In the platypus a meiotic chain of ten sex chromosomes shares genes with the bird Z and mammal X chromosomes

Frank Grützner (), Willem Rens, Enkhjargal Tsend-Ayush, Nisrine El-Mogharbel, Patricia C. M. O'Brien, Russell C. Jones, Malcolm A. Ferguson-Smith and Jennifer A. Marshall Graves
Additional contact information
Frank Grützner: Australian National University
Willem Rens: University of Cambridge
Enkhjargal Tsend-Ayush: Australian National University
Nisrine El-Mogharbel: Australian National University
Patricia C. M. O'Brien: University of Cambridge
Russell C. Jones: The University of Newcastle
Malcolm A. Ferguson-Smith: University of Cambridge
Jennifer A. Marshall Graves: Australian National University

Nature, 2004, vol. 432, issue 7019, 913-917

Abstract: Abstract Two centuries after the duck-billed platypus was discovered, monotreme chromosome systems remain deeply puzzling. Karyotypes of males1, or of both sexes2,3,4, were claimed to contain several unpaired chromosomes (including the X chromosome) that form a multi-chromosomal chain at meiosis. Such meiotic chains exist in plants5 and insects6 but are rare in vertebrates7. How the platypus chromosome system works to determine sex and produce balanced gametes has been controversial for decades1,2,3,4. Here we demonstrate that platypus have five male-specific chromosomes (Y chromosomes) and five chromosomes present in one copy in males and two copies in females (X chromosomes). These ten chromosomes form a multivalent chain at male meiosis, adopting an alternating pattern to segregate into XXXXX-bearing and YYYYY-bearing sperm. Which, if any, of these sex chromosomes bears one or more sex-determining genes remains unknown. The largest X chromosome, with homology to the human X chromosome, lies at one end of the chain, and a chromosome with homology to the bird Z chromosome lies near the other end. This suggests an evolutionary link between mammal and bird sex chromosome systems, which were previously thought to have evolved independently.

Date: 2004
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/nature03021 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:432:y:2004:i:7019:d:10.1038_nature03021

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature03021

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().