Gileva E A, Khopunova S E, Novokshanova T G, Zybina E V
Institute of Plant and Animal Ecology, Russian Academy of Sciences (the Urals Division), St.-Petersburg.
Zh Obshch Biol. 1994 Nov-Dec;55(6):700-7.
Karyotypes of Dicrostonyx torquatus torquatus and D. vinogradovi that are very similar phenotypically differ at least by 13-14 chromosomal rearrangements including centric and tandem fusions, fissions and paracentric inversion. In their male hybrid F1 spermatogenesis is arrested on early pre-meiotic stages, the female hybrids are semisterile. Histological investigation of ovaries has demonstrated reduced number of follicles, higher percentage of atretic follicles and an acceleration of folliculogenesis in hybrids as compared with the parental forms. As a result of the acceleration, the number of mature follicles and ovulations is not significantly diminished in the hybrid females, and their semisterility is caused, to a great extent, by high prenatal loss which most likely arises from the chromosomal imbalance in F2 hybrids. Thus, the mechanism suggested by the concept of chromosomal speciation is active, but not alone in forming reproductive isolation between twin species of the varying lemming.
毛色颈纹旅鼠指名亚种（Dicrostonyx torquatus torquatus）和维氏旅鼠（D. vinogradovi）的核型在表型上非常相似，但至少有13 - 14种染色体重排差异，包括着丝粒融合和串联融合、裂变和臂间倒位。在它们的雄性杂交F1中，精子发生在减数分裂前的早期阶段就停止了，雌性杂种是半不育的。与亲本形态相比，对卵巢的组织学研究表明，杂种中卵泡数量减少，闭锁卵泡的百分比更高，卵泡发生加速。由于这种加速，杂种雌性中成熟卵泡和排卵的数量没有显著减少，它们的半不育在很大程度上是由高产前损失引起的，这很可能是由于F2杂种中的染色体不平衡所致。因此，染色体物种形成概念所提出的机制是活跃的，但并非唯一导致不同旅鼠孪生物种之间生殖隔离的因素。
