Worm Breeder's Gazette 9(1): 17
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 free-living nematode Caenorhabditis a sperm specific protein implicated in the pseudopodial movement of the amoeboid sperm. It is encoded by a large (30 member) multigene family. Only a few members of this family are non-transcribed pseudogenes while most of the other members are transcribed. This multigene family is exceptional in that the different MSP genes exhibit the same temporal and spatial regulation. All of the active MSP genes are transcribed during spermatogenesis in the gonad. In an attempt to determine the basis for this tissue specific regulation we have performed a sequence comparison of the 5 flanking regions of a large number of the MSP genes. Utilizing the fact that the structural sequence of the MSP genes are >90% homologous we used a synthetic oligonucleotide (a gift from D. Hirsh) as a sequencing primer for all of the MSP genes. The nucleotide sequence was determined for the first 250 nucleotides 5' of the translation initiation codon. As shown below in figure 1 all of the sequences examined demonstrated a high degree of homology for the first 100 nucleotides 5' of the AUG start codon. There are four highly conserved regions in the 5' flanking region of all of the MSP genes examined. The first is the sequence CCATGG encompassing the translational start codon. This sequence is found in all MSP genes with three notable exceptions where a GUG has replaced the AUG start codon. The second highly conserved sequence is CATAATCTTCA found immediately 5' of the transcription initiation site 35 nucleotides from the translational start codon. Third is the highly conserved sequence TATAAA located 66 nucleotides from the AUG start codon. The last highly conserved sequence is AGATCT (the MSP box) located 94 nucleotides from the translational start. Not only are these sequences highly conserved but their spacing is extremely constant varying only one or two nucleotides. This data is summarized in figure 2. Another interesting observation is that further 5' of the MSP box all sequence homology falls off dramatically with a very high AT content (>70%) being observed. Attempts to utilize this information in an in situ promoter assay are continuing. [See Figure 1] [See Figure 2]