Baker Robert J, Wichman Holly A
Department of Biological Sciences and The Museum, Texas Tech University, Lubbock, TX, 79409, USA.
Department of Biological Science, University of Idaho, Moscow, ID, 83843, USA.
Evolution. 1990 Dec;44(8):2083-2088. doi: 10.1111/j.1558-5646.1990.tb04313.x.
Chromosomal distribution of the mys retrotransposon was examined by in situ hybridization with a biotinylated probe. Thirty-six mice from four species of the Peromyscus leucopus/maniculatus complex were examined. Mys hybridized to every chromosome in all individuals examined. However, the pattern of hybridization was nonrandom. Mys elements were excluded from C-banding regions of the autosomes, and hybridized preferentially to G-bands. The most prominent feature of these hybridizations was the preferential accumulation of mys on the X and Y chromosomes of all four species examined. Accumulation of mys on the X is incompatible with the hypothesis that selection acting on deleterious mutations is the major mechanism regulating the copy number of this element. Rather, this supports the Langley model for containment of transposable element copy number by unequal exchange during meiosis.
通过用生物素化探针进行原位杂交，研究了mys逆转座子的染色体分布。对来自白足鼠/野鼠复合体四个物种的36只小鼠进行了检查。在所有检查的个体中，mys与每一条染色体都发生了杂交。然而，杂交模式并非随机。Mys元件被排除在常染色体的C带区域之外，并优先与G带杂交。这些杂交最显著的特征是在所有四个被检查物种的X和Y染色体上mys的优先积累。mys在X染色体上的积累与以下假设不一致：即作用于有害突变的选择是调节该元件拷贝数的主要机制。相反，这支持了兰利模型，即在减数分裂期间通过不等交换来控制转座元件的拷贝数。
