Morphological and Functional Characterization of Cow Oocytes for Assisted Reproduction Techniques

OPIZZO, BIANCA ANA; LIAUDAT, ANA CECILIA; BLOIS, DAMIAN ; GONZALEZ, MARINA AURORA; RODRIGUEZ, NANCY; BOSCH, PABLO

Corpus Journal of Dairy and Veterinary Science

corpus publishers

Lugar: East Windsor, New Jersey; Año: 2023 vol. 4

2833-0986

In in vitro production of embryos (IVP), oocytes from the ovaries of slaughterhouse animals are commonly used. However, the quality of these oocytes is highly variable due to unknown category and condition of the slaughtered females. As a result, a heterogeneous population of oocytes with varying capacities for maturation and supporting embryonic development is obtained. The aim of this study was to investigate the morphological and biological characteristics of ovaries and oocytes from slaughtered bovines in order to establish selection criteria for oocytes to be used in IVP. To achieve this, the ovaries were categorized based on the presence or absence of structures such as Corpus Luteum (CL), Dominant Follicle (DF), both (CL+DF), or none (NO). The number and diameter of the follicles were also determined and grouped into three categories: 8 mm. The Cumulus-Oocyte Complexes (COCs) obtained through follicular aspiration were analyzed for several parameters. These included, oocyte coverage by the Cumulus Cells (CC), the number of layers of CC, compaction and thickness of the CC layers. In denuded oocytes, the area, perimeter and diameter of the ooplasm as well as the thickness of the Zona Pellucida (ZP) were measured. Additionally, staining with Hoechst 33342, propidium iodide, or Rhodamine 123 was performed to analyze nuclear and metaphase morphology, cell viability, and mitochondrial functionality, respectively. All these determinations were made on microphotographs captured using a camera attached to an inverted microscope and processed using the Fiji software. Statistical analysis was conducted using ANOVA and Bonferroni’s Test. The results revealed a predominance of ovaries with CL+DF, and in terms of follicular size, the