Role of Epigenetics in eye loss occurs in blind cavefish

According to a study led by the National Institutes of Health, epigenetic silencing of eye-related genes causes loss of eye tissue in blind Cavefish (Astyanax mexicanus). Typically in a reversible or temporary manner genes are turned off or on by the epigenetics regulation process. A mexicanus may be a tropical freshwater fish native to North American nation. Some million years ago, a number of these fish presumptively got trapped in dark caves and gave rise to fully completely different varieties, or "morphs," that lack eyes and have many alternative distinctive physical, behavioural and physiological changes. Despite their dramatic variations, surface and cave morphs share similar genomes and may interbreed. Cave morphs begin eye development early however fail to keep up this program, undergoing eye degeneration within a couple of days of development. Previous analysis has not discovered any obvious mutations in genes vital for his or her eye development.

Morden study, conducted by researchers at the University of Maryland, college Park and also NICHD, shows that epigenetics-based silencing of a large set of genes limits the eye development of cave-dwelling A. mexicanus fish. Twenty-six of those genes also are expressed in human eyes, and nineteen are connected to human eye disorders. The study team found additional DNA methylation of eye development genes and subsequently, less activity of those genes in cavefish. DNA methylation is an epigenetic method in which DNA is changed with tags known as methyl groups. The authors found that cavefish have higher levels of a DNA methyltransferase, referred to as DNMT3B, in their developing eyes. Once, DNMT3B is mutated in other kind of fish with eyes, zebrafish, they found that the mutant zebrafish have additional active eye genes and bigger eyes.

For more details: https://epigenetics.geneticconferences.com/