In vitro embryo production in the Iberian lynx (Lynx pardinus) - Assisted reproductive technologies and early IVF development

Oct 5, 2026

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The study addresses conservation challenges faced by the Iberian lynx (Lynx pardinus) by evaluating the feasibility of assisted reproductive technologies for in vitro embryo production. It reports the first IVF and early embryo development using oocytes recovered post-mortem combined with cryopreserved spermatozoa. Oocytes from six females were matured under two incubation durations, achieving differing maturation rates. Co-incubation enabled cleavage and the vitrification of a blastocyst and multiple morulae. Findings support adapting domestic cat IVF protocols and provide a foundation for improving future embryo cryopreservation and embryo transfer in conservation programs.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Introduction

Background: species extinction and climate change

Conservation role of in situ and ex situ programs

Assisted reproductive technologies for wild felids

Domestic cat protocols as a model

Theriogenology Wild 8 (2026) 100142 Contents lists available at ScienceDirect Theriogenology Wild journal [homepage:](homepage: www.journals.elsevier.com/theriogenology-wi)[ www.journals.elsevier.com/theriogenology-wi](homepage: www.journals.elsevier.com/theriogenology-wi)ld | In vitro embryo production in the Iberian lynx (Lynx pardinus) using oocytes recovered post-mortem and cryopreserved spermatozoa
Andrea Priego-Gonz´alez a,1 , Ana Munoz-Maceda a,1 , Raquel Gonz´alez b,1 ,
Juan Antonio Rielob, Natalia Ga˜´nanb, Ana Sanchez-Rodriguez b , Pilar Villar-Moya b, Ana Cantos Rubertc, María Jesús S´anchez-Calabuiga, Eduardo R.S. Roldanb,*
a Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Complutense University of Madrid, Spain b Department of Biodiversity and Evolutionary Biology, National Museum of Natural Sciences (MNCN-CSIC), Madrid, Spain c Centro de Rescate de Fauna Amenazada CERI, Sevilleja de la Jara, Toledo, Spain | | | | --- | --- | --- | | A R T I C L E I N F O | | A B S T R A C T | | Keywords:
Assisted reproductive technologies in vitro fertilization Cryopreservation
Genetic rescue Iberian lynx Conservation biology | | The Iberian lynx (Lynx pardinus), once considered the most endangered felid in the world, has become a remarkable example of conservation success thanks to intensive ex situ and in situ management efforts. However, the long-term viability of the species remains under threat. The implementation of assisted reproductive technologies (ARTs) would contribute to ensure the species viability, but the use of ARTs is limited in this species and there are still important gaps in the knowledge of its physiology. Here, we report the first in vitro fertilization (IVF) and early embryo development in the Iberian lynx using oocytes retrieved post-mortem and cryopreserved spermatozoa. Oocytes from six females were subjected to in vitro maturation using two sets of conditions. In the first series, oocytes incubated in vitro for 24 h, exhibited a very low proportion (0–37 %) reaching metaphase II (MII). Attempted IVF with cryopreserved spermatozoa resulted in no fertilization. In a second series, oocytes were incubated in vitro for 28 h; grade I-II oocytes exhibited 40 % maturation rate (MII), whereas grade III oocytes showed 28 % maturation rate. Matured oocytes from one female were co-incubated with cryopreserved sperm for 18 h resulting in cleavage rates of 39.3 %(grade I–II) and 7.1 %(grade III) and the opportunity to vitrify one blastocyst and six morulae. These results demonstrate the feasibility of using ARTs in this species, validating domestic cat protocols for Iberian lynx gametes, and providing a foundation for further refinement of IVF protocols, embryo cryopreservation, and ultimately, embryo transfer strategies for use in conservation programs. | 1. Introduction The rapid extinction of animal species driven by human activity and the effects of climate change represent one of the most pressing challenges faced by the scientific community in the 21st century [1]. Despite the scale of this threat, significant progress has been made in the preservation of certain species through the implementation of coordinated in situ and ex situ conservation programs [2,3]. According to the IUCN Red List, nearly half of all wild felids are currently classified as either endangered or vulnerable [4]. The Iberian lynx (Lynx pardinus) serves as a notable example of the effectiveness of such conservation strategies. Once considered the most endangered felid species in the world, the Iberian lynx was reclassified as “vulnerable” in 2024 [4], following more than two decades of intensive conservation efforts. Thanks to the establishment of ex situ conservation programs, assisted reproductive technologies (ARTs) have begun to be applied over the past few decades to support and enhance conservation efforts in wild felids. These technologies include artificial insemination

FAQs

What assisted reproductive technology approach is evaluated for Iberian lynx conservation?

The study evaluates in vitro embryo production using assisted reproductive technologies, including in vitro maturation (IVM) and in vitro fertilization (IVF), combined with cryopreserved spermatozoa.

How were the oocytes and spermatozoa prepared for IVF?

Oocytes were retrieved post-mortem from six females and subjected to in vitro maturation under two incubation conditions, while spermatozoa were cryopreserved before co-incubation.

What embryo development outcomes were achieved?

The experiments produced cleavage after maturation and co-incubation, and enabled vitrification of one blastocyst and six morulae, demonstrating feasibility for this species.

Oct 5, 2026

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