DEVELOPMENTAL COMPETENCE GAMETOGENESIS

DEVELOPMENTAL COMPETENCE GAMETOGENESIS

1.2.3.     Developmental competence

Oocyte ability to produce normal, viable and fertile offspring after fertilization. During follicular development, the acquisition of developmental competence is a gradual process.

The percentage of oocytes that can develop to the blastocyst stage usually expressed the developmental competence. Developmental competence also evaluates by morphological evaluations such as the number of blastomeres or the ratio between trophectoderm cell numbers and inner cell mass.

Apoptosis

Throughout embryonic and neonatal life apoptosis plays an important role in the massive loss of oogonia and oocytes.

The vast majority of follicular populations go through atresia rather than ovulation.

1.2.4.     Oocyte Maturation

Oocyte maturation takes place when oocyte progresses from the diplotene to the metaphase II stage and it is a complex process because nuclear maturation also takes place in this phase. The transition from the diplotene stage to metaphase is called diakinesis. In response to the ovulatory LH, surge oocyte resumes its meiosis or removal of the secondary oocyte from the follicle takes place. During diakinesis, folding of nuclear membrane get starts, the disappearance of nuclear pores occur and then the fragmentation of nuclear membrane occur before quickly disappearing to leave only small sacs with double walls and all these events are identified as germinal vesicle breakdown (GVBD), which is the first visible sign of meiotic continuation. When nucleolus comes in the contact with the cytoplasm get disappears.


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