Worm Breeder's Gazette 13(1): 59 (October 1, 1993)
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.
We have previously described the cloning of fem-2 (WBG 12#4- p24 ).A plasmid which rescues the mutant phenotype was used to probe B. Barstead's lambda ZAP cDNA library. We were able to isolate 43 positive plaques at a frequency of one in 2000. Of the six characterized so far, four cDNAs map completely within the minimum rescuing region as defined by transformation and represent a single transcription unit. Three slightly different 3' ends have been identified among the four cDNAs. By searching for consensus sequences for donor and acceptor splice sites, we were able to determine the position of three introns within the cDNAs. (see Figure 1)
So far, the predicted fem-2 sequence shows sequence similarity to a number of proteins which binds either phosphate or nucleotide triphosphate groups. The largest open reading frame present is approximately 1.2 kb and has identity to the mammalian protein phosphatase 2C (36% identical and 52% similar over 120 codons), a yeast adenylate cyclase (30% identical and 61% similar over 72 codons) and a lower eukaryotic elongation factor EF1 (30% identical and 58% similar over 46 codons). (see Figure 2) At present, none of the sequenced cDNAs are full length, and determination of the 5' end is underway.
Northern analysis suggests that fem-2 is preferentially expressed during mid larval stages, consistent with temperature shift studies (Kimble,J., Edgar,L., Hirsh,D., 1984.Dev. Biol.105: 234-239). PCR is also being used to analyze fem-2 mutants and early results indicate that most are point mutations with no significant changes in transcript length.