We owe a great deal to Drosophila, the good old fruit fly and today I was alerted to a new study (published 22 August 2013) whereby the study of Drosophila is giving us a better understanding of the genetic processes governing heart function.
What is of particular interest is that the study involves tiny gene sequences called “small open reading frames” or smORFs. These smORFs encode short chain proteins know as peptides. Most proteins usually contain 500 or more amino acids whereas smORFs encode for peptides with 100 amino acids or less. Peptides perform a range of vital biological and physiological functions, for example you may have heard of penta-peptides which and are often used in cosmetics as they promote collagen production.
This study has enabled researchers to determine the genetic function of a peptide that regulates a calcium pump in the heart muscles of the fruit fly. What is particularly interesting from an evolutionary perspective is that this peptide is exactly the same one also regulates muscle contraction of the human heart, and a smORF has been conserved for more than 500 million years in order to do this – something that has not been shown before. Thus, these smORFs are ancient genetic sequences.
Human and animal genomes contains tens of thousands of normal genes and hundreds of thousands of smORFs, but with a few exceptions, no one knows what they do because their size makes them hard to identify and characterize. Like normal genes some may be functional other may be redundant. The computational work involved in predicting which of these smORFs are made into peptides and which are not is an enormous undertaking and has until now been simply ignored. The new found importance of these t hese tiny genes means that there will be a concerted effort to systematically study them.
