Classification of the sperm chromatin compaction alterations in bulls (Bos taurus) and its correlation with the efficiency of the in vitro production of embryos

Sara Hissae Hiraiwa,Bruno Augusto Nassif Travençolo,Muller Carrara Martins,Paulo Henrique Mazzutti Alves,Marcelo Emílio Beletti

doi:10.14393/bj-v37n0a2021-47967

Sara Hissae Hiraiwa, Bruno Augusto Nassif Travençolo + Show 3 more

Open Access

https://doi.org/10.14393/bj-v37n0a2021-47967

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Journal: Bioscience Journal	Publication Date: Jun 10, 2021
Citations: 1	License type: cc-by

Affiliation: Universidade Federal de Uberlândia

Abstract

This paper proposes to classify the sperm chromatin compaction alterations in bulls, according to the affected area location and its objective is evaluating the correlation of the intensity, the heterogeneity and these kinds of chromatin decompaction with the rates of cleavage and the formation of blastocysts of in vitro production of embryos (IVPE). It was used several subfertile animals sperm samples, which were evaluated using the toluidine blue staining and computer image analysis, making possible the categorization of the chromatin decompaction according to their location. The percentages of chromatin decompaction and heterogeneity were also evaluated. IVPEs were done and the rates of cleavage and of blastocysts were correlated with the chromatin characteristics. It made possible the classification of the chromatin decompaction according to the head affected part in at least four types: base decompaction, basal half decompaction, central axis decompaction, total decompaction. Based on the correlation, it can be implicated that each type of classification has different influences on the bull fertility. It made possible understanding that sperms amount with 5% or more of chromatin decompaction intensity interferes in the bull fertility and this condition can be featured as an uncompensable defect, while the heterogeneity of chromatin is not an important factor in the IVPE results.

Highlights

Sperm are cells with a differentiated structure and specialized in carrying the paternal genetic and epigenetic charge to the oocyte
This paper proposes to classify the sperm chromatin compaction alterations in bulls, according to the affected area location and its objective is evaluating the correlation of the intensity, the heterogeneity and these kinds of chromatin decompaction with the rates of cleavage and the formation of blastocysts of in vitro production of embryos (IVPE)
It made possible understanding that sperms amount with 5% or more of chromatin decompaction intensity interferes in the bull fertility and this condition can be featured as an uncompensable defect, while the heterogeneity of chromatin is not an important factor in the IVPE results

Summary

Introduction

Sperm are cells with a differentiated structure and specialized in carrying the paternal genetic and epigenetic charge to the oocyte. The condensation of the sperm chromatin is an important phase in the distinction that comes during the spermatogenesis, at about 90 to 95% of the somatic histones are changed by protamines (Oliva 2006), configuring a highly compacted structure, the toroid of the protamine, which is important for the protection and maintenance of the stability of the DNA (Beletti 2013). Gineitis et al (2000) believe that the histones can be connected to the telomeres, specific structures of the DNA and proteins found at the extremity of the chromosomes (Shammas 2011), and to the first events of the sperms that respond to signs of the oocyte for the formation of the male pronucleus. The histones are important sites of epigenetic signalization and they can be related to the paternal epigenetic heritage (Carrel 2012).

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