The effect of the butterfly

A mutation was found that gave rise to a dark variety of birch pills

The insightful Karl Linney, who first described this butterfly, christened her Biston Betularia (Latin Betula - Birch). The generic name comes from the name of Biston - the mythical ancestor of the Thracian, known for its militancy and love for tattoos. Biston was the son of Ares, the god of war, and a modest night butterfly named in his honor, for more than a century, causes boiling disputes.

In 1848, a dark variety of birch backwaters was first seen in Manchester. Its distribution coincided with the peak of the English industrial revolution, and the subsequent fight against air pollution caused a decrease in the share of the dark variety in the population. As it turned out, the air pollution killed light lichens, against which the usual recesses were invisible to birds; Against the background of the bare trunks, dark butterflies turned out to be more invisible. This story entered the textbooks as a classic example of natural selection, however, the ignorance of journalists and their love for “refutations of evolution” for many years made a birch background of creationists' favorite target (about this, see [1]). The situation was overshadowed by the fact that, despite the more than a century of study, the molecular mechanisms of this adaptation could not be established. Until recently.

Last week, the results of two independent studies were published in Nature magazine. According to one of them, a dark variety of birch pills arose thanks to a mutation in the non -dodging part of the Cortex gene [2]. The results of the second study show that the variants of this gene determine the color of the wings in many other types of butterflies, which indirectly confirms the correctness of the first work [3]. The mysterious mutation, which caused a change in the coloring of the birch background, turned out to be an insert of the “jumping gene” - the transposon.

It is funny that the very discovery of “jumping genes” was also associated with their ability to influence coloring. Barbara McClintka discovered transposons in the genome of corn, studying the causes of mosaic ears. Subsequently, the transposons were found in the genomes of most organisms, including in the human genome. However, as a rule, the insertion of a new transposon either does not have functional consequences, or leads to a gene breakdown, provoking, for example, diseases such as the rectum and hemophilia cancer. The history of the birch pile contains a rare example of a useful transposon, which not only does not spoil the functional sequence, but even enhances the expression of the host gene. This discovery again returns a birch pile on the advanced evolutionary biology.

Zoya Chervontseva

1. Glagolev S. M. The most popular butterfly of the world // "New Gazeta" No. 20 of February 27, 2009.

2. Vanomet Hof ae et al. The Industrial Melanism Mutation in British Peppered Moths is a Transposable Element // Nature. 2016. 534 (7605): 102-105.

3. Nadeau nj, et al. The Gene Cortex Controls Mimicry and Crypsis in Butterfies and Moths // Nature. 2016. 534 (7605): 106-110.