Recent advances in tools and technologies for monitoring and controlling ovarian activity in marsupials

Modeling genetic benefits and financial costs of integrating biobanking into the conservation breeding of managed marsupials

“…Applied research investment of A$133 million could deliver biobanking protocols for 15 of Australia's most at‐risk marsupial species and 7 appropriate model species (Appendices S10–S16). The costs to develop these technologies are not insignificant due to the knowledge gaps remaining for various species (Rodger, 2019; Rodger et al., 2009; Witt & Rodger, 2018). Increased funding may not guarantee success within the time frames indicated or within the time frame of the black‐footed ferret program, and program time frames and resources may need to be expanded if additional challenges arise.…”

“…Time frames of 3–10 years for reproductive cycles of various species would establish challenging to realistic time frames to conduct applied research necessary to develop the biobanking approach and achieve further understanding of the female cycle before the F 1 generation would be required if rolling out biobanking was deemed a priority (Howell, Frankham, et al., 2021; Rodger et al., 2009; Witt & Rodger, 2018). Existing captive colonies of species, such as Tasmanian devils, koalas, and numbats, in zoos or wildlife hospitals represent opportunities to develop insurance biomaterials that may mitigate against future mass mortality events and emerging threats (Rodger, 2019).…”

“…Suitable backcross tools to use frozen sperm, including artificial insemination (Rodger et al., 2009) and intracytoplasmic sperm injection (ICSI) (Rodger, 2019; Salamone et al., 2017), are associated with significant knowledge gaps that restrict their implementation and optimization (Rodger, 2019; Rodger et al., 2009; Witt & Rodger, 2018). Artificial insemination requires species‐specific knowledge of estrus and ovulation and detailed knowledge of highly variable vaginal anatomy (Tyndale‐Biscoe & Renfree, 1987).…”

“…We present pathways for the dibbler and numbat and 15 other threatened marsupials across diverse marsupial family groups. We matched model and target species based on existence of established model species (e.g., tammar wallaby [ N. eugenii ] and fat‐tailed dunnart [ S. crassicaudata ]) (Witt & Rodger, 2018; Witt, Hinds, et al., 2018; Witt, Rodger, et al., 2018; Witt et al., 2020); similarities in life history, body size, and reproductive strategy (e.g., monovular or polyestrous and polyovular or polyestrous species); species phylogenetically similar or from a related genus or family group; species of appropriate conservation status in situ (least concern or not threatened under appropriate listings); or species readily bred in ex situ facilities now to maximize public acceptance and provide sufficient founder animals.…”

“…Marsupials are highly unique and share a reproductive strategy in which young are born in an embryo‐like state and development to independence is supported by lactation, usually in a pouch or marsupium (Tyndale‐Biscoe, 2005). Despite decades of research, practical advances in marsupial research have been isolated and major knowledge gaps remain (Rodger, 1991, 2019; Rodger et al., 2009; Witt & Rodger, 2018). Artificial insemination with frozen and thawed sperm has been attempted but without success; only the koala has had live births (Johnston & Holt, 2019).…”