Related Experiment Video
Updated: Jun 23, 2026

An Integrated Approach for Microprotein Identification and Sequence Analysis
Published on: July 12, 2022
A new pericentromeric repeated DNA sequence in Microtus thomasi
M J Acosta1, J A Marchal, G P Mitsainas
1Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Jaén, Spain.
Abstract:
Several karyotypic forms have been previously described in populations of the vole species Microtus thomasi from Greece. In particular, the karyomorphs Microtus thomasi 'thomasi' and 'atticus' differ in X chromosome morphology, being acrocentric and subtelocentric, respectively. Furthermore, remarkable heterochromatin content variability has been described in sex chromosomes of both karyomorphs. Genomic DNA digestion with AluI allowed us to clone an 884 bp long repeated DNA sequence (Mth-Alu900) from the karyomorph M. thomasi 'atticus'. This repeated DNA is AT rich and seems to be organized mainly as a dimer of the 884-bp unit, which presents three simple repeats (CAAAT, CAGAT and CAGAC) that constitute 80% of the total unit length. This repeated DNA is exclusive to M. thomasi, since it is absent from the genome of other studied Arvicolinae species. The chromosomal location of Mth-Alu900 was analyzed on M. thomasi 'thomasi' and M. thomasi 'atticus' karyomorphs, with different sex chromosome constitution. It was mainly located on the pericentromeric heterochromatin of most autosomes and X chromosomes on both karyomorphs. Results are also discussed in relation to karyotypic and sex chromosome variations in M. thomasi. To our knowledge, Mth-Alu900 constitutes a new - the third discovered so far - pericentromeric repeated DNA sequence described in Microtus species.
Related Concept Videos
Multi-species Conserved Sequences
Although the genome of each species varies greatly from each other, a few sequences are highly conserved. Such conserved DNA...
Cis-regulatory Sequences
Histone Variants at the Centromere
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Non-LTR Retrotransposons
LTR Retrotransposons
The internal coding region of LTR retrotransposons and their mechanism of transposition closely resembles a...

