The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies ...The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies using hundreds of nuclear genes. The researchers suggested that urochordates, but not cephalochordates, should be the closest living relatives to vertebrates. In the present study, by using data generated from hundreds of mtDNA sequences, we revalue the deuterostome phylogeny in terms of whole mitochondrial genomes （mitogenomes）. Our results firmly demonstrate that each of extant deuterostome phyla and chordate subphyla is monophyletic. But the results present several alternative phylogenetic trees depending on different sequence datasets used in the analysis. Although no clear phylogenetic relationships are obtained, those trees indicate that the ancient common ancestor diversified rapidly soon after their appearance in the early Cambrian and generated all major deuterostome lineages during a short historical period, which is consistent with ＂Cambrian explosion＂ revealed by paleontologists. It was the 520-million-year＇s evolution that obscured the phylogenetic relationships of extant deuterostomes. Thus, we conclude that an integrative analysis approach rather than simply using more DNA sequences should be employed to address the distant evolutionary relationship.展开更多
A set of representative 146 adzuki (Vigna angular is var. angularis, and var. nipponensis) germplasm from 6 Asian countries traditionally for adzuki bean production, together with an out group standard rice bean (Vign...A set of representative 146 adzuki (Vigna angular is var. angularis, and var. nipponensis) germplasm from 6 Asian countries traditionally for adzuki bean production, together with an out group standard rice bean (Vigna umbellata), were analyzed by AFLP methodology using 12 informative primer pairs. 313 unambiguous polymorphic bands were created. According to the dendrogram by cluster analysis based on AFLP banding, 143 of the accessions were distinct and revealed enough genetic diversity for identification and classification of accessions within Vigna angularis. A neighbor joining tree was generated using newly developed Innan's nucleotide diversity estimate from the AFLP data. From analysis, 7 distinct evolutionary groups, named as "Chinese cultivated", "Japanese cultivated", "Japanese complex-Korean cultivated", "Chinese wild", "China Taiwan wild", "Nepal-Bhutan cultivated" and "Hymalayan wild", were detected. Nucleotide diversity with geographical distribution of each group is discussed, regarding the evolutionary relationships between wild and cultivated adzuki beans. The preliminary results indicated that cultivated adzuki bean should be domesticated from at least 4 progenitors in at least 3 geographical origins.展开更多
We report in this paper primary studies on inter specific species of cotton vis GISH(ge nomic in si-tu hybridization).We use interspecific triploid hybrids(F1 from hybridization of allotetraploid culti-vated species w...We report in this paper primary studies on inter specific species of cotton vis GISH(ge nomic in si-tu hybridization).We use interspecific triploid hybrids(F1 from hybridization of allotetraploid culti-vated species with diploid A,D,or C geno me species)and two cultivated tetraploids to study the chromosome paring during meio sis of pollen mother cellls(PMCs)and to estimate the consequences on synap sis between the se three subge nome s after synthetic polyploid formation.PMC GISH with ge-nomic DNA(gDNA)from the diploid parent species as probes resulted in fragmented signals,and the translocations of the chromosomes in ADC type hybrids were more frequent than in ADD type hy-brids,which suggested the more distant relationship between A and C geno me.展开更多
The knowledge of origin and evolution of cultivated soybeans is one of the basic issues in both biology and agronomy of the crop.In order to investigate the nuclear and cytoplasmic genetic diversity,geographic differe...The knowledge of origin and evolution of cultivated soybeans is one of the basic issues in both biology and agronomy of the crop.In order to investigate the nuclear and cytoplasmic genetic diversity,geographic differentiation and genetic relationship among geographic ecotypes of cultivated(Glycine max)and wild(G.soja)soybeans,the allelic profiles at 60 nuclear simple-sequence repeat(nuSSR)loci and 11 chloroplastic SSR(cpSSR)loci evenly distributed on whole genome of 393 landraces and 196 wild accessions from nation-wide growing areas in China were analyzed.(i)The genetic diversity of the wild soybean was obviously larger than that of the cultivated soybean,with their nuSSR and cpSSR alleles as 1067 vs.980 and 57 vs 44,respectively.Of the 980 nuclear alleles detected in the cultivated soybean,377 new ones(38.5%)emerged,while of the 44 chloroplastic alleles in the cultivated soybean,seven new ones(15.9%)emerged after domestication.(ii)Among the cultivated geographic ecotypes,those from southern China,including South-Central China,Southwest China and South China possessed relatively great genetic diversity than those from northern China,while among the wild geographic ecotypes,the Middle and Lower Changjiang Valleys wild ecotype showed the highest genetic diversity.(iii)The analysis of molecular variance,association analysis between geographic grouping and molecular marker clustering and analysis of specific-present alleles of ecotypes demonstrated that the geographic differentiation of both cultivated and wild soybeans associated with their genetic differentiation,or in other words,had their relevant genetic bases.(iv)The cluster analysis of all accessions clearly showed that the wild accessions from Middle and Lower Changjiang Valleys and South-Central&Southwest China had relatively small genetic distances with all cultivated accessions.The UPGMA dendrogram among geographic ecotypes further showed that the genetic distances between all cultivated ecotypes and the Middle and Lower Changjiang Valleys wild ecotype were smaller than those with other wild ones,including their local wild counterparts.Therefore,it is inferred that the wild ancestors in southern China,especially those from Middle and Lower Changjiang Valleys might be the common ancestor of all the cultivated soybeans.展开更多
To reveal the evolutionary relationship of three mitten crabs(Eriocheir sinensis,E.hepuensis,and E.japonica),complete mitogenomes and nuclear 5S rDNA sequences were analyzed.Sequencing revealed that the mitogenomes an...To reveal the evolutionary relationship of three mitten crabs(Eriocheir sinensis,E.hepuensis,and E.japonica),complete mitogenomes and nuclear 5S rDNA sequences were analyzed.Sequencing revealed that the mitogenomes analyzed shared conserved organization of the coding and non-coding regions but genetic variation was identified.Among the three mitten crabs distinct tandem repeats were identified in the mitochondrial D-loop region.The 5S gene(5S rDNA)sequence was highly conserved across the three species,whereas non-transcribed spacer(NTS)region exhibit high levels of variation including insertions,deletions and point mutations.Cluster analysis suggested that the three mitten crabs had their own independent 5S rDNA sequence variation and evolutionary pattern.Both mitogenome and 5S rDNA sequence analysis revealed significant genetic variation across the mitten crabs species.Phylogenetic analysis using mitogenome and 5S rDNA sequences demonstrated that E.japonica was relatively more distant from E.sinensis and E.hepuensis.This study extended our previous knowledge and confirmed that the three mitten crabs are likely to be genetically differentiated species.In addition,our study also provided insights into the conservation of pure natural resources of E.sinensis,an important aquaculture species.展开更多
The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and cla...The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysisthe discovery of the evolutionary relationships among a group of species;and Classificationthe grouping of species,ultimately on the basis of evolutionary relationships.展开更多
The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and cla...The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysisthe discovery of the evolutionary relationships among a group of species;and Classification-the grouping of species,ultimately on the basis of evolutionary relationships.展开更多
The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000 (1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and c...The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000 (1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysis—the discovery of the evolutionary relationships among a group of species;and Classification—the grouping of species,ultimately on the basis of evolutionary relationships.展开更多
This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification t...This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification technology, aiming at dis- cussing the structure evolution law of Vicia plants and providing scientific reference for research about classification, genetic relationship and evolutionary trend of this genus. The comparison of leaf anatomical structures of Vicia lilacina, V. pseu- dorobus and V. unijuga showed that： V. unijuga has tidily arranged leaf epidermal cells, thickened outer tangential wall cuticle, large diameter of xylem vessels, and developed midrib fibrocytes which form vascular bundle sheaths. Plant print identifi- cation results showed that the tested 3 plants showed remarkable differences in leaf apparent texture and anticlinal wall type though plant print characteristics of appar- ent structures of plants in the same genus had homologous similarity. V. lilacina has no subsidiary cells, and apparent textures of V. pseudorobus and V. unijuga are both of paracytic unequal type. Statistical analysis showed that V. unijuga is more advanced than V. pseudorobus. The 3 tested plants are in evolutionary rela- tionship of V. lilacina〈V, pseudorobus〈V, unijuga.展开更多
The zinc finger homeodomain(ZF-HD)genes belong to the homeobox gene family,playing critical roles in flower development and stress response.Despite their importance,however,to date there has been no genome-wide identi...The zinc finger homeodomain(ZF-HD)genes belong to the homeobox gene family,playing critical roles in flower development and stress response.Despite their importance,however,to date there has been no genome-wide identification and characterization of the ZF-HD genes that are probably involved in stress responses in maize.In this study,24 ZF-HD genes were identified,and their chromosomal locations,protein properties,duplication patterns,structures,conserved motifs and expression patterns were investigated.The results revealed that the ZF-HD genes are unevenly distributed on nine chromosomes and that most of these genes lack introns.Six and two ZF-HD genes have undergone segmental and tandem duplication,respectively,during genome expansion.These 24 ZF-HD transcription factors were classified into six major groups on the basis of protein molecular evolutionary relationship.The expression profiles of these genes in different tissues were evaluated,resulting in producing two distinct clusters.ZF-HD genes are preferentially expressed in reproductive tissues.Furthermore,expression profiles of the 24 ZF-HD genes in response to different kinds of stresses revealed that ten genes were simultaneously up-regulated under ABA,salt and PEG treatments;meanwhile four genes were simultaneously down-regulated.These findings will pave the way for deciphering the function and mechanism of ZF-HD genes on how to implicate in abiotic stress.展开更多
Fusarium oxysporum and Geotrichum candidum, which are among important pathogens of Solanum lycopersicum L. (Tomato), are sometimes misidentified during morphological misidentification. The study was carried out to eva...Fusarium oxysporum and Geotrichum candidum, which are among important pathogens of Solanum lycopersicum L. (Tomato), are sometimes misidentified during morphological misidentification. The study was carried out to evaluate molecular diversity of F. oxysporum and G. candidum isolated from two tomato varieties obtained from Akure, Ilorin and Ibadan, Nigeria. The tomato samples were collected and brought back to the laboratory for fungal isolation. Isolation of the pathogens were done following standard procedures. DNA extraction from pure cultures of the pathogens was done at the Centre Laboratory of University of Ibadan. Genetic relationships among the organisms were also estimated by constructing a Dendrogram through UPGMA using the Mega6 Software and genetic distance was computed also using the Mega6 Software. Five strains of F. oxysporum and seven strains of G. candidum were identified. Percentage similarity of the pathogens with those in GenBank was 99.17% - 100.00% for F. oxysporum and 98.48% - 100.00% for G. candidum. The T-01 marker showed the lowest major allele frequency of 0.0833, while T-10 marker has the highest value for major allele frequency of 0.6667 and an average value of 0.3958. Evolutionary relationship showed that the two strains of G. candidum (MN650247 and MN650250) were similar. The three strains of F. oxysporum (MN650246 and MN650248, MN650245 and MN650253) were also similar. Genetic distances among pairs of the fungal strains ranged from 0.12 to 6.30 in pairwise fashion, with an average of 1.32. Evolutionary relationship or closeness among strains of a fungal species can thus be said not to depend on location.展开更多
Potato is a remarkable plant—it is the third most important crop worldwide and the most important non-seed crop,and it is successfully cultivated in a wide array of environments and geographical areas.But where did i...Potato is a remarkable plant—it is the third most important crop worldwide and the most important non-seed crop,and it is successfully cultivated in a wide array of environments and geographical areas.But where did it come from,and how is it such a success?The evolutionary relationships within the Petota lineage(diploid and polyploid tuber-bearing species)of the genus Solanum are challenging and have often been conflicted among different studies(Hawkes,1990;Spooner et al.,2007).The exact relationship of Petota with the closely related non-tuberizing diploids in the Tomato lineage(tomato species)and species in the Etuberosum lineage has also been difficult to pinpoint.Previous studies mainly relied on morphological characters or a few DNA fragments,but frequent interspecies hybridization and polyploidization in Petota complicate the matter.However,vast and diverse genome data now provide new insights into the origin of the common ancestor of all species within the Petota lineage.展开更多
Ciliates of the heterotrich family Folliculinidae are widespread in various habitats and are distinguished by their transparent loricae of various shapes,conspicuous peristomial lobes,and dimorphic life cycles.They us...Ciliates of the heterotrich family Folliculinidae are widespread in various habitats and are distinguished by their transparent loricae of various shapes,conspicuous peristomial lobes,and dimorphic life cycles.They usually attach firmly to the surface of substrates,feed on bacteria and microalgae,and play a significant role in energy flow and material cycling in the microbial food web.However,little is known regarding their biodiversity and systematics.In this work,we establish the terminology of the family Folliculinidae and select six crucial features for genus recognition.Based on previous studies,we revise the classification of Folliculinidae,supply improved diagnoses for each of the 33 folliculinid genera,and provide a key to their identification.Moreover,phylogenetic analyses based on small subunit ribosomal DNA(SSU rDNA)sequences revealed that the family is monophyletic and comprises two subclades(subclades I II)which can be identified by the flexibility of their peristomial lobes and the sculpturing of their necks.Furthermore,we investigate the evolutionary relationships of folliculinids using the six chosen generic features.展开更多
The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and cl...The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysis—the discovery of the evolutionary relationships among a group of species;and Classification—the grouping of species,ultimately on the basis of evolutionary relationships.展开更多
基金supported by the National Natural Sci-ence Foundation of China (No. 30570208 and 30830023)the Specialized Research Fund for the Doctoral Pro-gram of Higher Education from the Ministry of Education, China (No. 20070384041).
文摘The traditional knowledge in textbooks indicated that cephalochordates were the closest relatives to vertebrates among all extant organisms. However, this opinion was challenged by several recent phylogenetic studies using hundreds of nuclear genes. The researchers suggested that urochordates, but not cephalochordates, should be the closest living relatives to vertebrates. In the present study, by using data generated from hundreds of mtDNA sequences, we revalue the deuterostome phylogeny in terms of whole mitochondrial genomes （mitogenomes）. Our results firmly demonstrate that each of extant deuterostome phyla and chordate subphyla is monophyletic. But the results present several alternative phylogenetic trees depending on different sequence datasets used in the analysis. Although no clear phylogenetic relationships are obtained, those trees indicate that the ancient common ancestor diversified rapidly soon after their appearance in the early Cambrian and generated all major deuterostome lineages during a short historical period, which is consistent with ＂Cambrian explosion＂ revealed by paleontologists. It was the 520-million-year＇s evolution that obscured the phylogenetic relationships of extant deuterostomes. Thus, we conclude that an integrative analysis approach rather than simply using more DNA sequences should be employed to address the distant evolutionary relationship.
文摘A set of representative 146 adzuki (Vigna angular is var. angularis, and var. nipponensis) germplasm from 6 Asian countries traditionally for adzuki bean production, together with an out group standard rice bean (Vigna umbellata), were analyzed by AFLP methodology using 12 informative primer pairs. 313 unambiguous polymorphic bands were created. According to the dendrogram by cluster analysis based on AFLP banding, 143 of the accessions were distinct and revealed enough genetic diversity for identification and classification of accessions within Vigna angularis. A neighbor joining tree was generated using newly developed Innan's nucleotide diversity estimate from the AFLP data. From analysis, 7 distinct evolutionary groups, named as "Chinese cultivated", "Japanese cultivated", "Japanese complex-Korean cultivated", "Chinese wild", "China Taiwan wild", "Nepal-Bhutan cultivated" and "Hymalayan wild", were detected. Nucleotide diversity with geographical distribution of each group is discussed, regarding the evolutionary relationships between wild and cultivated adzuki beans. The preliminary results indicated that cultivated adzuki bean should be domesticated from at least 4 progenitors in at least 3 geographical origins.
文摘We report in this paper primary studies on inter specific species of cotton vis GISH(ge nomic in si-tu hybridization).We use interspecific triploid hybrids(F1 from hybridization of allotetraploid culti-vated species with diploid A,D,or C geno me species)and two cultivated tetraploids to study the chromosome paring during meio sis of pollen mother cellls(PMCs)and to estimate the consequences on synap sis between the se three subge nome s after synthetic polyploid formation.PMC GISH with ge-nomic DNA(gDNA)from the diploid parent species as probes resulted in fragmented signals,and the translocations of the chromosomes in ADC type hybrids were more frequent than in ADD type hy-brids,which suggested the more distant relationship between A and C geno me.
基金Supported by the National Natural Science Foundation of China(Grant No.32671266)National Key Basic Research and Development Program of China(Grant Nos.2006CB101708 and 2009CB118404)+2 种基金Key Projects in the National Science&Technology Pillar Program(Grant No.2006BAD13B05-7)Special Public Sector Research of the Ministry of Agriculture(Grant No.200803060)Programme of Introducing Talents of Discipline to Universities(111 Project)(Grant No.B08025)
文摘The knowledge of origin and evolution of cultivated soybeans is one of the basic issues in both biology and agronomy of the crop.In order to investigate the nuclear and cytoplasmic genetic diversity,geographic differentiation and genetic relationship among geographic ecotypes of cultivated(Glycine max)and wild(G.soja)soybeans,the allelic profiles at 60 nuclear simple-sequence repeat(nuSSR)loci and 11 chloroplastic SSR(cpSSR)loci evenly distributed on whole genome of 393 landraces and 196 wild accessions from nation-wide growing areas in China were analyzed.(i)The genetic diversity of the wild soybean was obviously larger than that of the cultivated soybean,with their nuSSR and cpSSR alleles as 1067 vs.980 and 57 vs 44,respectively.Of the 980 nuclear alleles detected in the cultivated soybean,377 new ones(38.5%)emerged,while of the 44 chloroplastic alleles in the cultivated soybean,seven new ones(15.9%)emerged after domestication.(ii)Among the cultivated geographic ecotypes,those from southern China,including South-Central China,Southwest China and South China possessed relatively great genetic diversity than those from northern China,while among the wild geographic ecotypes,the Middle and Lower Changjiang Valleys wild ecotype showed the highest genetic diversity.(iii)The analysis of molecular variance,association analysis between geographic grouping and molecular marker clustering and analysis of specific-present alleles of ecotypes demonstrated that the geographic differentiation of both cultivated and wild soybeans associated with their genetic differentiation,or in other words,had their relevant genetic bases.(iv)The cluster analysis of all accessions clearly showed that the wild accessions from Middle and Lower Changjiang Valleys and South-Central&Southwest China had relatively small genetic distances with all cultivated accessions.The UPGMA dendrogram among geographic ecotypes further showed that the genetic distances between all cultivated ecotypes and the Middle and Lower Changjiang Valleys wild ecotype were smaller than those with other wild ones,including their local wild counterparts.Therefore,it is inferred that the wild ancestors in southern China,especially those from Middle and Lower Changjiang Valleys might be the common ancestor of all the cultivated soybeans.
基金The authors would like to thank to Mr.Yongju Luo at Guangxi Fisheries Institute in China for sampling the Hepu mitten crab.This work was funded by the Shanghai Agriculture Applied Technology Development Program,China(Grant No.G2017-02-08-00-10-F00076)the Shanghai Mitten Crab Industry Technology System Project(Grant No.2017e2021)+2 种基金Young teachers training Project of Shanghai Municipal Education Commission(A1-2056-16-0026)the Shanghai Science and Technology Project(Grant No.16391905300,13DZ2251800)Doctoral Program of Shanghai Ocean University(A2-0203-00-100315).
文摘To reveal the evolutionary relationship of three mitten crabs(Eriocheir sinensis,E.hepuensis,and E.japonica),complete mitogenomes and nuclear 5S rDNA sequences were analyzed.Sequencing revealed that the mitogenomes analyzed shared conserved organization of the coding and non-coding regions but genetic variation was identified.Among the three mitten crabs distinct tandem repeats were identified in the mitochondrial D-loop region.The 5S gene(5S rDNA)sequence was highly conserved across the three species,whereas non-transcribed spacer(NTS)region exhibit high levels of variation including insertions,deletions and point mutations.Cluster analysis suggested that the three mitten crabs had their own independent 5S rDNA sequence variation and evolutionary pattern.Both mitogenome and 5S rDNA sequence analysis revealed significant genetic variation across the mitten crabs species.Phylogenetic analysis using mitogenome and 5S rDNA sequences demonstrated that E.japonica was relatively more distant from E.sinensis and E.hepuensis.This study extended our previous knowledge and confirmed that the three mitten crabs are likely to be genetically differentiated species.In addition,our study also provided insights into the conservation of pure natural resources of E.sinensis,an important aquaculture species.
文摘The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysisthe discovery of the evolutionary relationships among a group of species;and Classificationthe grouping of species,ultimately on the basis of evolutionary relationships.
文摘The current journal is mainly focused on zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy-the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysisthe discovery of the evolutionary relationships among a group of species;and Classification-the grouping of species,ultimately on the basis of evolutionary relationships.
文摘The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000 (1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysis—the discovery of the evolutionary relationships among a group of species;and Classification—the grouping of species,ultimately on the basis of evolutionary relationships.
基金Supported by Natural Science Foundation of China(41271231)~~
文摘This study was conducted to compare leaf anatomical structures and ap- parent plant print characteristics of 3 Vicia plants from Changbai Mountains applying structural botany principle and fingerprint identification technology, aiming at dis- cussing the structure evolution law of Vicia plants and providing scientific reference for research about classification, genetic relationship and evolutionary trend of this genus. The comparison of leaf anatomical structures of Vicia lilacina, V. pseu- dorobus and V. unijuga showed that： V. unijuga has tidily arranged leaf epidermal cells, thickened outer tangential wall cuticle, large diameter of xylem vessels, and developed midrib fibrocytes which form vascular bundle sheaths. Plant print identifi- cation results showed that the tested 3 plants showed remarkable differences in leaf apparent texture and anticlinal wall type though plant print characteristics of appar- ent structures of plants in the same genus had homologous similarity. V. lilacina has no subsidiary cells, and apparent textures of V. pseudorobus and V. unijuga are both of paracytic unequal type. Statistical analysis showed that V. unijuga is more advanced than V. pseudorobus. The 3 tested plants are in evolutionary rela- tionship of V. lilacina〈V, pseudorobus〈V, unijuga.
基金supported by Importing,Cultivation and Production for Special Maize(2020LYXZ032).
文摘The zinc finger homeodomain(ZF-HD)genes belong to the homeobox gene family,playing critical roles in flower development and stress response.Despite their importance,however,to date there has been no genome-wide identification and characterization of the ZF-HD genes that are probably involved in stress responses in maize.In this study,24 ZF-HD genes were identified,and their chromosomal locations,protein properties,duplication patterns,structures,conserved motifs and expression patterns were investigated.The results revealed that the ZF-HD genes are unevenly distributed on nine chromosomes and that most of these genes lack introns.Six and two ZF-HD genes have undergone segmental and tandem duplication,respectively,during genome expansion.These 24 ZF-HD transcription factors were classified into six major groups on the basis of protein molecular evolutionary relationship.The expression profiles of these genes in different tissues were evaluated,resulting in producing two distinct clusters.ZF-HD genes are preferentially expressed in reproductive tissues.Furthermore,expression profiles of the 24 ZF-HD genes in response to different kinds of stresses revealed that ten genes were simultaneously up-regulated under ABA,salt and PEG treatments;meanwhile four genes were simultaneously down-regulated.These findings will pave the way for deciphering the function and mechanism of ZF-HD genes on how to implicate in abiotic stress.
文摘Fusarium oxysporum and Geotrichum candidum, which are among important pathogens of Solanum lycopersicum L. (Tomato), are sometimes misidentified during morphological misidentification. The study was carried out to evaluate molecular diversity of F. oxysporum and G. candidum isolated from two tomato varieties obtained from Akure, Ilorin and Ibadan, Nigeria. The tomato samples were collected and brought back to the laboratory for fungal isolation. Isolation of the pathogens were done following standard procedures. DNA extraction from pure cultures of the pathogens was done at the Centre Laboratory of University of Ibadan. Genetic relationships among the organisms were also estimated by constructing a Dendrogram through UPGMA using the Mega6 Software and genetic distance was computed also using the Mega6 Software. Five strains of F. oxysporum and seven strains of G. candidum were identified. Percentage similarity of the pathogens with those in GenBank was 99.17% - 100.00% for F. oxysporum and 98.48% - 100.00% for G. candidum. The T-01 marker showed the lowest major allele frequency of 0.0833, while T-10 marker has the highest value for major allele frequency of 0.6667 and an average value of 0.3958. Evolutionary relationship showed that the two strains of G. candidum (MN650247 and MN650250) were similar. The three strains of F. oxysporum (MN650246 and MN650248, MN650245 and MN650253) were also similar. Genetic distances among pairs of the fungal strains ranged from 0.12 to 6.30 in pairwise fashion, with an average of 1.32. Evolutionary relationship or closeness among strains of a fungal species can thus be said not to depend on location.
文摘Potato is a remarkable plant—it is the third most important crop worldwide and the most important non-seed crop,and it is successfully cultivated in a wide array of environments and geographical areas.But where did it come from,and how is it such a success?The evolutionary relationships within the Petota lineage(diploid and polyploid tuber-bearing species)of the genus Solanum are challenging and have often been conflicted among different studies(Hawkes,1990;Spooner et al.,2007).The exact relationship of Petota with the closely related non-tuberizing diploids in the Tomato lineage(tomato species)and species in the Etuberosum lineage has also been difficult to pinpoint.Previous studies mainly relied on morphological characters or a few DNA fragments,but frequent interspecies hybridization and polyploidization in Petota complicate the matter.However,vast and diverse genome data now provide new insights into the origin of the common ancestor of all species within the Petota lineage.
基金supported by the National Natural Science Foundation of China(No.31970398,No.32270473,No.31772431)a grant from the NRF Korea funded by the Ministry of Education(2021R1I1A2048744)。
文摘Ciliates of the heterotrich family Folliculinidae are widespread in various habitats and are distinguished by their transparent loricae of various shapes,conspicuous peristomial lobes,and dimorphic life cycles.They usually attach firmly to the surface of substrates,feed on bacteria and microalgae,and play a significant role in energy flow and material cycling in the microbial food web.However,little is known regarding their biodiversity and systematics.In this work,we establish the terminology of the family Folliculinidae and select six crucial features for genus recognition.Based on previous studies,we revise the classification of Folliculinidae,supply improved diagnoses for each of the 33 folliculinid genera,and provide a key to their identification.Moreover,phylogenetic analyses based on small subunit ribosomal DNA(SSU rDNA)sequences revealed that the family is monophyletic and comprises two subclades(subclades I II)which can be identified by the flexibility of their peristomial lobes and the sculpturing of their necks.Furthermore,we investigate the evolutionary relationships of folliculinids using the six chosen generic features.
文摘The current journal is mainly focused in zoological systematics.According to Systematics Agenda 2000(1994),systematics is the science built on the following tasks:Taxonomy—the science of discovering,describing,and classifying species or groups of species(together termed taxa);Phylogenetic analysis—the discovery of the evolutionary relationships among a group of species;and Classification—the grouping of species,ultimately on the basis of evolutionary relationships.
