii are similar in karyotypes to each other, indicating that there is close, inter-relationship between E. acoroides and T. hemprichii.
基金funded by the Special Fund for Agro-scientific Research in the Public Interest(201003079)Special Fund for Basic Scientific Research Project in the Central Scientific Research Institutes(Institute of Grassland Research of CAAS)(1610332014012)+1 种基金National Natural Science Foundation of China(41301049)the Ministry of Science and Technology of the Republic of China(2013DFR30760)
文摘The chromosome karyotypes of Chorthippus albomarginatus （De Geer） which represents the genus Chorthippus Fieber and Euchorthippus unicolor （Ikonnikov） which represents the genus Euchorthippus Tarbinsky were compared. The chromosome numbers for these two species fit 2n （♂） = 17 = 16 ＋ XO, in which five pairs of autosomal and sex chromosomes are terminal chromosomes, and the other three pairs of autosomes are metacentric chromosomes. This similarity between the two genera indicates that they have a close phylogenetic relationship. However, these two species can be distinguished by their different chromosome formula （CF） and the relative sex chromosome length （RL）. The CF in C. albomarginatus is K （2n,♂） = 6m ＋ 11t = 8L ＋ 4M ＋ 4S ＋ XO, whereas that ofE. unicolor is K （2n, ♂） = 6m ＋ 11t = 8L ＋ 6M ＋ 2S ＋ XO. The relative lengths of sex chromosomes in the two species are different. The sex-chromosome of C. albomarginatus is located at the ninth position and its relative length is 2.96% whereas that ofE. unicolor is at the eighth position and its relative length is 4.26%. These results show that significantly different genetic features exist for the two genera.
文摘The chromosomes of three odor frogs, Luetuosae- group of Rana were analyzed by conventional, as well as Obanding and silver staining techniques. The three species here examined all had 26 chromosome karyotypes encompassing 5 large and 8 small homologous pairs. Differences among them were found in gross shapes of chromosomes and positions of secondary constrictions. Generally speaking, karyotypes of R. andersonii and R. grahami resembled each other, while the karyotype of R. tiannanensis differed from the former two in several respects.Analyses of karyotypes by C-banding technique indicated that, centromeric areas of every chromosome and interstitial parts of some chromosomes of each species were hetero-chromatinized, and differences of distribution of heterochromatin were found among species. In early metaphase plates of R. andersonii, much more heterochromatinized areas were observed, and when it reached late metaphase, the numbers of heterochromatin sections in each chromosome pair reduced to a limited level, e. g. centromeres and a few interstitial parts.The active nucleolar organizer regions (NORs) were localized in long arms of pair No. 10, in connection with secondary constrictions for R. andersonii and R. grahami as in other odor frogs previously reported, but in the long arm of pair No. 6 for R. tiannanensis.The cytogenetic and taxonomic implications of the findings were discussed based on comparisons with each other, and with published literature.
文摘The karyotypes of three species of marine Veneroida molluscs, Solen grandis Dunker, Saxidomus purpuratus Sowerby and Mactra chinensis Philippi were studied by using the adult gill tissues. The chromosomes were-prepared through injecting phytohemagglutinin (PHA) and colchicine, hypotonic treatment, chopping air-dry, and squashing technology. The results show that the diploid chromosome numbers of the three Veneroida species are the same as 2n = 38. The karyotype of Solen grandis is 26m + 6sm + 2st + 4t, NF = 70, the karyotype of Saxidomus purpuratus is 32m + 2sm + 4st/t, NF = 72, and the karyotype of Mactra chinensis is 20m + 16sm + 2st/t, NF = 74. Satellite and sex chromosome were not found among the chromosomes of three species.
基金supported by the National Natural Science Foundation of China(NSFC)Major International(Regional)Joint Research Project Grant(31110103910)National Basic Research Program of China(2013FY111500)+1 种基金JSPS KAKENHI grant JP18H03602JSPS Core-to-Core Program B.Asia Africa Science Platforms
文摘Karyotypes of four Chinese species of field mice of the genus Apodemus were examined,including Apodemus chevrieri （diploid chromosome number,2n=48,fundamental number of autosomal arms,FNa=56）,A.draco （2n=48,FNa=48）,A.ilex （2n=48,FNa=48）,and A.latronum （2n=48,FNa=48）.Karyotypes of A.chevrieri,A.draco,and A.ilex are reported here for the first time,providing useful information for their species taxonomy.Determining the karyotypes of all species of Apodemus in Asia,both in this and previous studies,provides a solid overview of the chromosome evolution and species differentiation of the genus in East Asia.In addition to allopatric speciation,chromosome rearrangements likely played an important role in the formation of the four Apodemus species groups as well as speciation within each group in East Asia.For example,increased centromeric heterochromatin in A.latronum may have contributed to the post-mating reproductive isolation from the A.draco-A.ilex-A.semotus clade.
基金supported by the National Natural Science Foundation of China (31670206, 31360049) to Zhi-Min Limajor Program of NSFC (grant 31590823, 31590820) to Hang Sun,NSFC (31370004, 31570213) to Jian-Wen Zhang
文摘The Hengduan Mountains region is a biodiversity hotspot. In this study, we report the karyotypes of 19 species(21 populations) of Asteraceae from this region, 14 of which are reported for the first time. We also examined polyploidy in Asteraceae plants and summarized karyotype data in the literature for 69 congeneric taxa. In these genera, there were five different ploidy levels in the region, though the most dominant was diploid(73.08%). There is no direct evidence that ploidy level and karyotype asymmetry are associated with the distribution of recorded Asteraceae species from the Hengduan Mountains. This suggests that polyploidy(26.92%) may not play an important role in the evolutionary history of these plants, even though, among these genera, the ratio of paleopolyploidy was high(46.15%).
基金Supported by Chinese Medical Science and Technology Program of Zhejiang Province(2011ZB132)the Science and Technology Innovation Program for Undergraduate Students of Zhejiang Province(ZJRCKJCX201007)
文摘[ Objective] This study aimed at investigating the chromosomal characteristics and karyotypes of Gynura medica. [ Method ] Stem tips of G. medica seedlings were taken every 20 min from 6：30 to 10：30 am, and then were treated and squashed. The slices were observed under a microscope for investigating the chromosomal number and karyotypes of the cells in metaphase in which the chromosomes were well dispersed. [ Result] In the total 102 stem tip cells in meta- phase, 96.08% of cells were with 20 chromosomes, and 3.92% of cells were with 40 chromosomes. Optimal time for sampling was from 7：50 to 9：30 am, when more cells were in metaphase. [Conclusion] C. medica is the diploid plant with 20 chromosomes. Karyotype analysis gets formula 2n = 2x = 20m, and all 10 pairs of chromosomes belong to type 1A. The article reporls the chromosomes characteristics of G. rnedica firstly.
基金Supported by Science and Technology Support Program of Jiangxi Province(20133BBF60029)Earmarked Fund for Jiangxi Agriculture Research System(JXARS-10)
文摘In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amount of transcriptionally active nucleolar organizer regions on chromosomes were analyzed by Giemsa staining and Ag-NORs. The results showed that the number of diploid chromosomes of O. potamophila was 44; the genome of O. potamophila was composed of 44 telocentric chromosomes; the karyotype formula was 2 n = 44 t,NF = 44; Ag-NORs were found in the paracentromeric region of chromosome. The results may lay the foundation for revealing the genetic pattern and chromosomal evolution of O. potamophila and contribute to further genetic breeding of O. potamophila.
文摘By adopting the method based on colchicine-hypotonic-air drying technique with bone marrow cells, the paper presents the chromosome of four egg-type fowl breeds. The diploid chromosome 2n=78, chromosomal morphology are very similar and sex chromosome type are ZZ (♂) and ZW(♀) in four egg-type fowl breeds. According to standard of Leven in 1964, the euchromosome and sex chromosome of four breeds are measured and compared in relative length arm ratio and centromere index of each chromosome including all the microchromosome. The morphology of these chromosome is described as follows: pair1, 2, 8 and ZW are metacentric, pair 4 and 6 are submetacentric, and the rest is telocentric.
文摘The karyotypes and meiotic behaviors of three Carbula species( Carbula obtusangula Reuter, C.putoni (Jakovlev)and C. sinica Hsiao et Cheng)were studied.Karyotype analyses using specific software were made and model karyotype chart was presented.All three species have the typical diploid chromosome number of 14 for the family Pentatomidae and X Y sex chromosomal mechanism,but the behavior of autosomes and sex chromosomes during meiosis among three species are different,and one or two supernumerary chromosomes were detected in C.putoni. These characteristics may provide some useful clues on the study of pentatomid taxonomy and phylogeny.
文摘Haploid chromosome numbers （n） of parasitic Hymenoptera （= traditional Parasitica ＋ Chrysidoidea） vary from 2 to 23. However, this range can be subdivided into three intervals with n = 14-23 （less derived parasitic wasps, e.g., some Ichneumonidae and Braconidae as well as Gasteruptiidae）, 8-13 （many other parasitic Hymenoptera） and 2-7 （Dryinidae, the majority of Chalcidoidea and some advanced Braconidae, e.g. Aphidiinae）. The symmetric karyotype with a relatively high chromosome number （n -- 14-17） and the prevalence of biarmed chromosomes must be considered as a groundplan feature of parasitic Hymenoptera. Independent reductions of chromosome numbers （n ≤ 10-11） occurred in some groups of the superfamily Ichneumonoidea as well as in the common ancestor of the Proctotrupoidea sensu lato, Ceraphronoidea, Cynipoidea and Chalcidoidea. Further mul- tiple decreases in chromosome numbers （n ≤ 4-6） took place in some Braconidae, various lineages of the superfamily Chalcidoidea as well as in the family Dryinidae. Two main trends prevailed in the karyotype evolution of parasitic wasps： the reduction of chromosome numbers （mainly due to tandem fusions and less frequently due to centric ones） and karyotypic dissymmetrization （through an increase in size differentiation of chromosomes and/or in the share of acrocentrics in a chromosome set）. Although karyotypic features of parasitic Hymenoptera can be used for solving taxonomic problems at various levels, this method is the most effective at the species level.
文摘Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.This study evaluates the efficacy of multiple genetic technologies-including karyotyping,fluorescence in situ hybridization(FISH),chromosomal microarray analysis(CMA),and next-generation sequencing(NGS)-in detecting and characterizing derivative chromosomes in prenatal samples.methodology:We analyzed 150 cases of suspected chromosomal abnormalities,comparing detection rates,resolution,and clinical utility across these methods.Results:Our findings demonstrate that integrated multi-technology approaches significantly improve diagnostic accuracy,with NGS-based structural variation analysis achieving the highest detection sensitivity(99.2%)for cryptic rearrangements.Conclusions:Additionally,long-read sequencing(PacBio/Oxford Nanopore)enabled precise breakpoint mapping in 92%of cases,facilitating more accurate genetic counseling.Clinically,this approach enhances risk assessment for fetal anomalies,guides pregnancy management,and improves parental counseling for recurrence risks.
基金funded by National Natural Science Foundation of China(32372732,32372683,32460750,32072586,31500247)Sichuan Science and Technology Program(2023ZYD0090,24NSFSC0404,2025ZNSFSC1112)+2 种基金Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-05)Key Laboratory of Storage of Agricultural Products,Ministry of Agriculture and Rural Aairs(kt202410)Chengdu Science and Technology Program(2024-YF05-02375-SN).
文摘This study conducted karyotype analysis on 56 Chinese kale varieties from Guangdong and Fujian provinces using conventional chromosome analysis methods.The varieties were categorized into four groups based on their origin and flower color:white-flower Chinese kale originating from Guangdong(GW),yellow-flower Chinese kale originating from Guangdong(GY),white-flower Chinese kale originating from Fujian(FW),and yellow-flower Chinese kale originating from Fujian(FY).Karyotype differences among the four groups of Chinese kale were analyzed,and the evolutionary relationship between yellow-flower and white-flower Chinese kale from the two regions was inferred based on karyotype parameters.The results indicated that all Chinese kale varieties were diploid with 2n=2x=18,including a pair of satellites.The chromosome types included median-centromere(m)and sub-median-centromere(sm),and the karyotypes were 1A and 2A,a sper karyotype asymmetry index.The karyotype 1A of Chinese kale was identified for the first time.Partial least squares discriminant analysis(PLS-DA)identified nine karyotypic indicators that differentiated the four groups,and these differences were further visualized using heatmaps and box plots.Based on the evolution trends in the four groups and PLS-DA analysis,it was speculated that white-flower Chinese kale originated from Guangdong,yellow-flower Chinese kale originated from Fujian,and GY and FW were derived from the cross of GW and FY.This study provides a reference for understanding the genetic relationships between Chinese kale in Guangdong and Fujian,and offers a cytological basis for the evolution,hybridization,and phylogenetic relationships of Chinese kale.
文摘Hibiscus Linn.,an angiosperm genus belonging to Malvaceae,Malvales,is mainly distributed in tropic and subtropic regions.Numerous species within the Hibiscus genus exhibit large and visually appealing flowers that are highly prized for their ornamental beauty and enjoy widespread admiration.For instance,H.syriacus serves as the national flower of South Korea,H.rosa-sinensis is favored as the floral emblem of Malaysia,and Chengdu city has earned the moniker"City of H.mutabilis"owing to its substantial cultivation.
基金supported by the National Natural Science Foundation of China(31991211 to Bao Liu)the China Postdoctoral Science Foundation(2024 M760322 to Ruili Lyu)。
文摘Established allopolyploid species often contain specific gene(s)dedicated to suppressing the pairing of homoeologous chromosomes during meiosis.A longstanding question is whether such genes in allopolyploids with lower ploidy levels can retain full functionality when the ploidy level rises following the addition of a new subgenome during outcrossing.Here,we addressed this question by generating a synthetic allohexaploid wheat species,Triticum kiharae(GGAADD),by crossing the allotetraploid Triticum timopheevii(GGAA)to the diploid Aegilops tauschii(DD),followed by colchicine-induced chromosomal doubling.The gene Pairing homoeologous 1(Ph1)inherited from T.timopheevii was likely hypofunctional in nascent T.kiharae,as evidenced by irregularities during meiotic chromosome pairing and organismal numerical and structural chromosome variation in selfed progeny populations.The allohexaploidization event also induced substantial rewiring of gene expression among homoeologs and nonadditive gene expression,leading to distinct predicted biological functions for differentially expressed genes(DEGs)when they were partitioned into the subgenomes.F1hybrids from a cross between T.kiharae and bread wheat(T.aestivum,BBAADD)were male-sterile but female-fertile,confirming intrinsic postzygotic reproductive isolation between the two species while enabling backcrossing of these sterile F1hybrids to bread wheat.These features provide a feasible route to simultaneously introgress standing congeneric genetic variations from both T.timopheevii and Ae.tauschii,as well as heritable de novo variations that have arisen in T.kiharae into bread wheat.
基金supported by the National Key R&D Program of China(2022YFF1001400)postdoctoral innovative talents support program(517000-X92308)+2 种基金the specific research fund of The Innovation Platform for Academicians of Hainan Province(YSPTZX202154,YSPTZX202139)the Research Startup Funding from Hainan Institute of Zhejiang University(0202-6602-A12201)the Distinguished Discipline Support Program of Zhejiang University(226-2024-00205,226-2022-00100).
文摘The Malvaceae family,the most diverse family in the order Malvales,consists of nine subfamilies.Within the Firmiana genus of the Sterculioideae subfamily,most species are considered globally vulnerable,yet their genomes remain unexplored.Here,we present a chromosome-level genome assembly for a representative Firmiana species,F.hainanensis,2n=40,totaling 1536 Mb.Phylogenomic analysis shows that F.hainanensis and Durio zibethinus have the closest evolutionary relationship,with an estimated divergence time of approximately 21 millions of years ago(MYA)and distinct polyploidization events in their histories.Evolutionary trajectory analyses indicate that fissions and fusions may play a crucial role in chromosome number variation(2n=14 to 2n=96).Analysis of repetitive elements among Malvaceae reveals that the Tekay subfamily(belonging to the Gypsy group)contributes to variation in genome size(ranging from 324 Mb to 1620 Mb).Additionally,genes associated with P450,peroxidase,and microtubules,and thereby related to cell wall biosynthesis,are significantly contracted in F.hainanensis,potentially leading to its lower wood density relative to Hopea hainanensis.Overall,our study provides insights into the evolution of chromosome number,genome size,and the genetic basis of cell wall biosynthesis in Malvaceae species.
