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Morphological and Functional Evaluation of Kodkod (Leopardus guigna) Oocytes After In Vitro Maturation and Parthenogenetic Activation
by
, , , and
Deyna Toledo-Saldivia
1,
Alonso Cáceres-Hernández
2,
Daniela Doussang
1,3,
Camila Zapata-Rojas
4,
Sebastián Vergara
5,
Ingrid Carvacho Contreras
5,
Fidel Ovidio Castro
4
,
Lleretny Rodriguez-Alvarez
4 and
Daniel Veraguas-Dávila
2,* 1
Escuela de Medicina Veterinaria, Facultad de Ciencias de la Vida, Universidad Andres Bello, Viña del Mar 2531015, Chile
2
Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago 8820808, Chile
3
Sustainability Research Center (CIS), One Health Institute, Universidad Andres Bello, Santiago 8370146, Chile
4
Laboratorio de Biotecnología Animal, Departamento de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad de Concepción, Chillán 3812120, Chile
5
Laboratorio de Reproducción y Canales Iónicos, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca 3480112, Chile
*
Author to whom correspondence should be addressed.
Animals 2025, 15(20), 3031; https://doi.org/10.3390/ani15203031 (registering DOI)
Submission received: 14 September 2025
/
Revised: 15 October 2025
/
Accepted: 15 October 2025
/
Published: 19 October 2025
(This article belongs to the Special Issue Advances in the Reproduction of Wild and Exotic Animals)
Simple Summary
The kodkod (Leopardus guigna) is a small wild felid native to Chile, whose population is currently in decline. Assisted reproductive technologies (ARTs) offer valuable tools for the genetic preservation of endangered species, including the kodkod. Conservation strategies for the kodkod have included cryobanking and the generation of cloned embryos through interspecific somatic cell nuclear transfer (iSCNT). However, the reproductive physiology and embryo development of this species are poorly understood. Here, we applied optimized protocols developed for domestic cat oocytes to evaluate the in vitro oocyte maturation (IVM) and in vitro culture (IVC) of embryos from kodkod. Immature cumulus–oocyte complexes (iCOCs) were collected from a female kodkod, and their morphology and developmental competence were evaluated. Immature kodkod oocytes were smaller than domestic cat oocytes. Kodkod oocytes were able to mature in vitro and develop to the blastocyst stage following chemical activation. Our work demonstrates that the protocols used to manage domestic cat oocytes can be successfully adapted for IVM and in vitro embryo production (IVP) in the kodkod. Our research provides a foundation for improving ARTs aimed at conserving this endangered felid and enhancing our understanding of its reproductive biology.
Abstract
The kodkod (Leopardus guigna) is a vulnerable wild felid native to South America whose population is steadily declining. ARTs offer valuable tools for the preservation of its genetic diversity. Our study provides the first evaluation of the morphological and functional acquisition of competence in kodkod oocytes using protocols previously established for domestic cat oocytes. In total, 29 iCOCs were obtained from the ovaries of a single juvenile female kodkod that deceased in a wildlife rehabilitation center. Based on morphological criteria, 13 oocytes were selected for IVM and subsequently evaluated for developmental competence following parthenogenetic activation (PA) and in vitro culture (IVC). Kodkod oocytes appear to be smaller and have a thinner zona pellucida compared to those of domestic cat oocytes. These kodkod oocytes demonstrated the ability to mature in vitro, underwent cleavage, and developed in vitro to the blastocyst stage by day 9. Here, we show that protocols to manage domestic cat oocytes and embryos can support kodkod in vitro oocyte maturation, activation, and in vitro embryo development. However, given that the results were obtained from a single individual and the protocols were tested in a limited number of oocytes, further studies involving additional specimens are essential to validate these observations and refine ART applications for kodkod conservation.
