Cytogenetic Screening on Mediterranean Italian River Buffalo Males Intended for Reproduction and Females with Fertility Issues-A Pilot Study.

In Italy, karyotype analysis is routinely performed on all young males intended for reproduction to screen for chromosome abnormalities. This practice gained prominence following the identification of a complex chromosome abnormality in a well-known bull named Magnifico and its progeny. This procedure significantly enhances the value of the Mediterranean Italian River Buffalo breed, particularly in the context of artificial insemination both within Italy and in other countries importing semen. In the current study, 159 young Mediterranean Italian River Buffalo (MIRB) males intended for reproduction, 30 females with fertility issues, 3 young females and a male co-twin were investigated by analyzing their karyotype using both CBA- and RBA-banding. All males displayed a normal karyotype (2n = 50, XY), although one animal displayed an abnormal X-chromosome with C-band polymorphism, as it is C-band negative when this chromosome normally shows the largest C-band among all chromosomes. This result was also confirmed by the FISH-mapping technique using three bovine BAC-clones containing SAT-I, SAT-III and SAT-IV. Cytogenetic investigation showed that seven females, along with one male co-twin, were affected by freemartinism (XX/XY leukocyte chimerism) and were subsequently removed from the farm. In two of these females, clinical and necroscopic examinations showed severe damage of the internal reproductive organs.