Chromosome banding studies in cattle.

A recent advance in the field of cytogenetics has been the ability to stain differentially specific areas or bands on the fixed chromosome. In terms of clinical and paraclinical work C- and G-bands have been of most value to date in allowing precise identification of chromosome homologues even in species such as cattle, where the vast majority of chromosomes are of a similar morphology. These methods have allowed at the gross level of the chromosome the precise identification of a number of Robertsonian translocations and certain aneuploids. In this study 1/29 Robertsonian translocations were found in three separate breeds. Also a 14/20 and a 6/16 Robertsonian translocation were identified as was a 61XXY sterile bull. In the future these techniques will allow the identification of as yet unidentified anomalies in cattle such as reciprocal translocations and paracentric inversions. Since many anomalies have been correlated with such clinical problems as early embryonic death, abortion, congenital anomalies and reduced reproductive efficiency in the mammalia, it is important to use cytogenetics as an additional laboratory aid in such investigations.