Akagi H, Yokozeki Y, Inagaki A, Fujimura T
Biochemical Technology Section, Mitsui Chemicals Inc., Mobara, Japan.
Heredity (Edinb). 1998 Aug;81 ( Pt 2):187-97.
An ancestral sequence of twin microsatellites of rice was found in a wild species. Twin microsatellite loci, RM20A and RM20B, were located on separate regions of chromosomes 11 and 12, which had been duplicated during rice evolution. These twin microsatellites showed different allele diversities in A genome species of the genus Oryza. This difference was caused by repetition of a simple sequence consisting of (TAA)n. Oryza longistaminata contains a short poly(A) sequence in this region instead of the poly(TAA) found in other species. A sequence comparison of RM20-related amplicons suggested that the poly(A)-containing sequence is the ancestral sequence of the RM20A and RM20B microsatellites. A simple base substitution in the poly(A) sequence may have produced the longer microsatellite motif (TAA). This mutation may have occurred on one of the chromosomes of a hypothetical ancestor of the A genome species before duplication of the chromosome segments.
在一个野生稻种中发现了水稻双微卫星的祖先序列。双微卫星位点RM20A和RM20B分别位于第11号和第12号染色体的不同区域，这些区域在水稻进化过程中发生了复制。这些双微卫星在稻属A基因组物种中表现出不同的等位基因多样性。这种差异是由由(TAA)n组成的简单序列的重复引起的。长花药野生稻在该区域含有短的聚腺苷酸序列，而不是其他物种中发现的聚(TAA)。RM20相关扩增子的序列比较表明，含聚腺苷酸的序列是RM20A和RM20B微卫星的祖先序列。聚腺苷酸序列中的一个简单碱基替换可能产生了更长的微卫星基序(TAA)。这种突变可能发生在A基因组物种假想祖先的一条染色体上，然后染色体片段发生了复制。
