Kim A I, Belyaeva E S
Department of Genetics and Breeding, M. V. Lomonosov Moscow State University, USSR.
Mol Gen Genet. 1991 Oct;229(3):437-44. doi: 10.1007/BF00267467.
Using the in situ hybridization technique, we have analysed the distribution of mobile elements in the X chromosomes of male offspring of individual mutator strain (MS) males crossed to attached-X females. The experiments demonstrate varying cytological localization of the mobile elements gypsy (mdg4) and hobo among different individuals. The other mobile elements investigated (mdg1, mdg3, 412, 297, copia, 17.6, Doc, H. M. S. Beagle, Springer, FB) display no changes in insertion sites. Such an experiment is equivalent to analysis of separate gametes of an MS individual. Thus, the ability of gypsy and hobo to transpose in germ-line cells is demonstrated directly. Transpositions occur at premeiotic stages of germ cell development, since they appear in clusters. Analysis of gypsy and hobo transposition events shows that they occur independently. The same experiment demonstrates that gypsy localization varies significantly between different salivary gland cells of an MS individual. Two types of gypsy hybridization sites can be distinguished: "permanent" sites, common to all cells, and "additional" ones varying between neighbouring salivary gland cells. These additional sites indicate gypsy transposition in somatic cells of the MS. Transposition of the hobo element in somatic cells has also been observed.
利用原位杂交技术，我们分析了个体诱变菌株（MS）雄性与并联X雌性杂交产生的雄性后代X染色体中移动元件的分布。实验表明，移动元件gypsy（mdg4）和hobo在不同个体中的细胞学定位各不相同。所研究的其他移动元件（mdg1、mdg3、412、297、copia、17.6、Doc、H.M.S. Beagle、Springer、FB）在插入位点上没有变化。这样的实验等同于对一个MS个体的单个配子进行分析。因此，直接证明了gypsy和hobo在生殖系细胞中的转座能力。转座发生在生殖细胞发育的减数分裂前期，因为它们以簇状出现。对gypsy和hobo转座事件的分析表明它们是独立发生的。同样的实验表明，在一个MS个体的不同唾液腺细胞中，gypsy的定位有显著差异。可以区分出两种类型的gypsy杂交位点：所有细胞共有的“永久”位点，以及相邻唾液腺细胞之间不同的“额外”位点。这些额外的位点表明gypsy在MS的体细胞中发生了转座。还观察到hobo元件在体细胞中的转座。
