Open AccessSilent ribosomal cistrons are located at the pairing segment of the postreductional sex chromosomes of Apodemus sylvaticus (Rodentia, Muridae)
Author(s) -
Stitou S.,
Jiménez R.,
Díaz De La Guardia R.,
Burgos M.
Publication year - 2001
Publication title -
heredity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.441
H-Index - 118
eISSN - 1365-2540
pISSN - 0018-067X
DOI - 10.1046/j.1365-2540.2001.00771.x
Subject(s) - biology , apodemus , karyotype , nucleolus organizer region , genetics , ribosomal rna , chromosome , cytogenetics , y chromosome , microbiology and biotechnology , ribosomal dna , zoology , gene , phylogenetic tree
We analysed the karyotype of the rodent species Apodemus sylvaticus by G‐ and C‐banding, Ag‐NOR‐staining and in situ hybridization, with special attention to the sex chromosomes. NOR‐bearing chromosome pairs were identified with simultaneous staining of G bands and NORs. In situ hybridization with an rDNA probe revealed the presence of silent ribosomal cistrons in both sex chromosomes. Studies of meiosis demonstrated that these inactive ribosomal cistrons are located in the pairing segment, which occupies the proximal portion of the telocentric sex chromosomes, and may thus be involved in postreduction caused by an obligatory chiasma in this position.