Ymin colocalizes with kinetochore protein CENPA in 129/1 mouse embryonic stem (ES) cells using combined immuno-FISH. (A) Anti-centromere autoserum CREST#6 colocalizes with minor satellite DNA at all mouse telocentric centromeres, but not at the centromere of the acrocentric Y (solid arrowhead). (B,C) Ymin DNA FISH probe is highly specific for the Y centromere, showing precise colocalization with anti-centromere autoserum CREST#6 and anti-kinetochore anti-mouse CENPA antibody, respectively. (D) CENPA (green/yellow) consistently occupies a subdomain of the telocentric minor satellite DNA (red) on stretched interphase chromatin. (E) Stretched Ymin chromatin shows direct overlap of CENPA immunofluorescence signal and Ymin FISH probe. (F) Stretched Ymin chromatin (solid arrowhead) typically displays less stretching compared to other stretched telocentric centromeres (open arrowheads) by indirect immunofluorescence using antibodies to CENPA. D–F, scale bars, 2 μm.
