bachelorThesis
Implementación de un protocolo de maduración in vitro de ovocitos de cobaya (Cavia porcellus)
Fecha
2022-06-17Autor
Zhinin Criollo, Andrea Belén
Buñay Ortiz, Pedro Alexis
Institución
Resumen
One of the strategies used worldwide for the multiplication and conservation of
material of high genetic value or in danger of extinction is the production of in vitro
embryos. The objective was to evaluate an in vitro maturation protocol for
cumulus-oocyte complexes (COC´s) from guinea pigs (Cavia porcellus). 760
COC´s corresponding to 52 ovaries were obtained using the Slicing technique.
The COCs were selected according to the methodology described by Hawk and
Wall (1994) and modified by Ayala et al. (2019) for bovine COC´s (type A; B; C).
Once the COC´s of each type were obtained, 20% was used for pre-maturation
morphometry, another 20% was used as a control and went directly to the in vitro
maturation process (IVM) for 24 h. The remaining 60% was applied the Brilliant
Cresyl Blue (BCB) test and growth (BCB+) and those that were still growing
(BCB-) were determined, then each type and its subgroups (BCB+ and BCB-)
were matured. in vitro for 24 hours. Finally, the percentage of maturation and
post-maturation morphometry were established. The recovered oocytes were
morphologically classified as 35.8% type A COC´s, 30.9% B and 33.3% type C.
It was determined that 71.6%, 60%, 63.5% of COC´s type A, B and C respectively
reacted to the BCB test. When performing the morphometry, it was established
that the COC´s of Type A and B (suitable) were larger than the unsuitable COC´s
(type C), with a statistical difference. The COC´s of the control group of type A,
matured in 40.4%, types B 31.7% and type C 18.2%. However, the percentage
of nuclear maturation was affected when COC´s of types A; B and C, were
subjected to the BCB test and subsequently matured for 24 hours. In conclusion:
the maturation medium used allowed the oocytes to reach metaphase II;
however, these percentages are much lower than expected.