Laser microdissection-based analysis of the Y sex chromosome of the Antarctic fish Chionodraco hamatus (Notothenioidei, Channichthyidae)

Abstract

Microdissection, DOP-PCR amplification and microcloning were used to study the large Y chromosome of Chionodraco hamatus, an Antarctic fish belonging to the Notothenioidei, the dominant component of the Southern Ocean fauna. The species has evolved a multiple sex chromosome system with digametic males showing an X1YX2 karyotype and females an X1X1X2X2 karyotype. Fluorescence in situ hybridization, performed with a painting probe made from microdissected Y chromosomes, allowed a deeper insight on the chromosomal rearrangement, which underpinned the fusion event that generated the Y. Then, we used a DNA library established by microdissection and microcloning of the whole Y chromosome of Chionodraco hamatus for searching sex-linked sequences. One clone provided preliminary information on the presence on the Y chromosome of the CHD1 gene homologue, which is sex-linked in birds but in no other vertebrates. Several clones from the Y-chromosome mini-library contained microsatellites and transposable elements, one of which mapped to the q arm putative fusion region of the Y chromosome. The findings confirm that interspersed repetitive sequences might have fostered chromosome rearrangements and the emergence of the Y chromosome in Chionodraco hamatus. Detection of the CHD1 gene in the Y sex-determining region could be a classical example of convergent evolution in action.

Microdissection of the Ah01 chromosome in upland cotton and microcloning of resistance gene anologs from the single chromosome

“…However, the approach requires the operator to be trained well enough, or there should be much deviation operated by different persons or even in different personal statuses by an operator. The third method is laser cutting [44, 49], in which chromosome specimens are dispersed onto a special carrier covered with a membrane for dissection and collection. In most cases, dissection is much easier than collection.…”