Comparison of maturation, meiotic competence, and chromosome aneuploidy of oocytes derived from two protocols for in vitro culture of mouse secondary follicles.
OBJECTIVE
To compare maturation rates of mouse preantral follicles cultured using two previously reported follicle in vitro follicle culture protocols, and to compare the aneuploidy of oocytes derived from the two protocols with in vivo-matured control oocytes.


METHODS
Mouse preantral follicles were either mechanically isolated then cultured in individual microdroplets, or enzymatically isolated and cultured in groups in a modified culture medium. Maturation of the follicles/oocytes and resulting oocyte aneuploidy rates were evaluated and compared.


RESULTS
The mechanical isolation and individual culture protocol (M/I) resulted in higher follicle survival than the enzymatic isolation and group culture protocol (E/G) (89.1% versus 79.1%, p < 0.01), and better maturation to the metaphase 2 stage (61.5% versus 39.5%, p = 0.01) The rate of aneuploidy of oocytes not significantly higher in oocytes from the E/G group than the M/I group (15.4% versus 9.9%), but hypoploidy was significantly increased (4.7% versus 0.9%, p < 0.05). Both groups had a higher rate of aneuploidy than the control oocytes (2.9%, p < 0.02).


CONCLUSIONS
These results indicate an increased survival and competency of oocytes derived from the M/I protocol, compared to the E/G protocol. The data highlight an increased susceptibility to meiotic errors in early stage follicles undergoing in vitro culture, compared to in vivo-matured oocytes.
Carrell
Douglas T
DT
Andrology and IVF Laboratories, Department of Surgery, University of Utah School of Medicine, Salt Lake City, 84108, USA.
Liu
Lihua
L
Huang
Ivan
I
Peterson
C Matthew
CM
D000782:Aneuploidy; D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D002871:Chromosome Banding; D005260:Female; D005307:Fertilization in Vitro; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D009865:Oocytes / Q000254:growth & development*; D006080:Ovarian Follicle / Q000502:physiology*