Abnormal meiosis in fertile and sterile triploid cyprinid fish
Abnormal meiosis in fertile and sterile triploid cyprinid fish
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可育和不育三倍体鲤鱼减数分裂异常
DOI：
10.1007/s11427-020-1900-7
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发表时间：
2021-04-21
影响因子：
9.1
通讯作者：
Liu, Shaojun
中科院分区：
文献类型：
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作者：
Zhang, Chun;Li, Qi;Liu, Shaojun
减数分裂是产生成熟配子的关键过程。此前已经观察到自然可育的三倍体鲫鱼（Carassius auratus, 3nDTCC）和人工不育的三倍体鲫鱼（crucian carp, 3nCC），为研究三倍体鱼类减数分裂特性提供了合适的模式生物。本研究对这些鱼类精子发生的显微结构和超微结构进行了研究。采用tdt介导的dUTP缺口末端标记检测研究精母细胞凋亡情况。荧光原位杂交技术用于追踪染色质配对。此外，通过实时定量聚合酶链反应检测细胞周期相关基因（即细胞分裂控制2和细胞周期蛋白B） mRNA的表达，阐明3nCC细胞减数分裂异常的分子机制。结果表明，3nCC前期I不规则，染色体呈单极径向分布，部分配对，中期I受阻，后期细胞退化。同时，3nDTCC减数分裂前I期较为规则，偶联染色体对完整，染色体沿核细胞分布，切片显示为环状结构。仅在3nDTCC中容易检测到130-150条不规则染色体的扩散，提示其可能处于异常中期1。本研究为可育和不育三倍体鲤的减数分裂提供了新的认识。
Meiosis is the key process for producing mature gametes. A natural fertile triploid Carassius auratus population (3nDTCC) and an artificially derived sterile triploid crucian carp (3nCC) have been previously observed, providing suitable model organisms for investigating meiosis characteristics in triploid fish. In the present study, the microstructures and ultrastructures of spermatogenesis were studied in these fishes. TdT-mediated dUTP nick end labeling detection was performed to investigate the apoptosis of spermatocytes. Fluorescence in situ hybridization was employed to trace chromatin pairing. In addition, the mRNA expressions of cell cycle-related genes (i.e., cell division control 2 and cell cycle protein B) were determined by quantitative realtime polymerase chain reaction to illustrate the molecular mechanism of abnormal meiosis in the 3nCC. The results showed that the 3nCC undergoes an irregular prophase I, with the chromosomes distributed in a unipolar radial manner and exhibiting partial pairing, hindered metaphase I, and degenerated cells in the subsequent stages. Meanwhile, the 3nDTCC presented a relatively regular meiotic prophase I with complete conjugate chromosome pairs and chromosomes distributed along the karyotheca, which were presented as a ring structure by slicing. Only the spreads with 130-150 irregular chromosomes can be easily detected in the 3nDTCC, suggesting that it may undergo an abnormal metaphase I. This study provides new insights into the meiosis of fertile and sterile triploid cyprinid fish.