Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and co...Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.展开更多
GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 ...GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 classes. Through genomic analysis, we have identified three GATA factors, representing the GATA1/2/3 and GATA4/5/6 subfamilies respectively, and one GATA like protein in the genome of the basal chordate amphioxus （Branchiostoma floridae, cephalochordata）. Partial sequence of GATA123 in the amphioxus Branchiostoma belcheri （BbGATA123） was cloned and its expression pattern during early embryonic development was studied. Expression of BbGATA123 is first detected in the mesendoderm during gastrulation. Interestingly, in the late neurula and early larva stages, it is expressed strongly in the cerebral vesicle and the mid gut region. Its expression is compared to Otx, a gene known crucial for the development of anterior structures. Our observations suggest that GATA123, together with Otx, might play an important role in the development of amphioxus cerebral vesicle, the counterpart of the vertebrate brain.展开更多
Actins are a small family of ubiquitous proteins that are essential cytoskeletal components and are highly conserved during evolution. Actins are usually divided into two classes, the cytoplasmic and muscle actins, wh...Actins are a small family of ubiquitous proteins that are essential cytoskeletal components and are highly conserved during evolution. Actins are usually divided into two classes, the cytoplasmic and muscle actins, which have different functional roles. Here we systematically analyzed the actin genes in the genome of the primitive chordate amphioxus （Branchiostoma floridae）. We found that amphioxus contains more than 30 actin genes, many of which are linked. Phylogenetic analysis suggests the amphioxus actin genes have clearly undergone extensive expansion through tandem duplications. The actin genes＇ structure also varies a lot, containing 2 to 7 exons. We also cloned two muscle type of actin genes from the amphioxus （B. belcheri） and compared their expression patterns during early development. The slight difference in their expression suggests functional diversification of these actin genes. Our results shed light on the evolution both of actin genes themselves and their functional roles in chordate development.展开更多
A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open read...A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame （ORF） of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind grit and testis, hepatic caecum, gill, endostyle, and epipbaryngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary （CHO） cells transfected with the expression plasmid pEGFP-NI/Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.展开更多
[Objective]The paper was to establish simple and effective method to screen marker gene in maize with kanamycin resistance.[Method]Using inbred line "Chang 7-2" and hybrid "Zhengdan 958" of maize a...[Objective]The paper was to establish simple and effective method to screen marker gene in maize with kanamycin resistance.[Method]Using inbred line "Chang 7-2" and hybrid "Zhengdan 958" of maize as test materials,their seeds were soaked with different concentrations and volumes of kanamycin for3 and 4 d,respectively,the rate of albino seedlings and average seedling height after sowing for10 d were investigated.[Result]The rate of albino seedlings not only was related to kanamycin concentration,but also had relationship with solution volume during soaking process.The difference between inbred line and hybrid was no significant.When 100 ml of kanamycin solution with concentration of 200 mg/L was used to soak seeds for 3 d,the rate of albino seedlings basically could reach 100%.When 100 ml of kanamycin solution with concentration of 100 mg/L was used to soak 20 seeds for 3 d to carry out resistance screening,the accuracy was up to 84.8% after verifying the screening test of T1 transgenic maize plants.[Conclusion]The method was feasible,which could be used as a simple method for screening transgenic gene maize with kanamycin resistance.展开更多
We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and l...We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and larvae）, and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.展开更多
Smad family proteins are identified as intracellular signal mediators of the TGF-β superfamily.In this study,we identified two novel members of the Smad family,termed as AmphiSmad1/5/8 and AmphiSmad4,from Chinese amp...Smad family proteins are identified as intracellular signal mediators of the TGF-β superfamily.In this study,we identified two novel members of the Smad family,termed as AmphiSmad1/5/8 and AmphiSmad4,from Chinese amphioxus.Both AmphiSmad1/5/8 and AmphiSmad4 showed a typical domain structure of Smad proteins consisting of conserved MH1 and MH2 domains.Phylogenetic analysis placed AmphiSmad1/5/8 in the Smad1,5 and 8 subgroup of the R-Smad subfamily,and AmphiSmad4 in the Co-Smad subfamily.The spatial and temporal gene expression patterns of AmphiSmad1/5/8 and AmphiSmad4 showed that they may be involved in the embryonic development of notochord,myotome and alimentary canal,and may help to establish the specification of dorsal-ventral axis of amphioxus.Moreover,AmphiSmad1/5/8 and AmphiSmad4 showed extensive distribution in all adult tissues examined,suggesting that these two genes may play important roles in the morphogenesis of a variety of tissues especially notochord and gonad.展开更多
基金Supported by grants from NSFC (No.30570208)SRFDP of Ministry of Education, China (20070384041)The Education Department of Fujian Province, China (JB07063)
文摘Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.
基金Supported by grants from the National Natural Science Foundation of China (30425011 30530380)~~
文摘GATA factors are evolutionarily conserved and play crucial roles during embryonic development in both vertebrates and invertebrates. Vertebrate GATAs can be divided into two subgroups, the GATAI/2/3 and the GATA4/5/6 classes. Through genomic analysis, we have identified three GATA factors, representing the GATA1/2/3 and GATA4/5/6 subfamilies respectively, and one GATA like protein in the genome of the basal chordate amphioxus （Branchiostoma floridae, cephalochordata）. Partial sequence of GATA123 in the amphioxus Branchiostoma belcheri （BbGATA123） was cloned and its expression pattern during early embryonic development was studied. Expression of BbGATA123 is first detected in the mesendoderm during gastrulation. Interestingly, in the late neurula and early larva stages, it is expressed strongly in the cerebral vesicle and the mid gut region. Its expression is compared to Otx, a gene known crucial for the development of anterior structures. Our observations suggest that GATA123, together with Otx, might play an important role in the development of amphioxus cerebral vesicle, the counterpart of the vertebrate brain.
基金supported by grants from the National Natural Science Foundation of China (30425011 30530380)the Innovation Project of Chinese Academy of Sciences (KSCX2-YW-R-090)~~
文摘Actins are a small family of ubiquitous proteins that are essential cytoskeletal components and are highly conserved during evolution. Actins are usually divided into two classes, the cytoplasmic and muscle actins, which have different functional roles. Here we systematically analyzed the actin genes in the genome of the primitive chordate amphioxus （Branchiostoma floridae）. We found that amphioxus contains more than 30 actin genes, many of which are linked. Phylogenetic analysis suggests the amphioxus actin genes have clearly undergone extensive expansion through tandem duplications. The actin genes＇ structure also varies a lot, containing 2 to 7 exons. We also cloned two muscle type of actin genes from the amphioxus （B. belcheri） and compared their expression patterns during early development. The slight difference in their expression suggests functional diversification of these actin genes. Our results shed light on the evolution both of actin genes themselves and their functional roles in chordate development.
基金Supported by the Pilot Projects of Knowledge Innovation Project of Chinese Academy of Sciences (No. KZCX2-YW-211-03 and MGE2008KG06)
文摘A full length amphioxus cDNA, encoding a novel phosducin-like protein （Amphi-PhLP）, was identified for the first time from the gut cDNA library of Branchiostoma belcheri. It is comprised of 1 550 bp and an open reading frame （ORF） of 241 amino acids, with a predicted molecular mass of approximately 28 kDa. In situ hybridization histochemistry revealed a tissue-specific expression pattern of Amphi-PhLP with the high levels in the ovary, and at a lower level in the hind grit and testis, hepatic caecum, gill, endostyle, and epipbaryngeal groove, while it was absent in the muscle, neural tube and notochord. In the Chinese Hamster Ovary （CHO） cells transfected with the expression plasmid pEGFP-NI/Amphi-PhLP, the fusion protein was targeted in the cytoplasm of CHO cells, suggesting that Amphi-PhLP is a cytosolic protein. This work may provide a framework for further understanding of the physiological function of Amphi-PhLP in B. belcheri.
基金Supported by Major Projects for Cultivation of New Varieties ofGenetically Modified Organisms (2009ZX08010-011B)
文摘[Objective]The paper was to establish simple and effective method to screen marker gene in maize with kanamycin resistance.[Method]Using inbred line "Chang 7-2" and hybrid "Zhengdan 958" of maize as test materials,their seeds were soaked with different concentrations and volumes of kanamycin for3 and 4 d,respectively,the rate of albino seedlings and average seedling height after sowing for10 d were investigated.[Result]The rate of albino seedlings not only was related to kanamycin concentration,but also had relationship with solution volume during soaking process.The difference between inbred line and hybrid was no significant.When 100 ml of kanamycin solution with concentration of 200 mg/L was used to soak seeds for 3 d,the rate of albino seedlings basically could reach 100%.When 100 ml of kanamycin solution with concentration of 100 mg/L was used to soak 20 seeds for 3 d to carry out resistance screening,the accuracy was up to 84.8% after verifying the screening test of T1 transgenic maize plants.[Conclusion]The method was feasible,which could be used as a simple method for screening transgenic gene maize with kanamycin resistance.
基金Supported in part by Shandong Entry-Exit Inspection and Quarantine Bureau （SK200807） We thank Dr. LI Xiangning, who works in the CSR （Center for Scientific Review） of NIH （National Institutes of Health）, USA, for his critical reading of the manuscript.
文摘We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus （Branchiostoma belcheri tsingtauense）. We cultured and sampled the animals at different developmental stages （eggs and larvae）, and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.
基金supported by the National Basic Research Program of China(Grant No. 2007CB815800)the National High Technology Research and Development Program of China(Grant No. 2006330004104456)the National Natural Science Foundation of China(Grant Nos. 30300264,30270693 and 30570967)
文摘Smad family proteins are identified as intracellular signal mediators of the TGF-β superfamily.In this study,we identified two novel members of the Smad family,termed as AmphiSmad1/5/8 and AmphiSmad4,from Chinese amphioxus.Both AmphiSmad1/5/8 and AmphiSmad4 showed a typical domain structure of Smad proteins consisting of conserved MH1 and MH2 domains.Phylogenetic analysis placed AmphiSmad1/5/8 in the Smad1,5 and 8 subgroup of the R-Smad subfamily,and AmphiSmad4 in the Co-Smad subfamily.The spatial and temporal gene expression patterns of AmphiSmad1/5/8 and AmphiSmad4 showed that they may be involved in the embryonic development of notochord,myotome and alimentary canal,and may help to establish the specification of dorsal-ventral axis of amphioxus.Moreover,AmphiSmad1/5/8 and AmphiSmad4 showed extensive distribution in all adult tissues examined,suggesting that these two genes may play important roles in the morphogenesis of a variety of tissues especially notochord and gonad.
