New genomic data brings to light diabetes research

Over the past decade, scientists have been building the case for the Nile rat (Arvicanthis niloticus) as the superior rodent for studying human biology. By mapping the entire genome of the Nile rat, researchers can unveil its full potential to expand genetic studies beyond its predecessors, the house mouse (Mus musculus) and the brown rat (Rattus norvegicus). 

Visual representation encoded DNA strands for the Nile rat as it’s being processed by the Bionano optical mapper.

The Nile rat is a modest creature, with coarse, yellow and black hairs and orange patches around its eyes and ears. Also known as the African grass rat, this inconspicuous rodent spends its days nibbling leaves and stems across the vast arid savannas and subtropical terrain of Africa. Unlike the house mouse and brown rat, the Nile rat wakes with the sun and rests at night, making it a promising candidate for circadian rhythms in humans.

In the lab, scientists didn’t expect to find that Nile rats developed type-2 diabetes when fed conventional, high-carbohydrate lab rodent chow. Knowing that disruptions in sleep patterns in humans can be a hallmark symptom of metabolic, cardiovascular, and neurological disorders, scientists needed to investigate the genetic underpinnings of their observations. 

In a recent paper, a group of researchers led by Yury Bukhman at the Morgridge Institute for Research and the Vertebrate Genomes Project, constructed the full genetic code of the Nile rat  by using a unique method that pulls genetic information from both parents of a given individual to get a full record of the Nile rat’s complete set of chromosomes. After comparing their data to other rat species they found 14 genes that were unique to the Nile rat, two of which were directly associated with type-2 diabetes and metabolic dysfunctions.