In this post we want to draw some attention to one of the rather unknown but interesting genes that we have encountered, the LRIT2 gene specifically expressed in retina.

Our eyes are specialized sense organs that make it possible to see, keep balance, and maintain the circadian rhythm. Light enters the eye through the pupil, becomes refracted by the lens and reaches the retina where it is absorbed and transduced into nerve signals that are transported by the optical nerve to the visual centers in the brain. The retina consists of neuronal and glial cells connected via synapses, and in this multilayered neural tissue about 65% of all human genes are expressed and almost 400 genes are enriched according to RNA data.

Many of these retina enriched genes are well-known and well-studied, but among them we also find LRIT2 (Leucine rich repeat, Ig-like and transmembrane domains 2) a rather unknown gene with very little data and only transcript evidence in UniProt and no earlier connection to the eye except for a single publication in PubMed that regards its mouse ortholog. That this "Gene Doe" has a function in the retina is strongly suggested by both bulk and single cell RNA seq showing enrichment in retina and enhanced expression in Rod photoreceptor cells, Cone photoreceptor cells, Bipolar cells and Muller glia cells, respectively. Further, LRIT2 clusters together with other genes related to Visual perception and IHC imaging shows the protein being mainly expressed in rods and nerve fibers in retina. Let's see eye to eye and stop turning a blind eye to this protein that deserves a little bit more attention.