Worm Breeder's Gazette 14(4): 37 (October 1, 1996)
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.
Department of Insect Physiology and Behavior, National Institute of Sericultural and Entomological Science, Tsukuba, Ibaraki 305, Japan
ASABF is an antibacterial peptide in the body fluid of the intestinal parasitic nematode Ascaris suum [Moore et al., wbg 13(2), 25; Kato, wbg 14(2), 32]. The mature ASABF-alpha (previously designated as ASABF) of 71 residues is processed from the 93-residue precursor deduced from a cDNA clone. A C-terminally flanked four-residue peptide is thought to be removed in addition to the elimination of a putative signal peptide by the processing (Kato and Komatsu, J. Biol. Chem., in press). A cDNA for ASABF-alpha was cloned using three-step PCR amplification; (1) RT-PCR using the poly(A)+ RNA isolated from the body walls of the adult female A. suum as templates, (2) 5'-RACE using SL1 primer, and (3) 3'-RACE. In each step, the PCR-products were cloned into the pGEM-T vector. Recently, further analyses of the clones revealed three novel cDNA coding quite similar to the amino acid sequence of ASABF-alpha. They were designated as ASABF-beta, gamma, and delta. The mRNAs for these four ASABFs (alpha-delta) were detected in an individual using RT-PCR with specific primers. These results suggest that ASABF forms a multigene family. However, only the alpha and delta products have been so far detected in the body fluid. The physiological importance of this family formation is under examination. Furthermore, the ASABF homologs in C. elegans were searched. BLAST data base searches revealed significant sequence identity with a deduced protein from the cDNA sequence, yk150c7, in the cDNA catalog by Prof. Yuji Kohara. In addition, the protein deduced from the putative gene, T22H6.5, was found to be a protein most similar to both ASABF and yk150c7 using the MPsrch data base search. The transcript for T22H6.5 was detected using RT-PCR with total RNA from mix-stage worms as templates. The sequencing of the PCR-product revealed that the splicing deduced by GeneFinder occurred. The analyses of the gene regulation of T22H6.5 is currently progressing. Acknowledgement- We thank Prof. Yuji Kohara (National Institute of Genetics) for permission to cite yk150c7 from his unpublished data.