Azadi S, Zhang Y, Caffé A R, Holmqvist B, van Veen T
Department of Ophthalmology, Biomedical Center, University of Lund, Klinikgatan 26, S-221 84 Lund, Sweden.
Neuroreport. 2002 May 7;13(6):745-50. doi: 10.1097/00001756-200205070-00003.
In neonatal retinal explants cultured long-term green cones are missing. Recently it was reported that thyroid hormone beta2 receptors (TR-beta2) are essential for these green cones to differentiate. Therefore transcript level of these receptors was investigated in our mouse retinal explants. However, thyroid receptors function as heterodimers with retinoid receptors (RR); so the fate of selected RRs was similarly analyzed using semi-quantitative RT-PCR. Loss of TR-beta2 and RR (RXR-gamma and ROR-beta2) mRNAs was observed after culturing the neonatal retina for 12 days. This indicates that these proteins are involved in determination of green cone identity. In addition, levels of the selected RR transcripts are differentially affected by short- or long-term culture. In the latter case an attached retinal pigment epithelium seems to play a protective role. Furthermore, divergent diurnal peaks of RR mRNAs are present in young as well as aged mouse retina and neocortex. This data might be relevant in the context of human ageing disorders.
