Molecular Composition of Heterochromatin and Its Contribution to Chromosome Variation in the Microtus thomasi/Microtus atticus Species Complex

Genes

Michail Rovatsos¹  JuanAlberto Marchal²  Antonio Sánchez²  Eva Giagia-Athanasopoulou³ 

[1] Department of Ecology, Faculty of Science, Charles University, 12800 Prague, Czech Republic;Department of Experimental Biology, Faculty of Experimental Sciences, University of Jaén, Campus Las Lagunillas s/n, E-23071 Jaén, Spain;Section of Animal Biology, Department of Biology, University of Patras, GR-26500 Patras, Greece;

关键词: Microtus;    Msat-160;    polymorphism;    repeated DNAs;    sex chromosomes heterochromatin;    telomeric sequences;   

DOI  :  10.3390/genes12060807

来源: DOAJ

【 摘 要 】

The voles of the Microtus thomasi/M. atticus species complex demonstrate a remarkable variability in diploid chromosomal number (2n = 38–44 chromosomes) and sex chromosome morphology. In the current study, we examined by in situ hybridization the topology of four satellite DNA motifs (Msat-160, Mth-Alu900, Mth-Alu2.2, TTAGGG telomeric sequences) and two transposons (LINE, SINE) on the karyotypes of nine chromosome races (i.e., populations with unique cytogenetic traits) of Microtus thomasi, and two chromosomal races of M. atticus. According to the topology of the repetitive DNA motifs, we were able to identify six types of biarmed chromosomes formed from either Robertsonian or/and tandem fusions. In addition, we identified 14 X chromosome variants and 12 Y chromosome variants, and we were able to reconstruct their evolutionary relations, caused mainly by distinct mechanisms of amplification of repetitive DNA elements, including the telomeric sequences. Our study used the model of the Microtus thomasi/M. atticus species complex to explore how repetitive centromeric content can alter from chromosomal rearrangements and can shape the morphology of sex chromosomes, resulting in extensive inter-species cytogenetic variability.

【 授权许可】

Unknown