Independent regulation of two coexpressed delta-crystallin genes in chick lens and nonlens tissues.
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.
Head
M W
MW
Institute of Cell, Animal and Population Biology, University of Edinburgh, United Kingdom.
Triplett
E L
EL
Clayton
R M
RM
D000818:Animals; D015152:Blotting, Northern; D002642:Chick Embryo; D002645:Chickens; D003459:Crystallins / Q000145:classification / Q000235:genetics*; D015342:DNA Probes; D015870:Gene Expression; D007908:Lens, Crystalline / Q000502:physiology*; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes; D010857:Pigment Epithelium of Eye / Q000502:physiology; D010902:Pituitary Gland / Q000502:physiology; D012160:Retina / Q000502:physiology
D003459:Crystallins; D015342:DNA Probes; D015345:Oligonucleotide Probes