id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
ct-11238	Thundathil, Jacob C. ; Dance, Alysha L. ; Kastelic, John P. 	Bovine sperm abnormalities: prevalence, etiology and mechanisms leading to infertility	2014	8	.pdf	application/pdf	5680	305	45	Furthermore, contents of reactive oxygen species and ubiquitinated proteins were higher in pyriform sperm.35 Nuclear vacuoles Nuclear vacuoles (pouches, craters, diadems) have been described in bull sperm as well as in the sperm of other species.36-40 However, a definitive cause for nuclear vacuolation of spermatozoa has not been detected.6 Based on electron microscopic studies, vacuole formation in bulls begins as early as step 6 of spermiogenesis.42 Nuclear vacuoles appear in bull sperm in two forms; single apical vacuoles, which can be present anywhere in the sperm head, and multiple nuclear vacuoles at the acrosome post-acrosomal junction,43-46 appearing as a string of beads.47 These vacuoles are formed during the early stages of spermatid elongation by invagination of the inner nuclear membrane into the condensing nucleus.8 Breeding trials demonstrated that sperm with nuclear vacuoles caused infertility in the bull.45,46 Superovulated cows were bred with semen from a bull with 80% nuclear vacuoles; the fertilization rate was 18% compared to 72% for control bulls.45 The diadem/crater defect was studied over several months in two related 20- month-old Angus bulls.	cache/ct-11238.pdf	txt/ct-11238.txt