1. The ZW Micro-Sex Chromosomes of the Chinese Soft-Shelled Turtle (Pelodiscus sinensis, Trionychidae, Testudines) Have the Same Origin as Chicken Chromosome 15.
- Author
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Kawagoshi, T., Uno, Y., Matsubara, K., Matsuda, Y., and Nishida, C.
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TURTLES , *CHICKENS , *SEX chromosomes , *RIBOSOMAL DNA , *NUCLEIC acid hybridization , *GENETIC sex determination - Abstract
The Chinese soft-shelled turtle (Pelodiscus sinensis, Trionychidae, Testudines) has ZZ/ZW-type micro-sex chromosomes where the 18S-28S ribosomal RNA genes (18S-28S rDNA) are located. The W chromosome is morphologically differentiated from the Z chromosome by partial deletion and amplification of 18S-28S rDNA and W-specific repetitive sequences. We recently found a functional gene (TOP3B) mapped on the P. sinensis Z chromosome, which is located on chicken (Gallus gallus, GGA) chromosome 15. Then we cloned turtle homologues of 4 other GGA15-linked genes (GIT2, NF2, SBNO1, SF3A1) and localized them to P. sinensis chromosomes. The 4 genes all mapped on the Z chromosome, and 2 of them (SBNO1, SF3A1) were also localized to the W chromosome. Our mapping data suggest that at least one large inversion occurred between GGA15 and the P. sinensis Z chromosome, and that there are homologous regions in the distal portions of both the short and long arms between the Z and W chromosomes. W chromosomal differentiation in P. sinensis probably proceeded by the deletion of the proximal chromosomal region followed by 18S-28S rDNA amplification, after a paracentric inversion occurred at the breakpoints between the distal region of 18S-28S rDNA and the proximal region of SBNO1 on the Z chromosome. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2009
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