254 SYSTEMS BIOLOGY OF SPERM AND BULL FERTILITY

Abstract

Bull fertility, the ability of the spermatozoon to fertilize and activate the egg as well as support early embryonic development, is crucial for efficient production of cattle. With the major advances in fundamental science of reproduction, such as genomics, and in biotechnology, such as assisted reproductive technologies, bull influence on herd production has been accentuated. In addition to providing half of the genome for the zygote, sperm also contribute proteins, transcripts, and epigenetic traits that play important roles in sperm physiology, fertilization, and early embryonic development. Recently, using sperm from Holstein bulls with different in vivo fertility data, we have demonstrated that sperm Protamine 1 protein and a panel of microRNA are associated with bull fertility. In addition, molecular and cellular biology experiments on the analyses of sperm nuclear proteins showed that bull sperm have significant levels of histones that are also associated with bull fertility. This presentation will convey the results of most relevant research on discovery of sperm biomolecular markers associated with semen quality and bull fertility. Because of the available field data in bull fertility and the physiological similarities between bovine and other mammals, research results stemming from the systems biology of bull fertility are applicable to other species as well.