Eight molecular markers from bovine syntenic groups U2, U5, U24, U14, U12, U28, X and Y were fluorescence in situ mapped to eight river buffalo chromosomes

Initial Fluorescence in situ hybridization (FISH) mapping studies in river buffalo assigned three expressed gene loci: BuBu (MHC), IFNT and IFNW (Iannuzzi et al. 1993a,b). Since then, several loci have been FISH mapped in river buffalo in order to extend its physical map by using the cow genetic map as a framework map. One of the most important steps has been the assignment of at least one bovine molecular marker to each river buffalo chromosome or chromosome arm by using bovine probes. Owing to the high degree of homologies in the chromosome banding patterns of cattle and river buffalo (CSKBB, 1994) and homologous gene loci, we were able to indirectly assign several bovine syntenic groups to speci®c river buffalo chromosomes (BBU), confirming the genetic assignments made in river buffalo by somatic cell hybrid mapping procedures (El Nahas et al. 1996). In the present study we FISH mapped eight bovine markers, belonging to eight different syntenic groups, to the corresponding river buffalo chromosomes. Furthermore, as seven of these markers were physically mapped by FISH for the first time in buffalo, we were able to indirectly assign seven bovine syntenic groups to specific chromosomes of buffalo. With these assignments all the river buffalo chromosomes have now at least one marker assigned.