STUDIES ON RIBOSOMAL-RNA CISTRONS IN INTERSPECIFIC DROSOPHILA HYBRIDS .1. NUCLEOLAR DOMINANCE
STUDIES ON RIBOSOMAL-RNA CISTRONS IN INTERSPECIFIC DROSOPHILA HYBRIDS .1. NUCLEOLAR DOMINANCE
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DOI：
10.1016/0012-1606(77)90240-8
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发表时间：
1977-01-01
影响因子：
2.7
通讯作者：
KRIDER, HM
中科院分区：
文献类型：
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作者：
DURICA, DS;KRIDER, HM
种间杂种D. melanogaster和D.检查了模拟物的核仁组织区次级收缩形成的模式。在F1种间杂种的成神经细胞组织中，D. simulans的X染色体上有一条次缢痕;黑腹性染色体，不论母体卵细胞质的起源。当杂交种缺乏D.黑腹果蝇性染色体的构建，所产生的XO男性是可行的，并显示在D.拟核仁组织者从D.当两个物种的核仁组织者同时存在时，黑腹果蝇基因组可能发生，这种现象称为核仁优势。通过RNA-DNA杂交检测了常规种间F1后代rDNA的冗余度。父母的价值观符合以前报道的测量，但混合rDNA值是非加性的父母的贡献。杂种雌性具有rDNA水平。超过预测值的73个基因。由于F1杂交后代可能继承野生型的rDNA水平，这种不成比例的增加可能代表了一个功能，而不是物理，缺陷的反应。
Interspecific hybrids between D. melanogaster and D. simulans were examined for patterns of secondary constriction formation at the nucleolus-organizer regions. In neuroblast tissue taken from F1 interspecific hybrids, a nucleolar constriction was normally absent from the D. simulans X chromosome, while a secondary constriction was always associated with the D. melanogaster sex chromosome, regardless of the origin of maternal egg cytoplasm. When hybrids lacking a D. melanogaster sex chromosome were constructed, the resulting XO males were viable and displayed a constriction at the D. simulans nucleolus organizer. A preferential transcription of ribosomal DNA from the D. melanogaster genome probably occurs when nucleolus organizers from both species are present in conjunction, a phenomenon termed nucleolar dominance. rDNA redundancy in regular interspecific F1 progeny was monitored by RNA-DNA hybridization. Parental values conformed to previously reported measurements, but hybrid rDNA values were nonadditive with respect to the parental contributions. Hybrid females possessed rDNA levels .apprx. 73 genes in excess of predicted values. Since F1 hybrid progeny presumably inherit wild-type of rDNA levels this disproportionate increase may represent a response to a functional, rather than a physical, deficiency.