College of Fisheries, Engineering Research Center of Green Development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China.
Hubei Provincial Engineering Laboratory for Pond Aquaculture, No. 1 Shizishan Street, Hongshan District, Wuhan, 430070, Hubei Province, People's Republic of China.
Mar Biotechnol (NY). 2024 Dec;26(6):1206-1218. doi: 10.1007/s10126-024-10366-0. Epub 2024 Sep 7.
Cyclin-dependent kinases (Cdks) are major molecules related to cell cycle regulation. Polyploidy can be caused by the production of unreduced gametes, which is often related to the abnormal cell cycle of germ cells. Here, we successfully constructed a cdk1 mutation line (cdk1) in zebrafish, a commonly used model organism. It showed that cdk1 depletion resulted in the generation of both polyploid and aneuploid embryos of WT♀ × cdk1♂ zebrafish. In addition to normal sperms (1N), the depletion of cdk1 in zebrafish also led to the production of some large-head 2N sperms and higher ploidy sperms. Results of bivalent analysis of testis and ultrastructure analysis of spermatogonia suggested that the production of these large-head sperms was due to spermatogonia chromosome doubling in cdk1 zebrafish. Transcriptome analysis revealed aberrant expressions of some cell cycle and DNA replication-related genes in the early testis of cdk1 zebrafish relative to WT zebrafish. Through STRING correlation analysis, we further proved that cdk1 depletion affected the mitosis process and endoduplication initiation of spermatogonia by regulating expressions of some proteins related to cell cycle (i.e., Espl1 and Pp1) and DNA replication (i.e., Orc1 and Rnaseh2b), thereby leading to the formation of unreduced sperms. This study provides important information on revealing the molecular mechanisms of unreduced gamete formation caused by cdk1 mutation. Meanwhile, it also provides an important reference for the creation of fish polyploid germplasm.
细胞周期蛋白依赖性激酶（Cdks）是与细胞周期调控相关的主要分子。多倍体可由未减数配子的产生引起，这通常与生殖细胞的异常细胞周期有关。在这里，我们在斑马鱼中成功构建了一个细胞周期蛋白依赖性激酶 1（cdk1）突变系，这是一种常用的模式生物。结果表明，cdk1 耗竭导致 WT♀×cdk1♂ 杂交斑马鱼的胚胎产生多倍体和非整倍体。除了正常精子（1N）外，cdk1 在斑马鱼中的耗竭还导致产生一些大头 2N 精子和更高倍体的精子。睾丸二价体分析和精原细胞超微结构分析的结果表明，这些大头精子的产生是由于 cdk1 斑马鱼的精原细胞染色体加倍。转录组分析表明，与 WT 斑马鱼相比，cdk1 斑马鱼早期睾丸中一些与细胞周期和 DNA 复制相关的基因表达异常。通过 STRING 相关性分析，我们进一步证明 cdk1 耗竭通过调节与细胞周期（即 Espl1 和 Pp1）和 DNA 复制（即 Orc1 和 Rnaseh2b）相关的一些蛋白质的表达，影响精原细胞的有丝分裂过程和内复制起始，从而导致未减数精子的形成。这项研究为揭示 cdk1 突变导致未减数配子形成的分子机制提供了重要信息。同时，它也为鱼类多倍体种质资源的创造提供了重要参考。
