A backcrossed population （BC1） derived from a cross between C100 and Dazao was obtained. The quantitative trait loci （QTLs） of the economically important traits for whole cocoon weight, cocoon shell weight, ratio ...A backcrossed population （BC1） derived from a cross between C100 and Dazao was obtained. The quantitative trait loci （QTLs） of the economically important traits for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, etc., were analyzed for the first time using the multiple interval mapping software WinQTLCart2.0. In total 40 QTLs were detected and contributed to 21 groups based on the constructed linkage map. According to the mapping results, 2, 2, 3, and 2 major QTLs explained over 20% of total phenotypic variations, whereas four QTLs, namely qCW-19, qSW-2, qCSR-4, and qPW-23, explained more than 30% of total phenotypic variations for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, respectively. Correlated traits QTLs often share the same location. Furthermore, most of the detected QTLs were closed to one-side marker. By using the very closed markers, positive QTLs can be aggregated, which can form a basis for molecular marker-assisted selection and breeding.展开更多
Microsporidia are a group of intracelluar eukaryotic parasites, which can infected almost all animals, including human beings. Till now, no mitochodria but mitosome, a remnant of mitochondria was discovered in this ph...Microsporidia are a group of intracelluar eukaryotic parasites, which can infected almost all animals, including human beings. Till now, no mitochodria but mitosome, a remnant of mitochondria was discovered in this phylum. We present here the mitochondrial pyruvate dehydrogenase El （PDH, including PDHα and PDHβ） of the microsporidian Nosema bombycis, the pathogen of silkworm pebrine. Compared with PDH of microsporidian Encephalitozoon cuniculi and Antonospora locustae, both subunits are eonscrced. The phylogeny indicated that both subunits are mitochondrial. The syntenic maps revealed the subunits organization of NbPDH is distributed in different scaffolds, similar to that of EcPDH but different with AIPDH, and the relationship between phylogeny tree and organization of PDH suggest that the AlPDH subunits organization is the ancestral style of microsporidia, and through the genome evolution, the reshuffling of the chromosome of microsporidia occurred, the adjacent style of ALPDHE1 organization changed, and the two subunits separated and located to different chromosomes in E. cuniculi. For N. bombycis and N. ceranae, they locate to different scaffolds. In order to determine NbPDH subcellular localizations, we prepared the polyclonal antibodies against NbPDH prokaryotic fusion proteins, and adopted the colloidal gold immunological electron microscopy, the expression signals of NbPDH were observed in spores however, the subcellular localization were not definited. In general, through comparison of three mierosporidian PDH molecular phylogeny, subunits organization in chromosomes, localization indicated that PDH is an interesting marker in microsporidia evolution展开更多
The antifungal peptides, drosomycin （Drs） and its isoform drosomycin-like C （Drs-lC） from Drosophila melanogaster and Thanatin from Podisus maculiventris, have potent activity with broad spectrum against filamento...The antifungal peptides, drosomycin （Drs） and its isoform drosomycin-like C （Drs-lC） from Drosophila melanogaster and Thanatin from Podisus maculiventris, have potent activity with broad spectrum against filamentous fungi. Secretive expression of these genes in yeasts makes it possible to utilize the supernatants of yeast culture as protective reagents on fruit, vegetable, food and other agricultural products. So the study of effective secretion by yeast expression system is of great importance. Three genes, Drs, Drs-lC, and Thanatin, were cloned into pPICZαA and the recombinant vectors, pPICZαA-Drs, pPICZαA-Drs-lC, and pPICZαA-Thanatin were transformed into Pichia pastoris by the electric transfer method. The recombinant P. pastoris, which was screened by phenotype selection and PCR amplification, was induced to express antifungal peptide by methanol. The expressive products of the three recombinants showed antifungal activity against 5 out of 6 test fungi strains, and the products of Thanatin also had strong activity against the tested bacteria. The three antifungal peptide genes, Drs, Drs-lC, and Thanatin, were constructed into yeast P. pastoris. The expressed peptides were successfully secreted into the culture medium and exhibited potent activities against the test strains.展开更多
Imprinted genes play significant roles in the regulation of fetal growth, development, function of the placenta and postnatal behavior in mammals, but little is known in pigs. In order to investigate the imprinting st...Imprinted genes play significant roles in the regulation of fetal growth, development, function of the placenta and postnatal behavior in mammals, but little is known in pigs. In order to investigate the imprinting status of porcine retro-transposon like 1 （RTL1） and type 3 iodothyronine deiodinase （DIO3） genes, DNA or RNA samples of the parents and F1 animals, generated with reciprocal crosses between Large White and Meishan breeds, were isolated, and analyzed by reverse transcription polymerase chain reaction restriction fragment length polymorphism （RT-PCR-RFLP）. The results demonstrated that the RTL1 gene was paternally expressed in 10 tissues, such as the skeletal muscle, heart, spleen, liver, kidney, lung, stomach, fat, small intestine and brain, and D103 gene exhibited paternal expression in the skeletal muscle, heart, spleen, lung, stomach, and brain, in 2-month-old pigs. The association of RTL1 and DI03 with carcass traits was further analyzed in the F2 population of Large White×Meishan pigs. The statistical results showed that the R TL1 A1101G polymorphism （EU781029） was significantly associated with lean meat percentage （LMP） and fat meat percentage （FMP） （P〈0.05）, while the D103 A744C polymorphism （AY533208） was not significantly associated with any carcass traits. These results indicate that the imprinting status of RTL1 and DIO3 is well kept across the mammalian species, and porcine RTL1 may have important roles in muscle growth and fat deposition.展开更多
This article mainly studied Humulus scandens’ ITS sequence, its system position and its divergent time. ITS is 624 bp with a GC percentage content of 57.21%. It only has the variation in 585 (C changes T), systematic...This article mainly studied Humulus scandens’ ITS sequence, its system position and its divergent time. ITS is 624 bp with a GC percentage content of 57.21%. It only has the variation in 585 (C changes T), systematic position in Humulus lupulus (GenBank: EF136401) and Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990), with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) has the near sibship. Humulus in Moraceae family system position between Cudrania tricuspidata and Artocarpeae, support the Cannabiodeae promotion for Cannabinaceae. The divergent time of Humulus is 70.88 mya in Moraceae, Humulus scandens and Humulus lupulus (GenBank: EF136401) is 12.78 mya, with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) is 1.10 mya. In the Moraceae branch’s molecular systematics research, the suitable choice is to choose Humulus scandens as Moraceae’s outgroup.展开更多
Gene expression quantification at mRNA level is very important for postgenomic studies, as gene expression level is the reflection of the special biological function of the target gene. Methods used for gene expressio...Gene expression quantification at mRNA level is very important for postgenomic studies, as gene expression level is the reflection of the special biological function of the target gene. Methods used for gene expression quantification, such as microarray or quantitative real-time polymerase chain reaction （qRT-PCR）, require stable expressed reference genes. Thus, finding suitable control genes is essential for gene quantification. In this study, a genome-wide survey of reference genes during metamorphism was performed on silkworm Bombyx mori. Twelve genes were chosen as putative reference genes based on a whole genome oligonucleotide microarray normalized by external controls. Then, qRT- PCR was employed for further validation and selection of potential reference gene candidates. The results were analyzed, and stable genes were selected using geNorm 3.4 and NormFinder software. Finally, considering factors from every aspect, translation initiation factor 4A, translation initiation factor 3 subunit 4, and translation initiation factor 3 subunit 5 （represented by sw22934, sw14876, and sw13956） were selected as reliable internal controls across the examined developmental stages, while cytoplasmic actin （sw22671）, the commonly used reference gene in a previous study was shown to vary drastically throughout the examined developmental stages. For future research, we recommend the use of the geometric mean of those three stable reference genes as an accurate normalization factor for data normalization of different developmental stages during metamorphism.展开更多
Cathepsin B belongs to lysosomal cysteine protease of the papain family. Temporal and spatial expression analysis of cathepsin B of Bombyx mori （BmCtB） was carried out based on Expression Sequence Tags （ESTs） data...Cathepsin B belongs to lysosomal cysteine protease of the papain family. Temporal and spatial expression analysis of cathepsin B of Bombyx mori （BmCtB） was carried out based on Expression Sequence Tags （ESTs） data, oligonucleotide microarray, reverse transcription polymerase chain reaction （RT-PCR） and quantitative real-time PCR. Expression of BmCtB was observed in all of the tissues and stages. Among the 10 tested tissues, the fat body and posterior silk gland are the two most enriched tissues with BmCtB. During Bombyx development, there was an expression fastigium of BmCtB during metamorphosis. RNA interference was used to suppress the expression of cathepsin B during metamorphosis. Significant developmental defective phenotypes were obtained in the RNAi treated group. The dramatically reduced expression of BmCtB was con^rmed by Northern blot and quantitative real-time PCR. These evidences strongly suggest cathepsin B proteinase was predominantly involved in the metabolism process of fat body and the posterior silk gland and was critical for metamorphism and development of silkworm, Bombyx mori.展开更多
We have searched the Bombyx mori genome for members of the major enzyme family,the Cytochrome P450s,which carry out multiple reactions to enable organisms to rid themselves of foreign compounds.As a result,86 putative...We have searched the Bombyx mori genome for members of the major enzyme family,the Cytochrome P450s,which carry out multiple reactions to enable organisms to rid themselves of foreign compounds.As a result,86 putative P450s were discovered in silkworm genome,which are thought to belong to 32 subfamilies.A comparative genomic analysis with Drosophila melanogaster reveals that the two insects have some similar P450 distribution pat-terns but still have some obvious differences.Especially,the diverse distribution exists in 7 p450 subfamilies,which are CYP4A,CYP4C,CYP4D,CYP6A,CYP6AE,CYP6B and CYP9A.Fur-thermore,we collected expression sequence tag(EST)evidence for 49 putative P450s genes,which are expressed at the transcriptional level and more likely to be true P450s.展开更多
To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for...To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for the germline transformation of diapause silkworm strains. Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains. By incu- bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃ （15℃-IME）, we were able to prevent the diapause of their daughter eggs; a similar strategy （15℃-IMES） for the germline transformation of the same strains was that the mother eggs were incubated at 15℃, and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs. By combining tempera- ture and light controls, the improved 15℃-IMES strategy prevented diapause in daughter eggs, and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains. Although each of the strategies developed here has advantages and disadvantages, we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects. These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.展开更多
The sericulture industry plays a very important role in our national economy. Silkworm (Bombyx mori) is always regarded as a model animal and biological reactor. There have been detailed studies on the structure, expr...The sericulture industry plays a very important role in our national economy. Silkworm (Bombyx mori) is always regarded as a model animal and biological reactor. There have been detailed studies on the structure, expression and control and molecular evolution of silk genes. However, few, if any, reports are available on the localization of structural genes in silkworm by molecular cytogenetics. The present experiment has tentatively localized the Fib-H gene at the distal end of the 25th linkage group, namely at the 25-0.0 position, and verified that Fib-H has only one locus, thus providing a temporary solution to the problem about its localization.展开更多
he silkworm, Bombyx mori, is an economically important insect with a 5 000-year history of domestication. During evolution, the silkworm has developed highly effective defenses against invasion and parasitization by m...he silkworm, Bombyx mori, is an economically important insect with a 5 000-year history of domestication. During evolution, the silkworm has developed highly effective defenses against invasion and parasitization by microorganisms. In this study, two microorganisms Escherichia coli and Bacillus bombyseptieus were orally infected to silk- worm larvae. After infection with E. coli and B. bombyseptieus for 24 h, we investigated the polypeptide changes in the hemolymph, midgut and integument using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spec- trometry. Forty-seven differentially expressed proteins were identified in these tissues. They belonged to a variety of functional classes, including immune proteins, metabolic proteins and structural proteins. Compared with controls, E. coli-infected silkworms showed 21 up- regulated proteins, 25 down-regulated proteins and lost one protein. After infection with B. bombyseptieus, silkworms showed 15 up-regulated proteins, 27 down-regulated pro- teins, lost three proteins and retained two proteins unchanged. We speculate that all these proteins may play a role in the silkworm immune response, although it is unclear why and how the two kinds of bacteria can so markedly alter expression of these proteins. These re- sults offer valuable insights for measuring the proteomic responses of the silkworm innate immune mechanism.展开更多
Methoprene-tolerant （Met） gene has been found to be involved in juvenile hormone （JH） action in insects. Herein, we isolated a silkworm （Bombyx mori） homolog of Met gene from Drosophila melanogaster using bio-in...Methoprene-tolerant （Met） gene has been found to be involved in juvenile hormone （JH） action in insects. Herein, we isolated a silkworm （Bombyx mori） homolog of Met gene from Drosophila melanogaster using bio-informatics analysis and rapid amplification of cDNA ends - polymerase chain reaction method, and defined it as BmMet. The full-length cDNA ofBmMet gene consists of 1 917 nucleotides and includes a 1 368 bp of open reading frame for a deduced protein of 455 amino acids. All deduced protein sequences from Met genes in B. mori and other surveyed insects contain four typical domains ofbHLH, PAS-A, PAS-B and PAC, highlighting a high sequence conservation of Met genes during insect evolution. Also, genomic structure and phylogenic analysis suggested that Met in both B. mori and Drosophila species may originate from an ancestor gene with gce, another member of bHLH-PAS family, via gene duplication. In addition, BmMet was detected in all surveyed tissues and throughout the whole life of silkworm at transcriptional levels. Furthermore, silkworm individuals with RNAi silencing of BmMet gene in the early stage of the fourth instar larvae could molt normally and pupate successfully. This result was different from the observation in T. castaneum but similar to that in D. melanogaster after Met knockdown, revealing that the action mode of Met in B. mori and D. melanogaster should be divergent with that in other insect species.展开更多
Selenium (Se) is an essential trace element in vivo. Its biological function is mainly exerted through selenoproteins. Selenocysteine (Sec), the active site of selenoproteins, is incorporated into the protein at an in...Selenium (Se) is an essential trace element in vivo. Its biological function is mainly exerted through selenoproteins. Selenocysteine (Sec), the active site of selenoproteins, is incorporated into the protein at an in-frame TGA codon under the guidance of Sec insertion sequence (SECIS) element in the 3′-untranslated region (UTR) of the gene. In this work, a method was developed and a series of programs were edited by PERL language to in silico identify selenoproteomes from the genome of domesticated silkworm (Bombyx mori). Out of 18510 annotated genes, 6348 was terminated with TGA codons, 249 containing both in-frame TGAs and SECIS elements in the 3′-UTRs. Alignments of those selenoprotein candidates with their cysteine (Cys)-containing homologs revealed that 52 genes had TGA/Cys pairs and similar flanking regions around the in-frame TGAs. Restricted by the patterns of SECIS elements only 5 genes were screened out to fully meet the requirements for selenoproteins. Among them glutathione S-transferase (GST) has been reported as a microbial selenoprotein, the other four are novel selenoproteins annotated as CG6024, CG5195, ATP-binding cassette transporter subfamily A (ABCA), and nuclear VCP-like protein. Derived from the general properties of GST, ABCA and VCP, silkworm selenoproteins may play important roles in redox regulation, Se storage and transportation, as well as cell apoptosis.展开更多
文摘A backcrossed population （BC1） derived from a cross between C100 and Dazao was obtained. The quantitative trait loci （QTLs） of the economically important traits for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, etc., were analyzed for the first time using the multiple interval mapping software WinQTLCart2.0. In total 40 QTLs were detected and contributed to 21 groups based on the constructed linkage map. According to the mapping results, 2, 2, 3, and 2 major QTLs explained over 20% of total phenotypic variations, whereas four QTLs, namely qCW-19, qSW-2, qCSR-4, and qPW-23, explained more than 30% of total phenotypic variations for whole cocoon weight, cocoon shell weight, ratio of cocoon shell and weight of pupae, respectively. Correlated traits QTLs often share the same location. Furthermore, most of the detected QTLs were closed to one-side marker. By using the very closed markers, positive QTLs can be aggregated, which can form a basis for molecular marker-assisted selection and breeding.
基金supported by the Project of Chongqing Science and Technology Commission(CSTC,2006AA5019)National Basic Research Program of China under the grant No.2005CB121000
文摘Microsporidia are a group of intracelluar eukaryotic parasites, which can infected almost all animals, including human beings. Till now, no mitochodria but mitosome, a remnant of mitochondria was discovered in this phylum. We present here the mitochondrial pyruvate dehydrogenase El （PDH, including PDHα and PDHβ） of the microsporidian Nosema bombycis, the pathogen of silkworm pebrine. Compared with PDH of microsporidian Encephalitozoon cuniculi and Antonospora locustae, both subunits are eonscrced. The phylogeny indicated that both subunits are mitochondrial. The syntenic maps revealed the subunits organization of NbPDH is distributed in different scaffolds, similar to that of EcPDH but different with AIPDH, and the relationship between phylogeny tree and organization of PDH suggest that the AlPDH subunits organization is the ancestral style of microsporidia, and through the genome evolution, the reshuffling of the chromosome of microsporidia occurred, the adjacent style of ALPDHE1 organization changed, and the two subunits separated and located to different chromosomes in E. cuniculi. For N. bombycis and N. ceranae, they locate to different scaffolds. In order to determine NbPDH subcellular localizations, we prepared the polyclonal antibodies against NbPDH prokaryotic fusion proteins, and adopted the colloidal gold immunological electron microscopy, the expression signals of NbPDH were observed in spores however, the subcellular localization were not definited. In general, through comparison of three mierosporidian PDH molecular phylogeny, subunits organization in chromosomes, localization indicated that PDH is an interesting marker in microsporidia evolution
基金the grants from the National Basic Research Program of Ministry of Science and Technology, China （973 Program, 2005CB 121000） the Science and Technology Project of Guangdong Province, China （2003C104042） the Natural Science Foundation of Guangdong Province, China （032256, 04020553）.
文摘The antifungal peptides, drosomycin （Drs） and its isoform drosomycin-like C （Drs-lC） from Drosophila melanogaster and Thanatin from Podisus maculiventris, have potent activity with broad spectrum against filamentous fungi. Secretive expression of these genes in yeasts makes it possible to utilize the supernatants of yeast culture as protective reagents on fruit, vegetable, food and other agricultural products. So the study of effective secretion by yeast expression system is of great importance. Three genes, Drs, Drs-lC, and Thanatin, were cloned into pPICZαA and the recombinant vectors, pPICZαA-Drs, pPICZαA-Drs-lC, and pPICZαA-Thanatin were transformed into Pichia pastoris by the electric transfer method. The recombinant P. pastoris, which was screened by phenotype selection and PCR amplification, was induced to express antifungal peptide by methanol. The expressive products of the three recombinants showed antifungal activity against 5 out of 6 test fungi strains, and the products of Thanatin also had strong activity against the tested bacteria. The three antifungal peptide genes, Drs, Drs-lC, and Thanatin, were constructed into yeast P. pastoris. The expressed peptides were successfully secreted into the culture medium and exhibited potent activities against the test strains.
基金supported by the National Natural Sci-ence Foundation of China (30571331)the China Postdoctoral Science Foundation (2005038161)
文摘Imprinted genes play significant roles in the regulation of fetal growth, development, function of the placenta and postnatal behavior in mammals, but little is known in pigs. In order to investigate the imprinting status of porcine retro-transposon like 1 （RTL1） and type 3 iodothyronine deiodinase （DIO3） genes, DNA or RNA samples of the parents and F1 animals, generated with reciprocal crosses between Large White and Meishan breeds, were isolated, and analyzed by reverse transcription polymerase chain reaction restriction fragment length polymorphism （RT-PCR-RFLP）. The results demonstrated that the RTL1 gene was paternally expressed in 10 tissues, such as the skeletal muscle, heart, spleen, liver, kidney, lung, stomach, fat, small intestine and brain, and D103 gene exhibited paternal expression in the skeletal muscle, heart, spleen, lung, stomach, and brain, in 2-month-old pigs. The association of RTL1 and DI03 with carcass traits was further analyzed in the F2 population of Large White×Meishan pigs. The statistical results showed that the R TL1 A1101G polymorphism （EU781029） was significantly associated with lean meat percentage （LMP） and fat meat percentage （FMP） （P〈0.05）, while the D103 A744C polymorphism （AY533208） was not significantly associated with any carcass traits. These results indicate that the imprinting status of RTL1 and DIO3 is well kept across the mammalian species, and porcine RTL1 may have important roles in muscle growth and fat deposition.
文摘This article mainly studied Humulus scandens’ ITS sequence, its system position and its divergent time. ITS is 624 bp with a GC percentage content of 57.21%. It only has the variation in 585 (C changes T), systematic position in Humulus lupulus (GenBank: EF136401) and Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990), with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) has the near sibship. Humulus in Moraceae family system position between Cudrania tricuspidata and Artocarpeae, support the Cannabiodeae promotion for Cannabinaceae. The divergent time of Humulus is 70.88 mya in Moraceae, Humulus scandens and Humulus lupulus (GenBank: EF136401) is 12.78 mya, with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) is 1.10 mya. In the Moraceae branch’s molecular systematics research, the suitable choice is to choose Humulus scandens as Moraceae’s outgroup.
文摘Gene expression quantification at mRNA level is very important for postgenomic studies, as gene expression level is the reflection of the special biological function of the target gene. Methods used for gene expression quantification, such as microarray or quantitative real-time polymerase chain reaction （qRT-PCR）, require stable expressed reference genes. Thus, finding suitable control genes is essential for gene quantification. In this study, a genome-wide survey of reference genes during metamorphism was performed on silkworm Bombyx mori. Twelve genes were chosen as putative reference genes based on a whole genome oligonucleotide microarray normalized by external controls. Then, qRT- PCR was employed for further validation and selection of potential reference gene candidates. The results were analyzed, and stable genes were selected using geNorm 3.4 and NormFinder software. Finally, considering factors from every aspect, translation initiation factor 4A, translation initiation factor 3 subunit 4, and translation initiation factor 3 subunit 5 （represented by sw22934, sw14876, and sw13956） were selected as reliable internal controls across the examined developmental stages, while cytoplasmic actin （sw22671）, the commonly used reference gene in a previous study was shown to vary drastically throughout the examined developmental stages. For future research, we recommend the use of the geometric mean of those three stable reference genes as an accurate normalization factor for data normalization of different developmental stages during metamorphism.
文摘Cathepsin B belongs to lysosomal cysteine protease of the papain family. Temporal and spatial expression analysis of cathepsin B of Bombyx mori （BmCtB） was carried out based on Expression Sequence Tags （ESTs） data, oligonucleotide microarray, reverse transcription polymerase chain reaction （RT-PCR） and quantitative real-time PCR. Expression of BmCtB was observed in all of the tissues and stages. Among the 10 tested tissues, the fat body and posterior silk gland are the two most enriched tissues with BmCtB. During Bombyx development, there was an expression fastigium of BmCtB during metamorphosis. RNA interference was used to suppress the expression of cathepsin B during metamorphosis. Significant developmental defective phenotypes were obtained in the RNAi treated group. The dramatically reduced expression of BmCtB was con^rmed by Northern blot and quantitative real-time PCR. These evidences strongly suggest cathepsin B proteinase was predominantly involved in the metabolism process of fat body and the posterior silk gland and was critical for metamorphism and development of silkworm, Bombyx mori.
基金This work was supported by the Hi-Tech Research and Development Program of China(863 Program,No.2004AA2Z1020)the National Natural Science Foundation of China(Grant No.30300262).
文摘We have searched the Bombyx mori genome for members of the major enzyme family,the Cytochrome P450s,which carry out multiple reactions to enable organisms to rid themselves of foreign compounds.As a result,86 putative P450s were discovered in silkworm genome,which are thought to belong to 32 subfamilies.A comparative genomic analysis with Drosophila melanogaster reveals that the two insects have some similar P450 distribution pat-terns but still have some obvious differences.Especially,the diverse distribution exists in 7 p450 subfamilies,which are CYP4A,CYP4C,CYP4D,CYP6A,CYP6AE,CYP6B and CYP9A.Fur-thermore,we collected expression sequence tag(EST)evidence for 49 putative P450s genes,which are expressed at the transcriptional level and more likely to be true P450s.
文摘To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for the germline transformation of diapause silkworm strains. Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains. By incu- bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃ （15℃-IME）, we were able to prevent the diapause of their daughter eggs; a similar strategy （15℃-IMES） for the germline transformation of the same strains was that the mother eggs were incubated at 15℃, and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs. By combining tempera- ture and light controls, the improved 15℃-IMES strategy prevented diapause in daughter eggs, and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains. Although each of the strategies developed here has advantages and disadvantages, we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects. These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.
基金This work was supported by the Key Project from National Natural Science Foundation of China (Grant No. 39730730) General Program from National Natural Science Foundation of China (Grant No. 39770574) Foundation for University Key Teacher by the
文摘The sericulture industry plays a very important role in our national economy. Silkworm (Bombyx mori) is always regarded as a model animal and biological reactor. There have been detailed studies on the structure, expression and control and molecular evolution of silk genes. However, few, if any, reports are available on the localization of structural genes in silkworm by molecular cytogenetics. The present experiment has tentatively localized the Fib-H gene at the distal end of the 25th linkage group, namely at the 25-0.0 position, and verified that Fib-H has only one locus, thus providing a temporary solution to the problem about its localization.
文摘he silkworm, Bombyx mori, is an economically important insect with a 5 000-year history of domestication. During evolution, the silkworm has developed highly effective defenses against invasion and parasitization by microorganisms. In this study, two microorganisms Escherichia coli and Bacillus bombyseptieus were orally infected to silk- worm larvae. After infection with E. coli and B. bombyseptieus for 24 h, we investigated the polypeptide changes in the hemolymph, midgut and integument using two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spec- trometry. Forty-seven differentially expressed proteins were identified in these tissues. They belonged to a variety of functional classes, including immune proteins, metabolic proteins and structural proteins. Compared with controls, E. coli-infected silkworms showed 21 up- regulated proteins, 25 down-regulated proteins and lost one protein. After infection with B. bombyseptieus, silkworms showed 15 up-regulated proteins, 27 down-regulated pro- teins, lost three proteins and retained two proteins unchanged. We speculate that all these proteins may play a role in the silkworm immune response, although it is unclear why and how the two kinds of bacteria can so markedly alter expression of these proteins. These re- sults offer valuable insights for measuring the proteomic responses of the silkworm innate immune mechanism.
文摘Methoprene-tolerant （Met） gene has been found to be involved in juvenile hormone （JH） action in insects. Herein, we isolated a silkworm （Bombyx mori） homolog of Met gene from Drosophila melanogaster using bio-informatics analysis and rapid amplification of cDNA ends - polymerase chain reaction method, and defined it as BmMet. The full-length cDNA ofBmMet gene consists of 1 917 nucleotides and includes a 1 368 bp of open reading frame for a deduced protein of 455 amino acids. All deduced protein sequences from Met genes in B. mori and other surveyed insects contain four typical domains ofbHLH, PAS-A, PAS-B and PAC, highlighting a high sequence conservation of Met genes during insect evolution. Also, genomic structure and phylogenic analysis suggested that Met in both B. mori and Drosophila species may originate from an ancestor gene with gce, another member of bHLH-PAS family, via gene duplication. In addition, BmMet was detected in all surveyed tissues and throughout the whole life of silkworm at transcriptional levels. Furthermore, silkworm individuals with RNAi silencing of BmMet gene in the early stage of the fourth instar larvae could molt normally and pupate successfully. This result was different from the observation in T. castaneum but similar to that in D. melanogaster after Met knockdown, revealing that the action mode of Met in B. mori and D. melanogaster should be divergent with that in other insect species.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.30370352&30570420)the Major State Basic Research Development Program of China(Grant No.2005CB121000).
文摘Selenium (Se) is an essential trace element in vivo. Its biological function is mainly exerted through selenoproteins. Selenocysteine (Sec), the active site of selenoproteins, is incorporated into the protein at an in-frame TGA codon under the guidance of Sec insertion sequence (SECIS) element in the 3′-untranslated region (UTR) of the gene. In this work, a method was developed and a series of programs were edited by PERL language to in silico identify selenoproteomes from the genome of domesticated silkworm (Bombyx mori). Out of 18510 annotated genes, 6348 was terminated with TGA codons, 249 containing both in-frame TGAs and SECIS elements in the 3′-UTRs. Alignments of those selenoprotein candidates with their cysteine (Cys)-containing homologs revealed that 52 genes had TGA/Cys pairs and similar flanking regions around the in-frame TGAs. Restricted by the patterns of SECIS elements only 5 genes were screened out to fully meet the requirements for selenoproteins. Among them glutathione S-transferase (GST) has been reported as a microbial selenoprotein, the other four are novel selenoproteins annotated as CG6024, CG5195, ATP-binding cassette transporter subfamily A (ABCA), and nuclear VCP-like protein. Derived from the general properties of GST, ABCA and VCP, silkworm selenoproteins may play important roles in redox regulation, Se storage and transportation, as well as cell apoptosis.
