A group of scientists has identified a gene that is vital for the development of photoreceptor cells in the back of the retina that capture and process light and send signals to the brain to activate vision, according to a study published Tuesday ( 07.12.2022) by the journal Proceedings of the National Academy of Sciences (PNAS).
Scientists at the Center for Genomic Regulation (CRG) in Barcelona -Spain- have discovered that the ‘Srrm3’ gene regulates microexons, small DNA fragments that affect cell function, many of which are found in genes that are crucial for the ability to the cell when processing light and transforming it into vision.
The work revealed that deleting this gene in the zebrafish used in the experiments caused severe visual impairment. According to the publication, Srrm3 in vertebrates regulates alternative splicing, a process that allows cells to make more than one type of protein from a single gene.
“Alternative splicing activity is particularly prominent in neuronal cells, and its misregulation can have a devastating impact on human health, for example in cancer or neurological disorders,” said one of the authors Ludovica Ciampi, from the CRG..
The Srrm3 gene specifically regulates the splicing of microexons, small fragments of DNA that are only 3 to 27 letters long, but which, despite their small size, play a fundamental role in protein and cellular function.
According to Ciampi, retinal cells depend on many unique genes for their development, any one of which can have a mutation that causes disease and vision loss.
One of the most common causes of hereditary vision loss is retinitis pigmentosa, a genetic disorder that in almost half of cases is unexplained, which means that they carry mutations in genes yet to be identified.
The study authors plan further research to assess whether Srrm3 or the microexons involved could explain some of these cases: “Until now, the Srrm3 gene has not been associated with photoreceptor cell development or retinal disease. We are already exploring the role of the gene in patients without a genetic diagnosis,” Ciampi added.
“If we find cases with mutations in this specific gene, or in any microexon of the retina, it could lead us to possible new therapeutic strategies to control the condition,” the expert stressed.