Phenotypes of the ovarian follicular basal lamina predict developmental competence of oocytes.
BACKGROUND
The ovarian follicular basal lamina underlies the epithelial membrana granulosa and maintains the avascular intra-follicular compartment. Additional layers of basal lamina occur in a number of pathologies, including pili annulati and diabetes. We previously found additional layers of follicular basal lamina in a significant percentage of healthy bovine follicles. We wished to determine if this phenomenon existed in humans, and if it was related to oocyte function in the bovine.


RESULTS
We examined follicles from human ovaries (n = 18) by electron microscopy and found that many follicles had additional layers of basal lamina. Oocytes (n = 222) from bovine follicles with normal or unusual basal laminas were isolated and their ability to undergo in vitro maturation, fertilization and culture to blastocyst was compared. Healthy bovine follicles with a single layer of basal lamina had oocytes with significantly (P < 0.01) greater developmental competence than healthy follicles with additional layers of follicular basal lamina (65% versus 28%).


CONCLUSIONS
These findings provide direct evidence that the phenotype of the follicular basal lamina is related to oocyte competence.
Irving-Rodgers
Helen F
HF
Research Centre for Reproductive Health, School of Paediatrics and Reproductive Health, University of Adelaide, Adelaide, Australia.
Morris
Stephanie
S
Collett
Rachael A
RA
Peura
Teija T
TT
Davy
Margaret
M
Thompson
Jeremy G
JG
Mason
Helen D
HD
Rodgers
Raymond J
RJ
D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D001755:Blastocyst / Q000166:cytology; D002417:Cattle; D002452:Cell Count; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D046529:Microscopy, Electron, Transmission; D054315:Oocyte Retrieval; D009865:Oocytes / Q000254:growth & development*; D006080:Ovarian Follicle / Q000648:ultrastructure*; D010641:Phenotype; D027724:Reproductive Techniques, Assisted; D013045:Species Specificity