Molecular cloning of the heat shock protein 20 gene from Paphia textile and its expression in response to heat shock

P. textile is an important aquaculture species in China and is mainly distributed in Fujian, Guangdong, and Guangxi Provinces. In this study, an HSP20 c DNA designated Pt HSP20 was cloned from P. textile. The full-length c DNA of Pt HSP20 is 1 090 bp long and contains a 5′ untranslated region(UTR) of 93 bp, a 3′ UTR of 475 bp, and an open reading frame(ORF) of 522 bp. The Pt HSP20 c DNA encodes 173 amino acid residues and has a molecular mass of 20.22 k Da and an isoelectric point of 6.2. Its predicted amino acid sequence shows that Pt HSP20 contains a typical α-crystallin domain(residues 77–171) and three polyadenylation signal-sequences at the C-terminus. According to an amino acid sequence alignment, Pt HSP20 shows moderate homology to other mollusk s HSPs. Pt HSP20 m RNA was present in all of the test tissues including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, with the highest concentration found in the gonad. Under the stress of high temperature, the expression of Pt HSP20 m RNA was down-regulated in all of the tissues except the adductor muscle and gonad.     

fSSR分析技术的建立及在大黄鱼(Larimichthys crocea)亲子鉴定中的应用

以大黄鱼(Larimichthys crocea)为材料,对荧光标记微卫星(fSSR)分析体系进行了优化,建立了适合大黄鱼fSSR分析的最佳条件.与常规的银染法相比,该方法成本略高,但其分辨率高,可重复性强,检测效率为银染法的6～10倍.利用优化的fSSR 技术进行了大黄鱼亲于鉴定的研究,结果显示在使用6对引物的情况下...     

不同生长时期大黄鱼形态性状与体重的相关性分析

研究不同生长时期大黄鱼Pseudosciaena crocea形态性状对体重的影响效果,分别测定了1704尾13月龄和596尾20月龄闽-粤东族大黄鱼的全长(x1)、体长(x2)、体高(x3)和体重(y),计算相关系数,采用通径分析方法计算了以体重(y)为依变量、其他性状为自变量的通径系数和决定系数.结果表明,在两个不同生长时期,全长、体长、体高和体重4个性状两两之间的相关系数在0.800-0.977之间,均达到极显著水平(P<0.01);在13月龄,体高对体重的直接影响(0.522)最大,其次为体长(0.445),全长对体重的直接影响不显著(P>0.05).在20月龄,体高对体重的直接影响(0.394)最大,其次为体长(0.328)、全长(0.271),各性状对体重的直接影响均达到极显著水平(P<0.01).研究结果表明在不同生长时期,各形态性状对体重的直接影响是不同的,早期选种(13月龄)时要注意体高和体长的挑选,而在晚些时候(20月龄)选种,对体高、体长和全长均要考虑,才能够保证选择效果.     

织锦巴菲蛤(Paphia textile)过氧化氢酶基因cDNA全长克隆、序列同源分析与组织表达

Catalase is an important antioxidant protein that can protect organisms against various forms of oxidative damage by eliminating hydrogen peroxide. In this study, the catalase c DNA of Paphia textile(Pt CAT) was cloned using RTPCR and rapid amplification of c DNA ends(RACE). Pt CAT is 1 921 bp long and consists of a 5′-UTR of 50 bp, a 3′-UTR of 349 bp, and an ORF of 1 542 bp that encodes 513 amino acids with a molecular weight of 58.4 k D and an estimated isoelectric point of 8.2. Sequence alignment indicated that Pt CAT contained a highly conserved catalytic signature motif(~(61)FNRERIPERVVHAKGAG~(77)), a proximal heme-ligand signature sequence(~(352)RLFSYSDP~(359)), and three catalytic amino acid residues(H~(72), N~(145), and Y~(356)). Pt CAT also contains two putative N-glycosylation sites(~(34)NKT~(36) and ~(437)NFT~(439)) and a peroxisome-targeting signal(~(511)AQL~(513)). Furthermore, Pt CAT shares 53%–88% identity and 29%–89% similarity with other catalase amino acid sequences. Pt CAT m RNA was present in all tested organs, including the heart, digestive gland, adductor muscle, gonad, gill, and mantle, but its expression was highest in the digestive gland. High-temperature-induced stress produced two expression patterns of Pt CAT m RNA: first, an initial up-regulation followed by a down-regulation in the heart, digestive gland, and gonad and, second, consistent down-regulation in all other organs. These results demonstrate that Pt CAT is a typical member of the catalase family and might be involved in the responses to harmful environmental factors.