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Defeating enemy within: How evolution helps clone fish with their genetic burden
According to scientific theories, clonal vertebrates actually have a harder time succeeding than species that reproduce sexually.
Clonal fish and still successful: the Amazon molly. | Photo: Davied Bierbach
One natural clone is the Amazon molly. A research team led by the Biozentrum of the University of Würzburg with the Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB) has shown that over hundreds of thousands of years, this small fish has found a way to cope with the challenges of its origin and reproduction.
In the course of evolutionary adaptation, traits emerge that tend to be advantageous or disadvantageous to the survival or reproductive success of a species. This happens through natural mutation and subsequent selection. For a new trait to be inherited, it must have a genetic basis. Here, sexual reproduction has an advantage, because the offspring carry equal part
Credit: www.biorescue.org/Leibniz-IZW
The BioRescue research project, a programme aiming at saving the northern white rhinoceros from extinction, exemplifies the challenges to overcome when conducting research and conservation in an international consortium in times of a global pandemic. COVID-19 hampered communication and travels, prevented or delayed crucial procedures, caused losses in revenues and by that may have lowered the chances of a survival of the northern white rhino. The consortium adjusted strategies, gained valuable knowledge during these challenging times and continued with its mission. The effects of the pandemic on the BioRescue project are described in detail in a scientific paper published in the
Credit: C Voigt/Leibniz-IZW
What are the reasons for such a contrast in outcomes? A scientist team led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) has now analysed the humoral innate immune defence of European greater mouse-eared bats to the fungus. In contrast to North American bats, European bats have sufficient baseline levels of key immune parameters and thus tolerate a certain level of infection throughout hibernation. The results are published in the journal
Developmental and Comparative Immunology .
During infections caused by Pseudogymnoascus destructans (Pd), North American bats arouse frequently from hibernation to trigger a more elaborate immune response, whereas European bats remain dormant, owing, as the new results reveal, to their competent baseline immunity. Not being able to deal with the fungus by baseline immunity causes North American bats to deplete fat stores before the end of winter bnecause of the need for additional and energeti
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IMAGE: A team of scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) in Germany, Givskud Zoo - Zootopia in Denmark and the University of Milan in Italy succeeded. view more
Credit: Jennifer Zahmel/Leibniz-IZW
For this specific method of cryopreservation, oocytes are collected directly after an animal is castrated or deceased and immediately frozen at -196°C in liquid nitrogen. This technique allows the storage of oocytes of valuable animals for an unlimited time, so that they can be used to produce offspring with the help of assisted reproduction techniques. The aim is to further improve and apply these methods to save highly endangered species such as the Asiatic lion from extinction. The current research on African lions as a model species is an important step in this direction. The results are reported in the scientific journal
Credit: Rio the Photographer
Happy end to a challenging year: Two new northern white rhino embryos created at Christmas - now there are five
The international consortium of scientists and conservationists that is working towards preventing the extinction of the northern white rhino through advanced assisted reproduction technologies is happy to announce that in December 2020, two new northern white rhino embryos were produced. On December 13, the team of Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW), Safari Park Dv?r Králové, Kenya Wildlife Service and Ol Pejeta Conservancy successfully performed an oocyte collection in Kenya. After immediate transportation of the recovered oocytes across continents, the embryos were created at Avantea laboratory in Cremona (Italy) following maturation and fertilisation of the oocytes with the semen of Suni. They were cryopreserved on Christmas eve when they reached the blastocyst stage suitable for freezing and increase the total