Garagna S, Ronchetti E, Mascheretti S, Crovella S, Formenti D, Rumpler Y, Manfredi Romanini M G
Dipartimento di Biologia Animale, Universita degli Studi di Pavia, Italia.
Chromosome Res. 1997 Nov;5(7):487-91. doi: 10.1023/a:1018425215516.
The chromosomal distribution of the (TTAGGG)n telomeric repetitive sequences was studied in the Malagasy species Eulemur fulvus fulvus (2n = 60), Eulemur rubriventer (2n = 50), Eulemur coronatus (2n = 46) and Eulemur macaco (2n = 44). These sequences hybridize to the telomeres of all chromosomes of the four species and also to the pericentromeres of all chromosomes of E. fulvus, E. coronatus and E. macaco, with the exception of the pericentromeres of E. coronatus and E. macaco chromosomes 9, the homeologous E. fulvus chromosomes 2 and E. macaco chromosomes 1. In E. rubriventer only a very weak signal was detected at the pericentromeres of a few chromosomes. In E. fulvus, E. coronatus and E. macaco, non-telomeric (TTAGGG)n sequences collocalize with constitutive heterochromatin. The interspecific differences of the hybridization pattern of (TTAGGG)n sequences at the pericentromeres suggest that E. rubriventer branched off the common trunk before amplification of endogenous (TTAGGG)n sequences occurred in pericentromeric regions.
对马达加斯加狐猴物种褐美狐猴(2n = 60)、红腹美狐猴(2n = 50)、冠美狐猴(2n = 46)和黑美狐猴(2n = 44)的(TTAGGG)n端粒重复序列的染色体分布进行了研究。这些序列与这四个物种所有染色体的端粒杂交,也与褐美狐猴、冠美狐猴和黑美狐猴所有染色体的着丝粒周围区域杂交,但冠美狐猴和黑美狐猴的9号染色体、褐美狐猴的同源2号染色体以及黑美狐猴的1号染色体的着丝粒周围区域除外。在红腹美狐猴中,仅在少数染色体的着丝粒周围区域检测到非常微弱的信号。在褐美狐猴、冠美狐猴和黑美狐猴中,非端粒(TTAGGG)n序列与组成型异染色质共定位。(TTAGGG)n序列在着丝粒周围区域杂交模式的种间差异表明,红腹美狐猴在内源(TTAGGG)n序列在着丝粒周围区域扩增之前就从共同的主干分支出来了。