Villagómez D A, Gustavsson I, Jönsson L, Plöen L
Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Hereditas. 1995;122(3):257-67. doi: 10.1111/j.1601-5223.1995.00257.x.
Cytogenetic investigations in a boar causing a 41% reduction in litter size and also producing piglets that died soon after birth revealed the presence of a reciprocal chromosome translocation, rcp(7;17)(q26;q11). The translocation resulted in one extremely small telocentric chromosome marker. Synaptonemal complex analysis of spread spermatocytes by electron microscopy revealed an unusual behaviour of the translocation. This formed not only different types of quadrivalents (78.1% of the cells), similar to those previously found in boars heterozygous for reciprocal exchanges, but also completely or incompletely paired trivalent configurations, plus univalent (21.9%). Association between the sex bivalent and the translocation configuration was observed (18.7%), but testicular histology was normal. Furthermore, the boar with the translocation was found to produce tertiary monosomy and trisomy in some of the liveborn piglets. Some of the tertiary monosomic offspring, which died in the early extra-uterine life, demonstrated ventricular septal defect and cleft palate.
对一头导致窝产仔数减少41%且所产仔猪出生后不久即死亡的公猪进行的细胞遗传学研究发现存在相互染色体易位，rcp(7;17)(q26;q11)。该易位产生了一个极小的端着丝粒染色体标记。通过电子显微镜对伸展的精母细胞进行联会复合体分析，揭示了该易位的异常行为。这不仅形成了不同类型的四价体（占细胞的78.1%），类似于先前在相互交换杂合的公猪中发现的那些，还形成了完全或不完全配对的三价体构型，以及单价体（21.9%）。观察到性二价体与易位构型之间的关联（18.7%），但睾丸组织学正常。此外，发现带有易位的公猪在一些存活仔猪中产生了三级单体和三体。一些在宫外早期死亡的三级单体后代表现出室间隔缺损和腭裂。
