Expression pattern and in situ localization of the mouse homologue of the human MYOC (GLC1A) gene in adult brain

The MYOC (GLC1A) gene has recently been associated with both juvenile-onset primary open angle glaucoma (JOAG) and typical late-onset primary open ang le glaucoma (POAG). As a result, much scrutiny has been focused on the path ology of these diseases. In order to better understand the pathophysiology of POAG, we have been developing a mouse model of the disease. As a step in this development, we have investigated the expression pattern of Myoc tran scripts in embryonic and adult mouse tissue using Northern blot and in situ hybridization analyses. Myoc transcripts were found in high levels in adul t eye, heart, brain, skeletal muscle and testis and to a lesser extent in l ung and kidney, They were also present, albeit in very low amounts, during mouse embryogenesis. We present new evidence using in situ hybridization an alysis that Myoc transcripts were present in widespread regions of the adul t brain including the ependymal Lining of the third and fourth ventricles, in the choroid plexus, the zonal layer of the junction of the inferior and superior colliculi, the neurons of the habenula, the piriform cortex, the m edian pre-optic nucleus of the hypothalamus, the olfactory tubercle, and in the inferior olive. In a functional sense, Myoc expression in the ependyma and choroid plexus, two regions of the brain involved in cerebrospinal flu id synthesis and resorption, parallels Myoc expression in the ciliary body and trabecular meshwork of the anterior segment of the eye where aqueous hu mor synthesis and outflow occur. (C) 1999 Published by Elsevier Science B.V . All rights reserved.