Some tigers in India look nearly black as their stripes are thick and run into each other. As Gizmodo reports, researchers have now found a genetic change that influences these tigers' stripes.
A team from the US and India collected genetic samples from a dozen of the thick-striped or pseudomelanistic tigers, which they compared to samples from nearly 400 other tigers. As they report in the Proceedings of the National Academy of Sciences, the researchers homed in on missense variant in the Transmembrane Aminopeptidase Q (Taqpep) gene. Changes in this gene, they note, have been linked to other coat patterns among other cats, like domestic tabby cats and king cheetahs.
Further, they found that the captive pseudomelanistic tigers — the trait is found among one wild and three captive tiger populations — all descendants of one tiger who may have introduced the trait into the zoo populations. About a third of tigers in the Similipal Tiger Reserve are pseudomelanistic, the researchers add, noting that the allele could be on its way to fixation.