Liu Jing-Xia, Gui Jian-Fang
State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan Center for Developmental Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Wuhan 430072, China.
Gene. 2005 Aug 15;356:181-92. doi: 10.1016/j.gene.2005.04.035.
In vertebrates, folliculogeneis establishes an intricate system for somatic cell-oocyte interaction, and ultimately leads to the acquisition of their respective competences. Although the formation process and corresponding interactions are strikingly similar in diverse organisms, knowledge of genes and signaling pathways involved in follicle formation is very incomplete and the underlying molecular mechanisms remain enigmatic. CNBP has been identified for more than ten years, and the highest level of CNBP transcripts has been observed in adult zebrafish ovary, but little is known about its functional significance during folliculogeneis and oogenesis. In this study, we clone CNBP cDNA from gibel carp (Carassius auratus gibelio), and demonstrate its predominant expression in gibel carp ovary and testis not only by RT-PCR but also by Western blot. Its full-length cDNA is 1402 bp, and has an ORF of 489 nt for encoding a peptide of 163 aa. And its complete amino acid sequence shared 68.5%-96.8% identity with CNBPs from other vertebrates. Based on the expression characterization, we further analyze its expression pattern and developmental behaviour during folliculogeneis and oogenesis. Following these studies, we reveal an unexpected discovery that the CagCNBP is associated with follicular cells and oocytes, and significant distribution changes have occurred in degenerating and regenerating follicles. More interestingly, the CagCNBP is more highly expressed in some clusters of interconnected cells within ovarian cysts, no matter whether the cell clusters are formed from the original primordial germ cells or from the newly formed cells from follicular cells that invaded into the atretic oocytes. It is the first time to reveal CNBP relevance to folliculogeneis and oogenesis. Moreover, a similar stage-specific and cell-specific expression pattern has also been observed in the gibel carp testis. Therefore, further studies on CNBP expression pattern and developmental behaviour will be of significance for understanding functional roles of CNBP during gametogenesis.
在脊椎动物中，卵泡发生建立了一个复杂的体细胞 - 卵母细胞相互作用系统，并最终导致它们各自获得相应的能力。尽管在不同生物中卵泡形成过程及相应的相互作用惊人地相似，但关于参与卵泡形成的基因和信号通路的知识仍非常不完整，其潜在的分子机制仍然神秘莫测。CNBP已被发现十多年，在成年斑马鱼卵巢中观察到CNBP转录本的最高水平，但对其在卵泡发生和卵子发生过程中的功能意义知之甚少。在本研究中，我们从银鲫（Carassius auratus gibelio）中克隆了CNBP cDNA，并通过RT-PCR和蛋白质免疫印迹法证明其在银鲫卵巢和睾丸中占主导地位的表达。其全长cDNA为1402 bp，有一个489 nt的开放阅读框，编码一个163个氨基酸的肽。其完整的氨基酸序列与其他脊椎动物的CNBP有68.5% - 96.8%的同一性。基于表达特征，我们进一步分析了其在卵泡发生和卵子发生过程中的表达模式和发育行为。经过这些研究，我们揭示了一个意外的发现，即CagCNBP与卵泡细胞和卵母细胞相关，并且在退化和再生卵泡中发生了显著的分布变化。更有趣的是，CagCNBP在卵巢囊肿内一些相互连接的细胞簇中表达更高，无论这些细胞簇是由原始的原始生殖细胞形成，还是由侵入闭锁卵母细胞的卵泡细胞新形成的细胞形成。这是首次揭示CNBP与卵泡发生和卵子发生的相关性。此外，在银鲫睾丸中也观察到了类似的阶段特异性和细胞特异性表达模式。因此，进一步研究CNBP的表达模式和发育行为对于理解CNBP在配子发生过程中的功能作用具有重要意义。
