Gene coding for a lens-specific protein, delta-crystallin, is transcribed in nonlens tissues of chicken embryos

The question of whether or not delta-crystallin gene (delta-gene) is transcribed in tissues of chicken embryos other than lens was examined by Northern blot analysis, using cloned delta-crystallin cDNA as a probe. delta-Crystallin mRNA was detected in neural retinas, brains, and limb buds of 3.5-day-old embryos. However, the distribution of delta-gene transcripts is limited to lens only in posthatched chickens. It was indicated that the ratio of large delta-crystallin RNA, probably precursor RNA, to mature delta-crystallin mRNA is always much higher in nonlens tissues.