March 14, 2007

WHICH WOULD BE MORE IMPRESSIVE IF TIGERS AND LIONS WERE SEPARATE SPECIES:

Big cat found on islands is entirely new species (Steve Connor, 15 March 2007, Independent)

A rare leopard found on the islands of Borneo and Sumatra turns out to be an entirely new species of large cat according to a study of the feline's DNA.

The secretive clouded leopard which lives in remote rainforests was thought to be the same species as leopards on mainland south-east Asia.

However, scientists from the US National Cancer Institute who analysed the cat's DNA found that the differences between the two types of leopard are about as great as the differences between other feline species such as lions and tigers.


Genetic diversity in domestic cats Felis catus of the Tsushima Islands, based on mitochondrial DNA cytochrome b and control region nucleotide sequences. (Tamada T, Kurose N, Masuda R., Division of Bioscience, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan.)
Nucleotide sequences of mitochondrial DNA (mtDNA) of 50 domestic cats (Felis catus) obtained from the Tsushima Islands were determined and the genetic diversity was analyzed. In the cats, six haplotypes of the complete cytochrome b sequences (1,140 base-pairs, bp) and ten haplotypes of the partial control region sequences (350 bp) were identified. Haplotypes obtained from both genes showed existence of at least 11 maternal lineages of domestic cats in Tsushima. Mean values of polymorphic site numbers and sequences differences in the control region were 2.4 times and 1.8 times higher than those in the cytochrome b gene, respectively. Our results support the idea that the evolutionary rate of the control region was faster than that of the cytochrome b as reported in other mammals. Molecular phylogenetic trees showed the similar clustering of haplotypes for both genes. Meanwhile, no individual variations within the Tsushima leopard cat (Felis bengalensis euptilura), which is native to Tsushima, were observed, possibly as a result of genetic drift in the small ancestral population by geographical isolation. In contrast, the diversity of the domestic cat population was higher than that of the leopard cats, because the genetic variability of the former's founders, which were repeatedly brought to Tsushima in the past, still remains. In addition, no sequences of the leopard cat mtDNA were detected in any domestic cats. However, because the possibility that the domestic cat would crossbreed with the leopard cat cannot be denied, genetic monitoring of two species is necessary to biological conservation in Tsushima.

Posted by Orrin Judd at March 14, 2007 8:58 PM
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