Natural selection and the function of genome imprinting:: beyond the silenced minority
Natural selection and the function of genome imprinting:: beyond the silenced minority
复制标题
DOI：
10.1016/s0168-9525(00)02134-x
复制
发表时间：
2000-12-01
影响因子：
11.4
通讯作者：
Sapienza, C
中科院分区：
文献类型：
--
作者：
de Villena, FPM;de la Casa-Esperón, E;Sapienza, C
大多数关于基因组印记进化起源的假说都假定，自然选择所起作用的生化特征是在受影响的基因座上只表达来自一个亲本的等位基因。我们提出了一个替代方案-自然选择的母亲和父亲的染色体的染色质结构的差异，以促进配对过程中减数分裂，并保持在减数分裂和有丝分裂细胞的DNA修复和重组同源物之间的区别。体细胞中染色质结构差异的维持有时会导致在一个基因座上仅一个等位基因的转录。在同样的情况下，选择这种转录模式的原因可能与最初建立印记无关。同源染色体染色质结构的差异可能有助于减数分裂期间的配对和重组，但某些此类差异也可能导致染色体的非随机分离，导致亲本来源依赖的传递率失真。这一假说将两大类亲本起源效应统一在一个单一的选择力下，并确定了一个单一的底物，通过该底物可能违反孟德尔第一和第二定律。
Most hypotheses of the evolutionary origin of genome imprinting assume that the biochemical character an which natural selection has operated is the expression of the allele from only one parent at an affected locus. We propose an alternative - that natural selection has operated on differences in the chromatin structure of maternal and paternal chromosomes to facilitate pairing during meiosis and to maintain the distinction between homologues during DNA repair and recombination in both meiotic and mitotic cells. Maintenance of differences in chromatin structure in somatic cells can sometimes result in the transcription of only one allele at a locus. This pattern of transcription might be selected, in same instances, for reasons that are unrelated to the original establishment of the imprint. Differences in the chromatin structure of homologous chromosomes might facilitate pairing and recombination during meiosis, but some such differences could also result in non-random segregation of chromosomes, leading to parental-origin-dependent transmission ratio distortion. This hypothesis unites two broad classes of parental origin effects under a single selective force and identifies a single substrate through which Mendel's first and second laws might be violated.