Common goals, different stages: the state of the ARTs for reptile and amphibian conservation

Abstract

Amphibians and reptiles are highly threatened vertebrate taxa with large numbers of species threatened with extinction. With so many species at risk, conservation requires the efficient and cost-effective application of all the tools available so that as many species as possible are assisted. Biobanking of genetic material in genetic resource banks (GRBs) in combination with assisted reproductive technologies (ARTs) to retrieve live animals from stored materials are two powerful, complementary tools in the conservation toolbox for arresting and reversing biodiversity decline for both amphibians and reptiles. However, the degree of development of the ARTs and cryopreservation technologies differ markedly between these two groups. These differences are explained in part by different perceptions of the taxa, but also to differing reproductive anatomy and biology between the amphibians and reptiles. Artificial fertilisation with cryopreserved sperm is becoming a more widely developed and utilised technology for amphibians. However, in contrast, artificial insemination with production of live progeny has been reported in few reptiles, and while sperm have been successfully cryopreserved, there are still no reports of the production of live offspring generated from cryopreserved sperm. In both amphibians and reptiles, a focus on sperm cryopreservation and artificial fertilisation or artificial insemination has been at the expense of the development and application of more advanced technologies such as cryopreservation of the female germline and embryonic genome, or the use of sophisticated stem cell/primordial germ cell cryopreservation and transplantation approaches. This review accompanies the publication of ten papers on amphibians and twelve papers on reptiles reporting advances in ARTs and biobanking for the herpetological taxa.

Strategies for establishing and using genome resource banks to protect genetic diversity in conservation breeding programs

“…Historically, GRBs have focused on cryopreserved gametes, and more specifically primarily sperm, reflecting the early development of artificial insemination in domestic animals and humans, which has provided models for many of their wild cousins. Recently, newer technologies such as somatic cell nuclear transfer (Iqbal et al, 2021) and induced pluripotent stem cells (Hildebrandt et al, 2021; Korody et al, 2021) are expanding roles for somatic cells in GRBs (Clulow et al, 2022; Praxedes et al, 2018; Ryder & Onuma, 2018). These technologies are not yet developed and tested for most species of conservation concern; as they become more widely available and used, customized guidelines for optimally using such GRBs to advance population management should be developed.…”

Modelling the sustainable harvest of wild populations for the conservation of a threatened amphibian

“…If the goal is to capture genetic diversity from small populations, then assisted reproductive technologies, including hormonally induced gamete release, sperm cryopreservation (biobanking), and in vitro fertilization provide a low‐risk alternative to harvesting whole animals (Clulow et al., 2022). Protocols for L. raniformis sperm collection and cryopreservation exist (J. Clulow, pers.…”

Opportunities for research and conservation of freshwater turtles in Australia

“…Improved river management, such as managed flow delivery in regulated systems, has attempted to improve wetland habitats and the condition of rivers (Espinoza et al, 2022; Francis et al, 2022). More broadly, technological advances such as biobanking gametes, controlling diseases, and advances in genetic and bioinformatic tools should assist future conservation measures (Clulow et al, 2022). However, knowledge of the most effective conservation actions, the effectiveness of attempts to aid population recovery, and whether these actions are required at all, remains lacking for many species.…”