The tiger. Magnificent. Powerful. Sleek. A symbol of majestic grace and elegant beauty.

Unfortunately, the very survival of the tiger is threatened. The global tiger population has plummeted from more than a 100 000 animals a century ago to just over 3 000 today. It is estimated that there are only 50 wild tigers left in the whole of China.

To date, the tiger genome has not been sequenced, and the only genetic information of this species available on public databases is confined mostly to Major Histocompatibility Complex (MHC) regions and mitochondrial sequences. The MHC is a large genomic region found in most vertebrates. In mammalian genomes, this region is highly dense with genes and plays a vital role in the immune system.

MHC genes encode for proteins that enable the immune system to recognise foreign invaders; the more diverse the MHC genes of the parents, the stronger the immune system of the offspring. The role of MHC proteins in the rejection or acceptance of tiger embryos in surrogates has only recently been studied.

An interesting conservation method is the use of inter- and intra-species surrogates, whereby an embryo is transplanted into another tiger or a member of a closely-related cat species. In these situations rejection of the embryo is highly dependent on the potential immune response.

We will explore how analysis of the MHC class genes and proteins can help save the tiger.

SynaSearch™ can be used to find homologous proteins in the tiger’s MHC. Knowing such homologies may help boost conservation efforts by helping identify surrogates that are less likely to reject implanted embryos.

Click here, then click on .

From the result, the next closest match belongs to Pallas’s cat and subsequently, the leopard. It is also interesting to note that there is one match to Homo sapiens too!

References:

1) Shu-Jin Luo, Jae-Heup Kim, et al. Phylogeography and Genetic Ancestry of Tigers (Panthera tigris) PLoS Biol. 2004 December

2) Belov, Katherine; Janine E. Deakin, Anthony T. Papenfuss, et al. (March 2006). “Reconstructing an Ancestral Mammalian Immune Supercomplex from a Marsupial Major Histocompatibility Complex”. PLoS Biol4(3) (e46): e46. doi:10.1371/journal.pbio.0040046

3) Meghan M. Smith, Susan M.G. Hoffman. A class I MHC locus compared among felid species. Mammalian Genome 12, 394-396 (2001)