Uniparental chromosome elimination in the early embryogenesis of the inviable salmonid hybrids between masu salmon female and rainbow trout male
Uniparental chromosome elimination in the early embryogenesis of the inviable salmonid hybrids between masu salmon female and rainbow trout male
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DOI：
10.1007/s004120050223
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发表时间：
1997-06-01
期刊：
影响因子：
1.6
通讯作者：
Yoshida, MC
中科院分区：
文献类型：
--
作者：
Fujiwara, A;Abe, S;Yoshida, MC
通过染色体丢失和部分缺失来消除染色体是一些鲑科种间杂交种胚胎丧失活力的原因之一。利用荧光原位杂交及相关技术，包括全染色体涂染和比较基因组杂交，对死前早期胚胎期的雌性马哈鱼(MS，Oncorhynchus Masou)与雄性虹鲑鱼(Rb，O.mykiss)杂交后代中缺失染色体的亲本来源进行了鉴定。在这些杂交种中，单倍体Rb染色体数量减少到近一半，而ms染色体保留为一个或偶尔两个完整的单倍体互补。Rb染色体也参与了常见的碎片和微核。而染色体片段的出现在整个观察期间是恒定的，染色体丢失主要发生在受精后至囊胚期。在晚期囊胚的组织切片和细胞铺展过程中，部分Rb染色体被困在Ana-末期的中间带，导致随后的间期出现微核。在雄核发育的单倍体杂种中也观察到了微核和有丝分裂异常。然而，这种异常很少或从未在可存活的正反交中观察到。本研究结果表明，在胚胎发育早期，由于母本的MS细胞质与父本的Rb基因组之间可能存在不亲和性，在不能存活的杂种中，父本的Rb染色体优先通过有丝分裂异常被消除。
Chromosome elimination through chromosome loss and partial deletion is known to be one of the causes of embryonic inviability in some salmonid interspecific hybrids. Using fluorescence in situ hybridization and related techniques, including whole chromosome painting and comparative genomic hybridization, parental origin of eliminated chromosomes was identified in the inviable hybrids between masu salmon (Ms, Oncorhynchus masou) female and rainbow trout (Rb, O. mykiss) male at the early embryonic stage prior to death. In these hybrids, the haploid Rb chromosome number decreased to nearly half, whereas the Ms chromosomes were retained as one or occasionally two full haploid complements. The Rb chromosomes were also involved in the frequently observed fragments and micronuclei. Whereas the occurrence of fragments was constant throughout the observed period, chromosome loss occurred mainly from just after fertilization to the blastulae stage. In tissue sections and cell spreads of late blastula, some Rb chromosomes were trapped in the midzone from ana- to telophase, resulting in micronuclei at the subsequent interphase. Micronuclei and mitotic abnormalities were also observed in the androgenetic haploid hybrids. However, such abnormalities were seldom or never observed in the viable reciprocal hybrids. The present findings suggest that the paternal Rb chromosomes in the inviable hybrids are preferentially eliminated through mitotic abnormalities during early embryogenesis, owing to a possible incompatibility between the maternal Ms cytoplasm and paternal Rb genome.