Page 59 - University of Pretoria RESEARCH REVIEW 2018

Improving genetic diversity – endangered species
Isabel Callealta, Department of Anatomy and Physiology, and MRI
Habitat loss and fragmentation, illegal wildlife trade and human-wildlife conflict affect all cat species with 25 of the 36 listed as vulnerable or endangered on the International Union for the Conservation of Nature red list. The African lion (Panthera leo) population is estimated to have decreased by more than 60% over the past two decades, with only about 18 000 remaining in the wild in 2018.
In South Africa this big cat is classified as ‘least concern’, as there is an increasing number of captive animals living on private
and national reserves that breed quite well. While this makes the African lion an accessible model species to study, most populations have limited genetic variation and a tendency for inbreeding, which leads to reproductive anomalies and an increased risk of extinction.
Dr Isabel Callealta, a veterinarian,
has focused her doctoral studies at UP on the fundamental reproduction physiology of the African lioness. Working under the supervision of Professor André Ganswindt and
Dr Imke Lüders at the Mammal Research Institute (MRI), her research also feeds into the development of a protocol for ovulation induction and non-surgical artificial insemination. Assisted reproduction techniques (ART) may help to improve the genetic diversity by introducing new genes into isolated populations, and thereby increase their breeding success.
Information regarding physiological parameters, such as normal ranges for haematology and blood chemistry, or endocrine mechanisms, is currently
scarce for large felids, mainly because diagnostic or therapeutic procedures are quite challenging to perform in both wild and captive individuals.
Dr Callealta closely observed, over
a period of two years, five female African lionesses hosted at Ukutula Conservation Center in the North West province. The lions were trained through positive reinforcement conditioning to voluntarily allow frequent collection of vaginal
smears and blood. Faecal and blood hormones were monitored and the analysis undertaken at UP’s Endocrine Research Laboratory. All this information has helped to build an in-depth understanding of the lioness’
oestrous cycle, and to identify the right timing for artificial insemination.
The team of UP scientists made world headline news in September 2018 when a lioness at the Ukutula Centre gave birth to the first cubs conceived by artificial insemination.
Research is ongoing as to the feasibility of implementing ARTs in lion ex-situ breeding programmes, and the possibility of adapting this method to other felid species. The team anticipates that the programme will open new opportunities to improve breeding of captive and wild lion populations, and thereby assist conservation efforts.
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