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Effect of Epidermal Growth Factor and 6-Dimethylaminopurine on In Vitro Maturation and Artificial Activation of Spix’s Yellow-Toothed Cavy (Galea spixii Wagler, 1831) Oocytes
by
, ,
Leonardo V. C. Aquino
1
,
Samara L. Olindo
1,
Yara L. F. Silva
1,
Vinícius D. Silva
1,
Lhara R. M. Oliveira
1,
Moacir F. Oliveira
2 and
Alexsandra F. Pereira
1,* 1
Laboratory of Animal Biotechnology, Federal Rural University of the Semi-Arid, Mossoró 59625-900, RN, Brazil
2
Center of Multiplication of Wild Animals, Federal Rural University of the Semi-Arid, Mossoró 59625-900, RN, Brazil
*
Author to whom correspondence should be addressed.
Animals 2025, 15(16), 2403; https://doi.org/10.3390/ani15162403
Submission received: 7 July 2025
/
Revised: 10 August 2025
/
Accepted: 14 August 2025
/
Published: 15 August 2025
(This article belongs to the Section Wildlife)
Simple Summary
In vitro maturation (IVM) and artificial oocyte activation are crucial steps in the development of assisted reproductive technologies (ARTs), including somatic cell nuclear transfer. While these techniques are well-established in laboratory rodents, such as mice and rats, they remain underdeveloped in wild species, like Spix’s yellow-toothed cavy. Advancing ARTs in this species could support its conservation and help preserve biodiversity. This study evaluated the effects of two concentrations of epidermal growth factor (EGF; 10 or 50 ng/mL) in IVM medium, as well as the use of 6-dimethylaminopurine (6-DMAP) during artificial oocyte activation. Results showed that 10 ng/mL EGF enhanced cumulus cell viability and improved oocyte morphometric quality compared to 50 ng/mL. Although 6-DMAP positively influenced cleavage rates, it did not significantly affect morula formation. In conclusion, 10 ng/mL EGF is recommended for IVM in Spix’s yellow-toothed cavy oocytes, and 6-DMAP shows potential to support early embryonic development, contributing to the establishment of ART protocols for this species.
Abstract
The successful application of assisted reproductive technologies (ARTs), such as in vitro maturation (IVM) and artificial oocyte activation, requires species-specific adaptations. Although these methods are routinely used in laboratory rodents, their use in wild or non-model species remains limited, such as the Spix’s yellow-toothed cavy, a Neotropical species of ecological and reproductive interest. This study evaluated the effects of different concentrations of epidermal growth factor (EGF; 10 or 50 ng/mL) on IVM (Experiment 1) and of 6-dimethylaminopurine (6-DMAP) on artificial oocyte activation (Experiment 2). EGF at 10 ng/mL (93.8% ± 1.6; 84.9% ± 0.7) promoted greater viability and less apoptosis in cumulus cells, compared to 50 ng/mL (83.0% ± 1.6; 78.9% ± 2.7), maintaining cumulus expansion, ultrastructural integrity, and better morphometric quality of oocytes. Thus, this concentration was used in the next step, where oocytes were activated with or without 6-DMAP. After five days, the presence of 6-DMAP increased cleavage rates (69.3% ± 5.0) compared to activation without the compound (53.5% ± 3.5), without significantly affecting morula formation (13.2% ± 3.1 to 17.3% ± 2.9). It is concluded that EGF improves the oocyte microenvironment, while 6-DMAP enhances cleavage, with these being the initial steps in the development of ARTs for Spix’s yellow-toothed cavy.
