Thirteen loci physically assigned to sheep chromosome 2 by cell hybrid analysis and in situ hybridization

Use of the Indian muntjac idiogram to align conserved chromosomal segments in sheep and human genomes by chromosome painting

We have hybridized all 28 chromosome-specific painting probes from the domestic sheep (Ovis aries, 2n = 54) onto metaphase chromosomes of the Indian muntjac deer (Muntiacus muntjak vaginalis, 2n = 6,7) and identified 35 conserved chromosomal segments. Results from this study show that most of the sheep acrocentric chromosomes hybridized to single regions in the Indian muntjac genome. This conserved hybridization pattern supports the concept that the large Indian muntjac chromosomes were derived from multiple tandem fusions from an ancestral deer species. Using previously reported fluorescence in situ hybridization data in which human chromosomes were hybridized onto the Indian muntjac genome, we were able to align chromosomal segments of the sheep and human genomes. Using this three-species genome alignment approach, we have identified a minimum of 42 conserved chromosomal segments between sheep and human genomes including 7 new regions not previously reported.

Comparative FISH-mapping of villin (VIL) gene in river buffalo, sheep and goat chromosomes

Two genomic clones of the villin (VIL) gene were independently hybridized on river buffalo (Bubalus bubalis, BBU), sheep (Ovis aries, OAR) and goat (Capra hircus, CHI) chromosomes by using sequential fluorescence in situ hybridization (FISH) and R-banding (RBP- and RBA-banding). Clear hybridization signals revealed that VIL is located in BBU 2q33, OAR 2q33 and CHI 2q33. These chromosomes and chromosome bands are believed to be homologous and the VIL locus is the same as that previously found on cattle chromosome 2q43. VIL localization in these three species allows us tentatively to assign all cattle U17 to BBU and CHI 2q and to extend the physical map to OAR 2q.