Imai H T, Taylor R W, Crosland M W, Crozier R H
National Institute of Genetics, Mishima.
Jpn J Genet. 1988 Apr;63(2):159-85. doi: 10.1266/jjg.63.159.
Aspects of chromosomal mutation and karyotype evolution in ants are discussed with reference to recently accumulated karyological data, and to detailed karyotype analyses of several species or species complexes with low chromosome number and unusual chromosomal mutations (the complexes of Myrmecia pilosula (Smith) (n = 1, 5 or 9 to 16); M. piliventris Smith (n = 2, 3-4, 17 or 32), and Ponera scabra Wheeler (n = 3 or 4, 2n = 7 or 8). Translocations and Robertsonian polymorphisms are confirmed to be non-randomly distributed among ants -the former are found at high frequencies in species with low chromosome numbers (n less than or equal to 12), while the latter predominate in those with high numbers (n greater than 12). This situation is consistent with the minimum interaction hypothesis of Imai et al. (1986), under which translocations are expected to occur most frequently in low-numbered karyotypes, and that the resulting genetic risks are minimized by increases in chromosome and/or arm numbers through centric fission and pericentric inversion. Centric fusion is considered to be a transient event in karyotype evolution, resulting from telomere instability in acrocentric chromosomes.
本文参考近期积累的核型数据，以及对几种染色体数目少且有异常染色体突变的物种或物种复合体（如多毛牛蚁复合体（史密斯）（n = 1、5或9至16）；毛腹牛蚁史密斯（n = 2、3 - 4、17或32），以及粗糙弓背蚁惠勒（n = 3或4，2n = 7或8））的详细核型分析，讨论了蚂蚁染色体突变和核型进化的相关方面。易位和罗伯逊多态性在蚂蚁中被证实是非随机分布的——前者在染色体数目少的物种（n小于或等于12）中高频出现，而后者在染色体数目多的物种（n大于12）中占主导。这种情况与今井等人（1986年）的最小相互作用假说一致，根据该假说，易位预计在低数目核型中最频繁发生，并且通过着丝粒分裂和臂间倒位增加染色体和/或臂的数目可将由此产生的遗传风险降至最低。着丝粒融合被认为是核型进化中的一个短暂事件，是由近端着丝粒染色体的端粒不稳定性导致的。
