Comparison between CMA3 test and toluidine blue for evaluation of chromatin compactation in thawed bovine semen

• Grant number: 14/00050-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2014
• End date: February 28, 2015
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: Janaina Torres Carreira
• Grantee: Lays Fernanda Adami Damasceno
• Host Institution: Pró-Reitoria Acadêmica. Centro Universitário de Rio Preto (UNIRP). Sociedade Riopretense de Ensino e Educação. São José do Rio Preto , SP, Brazil

Abstract

Semen analysis within the breeding soundness exam is an excellent fertility diagnostic method, however, fails to assess cell functional damage and chromatin structure. To achieve a compact, protective, hydrodynamic and functional state, sperm chromatin needs to be compacted in a unique way, with extensive replacement of histones by protamine. Compaction failures can generate changes the shape of the sperm head and problems in the future embryonic development. This study aims to compare and correlate different methods of assessing the maturity and compaction of sperm chromatin in cryopreserved spermatozoa of Bos indicus Nellore bulls. A bull will be chosen randomly in the insemination centre (CCPS), ejaculate will be frozen in accordance with established standards CCPS. Ten batches will be evaluated with six replicates of each. The toluidine blue staining, which allows the simultaneous evaluation of chromatin compaction and sperm head morphometry and chromomycin A3 will be used. Analysis of variance (ANOVA) will be used to investigate differences in semen parameters and results of maturity and chromatin compaction tests and the means were compared by Tukey test. Correlation analysis of the variables within each group will be held.