title: Centromere inactivation on a neo-Y fusion chromosome in threespine stickleback fish.
abstract: Having one and only one centromere per chromosome is essential for proper chromosome segregation during both mitosis and meiosis. Chromosomes containing two centromeres are known as dicentric and often mis-segregate during cell division, resulting in aneuploidy or chromosome breakage. Dicentric chromosome can be stabilized by centromere inactivation, a process which reestablishes monocentric chromosomes. However, little is known about this process in naturally occurring dicentric chromosomes. Using a combination of fluorescence in situ hybridization (FISH) and immunofluorescence combined with FISH (IF-FISH) on metaphase chromosome spreads, we demonstrate that centromere inactivation has evolved on a neo-Y chromosome fusion in the Japan Sea threespine stickleback fish (Gasterosteus nipponicus). We found that the centromere derived from the ancestral Y chromosome has been inactivated. Our data further suggest that there have been genetic changes to this centromere in the two million years since the formation of the neo-Y chromosome, but it remains unclear whether these genetic changes are a cause or consequence of centromere inactivation.
authors.affiliation: Divisions of Basic Sciences and Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave North, Mailstop C2-023, Seattle, WA, 98109, USA.|Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA, 98195, USA.
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Cech
authors.affiliation: Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012, Bern, Switzerland. cpeichel@fhcrc.org.
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Peichel
mesh_terms: D000818:Animals; D002503:Centromere / Q000235:genetics*; D044127:Epigenesis, Genetic; D019143:Evolution, Molecular; D017404:In Situ Hybridization, Fluorescence; D008677:Metaphase / Q000235:genetics; D023701:Smegmamorpha / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics*
keywords: CENP-A; Centromere inactivation; ChIP-seq; Dicentric chromosome fusion; Gasterosteus aculeatus; Gasterosteus nipponicus