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
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.
