Tonzetich J, Hayashi S, Grigliatti T A
Department of Biology, Bucknell University, Lewisburg, Pennsylvania 17837.
J Mol Evol. 1990 Feb;30(2):182-8. doi: 10.1007/BF02099944.
The sites of seven tRNA genes (Arg-2, Lys-2, Ser-2b, Ser-7, Thr-3, Thr-4, Val-3b) were studied by in situ hybridization. 125I-labeled tRNA probes from Drosophila melanogaster were hybridized to spreads of polytene chromosomes prepared from four Drosophila species representing different evolutionary lineages (D. melanogaster, Drosophila hydei, Drosophila pseudoobscura, and Drosophila virilis). Most tRNA loci occurred on homologous chromosomal elements of all four species. In some cases the number of hybridization sites within an element varied and sites on nonhomologous elements were found. It was observed that both tRNA(2Arg) and tRNA(2Lys) hybridized to the same site on homologous elements in several species. These data suggest a limited amount of exchange among different linkage groups during the evolution of Drosophila species.
通过原位杂交研究了七个tRNA基因（Arg-2、Lys-2、Ser-2b、Ser-7、Thr-3、Thr-4、Val-3b）的位点。将来自黑腹果蝇的125I标记的tRNA探针与从代表不同进化谱系的四种果蝇（黑腹果蝇、海德氏果蝇、拟暗果蝇和粗壮果蝇）制备的多线染色体铺片进行杂交。大多数tRNA基因座出现在所有四个物种的同源染色体元件上。在某些情况下，一个元件内的杂交位点数量有所不同，并且在非同源元件上也发现了位点。观察到在几个物种中，tRNA(2Arg)和tRNA(2Lys)都与同源元件上的同一位点杂交。这些数据表明在果蝇物种进化过程中，不同连锁群之间的交换量有限。
