Improvement of milk protein quality by gene technology

Abstract

Through our current knowledge of milk protein structure and polymorphism, and the molecular biology of the relevant genes, we show how DNA technology can contribute to improving milk protein quality. Characterization of the goat α s1-casein gene polymorphism and the establishment of its overall structural organization have provided information necessary for developing an allele specific typing procedure. Relying on the polymerase chain reaction technique, this procedure has proven to be a potential tool for selection, which still remains the most efficient way to improve livestock production traits. Alternatively, recent progress in gene transfer technology makes feasible generation of transgenetic dairy animals, producing milk whose composition would be modified to alter its physicochemical and nutritional properties for specific purposes such as producing “humanized” milk in the mammary gland of ruminants. Due to the lack of embryo-derived stem cells from large domestic animals, we can only anticipate that gene targeting, which seems to be the method of choice to direct specific mutations within any coding or regulating region of endogenous genes, will undoubtedly result in modifying livestock genomes.