红鲫与湘江野鲤杂交的受精细胞学研究

CYTOLOGY STUDY ON THE CROSS FERTILIZA TION BETWEEN Carassius auratus RED VARIETY (?) AND Cyprinus carpio XIANGJIANESIS (?)

红鲫成熟卵直径680—720μm;卵膜孔为精子入卵的唯一通道,包括前庭和精孔管两部分;精孔管内径约5μm。湘江野鲤精子头部直径约2.5μm。在通常情况下,红鲫卵为单精受精。尽管红鲫与湘江野鲤不同属,但杂交仍具有正常的受精细胞学程序。红鲫卵子处于第二次成熟分裂中期接受湘江野鲤精子入卵,精子入卵5min后,出现明显的精子星光;15min后,雄性原核及雌性原核形成;25min后,雌、雄性原核融合;30min后、开始卵裂,发现1个受精卵切片上有4个即将融合的原核,这可能是由于双精受精所致。

This paper deals with the study on the cross fertilization between Carassius auratus red variety ( +) and Cyprinus carpio xiangjianesis (c). Mature oocytes of C. auratus red variety have a diameter of 680-720 μm. The micropyle is contained by micropylar vestibule (MV) and canal (MC) which has a diameter of 5μm. While the sperm has a half diameter of MC, through the micropyle only single sperm usully enters the egg, which is known as monospermic egg, C. aurutus red variety and C. carpio xiangjianesis belong different genus, even then the process of their cross fertilization are normal. The appropriate time of insemination is at the metaphase of the meiosis. By the 5 min postinsemination, conspicuous spermast is seen in the egg cytoplasm of C.aurutus red variety. By the 15 min postinsemination, the male and female pronuclei are formed. By the 25 min postinsemination, the male and female pronuclei are fused to form the nucleus of the zygote. By the 30 min postinsemination, segmentation begins in the zygote. The 4 pronuclei being fused are found in the section of 1 zygote. Perhaps it comes from bispermism.