Quality Evaluation of Gilts and Sow’s Oocytes During In Vitro Maturation Based on Mitochondria Distribution

Abstract

Mitochondria is the most frequently studied cell organelle in relation to development competence of the oocytes both in vivo and in vitro. Developmental competence of oocyte is crucial for embryonic development, the molecular activity until the activation of the embryonic genome being based on the maternal reserves stored in the oocyte. Study was designed to qualitatively evaluate 133 COC class C1 and class C2 gilts and sow’s oocytes according to the distribution of mitochondria after IVM, based on Rhodamine 123 stain solution. Regarding mitochondrial distribution, the percentage of oocytes that had a homogeneous distribution around the germinal vesicle was higher in group C1 than C2 and also higher in sow oocytes than in gilts oocytes. For class 1, the difference was 10.58% in favor of sows, the same trend is maintained for C2, the difference being 4.37%. The results are confirmed by morphological examination, where C1 sow’s oocytes matured 26.09% more, compared to gilts oocytes, a difference maintained for C2 oocytes, being 27.4% more sow’s oocytes IVM compared to gilts. Based on mitochondrial distribution we observed that the stage of sexual development of females influences the IVM of oocytes. For pig’s IVF it’s recommended to use C1 sow oocytes.