Yu Dahui

Establishment and genetic analysis of complete diallel cross families of pearl oyster (Pinctada fucata).

In order to build base populations for selective breeding,ninety families in nine groups were constructed using a full diallel cross design with parents of Pinctada fucata from three different places [Beihai (B),Xuwen (X) and Sanya (S)]. Comparisons of the breeding value and general evaluation among families were studied after 60 days culture in out-door pond. The results showed that the Kung breeding values of shell length were over 20 in eight families (BX2,BX9,BB4,BB5,BB8,BS9,XS3 and SB8). The family XS3 had the largest breeding values in shell length and shell width and comprehensive value,whereas XX3 had the smallest ones. The overall values of BB4 and XS3 were over one. General combining abilities (GCA) in shell length for Sanya,Xuwen and Beihai parents were 17.40,17.45 and 18.27,respectively while GCAs in shell height were 14.74,14.79 and 15.54,respectively. Specific combining abilities (SCA) in shell length were 17.75,18.27 and 18.12 for Sanya(♂)-Xuwen(♀),Sanya-Beihai and Xuwen-Beihai matings,respectively while SCAs in shell height were 14.98,15.51 and 15.46,respectively. Average heteroses in shell length were 1.41,0.96 and 0.67 for Sanya-Xuwen,Sanya-Beihai and Xuwen-Beihai matings,respectively while average heteroses in shell height were 1.13,1.60 and 1.19,respectively. This study suggested that the parents from Beihai are preferable.

合浦珠母贝 BMP 7 b 基因的克隆与表达分析

为了解骨形态发生蛋白(BMP)在贝类生物矿化方面的作用，该研究发现并克隆了合浦珠母贝( Pinctada fucata ) BMP 7的同源基因 BMP 7 b ，并对其进行了组织表达分析。结果显示，该基因cDNA长2 464 bp，其中ORF长1 194 bp，编码397个氨基酸。BMP7b蛋白无跨膜结构，含有1个信号肽(1~26 aa)，1个TGF-β前肽结构域(25~240 aa)和1个TGF-β结构域(299~396 aa)。 BMP 7 b 在各组织和各胚胎发育时期中均有表达，在鳃和外套膜的表达量高，在肠和肝胰腺的表达量低；在担轮幼虫期的表达量远远高于其他时期。贝壳缺刻实验显示24 h后， BMP 7 b 表达量显著上升。以上结果表明 BMP 7 b 可能在合浦珠母贝贝壳形成和修护过程中起重要作用。

合浦珠母贝 matrilin -1基因的克隆和表达分析

以合浦珠母贝( Pinctada fucata )转录组中的 matrilin -1基因片段为基础，开展了matrilin-1的cDNA全长( Pfmatrilin -1)克隆和定量表达分析。 Pfmatrilin -1基因cDNA全长2 036 bp，开放阅读框(open reading frame，ORF)1 194 bp，编码397个氨基酸，包括1个信号肽序列和2个血管性血友病因子A(von Willebrand factor A，VWA)样结构域。系统进化分析显示无脊椎动物的matrilins与脊椎动物的matrilins进化关系较远。荧光定量PCR表达分析结果显示， Pfmatrilin -1 mRNA在合浦珠母贝各个组织中均有表达，其中在血液中表达量最高( P Pfmatrilin -1从担轮幼虫期至变态期均有表达，眼点期表达量最高( P Pfmatrilin -1在合浦珠母贝生物矿化中发挥重要作用。