Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China.
Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Pearl Breeding and Processing Engineering Technology Research Centre of Guangdong Province, Zhanjiang 524088, China.
Sci Total Environ. 2019 May 20;666:46-56. doi: 10.1016/j.scitotenv.2019.02.221. Epub 2019 Feb 15.
Similar to other marine bivalves, Pinctada fucata martensii presents unsynchronized growth, which is one of the problems farmers currently face. However, the underlying mechanisms have not been studied. In the present study, pearl oyster P. f. martensii from cultured stocks were selected to produce a progeny stock. At 180 days, the stock was sorted by size, and fast- and slow-growing individuals were separately sampled. Then, metabolomic and transcriptomic approaches were applied to assess the metabolic and transcript changes between the fast- and slow-growing P. f. martensii groups and understand the mechanism underlying their unsynchronized growth. In the metabolomics assay, 30 metabolites were considered significantly different metabolites (SDMs) between the fast- and slow-growing groups and pathway analysis indicated that these SDMs were involved in 20 pathways, including glutathione metabolism; sulfur metabolism; valine, leucine, and isoleucine biosynthesis; and tryptophan metabolism. The transcriptome analysis of different growth groups showed 168 differentially expressed genes (DEGs) and pathway enrichment analysis indicated that DEGs were involved in extracellular matrix-receptor interaction, pentose phosphate pathway, aromatic compound degradation. Integrated transcriptome and metabolome analyses showed that fast-growing individuals exhibited higher biomineralization activity than the slow-growing group, which consumed more energy than the fast-growing group in response to environmental stress. Fast-growing group also exhibited higher digestion, anabolic ability, and osmotic regulation ability than the slow-growing group. This study is the first work involving the integrated metabolomic and transcriptomic analyses to identify the key pathways to understand the molecular and metabolic mechanisms underlying unsynchronized bivalve growth.
类似于其他海洋双壳贝类，马氏珠母贝呈现出非同步生长的现象，这是养殖户目前面临的问题之一。然而，其潜在机制尚未得到研究。本研究从养殖种群中选择珍珠贝马氏珠母贝来生产一个后代种群。在 180 天时，按大小对种群进行分类，分别从快速生长和缓慢生长的个体中取样。然后，应用代谢组学和转录组学方法来评估快速生长和缓慢生长的马氏珠母贝群体之间的代谢和转录变化，以了解其非同步生长的机制。在代谢组学分析中，有 30 种代谢物被认为是快速生长和缓慢生长组之间的差异代谢物（SDM），通路分析表明这些 SDM 参与了 20 种途径，包括谷胱甘肽代谢、硫代谢、缬氨酸、亮氨酸和异亮氨酸生物合成以及色氨酸代谢。不同生长组的转录组分析显示有 168 个差异表达基因（DEGs），通路富集分析表明 DEGs 参与了细胞外基质受体相互作用、戊糖磷酸途径、芳香族化合物降解等途径。综合转录组和代谢组分析表明，快速生长个体的生物矿化活性高于缓慢生长个体，在应对环境压力时，快速生长个体比缓慢生长个体消耗更多的能量。快速生长组还表现出比缓慢生长组更高的消化、合成代谢和渗透压调节能力。本研究是首次涉及代谢组学和转录组学综合分析的工作，以确定关键途径，从而了解非同步双壳类动物生长的分子和代谢机制。
