Screening of Israeli Holstein-Friesian Cattle for Restriction Fragment Length Polymorphisms Using Homologous and Heterologous Deoxyribonucleic Acid Probes

Genomic DNA of Israeli Holstein-Friesian dairy cattle were screened with a battery of 17 cloned or subcloned DNA probes in an attempt to document restriction fragment length polymorphisms at a number of genetic loci.Restriction fragment length polymorphisms were observed at the chymosin, oxytocin-neurophysin I, lutropin beta, keratin III, keratin VI, keratin VII, prolactin, and dihydrofolate reductase loci.Use of certain genomic DNA fragments as probes produced hybridization patterns indicative of satellite DNA at the respective loci.Means for distinguishing hybridizations to coding sequences for unique genes from those to satellite DNA were developed.Results of this study are discussed in terms of strategy for the systematic development of large numbers of bovine genomic polymorphisms.trait loci in dairy cattle (2).The feasibility of this approach has been demonstrated with several milk production traits in Friesian dairy cattle using a relatively limited number of protein markers ( 7).An expanded number of genetic markers would clearly increase genome coverage and, hence, the sensitivity and power of the approach.Restriction fragment length polymorphisms (RFLP) have the potential for providing the large numbers of genetic markers necessary for effectively using the linkage approach for detecting the action of quantitative genes upon productivity-related traits.In cattle, genomic RFLP have been demonstrated at only a limited number of loci.Systematic screening of the bovine genome should speed the process of accumulating numerous markers.In this study, a sample of Israeli Holstein-Friesian dairy cattle was screened with a battery of cloned DNA probes in an attempt to document RFLP at additional genomic loci.