Acland G M, Halloran-Blanton S, Boughman J A, Aguirre G D
Scheie Eye Institute, School of Medicine, University of Pennsylvania, Philadelphia 19104-6010.
Am J Med Genet. 1990 Mar;35(3):354-9. doi: 10.1002/ajmg.1320350309.
Segregation distortion was observed in inheritance of progressive rod-cone degeneration (prcd) in a colony of Miniature Poodle dogs. Breeding results, from both retrospective records and prospectively planned matings, were classified into five mating types: (1) affected to affected, (2) homozygous normal sire to any dam, (3) heterozygous to heterozygous, (4) heterozygous sire to affected dam, and (5) affected sire to heterozygous dam. For all but the last category, results were in accord with mendelian expectations for autosomal-recessive inheritance. However, litters of mating type 5 had fewer affected pups (20/77) than expected. The observed segregation ratio for this mating type (0.26) was significantly (P less than 0.001) less than the expected (0.50). The segregation distortion could not be accounted for by either pre- or postnatal loss of affected pups, as litter size and litter survivability were uniform among litters of different mating types. Either the prcd locus, or a linked locus, would appear to influence either gametic or zygotic fitness in the heterozygous mother. Comparison is drawn to the inheritance of retinitis pigmentosa in humans, in which decreased segregation ratios are also recognized.
在迷你贵宾犬群体中，观察到进行性视杆-视锥细胞变性（prcd）遗传过程中的分离畸变现象。根据回顾性记录和前瞻性计划交配的繁殖结果，分为五种交配类型：（1）患病个体与患病个体交配，（2）纯合正常公犬与任何母犬交配，（3）杂合子与杂合子交配，（4）杂合子公犬与患病母犬交配，（5）患病公犬与杂合子母犬交配。除最后一种交配类型外，其他所有类型的结果均符合常染色体隐性遗传的孟德尔预期。然而，第5种交配类型的窝中患病幼犬数量（20/77）比预期少。这种交配类型观察到的分离比例（0.26）显著低于预期比例（0.50）（P小于0.001）。患病幼犬在产前或产后的损失并不能解释这种分离畸变现象，因为不同交配类型的窝仔数和窝仔存活率是一致的。prcd基因座或与之连锁的基因座似乎会影响杂合子母犬的配子或合子适应性。文中还将此与人类视网膜色素变性遗传进行了比较，在人类视网膜色素变性遗传中也发现了分离比例降低的情况。
