A recently characterised gene present exclusively in the human genome is thought to have played a crucial role in the development of the unique cognitive characteristics of Homo sapiens that distinguish humans from other primate species. The gene miR-941 encodes a regulatory element made up of Ribonucleic Acid (RNA) that can inhibit the function of specific target genes.
Researchers at the University of Edinburgh identified the exclusivity and heightened expression of miR-941 in humans by comparison of the human genome with genomes of several other mammalian species. It is hypothesised that millions of years ago, following the evolution of humans from apes, the miR-941 emerged from a volatile region of “junk DNA” consisting of tandem repeated sequences. The regulatory RNA species encoded by the resultant miR-941 gene is a micro RNA (miRNA). miRNAs are short strands of nucleic acid that bind to and “silence” specific target genes; the production of proteins from the target gene is therefore inhibited. The miRNA product of the miR-941 gene has been shown to influence cell differentiation and lead to increased maintenance of adult stem cell populations accounting for the longevity of humans. miR-941 also interferes with neurotransmitter signalling thereby impacting on human cognitive function.
The identification of a gene that provides an explanation for the development of unique cognitive characteristics in humans should enhance our understanding of the evolution of humans from apes. Scientists hope that more genes will be identified that may account for attributes that differentiate humans from the rest of the mammalian class. Furthermore, information on the gene abundance in different ethnic groups may shed light onto migratory behaviours of early human beings.