Origin and spread of the SRY gene on the X and Y chromosomes of the rodent Microtus cabrerae: role of L1 elements.
In the rodent species Microtus cabrerae, males as well as females present several copies of the SRY gene, a single-copy gene located on the Y chromosome in most mammals. Using different PCR approaches, we have characterized the sequence, structure, and organization of the SRY copies and their flanking regions distributed on the X and Y chromosomes of this species. All copies of SRY analyzed, including those from the Y chromosome, proved to be nonfunctional pseudogenes, as they have internal stop codons. In addition, we demonstrated the association of SRY pseudogenes with different fragments of L1 and LTR retroelements in both sex chromosomes of M. cabrerae. Examining the possible origin of SRY pseudogene and retroposons association, we propose that retroposons could have been involved in the mechanism of SRY gene amplification on the Y chromosome and in the transference of the Y-linked SRY copies to the X-chromosome heterochromatin.
Departamento de Biología Experimental, Facultad de Ciencias Experimentales, Universidad de Jaén, Campus Las Lagunillas s/n, E-23071 Jaén, Spain.
Juan A
JA
Marchal
Manuel J
MJ
Acosta
Mónica
M
Bullejos
Rafael
R
Díaz de la Guardia
Antonio
A
Sánchez
D000818:Animals; D003411:Arvicolinae / Q000235:genetics*; D005260:Female; D024282:Genes, sry; D006570:Heterochromatin; D008297:Male; D011544:Pseudogenes; D018626:Retroelements; D014960:X Chromosome / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics*
D006570:Heterochromatin; D018626:Retroelements