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1.
The mitochondrial genome(mitogenome) was 16792 bp in length, containing 13 protein coding genes(PCGs), two rRNA genes(12 S rRNA and 16 S rRNA), 22 tRNA genes, and two main non-coding regions. Among these 37 genes, 28 genes were encoded on the heavy strand, while 9 genes were transcribed on the light strand. The non-coding regions of A. dispar included a control region, a light strand replication and another 11 intergenic spacers. The CR of A. dispar contained 8 conserved sequence blocks(CSBs), a termination-associated sequence(TAS) and a pyrimidine tract. Phylogenetic analysis based on 12 PCGs revealed that A. dispar was genetically closest to Arius arius. The families Schilbeidae, Claroteidae, Mochokidae, and Ariidae formed a closely evolved clade. Molecular information from this research introduces mitogenomice data of A. dispar and suggests the phylogenetic relationships among Siluriformes.  相似文献   

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Perciformes, the largest order of vertebrates with 20 suborders, is the most diverse fish order that dominates vertebrate ocean life. The complete mitochondrial control region (CR) of Trichiurus japonicus (Trichiuridae, Scombroidei) and Pampus sp. (Stromateidae, Stromateoidei) were amplified and sequenced. Together with data from GenBank, the tandem repeats in the mitochondrial CR from 48 species, which covered nine suborders of Perciformes, are reported in this study. The tandem repeats tend to be long in the suborder Percoidei and Stromateoidei. The identical repeats in 21 species of Cichlidae suggest a common origin and have existed before species divergence. Larimichthys crocea shows tandem repeats instead of the typical structure of the central conserved sequence blocks, which was first reported in Perciformes and vertebrates. This might have resulted from interruption of the polymerase activity during the H-strand synthesis. The four broader patterns presented here for the tandem repeats, including those in both the 5′ and 3′ ends, only in the either 5′ or 3′ end, and in the central conserved domain of the control region, will be useful for understanding the evolution of species.  相似文献   

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Seagrass habitats are structurally complex ecosystems, which support high productivity and biodiversity. In temperate systems the density of seagrass may change seasonally, and this may influence the associated fish and invertebrate community. Little is known about the role of seagrass beds as possible nursery areas for fish and invertebrates in China. To study the functioning of a seagrass habitat in northern China, demersal fish and invertebrates were collected monthly using traps, from February 2009 to January 2010. The density, leaf length and biomass of the dominant seagrass Zostera marina and water temperature were also measured. The study was conducted in a Seagrass Natural Reserve(SNR) on the eastern coast of the Shandong Peninsula, China. A total of 22 fish species and five invertebrate species were recorded over the year. The dominant fish species were Synechogobius ommaturus, Sebastes schlegelii, Pholis fangi, Pagrus major and Hexagrammos otakii and these species accounted for 87% of the total number of fish. The dominant invertebrate species were Charybdis japonica and Octopus variabilis and these accounted for 98% of the total abundance of invertebrates. There was high temporal variation in species composition and abundance. The peak number of fish species occurred in August–October 2009, while the number of individual fish and biomass was highest during November 2009. Invertebrate numbers and biomass was highest in March, April, July and September 2009. Temporal changes in species abundance of fishes and invertebrates corresponded with changes in the shoot density and leaf length of the seagrass, Zostera marina.  相似文献   

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The phylogenetic relationship among Chinese Parapenaeopsis species was studied by comparing 16S rDNA and COI gene sequence. The results showed that Parapenaeopsis hardwickii (Miers, 1878) and P. cultrirostris Alcock, 1906 identified from Chinese samples were the same species. Parapenaeopsis cornuta (Kishinouye, 1900), P. incisa Liu and Wang, 1987, and P. sinica Liu and Wang, 1987 were different species. However, their systematic relationship were closer than those of other species, and they formed an advanced branch in the phylogenetic trees. Additionally, the systematic position of P. hardwickii (Miers, 1878), P. hungerfordi Alcock, 1905, and P. tenella (Bate, 1888) were not stable in the phylogenetic trees. More genetic markers such as 18S rDNA and 28S rDNA were supposed to be used to confirm the phylogenic relationship of Parapenaeopsis species.  相似文献   

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DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop (Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher (P<0.05) in testis than in ovary at the same stage, showing a sex-dimorphic expression pattern. Furthermore, immunohistochemical detection found that Cf-DAX1 mainly located in spermatogonia and spermatocytes of testis and in oogonia and oocytes of ovary, implying that DAX1 may involve in gametogenesis of bivalves.  相似文献   

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A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and identified as D. megalolepis by morphological characterization. The coloration, meristic traits, and morphometric measurements were consistent with previously published records. In general, it is a silver-white, laterally compressed and deep bodied ponyfish with 6–9 rows of scales on cheek; scale rows above lateral line 6–8; scale rows below lateral line 14–17. Mitochondrial cytochrome oxidase I subunit (COI) gene fragment was sequenced for phylogenetic analysis. There is no sequence variation of COI gene between the specimens collected in this study. The genetic distances between D. megalolepis and other congeneric species range from 3.6% to 14.0%, which were greater than the threshold for fish species delimitation. The COI sequence analysis also supported the validity of D. megalolepis at genetic level. However, the genetic distance between Chinese and Philippine individuals was about 1.2% and they formed two lineages in gene tree, which may be caused by the geographical distance.  相似文献   

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以勒氏笛鲷(Lutjanus russellii)基因组DNA为模板,采用同源克隆的方法,获得2 887 bp的肌肉生长抑制素(myostatin,MSTN)基因组序列,该MSTN序列具有3个外显子和2个内含子,包括101 bp的5′-UTR、385bp的外显子1、354 bp的内含子1、370 bp的外显子2、761 bp的内含子2、381 bp的外显子3和1 932 bp的3′-UTR。整个开放阅读框编码了378个氨基酸,前面的22个氨基酸为信号肽,具有9个保守的半胱氨基酸及一个RVRR的蛋白酶解加工位点。氨基酸序列分析发现,该基因编码的蛋白质与其他鱼类的I型同源性较高,与其他鱼类的2型MSTN同源性较低,且与鲈形目的同源性最高,与鲤形目的同源性较低,与人、鼠和鸡的同源性最低。采用邻接法(Neighbor-Joining)构建的MSTN的系统发育树表明,勒氏笛鲷MSTN与鲈形目鱼类的狼鲈属亲缘关系较近,且与鱼类的MSTN-1聚为1支。这表明该基因属于Ⅰ型MSTN基因。  相似文献   

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The culture of Sertoli cells has become an indispensable resource in studying spermatogenesis. A new Sertoli cell line (POSC) that consisted predominantly of fibroblast-like cells was derived from the testis of the olive flounder Paralichthys olivaceus and sub-cultured for 48 passages. Analysis of the mtDNA COI gene partial sequence confirmed that the cell line was from P. olivaceus. Cells were optimally maintained at 25°C in DMEM/F12 medium supplemented with fetal bovine serum, basic fibroblast growth factor, and epidermal growth factor. The growth curve of POSC showed a typical “S” shape. Chromosome analysis revealed that the cell line possessed the normal P. olivaceus diploid karyotype of 2n=48t. POSC expressed dmrt1 but not vasa, which was detected using RT-PCR and sequencing. Immunocytochemistry revealed that the cells exhibited the testicular Sertoli cell marker FasL. Therefore, POSC appeared to consist of testicular Sertoli cells. Bright fluorescent signals were observed after the cells were transfected with pEGFP-N3 plasmid, with the transfection efficiency reaching 10%. This research not only offers an ideal model for further gene expression and regulation studies on P. olivaceus, but also serves as valuable material in studying fish spermatogenesis, Sertoli cell-germ cell interactions, and the mechanism of growth and development of testis.  相似文献   

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AMP deaminase catalyzes the conversion of AMP into IMP and ammonia. In the present study, a full-length cDNA of AMPD1 from skeletal muscle of Japanese flounder Paralichthys olivaceus was cloned and characterized. The 2 526 bp cDNA contains a 5’-UTR of 78 bp, a 3’-UTR of 237 bp and an open reading frame (ORF) of 2 211 bp, which encodes a protein of 736 amino acids. The predicted protein contains a highly conserved AMP deaminase motif (SLSTDDP) and an ATP-binding site sequence (EPLMEEYAIAAQVFK). Phylogenetic analysis showed that the AMPD1 and AMPD3 genes originate from the same branch, but are evolutionarily distant from the AMPD2 gene. RT-PCR showed that the flounder AMPD1 gene was expressed only in skeletal muscle. QRT-PCR analysis revealed a statistically significant 2.54 fold higher level of AMPD1 mRNA in adult muscle (750±40 g) compared with juvenile muscle (7.5±2 g) (P<0.05). HPLC analysis showed that the IMP content in adult muscle (3.35±0.21 mg/g) was also statistically significantly higher than in juvenile muscle (1.08±0.04 mg/g) (P<0.05). There is a direct relationship between the AMPD1 gene expression level and IMP content in the skeletal muscle of juvenile and adult flounders. These results may provide useful information for quality improvement and molecular breeding of aquatic animals.  相似文献   

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对裸体方格星虫(Sipunculus nudus)、可口革囊星虫(Phascolosoma esculenta)和澳洲管体星虫(Siphonosoma australe)的线粒体16S rRNA、COI和细胞色素b(Cytb)基因片段序列进行比较,并对其系统发生进行了初步探讨。采用PCR方法得到总长度分别为531~544bp(16S)、652~675bp(COI)和406~453bp(Cytb)的线粒体片段。片段碱基A+T比例较高(16S rRNA基因58.3%,COI基因56.9%,Cytb基因59.5%)。16S rRNA片段存在169个碱基变异位点(其中包括167个简约信息位点)和44个碱基插入/缺失,种内个体间变异较小;COI片段有512个碱基(333个简约信息位点)存在变异,79个碱基插入/缺失;Cytb片段存在347个碱基(318个简约信息位点)变异位点,16个碱基插入/缺失。数据分析结果支持3种星虫和环节动物的分类地位较近,与软体动物较远的分类观点。此外,裸体方格星虫与澳洲管体星虫之间亲缘关系较近(D=0.3159、0.3156、0.2361)。认为3种星虫线粒体16S rRNA、COI和Cytb基因在种间存在明显的多态性,证实了三种基因序列均普遍适用于星虫种及以上阶元的系统学分析。  相似文献   

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Eight hundred and thirty eight base pair fragment of mitochondrial COI gene of wild and cultured populations (CP1, CP4, CP5 and CP6) of Fenneropenaeus chinensis was amplified and sequenced. The A, T, G and C contents of the sequence were 235 bp (28.0%), 307 bp (36.6%), 138 bp (16.5%) and 158 bp (18.9%), respectively. Furthermore, 556 bp fragment of the sequence was used to discuss the phylogenetic relationship among 14 Penaeidae species using Alpheus armillatus as the outgroup. From the molecular phylogenetic tree constructed by neighbor-joining method, we obtained three large shrimp groups: Farfantepenaeus, Litopenaeus and Fenneropenaeus group. The results also indicated that there were a closer genetic relationships between F. aztecus and F. paulensis, L. schmitti and L. setiferus, F. indicus and F. merguiensis, and the genus Farfantepenaeus was closer to Litopenaeus.  相似文献   

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