Snyder M D, Fechheimer N S, Jaap R G
Cytogenet Cell Genet. 1975;14(1):63-75. doi: 10.1159/000130319.
Preparations for chromosomal analysis were made from 2107 chick embryos at 16 hours of incubation. The embryos resulted from intraline and reciprocal interline matings of two genetically different stocks (AG and D6). The two stocks had been previously characterized as producers of high (AG) and low (D6) frequencies of chromosomally aberrant embryos. The overall frequency of aberrant embryos was 4.0 plus or minus 0.42%. The types and frequencies of abnormalities were: haploidy and haploid-euploid mosaics, 57%; polyploidy and polyploid-diploid mosaics, 19%; aneuploidy, 17%; aneuploid-diploid mosaics, 5%; and structural aberrations, 2%. Although there were no significant differences among the four types of matings in the overall frequency of heteroploid embryos (P greater than 0.1), a significant difference (P smaller than 0.01) in the frequency of haploid and haploid-euploid mosaic embryos was found. The difference was entirely attributable to the line of dam; D6 dams had 1.2% and AG dams had 2.7% haploid and haploid-euploid mosaic embryos. The difference between lines of sires was not significant. In addition, there was evidence of nonrandom distribution, among dams of both lines, of haploid and haploid-euploid mosaic embryos. It was concluded that the genotype of dam is an important influencing factor in the production of haploid cell lines in embryos. The superfluous genome in triploid embryos is usually maternal in origin, resulting from retention of the second polar body in the ovum. Sex-chromosome aneuploidy in chick embryos apparently derives from nondisjunction at meiosis I of oogenesis. The sex proportion of 2023 chromosomally sexed, diploid embryos was 50.2 plus or minus 1.1% male. No significant heterogeneity was observed among the types of matings. Sex proportion was not significantly influenced by any of a number of nongenetic variables.
对2107个孵化16小时的鸡胚进行染色体分析准备。这些胚胎来自两个遗传上不同品系（AG和D6）的品系内交配和正反交。这两个品系先前已被鉴定为染色体异常胚胎高频率（AG）和低频率（D6）的产生者。异常胚胎的总体频率为4.0±0.42%。异常类型及频率如下：单倍体和单倍体 - 整倍体嵌合体，57%；多倍体和多倍体 - 二倍体嵌合体，19%；非整倍体，17%；非整倍体 - 二倍体嵌合体，5%；以及结构畸变，2%。尽管在异倍体胚胎的总体频率方面，四种交配类型之间没有显著差异（P大于0.1），但在单倍体和单倍体 - 整倍体嵌合胚胎的频率上发现了显著差异（P小于0.01）。这种差异完全归因于母本品系；D6母本有1.2%的单倍体和单倍体 - 整倍体嵌合胚胎，AG母本有2.7%。父本品系之间的差异不显著。此外，有证据表明，在两个品系的母本中，单倍体和单倍体 - 整倍体嵌合胚胎存在非随机分布。得出的结论是，母本的基因型是胚胎中单倍体细胞系产生的一个重要影响因素。三倍体胚胎中多余的基因组通常起源于母本，是由于卵子中第二极体的保留。鸡胚中的性染色体非整倍体显然源于卵子发生减数分裂I期的不分离。2023个经染色体鉴定性别的二倍体胚胎的性别比例为雄性50.2±1.1%。在交配类型之间未观察到显著的异质性。性别比例不受许多非遗传变量中的任何一个的显著影响。
