Temporal regulation of six crystallin transcripts during mouse lens development

Abstract

Using the polymerase chain reaction (PCR) and RNA blot analysis. we have examined the differential expression patterns of the γ-crystallins during lens development. Since only four of these genes had been previously characterized, the cDNAs for the remaining two genes. γC and γF, were isolated and sequenced. The steady-state mRNA profiles were then determined by RNA blot analysis of samples from embryonic stages to 180 days after birth, with gene-specific probes for γA, γB, γC, and γD, and a common probe for γE and γF. Due to the paucity of mismatches between the γE and γF-crystallin genes, the PCR technique was exploited to determine their relative abundance. The data showed that while all six γ-crystallin genes were expressed in the embryonic lens, they were differentially regulated during development. At early stages, the levels of γB and γC mRNAs were found to be relatively low in comparison to those for γA, γD, γE and γF. After 30-40 days however, the levels of γA, γE, and γF mRNAs declined rapidly, and the γB, γC and γD transcripts became the major γ-crystallin mRNA species. The utility of the PCR technique in studying the relative abundance of steady-state γ-crystallin mRNAs was also investigated.