Details

Autor(en) / Beteiligte

• Domínguez‐Castanedo, Omar
• Uribe, Mari Carmen
• Muñoz‐Campos, Tessy M.

Titel

Morphological patterns of cell death in ovarian follicles of primary and secondary growth and postovulatory follicle complex of the annual killifish Millerichthys robustus (Cyprinodontiformes: Cynolebiidae)

Ist Teil von

• Journal of morphology (1931), 2019-11, Vol.280 (11), p.1668-1681

Ort / Verlag

Hoboken, USA: John Wiley & Sons, Inc

Erscheinungsjahr

2019

Quelle

MEDLINE

Beschreibungen/Notizen

• The dynamics of cellular development and homeostasis of the ovary depend on the balance between proliferation and cell death throughout the reproductive cycle. Millerichthys robustus is an annual fish whose ovarian follicles develop asynchronously, allowing daily reproduction from sexual maturity until death. The objective of this research is to describe, histologically, the processes of follicular atresia and regression of postovulatory follicular complexes (POC) throughout a reproductive cycle of M. robustus. Patterns of cell death were documented by apoptosis in atretic follicles and POC, and necrosis in the POC after ovulation with an associated inflammatory response. Atretic follicles were seen from the onset of sexual maturity, during week three post‐hatching (PH), both in primary growth (from the Cortical alveoli step, with folliculogenesis completed) and secondary growth Stages, with a higher prevalence in the latter. POCs were observed in different stages of regression from week four PH until the death of the fish. The apoptotic characteristics found were: (i) fragmentation of the nuclear membrane and zona pellucida, and liquefaction of the cortical alveoli and yolk; (ii) follicular cells becoming phagocytic, increasing their size, and migrating within the oocyte; and (iii) formation of an intrafollicular lumen, a product of phagocytosis of the oocyte constituents and dispersed pigments that remain after the digestion of yolk and cortical alveoli. The morphological changes of the follicular cells of the POC, from a squamous morphology after ovulation to columnar during its regression with PAS+ contents, was documented, suggesting a secretory activity. Patterns of cell death by apoptosis and necrosis were analyzed in ovarian follicles of M. robustus. (a) Follicular cells (f) with phagocytic activity were documented during apoptosis in follicular atresia; (b) columnar follicular cells with PAS‐positive vesicles (v) were seen during the postovulatory follicular complex regression before apoptosis; and (c) cell death by necrosis (n) was observed during ovulation, with cells of the immune system (ic) during inflammatory response.