Multiple copies of SRY on the large Y chromosome of the Okinawa spiny rat, Tokudaia muenninki

The Okinawa spiny rat, Tokudaia muenninki, is the only species with a Y chromosome in the genus Tokudaia. Its phylogenic relationship with two XO/XO species, Tokudaia osimensis and Tokudaia tokunoshimensis, lacking a Y chromosome and the mammalian sex-determining gene SRY, is unknown. Furthermore, t...

Full description

Saved in:
Bibliographic Details
Published in:Chromosome research 2010-09, Vol.18 (6), p.623-634
Main Authors: Murata, Chie, Yamada, Fumio, Kawauchi, Norihiro, Matsuda, Yoichi, Kuroiwa, Asato
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animal Genetics and Genomics
Animals
Base Sequence
Biomedical and Life Sciences
Cell Biology
Chromosomes
Cytogenetic Analysis
DNA-Binding Proteins - genetics
evolution
Evolution, Molecular
Female
Gene Dosage
Genes, RAG-1
Genes, sry
HMG-box
HMGB Proteins - chemistry
HMGB Proteins - physiology
Human Genetics
Life Sciences
Male
molecular phylogeny
Molecular Sequence Data
Muridae
Murinae - genetics
Phylogeny
Plant Genetics and Genomics
Rodents
Sequence Analysis, DNA
sex chromosomes
Sex-Determining Region Y Protein - genetics
X Chromosome
Y Chromosome
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The Okinawa spiny rat, Tokudaia muenninki, is the only species with a Y chromosome in the genus Tokudaia. Its phylogenic relationship with two XO/XO species, Tokudaia osimensis and Tokudaia tokunoshimensis, lacking a Y chromosome and the mammalian sex-determining gene SRY, is unknown. Furthermore, there has been little cytogenetic analysis of the sex chromosomes in T. muenninki. Therefore, we constructed molecular phylogenetic trees with nucleotide sequences of cyt b, RAG1, and IRBP. All trees strongly supported that T. muenninki was the first to diverge from the Tokudaia ancestor, indicating that loss of the Y chromosome and SRY occurred in the common ancestor of the two XO/XO species after T. muenninki diverged. We found that the X and Y chromosomes of T. muenninki consisted of large euchromatic and heterochromatic regions by conducting G- and C-banding analyses. PCR, Southern blotting, and FISH revealed that T. muenninki males had multiple SRY copies on the long arm of the Y chromosome. At least three of 24 SRY sequences contained a complete open reading frame (ORF). A species-specific substitution from alanine to serine was found in all copies at the DNA-binding surface within the HMG-box, suggesting that it occurred in an original SRY.
ISSN:0967-3849
1573-6849
DOI:10.1007/s10577-010-9142-y