Worm Breeder's Gazette 11(1): 30
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.
With the exception of the SL RNA genes, the snRNA genes of C. elegans are typical of those found in other lower eukaryotes. Most of the snRNAs are specified by small, disperse gene families. U1: The genome contains about 11 genes. We've cloned one (rsn-11) on chromosome I, and two others are found at the borders of the hsp-16 duplication on chromosome V(Russnak and Candido, 1985, MCB 5, 1268). U2: About 12 genes. We've cloned 10, which are found as a cluster of 3 (rsn-1) on chromosome IV, a pair (rsn-2) on the X, another pair ( rsn-3) at a still unidentified location, a single gene (rsn-4) on V, and two other single genes (rsn-5 and -6) not yet mapped. U4: About 6 genes. We've cloned 3: a pair (rsn-8) on V and a single gene (rsn-9) not yet mapped. U5: About 9 genes. We cloned 1 (rsn-10) located on chromosome IV and a pseudogene (rsn-12) located elsewhere. U6: About 10 genes. We cloned a pair (rsn-7) located on chromosome V. SL1 RNA: About 110 genes found on the 5S rRNA repeat on chromosome V (Krause and Hirsh, 1987, Cell 49,753) SL2 RNA: The genome contains 4 genes (Huang and Hirsh, personal communication). They have cloned 2, and mapped one of those to chromosome 11. The lengths of the C. elegans snRNAs predicted by the gene sequences and confirmed by Northern blots and primer extension sequencing are quite similar to those of other higher organisms. The U4/U6 structure was reported previously (Zucker-Aprison, Thomas and Blumenthal, 1988, NAR 16, 7188). The likely structures for U1, U2, and U5 are shown below. Microheterogeneity among the U1 and U2 genes ( and presumably RNAs) is indicated by showing all known bases that have been found in at least one cloned gene or in the RNA by primer extension. [See Figures 1-2]