title: Use of chromomycin A3 staining in bovine sperm  cells for detection of protamine deficiency.
abstract: Sperm chromatin integrity is essential for accurate transmission of male genetic information, and normal sperm chromatin structure is important for fertilization. Protamine is a nuclear protein that plays a key role in sperm DNA integrity, because it is responsible for sperm DNA stability and packing until the paternal genome is delivered into the oocyte during fertilization. Our aim was to investigate protamine deficiency in sperm cells of Bos indicus bulls (Nelore) using chromomycin A3 (CMA3) staining. Frozen semen from 14 bulls were thawed, then fixed in Carnoy's solution. Smears were prepared and analyzed by microscopy. As a positive control of CMA3 staining, sperm from one bull was subjected to deprotamination of nuclei. The percentage of CMA3-positive bovine sperm did not vary among batches. Only two bulls showed a higher percentage of CMA3-positive sperm cells compared to the others. CMA3 is a simple and useful tool for detecting sperm protamine deficiency in bulls.
authors.affiliation: Laboratory of in Vitro Fertilization, Cloning and Animal Transgenesis, Department of Animal Reproduction, School of Veterinary Medicine and Animal Sciences, University of Sao Paulo, Sao Paulo, Brazil. resimoes77@gmail.com
authors.forename: R
authors.initials: R
authors.lastname: Simões
authors.forename: W B
authors.initials: WB
authors.lastname: Feitosa
authors.forename: C M
authors.initials: CM
authors.lastname: Mendes
authors.forename: M G
authors.initials: MG
authors.lastname: Marques
authors.forename: A C
authors.initials: AC
authors.lastname: Nicacio
authors.forename: F R O
authors.initials: FR
authors.lastname: de Barros
authors.forename: J A
authors.initials: JA
authors.lastname: Visintin
authors.forename: M E O A
authors.initials: ME
authors.lastname: Assumpção
mesh_terms: D014128:Chromomycin A3; D005260:Female; D005307:Fertilization in Vitro; D005456:Fluorescent Dyes; D006801:Humans; D008297:Male; D011479:Protamines / Q000032:analysis*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000737:chemistry* / Q000502:physiology; D013194:Staining and Labeling / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D011479:Protamines; D014128:Chromomycin A3