Meiotic chromosome configurations in oocytes of Cobitis taenia and its polyploid hybrids

作者：Juchno Dorota^*; Arai Katsutoshi; Boron Alicja; Kujawa Roman

来源：Ichthyological Research, 2017, 64(2): 240-243.

DOI：10.1007/s10228-016-0556-1

• Unisexuality
• Bivalent
• Germinal vesicle
• Meiosis
• Polyploidy

Diploid and triploid hybrid females of Cobitis as a rule produce unreduced eggs which mainly develop gynogenetically, but some of the eggs incorporate sperm genome and develop into triploids and tetraploids, respectively. Here, we observed for the first time the meiotic chromosomes in the germinal vesicles (GVs) of mature oocytes of three diploid C. taenia (2n = 48) and 20 allopolyploid females of Cobitis (18 triploid 3n = 74 and 2 tetraploid 4n = 99). The majority of GVs in diploid, triploid and tetraploid females contained 24, 74 and 96 or 99 bivalents, respectively. These results directly indicated premeiotic endomitosis as a mechanism underlying the formation of unreduced eggs in allopolyploid females of Cobitis.

• 出版日期2017-4