Worm Breeder's Gazette 11(5): 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.
The X-linked sdc-1 gene is required for the hermaphrodite mode of sex determination and dosage compensation, acting at a point before the divergence of the two pathways. We have previously described (WBG 11(3):28) both the localization of the sdc-1 gene to a 10 kb interval of the cosmid R09G6 and the identification of a single 3.8 kb transcript from the region. This transcript is found at some level in all developmental stages, but is at least 10-fold more abundant in eggs than in any other stage. We have isolated three independent partial cDNA clones of the 3.8 kb transcript (2.2 kb, 2.8 kb and 3.6 kb) from Stewart Kim's mixed-stage library. [Four additional clones that contained double ligation events were also partially characterized.] We have sequenced the largest cDNA, genomic DNA upstream of 5' end of the cDNA, and selected other genomic regions. From this examination we believe the sdc-1 transcript is 3.75 kb in length (not counting the poly A tail) and contains at least 9 exons. sdc-1 encodes a 1203 amino acid protein containing seven TFIIIA-like zinc fingers (A) located in singlets and doublets scattered throughout the first two-thirds of the gene (B). sdc-1 does not appear to contain domains with homology to known transcriptional activating motifs. One additional note: Although we are capable of detecting an SL1 trans-spliced version of the sdc-1 transcript using PCR, primer extension experiments demonstrate that at least 90% of sdc-1 RNA found in embryos extends at least 50 bp upstream of the SL1 trans-splicing site. [See Figure 1]