Karyotyping of a sheep-goat hybrid born under natural conditions

The natural occurrence of live hybrid offspring between domestic goats and sheep is well documented in literature, although many studies report on goats mated with rams, whereas the reciprocal cross is much less documented. In this study, we report a cytogenetic characterization of a healthy female geep hybrid (ewemated with a buck) born in a flock under natural conditions. Peripheral blood samples were collected and treated with normal cultures and R-banding preparations by lateincorporation of BrdU and H33258, simultaneously added 6 h before harvesting. After the fixation, normal cultures were used for GTG-banding (by 0.05 % of trypsin solution and Giemsa staining) and C-banding, whereas R-preparations were used for sequential RBAbanding (by acridine orange staining) and NORs identification (by Ag-Nitrate staining). All cells showed 57 chromosomes in total (3 metacentric and 54 acrocentric chromosomes) as confirmed by C-banding. G- and Rbanding karyotypes revealed that the autosomes involved in the hybrid combination were CHI1,3; CHI2,8 and CHI5,11 corresponding to the metacentric chromosomes OAR1, OAR2, and OAR3. The sex chromosomes were correctly arranged. NORs were identified on OAR1p (CHI3), OAR2q (CHI2), OAR3q (CHI5), OAR4 (CHI4) and OAR25 (CHI28). No further morphological differences were evidenced by a classical cytogenetic investigation, whereas molecular cytogenetic and genetic analysis are still in progress to clarify the recombination events occurred in this rare interspecies hybrid.