Cytoplasmic RNA sequences complementary to cloned chick delta-crystallin cDNA show size heterogeneity

Double-stranded complementary DNA (cDNA) sequences were prepared from day-old chick lens total polysomal RNA and inserted into the unique PstI restriction site of the plasmid pBR322. Colonies containing sequences complementary to abundant lens poly(A)-containing RNA sequences were identified by using lens 32P-labelled cDNA. Some of these clones have been characterized as containing delta-crystallin mRNA coding sequences by genomic DNA blot hybridization and RNA blot hybridizations. Hybridization of labelled DNA from such clones to RNA blots detected four size classes of delta-crystallin RNA sequences, although Southern blots indicated that there are probably only two delta-crystallin genes.