The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite...The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.展开更多
2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果...2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果表明，在大珠母贝内脏囊缩足肌左右两侧各有一个适合培育游离珍珠的核位，分别称为左袋和右袋，实际操作中只有左袋可以植入珠核培育游离珍珠；不同术前处理实验组的植核贝休养期成活率差异不显著（P〉0．05），但留核率、成珠率显著差异（P〈0．05），其中采用传统术前处理和低温处理相结合的综合术前处理方法可有效提高留核率、成珠率平均达78．2％和80．1％；低温处理小片贝与传统方法制备的大珠母贝外套膜小片的育珠效果（成珠率、优珠率、正圆珠比例）存在显著差异（P〈0．05），且在实验温度范围内，成珠率、优珠率、正圆珠比例随处理温度的降低而增高，在4～8℃达到最好育珠效果，成珠率、优珠率和正圆珠比例分别达到98％、53％和30％左右；在术后休养期，植核贝吐核高峰出现植核后5-t5d，手术伤口愈合时间为15-20d，育殊贝的死亡高峰出现在术后的第20～30天。在水温25～30℃条件下，珠核表面形成珍珠层的时间为45d左右。展开更多
基金supported by the Hainan Province Science and Technology Talent Innovation Project(KJRC2023A02)Project of Sanya Yazhouwan Science and Technology City Management Foundation(SKJC-KJ-2019KY01)Sanya Science and Technology Special Fund(2022KJCX91)。
文摘The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.
文摘2008～2010年，在广西涠洲岛进行了大珠母贝（Pinctada maxima Jameson）游离珍珠培育实验。实验过程中采用解剖法优选植核核位、几种术前处理方法和低温处理小片贝制备外套膜小片等技术，旨在提高育珠贝留核率、成珠率和优珠率。结果表明，在大珠母贝内脏囊缩足肌左右两侧各有一个适合培育游离珍珠的核位，分别称为左袋和右袋，实际操作中只有左袋可以植入珠核培育游离珍珠；不同术前处理实验组的植核贝休养期成活率差异不显著（P〉0．05），但留核率、成珠率显著差异（P〈0．05），其中采用传统术前处理和低温处理相结合的综合术前处理方法可有效提高留核率、成珠率平均达78．2％和80．1％；低温处理小片贝与传统方法制备的大珠母贝外套膜小片的育珠效果（成珠率、优珠率、正圆珠比例）存在显著差异（P〈0．05），且在实验温度范围内，成珠率、优珠率、正圆珠比例随处理温度的降低而增高，在4～8℃达到最好育珠效果，成珠率、优珠率和正圆珠比例分别达到98％、53％和30％左右；在术后休养期，植核贝吐核高峰出现植核后5-t5d，手术伤口愈合时间为15-20d，育殊贝的死亡高峰出现在术后的第20～30天。在水温25～30℃条件下，珠核表面形成珍珠层的时间为45d左右。
