Worm Breeder's Gazette 6(1): 31
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
To study gene expression in embryogenesis, we are isolating clones of C. elegans genes that appear to be regulated in development (WBG 5, #1). We especially want to identify genes that are tissue-specific in their expression. We can obtain such clones by differential plaque hybridization, selecting cloned DNAs that hybridize to RNA from one tissue but not from others. Our plan is to use RNA from dissected tissues of Ascaris, on the assumption that tissue-specific gene products in Ascaris will also be tissue-specific in C. elegans. Hybridizations are carried out under less stringent conditions than used with homologous DNAs, such that 40% of C. elegans DNA can be driven to associate with Ascaris germ line DNA, while E. coli DNA is still unreactive. Radioactive cDNA probes are copied from poly-A RNAs from Ascaris intestine, muscle (with some nerve and hypodermis), ovary and precleavage egg. Complementary sequences in the C. elegans Charon clone library are detected by plaque hybridization on nitrocellulose filters. Some cloned DNAs hybridize to all four cDNAs, but others are tissue-specific, giving positive responses with cDNA from only one or two tissues. So far we have isolated about twenty clones that reproducibly hybridize to transcripts in only one or two of the four dissected tissues. As expected, all these DNAs also hybridize to cDNA copied from C. elegans RNA. We now want to find out whether the expression of these genes is restricted to certain tissues in C. elegans, and when the transcripts arise during development.