Zhong Yizhi, Zhao Wenbin, Tang Zhangsheng, Huang Liming, Zhu Xiangxing, Liang Xiang, Yan Aifen, Lu Zhifa, Yu Yanling, Tang Dongsheng, Wang Dapeng, Lu Zhuanling
Guangxi Academy of Fishery Sciences/Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Nanning, 530021, China.
Guangdong Provincial Key Laboratory of Animal Molecular Design and Precise Breeding, Guangdong Provincial Engineering and Technology Research Center for Gene Editing, School of Medical Engineering, Foshan University, Foshan, 528225, China.
BMC Genomics. 2021 Mar 21;22(1):199. doi: 10.1186/s12864-021-07537-x.
The red swamp crayfish Procambarus clarkii is a freshwater species that possesses high adaptability, environmental tolerance, and fecundity. P. clarkii is artificially farmed on a large scale in China. However, the molecular mechanisms of ovarian development in P. clarkii remain largely unknown. In this study, we identified four stages of P. clarkii ovary development, the previtellogenic stage (stage I), early vitellogenic stage (stage II), middle vitellogenic stage (stage III), and mature stage (stage IV) and compared the transcriptomics among these four stages through next-generation sequencing (NGS).
The total numbers of clean reads of the four stages ranged from 42,013,648 to 62,220,956. A total of 216,444 unigenes were obtained, and the GC content of most unigenes was slightly less than the AT content. Principal Component Analysis (PCA) and Anosim analysis demonstrated that the grouping of these four stages was feasible, and each stage could be distinguished from the others. In the expression pattern analysis, 2301 genes were continuously increase from stage I to stage IV, and 2660 genes were sharply decrease at stage IV compared to stages I-III. By comparing each of the stages at the same time, four clusters of differentially expressed genes (DEGs) were found to be uniquely highly expressed in stage I (136 genes), stage II (43 genes), stage III-IV (49 genes), and stage IV (22 genes), thus exhibiting developmental stage specificity. Moreover, in comparisons between adjacent stages, the number of DEGs between stage III and IV was the highest. GO enrichment analysis demonstrated that nutrient reservoir activity was highest at stage II and that this played a foreshadowing role in ovarian development, and the GO terms of cell, intracellular and organelle participated in the ovary maturation during later stages. In addition, KEGG pathway analysis revealed that the early development of the ovary was mainly associated with the PI3K-Akt signaling pathway and focal adhesion; the middle developmental period was related to apoptosis, lysine biosynthesis, and the NF-kappa B signaling pathway; the late developmental period was involved with the cell cycle and the p53 signaling pathway.
These transcriptomic data provide insights into the molecular mechanisms of ovarian development in P. clarkii. The results will be helpful for improving the reproduction and development of this aquatic species.
克氏原螯虾是一种具有高适应性、环境耐受性和繁殖力的淡水物种。克氏原螯虾在中国被大规模人工养殖。然而，克氏原螯虾卵巢发育的分子机制仍 largely未知。在本研究中，我们鉴定了克氏原螯虾卵巢发育的四个阶段，即卵黄发生前期（I期）、卵黄发生早期（II期）、卵黄发生中期（III期）和成熟期（IV期），并通过下一代测序（NGS）比较了这四个阶段的转录组学。
四个阶段的 clean reads总数在42,013,648至62,220,956之间。共获得216,444个单基因，大多数单基因的GC含量略低于AT含量。主成分分析（PCA）和Anosim分析表明，这四个阶段的分组是可行的，每个阶段都可以与其他阶段区分开来。在表达模式分析中，2301个基因从I期到IV期持续增加，2660个基因在IV期与I-III期相比急剧下降。通过同时比较每个阶段，发现四组差异表达基因（DEGs）在I期（136个基因）、II期（43个基因）、III-IV期（49个基因）和IV期（22个基因）中独特高表达，从而表现出发育阶段特异性。此外，在相邻阶段的比较中，III期和IV期之间的DEGs数量最高。GO富集分析表明，营养储存活性在II期最高，这在卵巢发育中起到了预示作用，并且细胞、细胞内和细胞器的GO术语在后期参与了卵巢成熟。此外，KEGG通路分析表明，卵巢的早期发育主要与PI3K-Akt信号通路和粘着斑有关；中期发育与细胞凋亡、赖氨酸生物合成和NF-κB信号通路有关；后期发育涉及细胞周期和p53信号通路。
这些转录组数据为克氏原螯虾卵巢发育的分子机制提供了见解。结果将有助于改善这种水生物种的繁殖和发育。
