Casavant N C, Hardies S C
Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284-7760.
J Mol Biol. 1994 Aug 19;241(3):390-7. doi: 10.1006/jmbi.1994.1515.
We have examined the dynamics of replication of the mouse LINE-1 retrotransposon within a single large expanding LINE-1 family found in a particular population of Mus spretus. This family has reached thousands of copies per haploid genome within 0.1 to 0.2 Myr and accounts for most, if not all, LINE-1 replication since 0.4 Myr ago. The family shows only one split into two clades during this time. From these data we propose a model that links the evolution of LINE-1 to the dynamics of its migration among mouse populations. We hypothesize that selected LINE-1 elements, referred to as master sequences, each amplify a subfamily within a distinct mouse population before migrating into the global mouse population. When these master sequences come in contact with each other by migration, generally one continues to expand at the expense of the other. We further discuss potential tests of this model.
我们研究了小家鼠（Mus spretus）特定种群中一个大型且不断扩张的LINE-1逆转座子家族内的复制动态。该家族在0.1至0.2百万年的时间内，每个单倍体基因组中的拷贝数已达到数千个，并且自40万年前以来，几乎（如果不是全部的话）占了LINE-1复制的大部分。在此期间，该家族仅出现过一次分裂为两个进化枝的情况。基于这些数据，我们提出了一个模型，将LINE-1的进化与其在小鼠种群间的迁移动态联系起来。我们假设，被称为主序列的特定LINE-1元件，会在迁移到全球小鼠种群之前，在不同的小鼠种群中各自扩增出一个亚家族。当这些主序列通过迁移相互接触时，通常其中一个会以另一个为代价继续扩张。我们还进一步讨论了该模型的潜在验证方法。
