MISCELLANY

The sixth living rhino species?

In April 2010, Colin Groves, Prithiviraj Fernando and Jan Robowsky cooperated in the publication of a pivotal paper (Groves et al., 2010) on the ‘sixth rhinoceros’. After reviewing a series of morphological, genetic and ecological data, they conclude that the taxon hitherto separated as the northern white rhinoceros on the subspecific level should actually be elevated to species status. Hence there are now six species of rhinoceros, the new one known scientifically as ‘Ceratotherium cottoni (Lydekker, 1908)’. This paper clearly shows the importance of taxonomy for policy in conservation.

Personally I believe that it is now time to move away from calling the taxa southern and northern white rhino. Historically, they have also been called Burchell’s and Cotton’s rhinoceroses, from their respective ‘discoverers’. These names may no longer be appropriate. I wonder if anybody can suggest good popular names for these two kinds of African rhinoceros?

The move of four northern white rhinos from Dvur Králové to Ol Pejeta in Kenya has been successful so far [see above, p. 168].Kees Rookmaaker in the newsletter of the Rhino Resource Center, No. 19 (May 2010), www.rhinoresourcecenter.com

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Housing amphibians in cargo containers

Insulated shipping containers can make ideal rescue facilities for amphibians. They are:
– relatively inexpensive, often cheaper than new ‘traditional’ structures;
– available everywhere in the world, often as discounted ‘retired’ units that are still fit for this use;
– easily modified to meet particular specifications (every major port in the world seems to have a company that specializes in adapting units for other uses);
– modular, easily placed adjacent to or on top of each other so that they can be added one at a time to increase capacity at a given facility;
– ideal where space is limited;
– mobile and made to be easily transported, so they can be delivered ‘ready-to-go’ to a point of use or, if need be, relocated from one site to another (all they need is a concrete pad to sit on and a link to the local water and electric supplies);
– the perfect size to house an entire rescue population of an average-sized amphibian;
– easily modified to be an attractive exhibit by adding large viewing windows and graphics.

The use of insulated shipping containers for housing amphibians was pioneered by Gerry Marantelli at the Amphibian Research Centre (ARC) in Australia. The ARC has modified containers to order and supplied them to other organizations, including Tidbinbilla Nature Reserve, Taronga Zoo, Chester Zoo [see IZN 55 (3), 171–2] and Durrell Wildlife Conservation Trust.

The Amphibian Ark organisation recommends that these containers can be practical in many applications, and its partners are available to discuss their experiences (and vendors): (Australia) Michael McFadden mmcfadden@zoo.nsw.gov.au; (U.K.) Richard Gibson richard@AmphibianArk.org; (U.S.A.) Ron Gagliardo ron@AmphibianArk.org.

Kevin Zippel, Program Director, Amphibian Ark

Cause of Tasmanian devil cancer revealed

The first set of Tasmanian devil genetic sequencing has revealed the origin of the unique transmissible cancer now devastating the species’ population [see IZN 52 (3), 163–4], offering hope that the rapid decline in devil numbers can be arrested and giving scientists new insights for cancer research.

The work was done by an international team of scientists led by Dr Elizabeth Murchison, who conducted the research at the Australian National University in the laboratory of Professor Jenny Graves of the Research School of Biology. The team made the breakthrough by studying and comparing the genes active in both healthy and sick Tasmanian devils. Their research reveals that the origin of the cancer is a tumour of a ‘Schwann cell’. Schwann cells normally wrap around nerves to insulate them.

The finding, published in the journal Science(Murchison et al., 2010), offers considerable hope that the cancer can be identified more rapidly and at earlier stages, as one of the Schwann cell proteins gives a clear and distinctive genetic signal that could help distinguish between the facial cancer and other types of cancer on the animals.

‘We found that about 14,000 genes are expressed at a low or high rate in normal tissues, and in the tumour, but their profiles are quite different,’ said Professor Graves. ‘We realised the tumour profile was fairly unusual and included genes that made some strange proteins that are highly expressed in Schwann cells. This was a real surprise – I don’t think anybody had guessed that. This tells us that the tumour arose from one Schwann cell in one animal in Tasmania probably less than 20 years ago. It was spread to other animals by biting because devils have little genetic variation, so cannot recognise cells from another animal as foreign and reject them. Now we have a better idea what we’re up against. The good news is that one of the active proteins is easy to detect, which will give us the chance to diagnose the cancer early, which is important for setting up cancer-free ‘insurance’ populations. It also allows us to study the way the cancer changes over a long period, which potentially offers new insights for all cancer research.’

Prof. Graves said the research was an essential step in safeguarding the future of the species. ‘The cancer has devastated Tasmanian devils,’ she said. ‘It eats up their mouths and eyes, and they soon die of starvation. It has wiped out around 60% of the world’s devils and is likely to lead to their extinction in the wild within 30 to 50 years. It’s a uniquely horrible cancer, and it is critical to know about it at the genetic level.’

Wildlife Extra News (www.wildlifeextra.com)

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Genetically speaking, frogs are surprisingly like humans

African clawed frogs (Xenopus tropicalis) have more in common with humans than one might think, according to their newly-sequenced genome (Hellsten et al., 2010), which shows a surprising number of commonalities with the human genome. This is the first time an amphibian genome has been sequenced, and it represents a great advance in the understanding not just of frogs but of the whole tree of life on earth.‘A lot of mammals have been sequenced, but far fewer other vertebrates,’ says Richard Harland, a biologist at the University of California, Berkeley, and a co-author of the study. ‘Having a complete catalog of the genes in Xenopus, along with those of humans, rats, mice and chickens, will help us reassemble the full complement of ancestral vertebrate genes.’Currently, more than 175 organisms – a minute fraction of the world’s life forms – have had their genetic information nearly completely sequenced. But in fact, many of Earth’s creatures are more similar to each other, genetically speaking, than might be guessed just by looking at them. When the scientists compared regions around specific genes in the frog genome to those same regions in chicken and human genomes, they found some amazing similarities, indicating a high level of conservation of organization, or structure, on the chromosomes.

‘When you look at segments of the Xenopus genome, you are literally looking at structures that are 360 million years old and were part of the genome of the last common ancestor of all birds, frogs, dinosaurs and mammals that ever roamed the earth,’ says study leader Uffe Hellsten of the Department of Energy’s Joint Genome Institute in Walnut Creek, California. ‘Chromosome archaeology helps us to understand the history of evolution, showing us how the genetic material has rearranged itself to create the present-day mammalian genome and present-day amphibian genome.’

At least 1,700 genes in the African clawed frog genome are very similar to genes in humans that are associated with specific diseases, such as cancer, asthma, and heart disease. So finding these connections means that experiments on the frogs could help doctors learn more about how to treat those conditions in people.

The frogs’ similarity to humans has come in handy before. In the early 20th century biologists discovered that these frogs were unusually sensitive to human chorionic gonadotropin (HCG), a hormone produced by pregnant women. The frogs gained popularity as a low-cost pregnancy test in the 1940s and 1950s. Doctors would inject a frog with a woman’s urine, and if she was pregnant, the frog would ovulate and produce eggs in eight to ten hours. The new genome could make the species even more useful for research and medicine in the future.

‘Having the genome in hand helps make Xenopus very attractive for the further study of gene organization, regulation and function,’ says co-author Jacques Robert, an immunologist at the University of Rochester Medical Center in Rochester, New York.

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