The insulin-like growth factors Ⅰ and Ⅱ （IGF-Ⅰ and IGF-Ⅱ） are important proteins involved in fish growth and develop- ment. Here, we report the isolation of IGF-Ⅱ and expression analysis of IGFs in turbot Scoph...The insulin-like growth factors Ⅰ and Ⅱ （IGF-Ⅰ and IGF-Ⅱ） are important proteins involved in fish growth and develop- ment. Here, we report the isolation of IGF-Ⅱ and expression analysis of IGFs in turbot Scophthalmus maximus, aiming to clarify their function in embryonic and larval development of fish. The deduced IGF-Ⅱ gene is 808 bp in full length, which encodes a protein of 219 amino acids and is 93% similar with that ofParalichthys olicaceus in amino acid sequence. The tissue abundance and the ex- pression pattern of IGFs in a turbot at early development stages were investigated via reverse transcription-polymer chain reaction. Result showed that the IGF-Ⅰ and IGF-Ⅱ genes were widely expressed in tissues of S. maximus. IGF-Ⅰ was detected in all tissues ex- cept intestines with the highest level in liver, while IGF-Ⅱ transcript presented in all tissues except muscle. At the stages of embry- onic and larval development, the mRNA levels of IGFs sharply increased from the stage of unfertilized egg to post larva, followed by a decrease with larval development. However, there was an increase in IGF-Ⅰ at the embryonic stage and IGF-Ⅱ at the gastrula stage, respectively. These results suggested that IGFs play important roles in cell growth and division of the turbot. Our study provides reference data for further investigation of growth regulation in turbot, which can guarantee better understanding of the physiological role that IGFs play in fish.展开更多
Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plas...Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plastid. Intensive work is in great demand from the perspective of genome colinearity. In this study, 118 sequence-tagged site(STS) markers were screened for phylogenetic analyses, 29 based on genome sequences, while 89 were based on expressed sequence tag(EST) sequences. EST-based STS marker development(29.37%) had an effi ciency twice as high as genome-sequence-based development(9.48%) as a result of high conservation of gene transcripts among the relative species. S. ochotensis, S. religiosa, S. japonica, and L. hyperborea showed great homogeneity in all 118 STS markers. Our result supports the view that the diversifi cation between the genera Saccharina and Laminaria was a more recent event and that Saccharina and Laminaria shared high phylogenetic affi nity. However, when it came to the single nucleotide polymorphism(SNP) level among the 41 SNPs, L. hyperborea owned 29 unique SNPs against 12 within the left three Saccharina species and 12 of the 13 indels were supposedly unique for L. hyperborea, indicated by its high variability. Originating from homologous ancestors, species between the recently diverged genera Laminaria and Saccharina may have taken in enough mutations at the SNP level only, in spite of different evolutionary strategies for better adaptation to the environment. Our study lays a solid foundation from a new perspective, although more accurate phylogenetic analysis is still needed to clarify the evolutionary traces between the genera Saccharina and Laminaria.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 the National Key Technologies R & D Program of China (Grant No. 2011BAD13B03)
文摘The insulin-like growth factors Ⅰ and Ⅱ （IGF-Ⅰ and IGF-Ⅱ） are important proteins involved in fish growth and develop- ment. Here, we report the isolation of IGF-Ⅱ and expression analysis of IGFs in turbot Scophthalmus maximus, aiming to clarify their function in embryonic and larval development of fish. The deduced IGF-Ⅱ gene is 808 bp in full length, which encodes a protein of 219 amino acids and is 93% similar with that ofParalichthys olicaceus in amino acid sequence. The tissue abundance and the ex- pression pattern of IGFs in a turbot at early development stages were investigated via reverse transcription-polymer chain reaction. Result showed that the IGF-Ⅰ and IGF-Ⅱ genes were widely expressed in tissues of S. maximus. IGF-Ⅰ was detected in all tissues ex- cept intestines with the highest level in liver, while IGF-Ⅱ transcript presented in all tissues except muscle. At the stages of embry- onic and larval development, the mRNA levels of IGFs sharply increased from the stage of unfertilized egg to post larva, followed by a decrease with larval development. However, there was an increase in IGF-Ⅰ at the embryonic stage and IGF-Ⅱ at the gastrula stage, respectively. These results suggested that IGFs play important roles in cell growth and division of the turbot. Our study provides reference data for further investigation of growth regulation in turbot, which can guarantee better understanding of the physiological role that IGFs play in fish.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A406)the Science and Technology Development Project of Shandong Province,China(No.2006GG3205001)+2 种基金the National Basic Scientific Special Fund of the Ministry of Science and Technology,China(No.2007FY210500)the National Public Benefit Research Foundation of the State Bureau of Oceanography,China(No.200805075)the Research Fund for Basic Sciences of Higher Education by National Ministry of Finance and Education,China(No.201262003)
文摘Laminaria and Saccharina have recently been recognized as two independent clades from the former genus Laminaria. Traditional morphological taxonomy is being challenged by molecular evidence from both nucleus and plastid. Intensive work is in great demand from the perspective of genome colinearity. In this study, 118 sequence-tagged site(STS) markers were screened for phylogenetic analyses, 29 based on genome sequences, while 89 were based on expressed sequence tag(EST) sequences. EST-based STS marker development(29.37%) had an effi ciency twice as high as genome-sequence-based development(9.48%) as a result of high conservation of gene transcripts among the relative species. S. ochotensis, S. religiosa, S. japonica, and L. hyperborea showed great homogeneity in all 118 STS markers. Our result supports the view that the diversifi cation between the genera Saccharina and Laminaria was a more recent event and that Saccharina and Laminaria shared high phylogenetic affi nity. However, when it came to the single nucleotide polymorphism(SNP) level among the 41 SNPs, L. hyperborea owned 29 unique SNPs against 12 within the left three Saccharina species and 12 of the 13 indels were supposedly unique for L. hyperborea, indicated by its high variability. Originating from homologous ancestors, species between the recently diverged genera Laminaria and Saccharina may have taken in enough mutations at the SNP level only, in spite of different evolutionary strategies for better adaptation to the environment. Our study lays a solid foundation from a new perspective, although more accurate phylogenetic analysis is still needed to clarify the evolutionary traces between the genera Saccharina and Laminaria.
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.
