Sumida M
Laboratory for Amphibian Biology, Faculty of Science, Hiroshima University, Higashihiroshima, Japan.
Experientia. 1994 Sep 15;50(9):860-6. doi: 10.1007/BF01956473.
In order to elucidate cytogenetically the cause of male sterility in intraspecific hybrids of Rana japonica, the behavior of chromosomes in the first meiosis was observed in spermatocytes from male reciprocal hybrids between two populations from Hiroshima and Ichinoseki. In the parental Hiroshima and Ichioseki populations, 2530 (96.7%) meiotic spreads had 13 bivalents and 78 (3.0%) contained 12 bivalents and two univalents, whereas in reciprocal hybrids only 337 (7.0%) contained 13 bivalents and the other 4445 (93.0%) had 2-26 univalents. A total of 31647 (93.4%) bivalents was ring-shaped and the other 2234 (6.6%) were rod-shaped in both parental populations, whereas in reciprocal hybrids 26352 (57.1%) and 19819 (42.9%) bivalents were ring- and rod-shaped, respectively. These results show that meiotic chromosomes of reciprocal hybrids are characterized by a remarkable increase in univalents and rod-shaped bivalents.
为了从细胞遗传学角度阐明日本林蛙种内杂交雄性不育的原因，对来自广岛和一之关两个种群的雄性正反交杂种精母细胞减数第一次分裂时染色体的行为进行了观察。在亲本广岛和一之关种群中，2530个（96.7%）减数分裂铺片有13个二价体，78个（3.0%）含有12个二价体和两个单价体，而在正反交杂种中，只有337个（7.0%）含有13个二价体，另外4445个（93.0%）有2 - 26个单价体。在两个亲本种群中，总共31647个（93.4%）二价体呈环状，另外2234个（6.6%）呈棒状，而在正反交杂种中，二价体分别有26352个（57.1%）呈环状和19819个（42.9%）呈棒状。这些结果表明，正反交杂种的减数分裂染色体具有单价体和棒状二价体显著增加的特征。
