The one with the smallest DNA sequence of all animals is an insect found in the south pole: the Antarctic midge. Small as it is, of length 2-6 millimeters long, this wingless insect has been endowed with the capability of surviving in the extreme environmental conditions of Antarctica.
Their DNA is made up of only around 99 million base pairs of nucleotidess. To appreciate the smallness better, compare this digit to that of humans: we have approximately 3.2 billion base pairs in our haploid genome. Other insects like the body lice have 105 million base pairs. The small genome has so far proved to be enough for the midge to get through the not-so-friendly conditions of Antarctica. It has been suggested that the tiny genome might, in fact, be the result of the harsh environment.
The life of the Antarctica midge
Their larval stage lasts for two years. They remain in this state in the frozen ice. When they reach the adult phase, they come out to live a life of approximately 10 days. During this short span of time, they mate and the females lay their eggs. At this stage of their life cycle, they have to face intense ultraviolet radiation. When they are exposed to the extreme light condition, they lose around three-quarter of the water making up their cells: amazingly, they are able to withstand such a great loss.
Their special abilities are conferred onto them by their genes, most of which account for their developmental processes and regulation.
Another particular aspect of the midge is that as a larva, it can synthesize heat shock proteins. Additionally, it can also detect odor.
The midge raised more questions about life in Antarctica
The midge has made scientists curious as to the other insects living near the south pole. Do they also have this kind of genome? Is a tiny genome a specific characteristic of the insects living in the southern part of the globe? More studies will have to be done to reply to these questions.