Head M W, Triplett E L, Clayton R M
Institute of Cell, Animal and Population Biology, University of Edinburgh, United Kingdom.
Exp Cell Res. 1991 Apr;193(2):370-4. doi: 10.1016/0014-4827(91)90109-8.
It is known that delta-crystallin is super-abundant in the early chick lens, but it is found at lower levels in certain other tissues. Ninety-nine percent of the lens delta-crystallin poly(A)+ RNA is from the delta 1-crystallin gene. We report here that the delta 1- and delta 2-crystallin genes are both transcribed in the chick lens and retina throughout embryonic development and that both RNAs are found in embryo adenohypophysis and epiphysis and in day-old posthatch chick tibiofemoral chondrocytes and striated muscle. delta 1-crystallin RNA is more abundant in lens tissues, while delta 2-crystallin RNA is more abundant in all nonlens tissues. However, delta 1-crystallin RNA is processed more efficiently than delta 2-crystallin RNA in all early embryonic tissues examined. A comparison of lens epithelium and fibers established that levels of delta 2-crystallin RNA are the same but those of delta 1-crystallin RNA are over 100-fold higher in fibers compared to epithelial cells. The evidence implies independent regulation both of transcription and of post-transcriptional events for these two genes.
