"Understanding how sloths maintain health with the slowest metabolism of any mammal could inform research into human conditions involving mitochondrial dysfunction."

Sloth Genetics Reveal 'Jumping Genes' That Enabled an Ultra-Slow Lifestyle

A genetic study of the two-toed sloth (Choloepus didactylus) has identified DNA sequences, known as transposons or 'jumping genes', that may have enabled the evolution of its extremely slow metabolism and low-energy lifestyle.

Methodology

An international team compared the sloth genome with dozens of other mammals, including anteaters and armadillos. They focused on transposons, which are DNA sequences that can move or copy themselves within the genome.

Key Findings

The analysis revealed transposon activity stretching back over 30 million years, originating in a common ancestor of modern sloths after they diverged from anteaters and armadillos. Several transposons were linked to mitochondrial genes and other metabolism-related genes.

Researchers proposed that sloths may have evolved genetic 'backup systems' that compensate for 'relaxed mitochondria' – mutations that accumulated in mitochondrial genomes due to low energy demands.

Broader Significance

Understanding how sloths maintain health with the slowest metabolism of any mammal could inform research into human conditions involving mitochondrial dysfunction. These include:

• Diabetes
• Aging-related disorders
• Neurodegeneration
• Muscle wasting
• Parkinson's disease

Future Research

Further studies are needed to determine the biological function of these conserved transposons and their role in mitochondrial and metabolic regulation. Sloth cell lines may serve as a model for low-energy states.

The research was published in BMC Biology.