The following studies have been carried out:
Cloning Drosophila cdc genes in yeast (cdcDm genes):
Using a complementation strategy, a Drosophila cdc2 homologue was identified which was able to rescue a cdc2ts Schizosaccharomyces pombe mutant. Similar complementation screens were carried out in mutant strains of S. pombe with the aim of isolating Drosophila cdc25 and wee1 homologues. An embryonic complementary deoxyribonucleic acid (cDNA) library which could be expressed in S. pombe was screened for various plasmids encoding various proteins or factors involved in cell cycle control.
Study of the cdcDm gene in Drosophila:
Two cdc25Dm genes have been identified, namely string and twine. Using in situ hybridization techniques, string but not twine transcripts were detected in proliferating cells of newly cellularized embryos, in third instar larval brains, and in imaginal discs. Both genes were abundantly expressed in nurse cells during oogenesis, the maternal transcripts persisting throughout the syncytial state of the embryonic development. In testis, twine transcripts were seen in the growing state of the premeiotic cysts. Using labelled twine cDNA, the twine loci has been mapped, and mutants with a deletion into this locus have been found. Analysis of twine mutants suggest a requirement for the gene during oogenesis, during syncytial embryonic development, and for male meiosis.
Study of the cdcDm gene in fission yeasts:
Transgenic yeasts, where the yeast cdc2 is replaced by the fly cdc2Dm homologue, were constructed in order to study the function and expression of these Drosophila cdc genes in yeasts.
For a better understanding of the molecular mechanism regulating wee1 protein kinase, a new gene has been isolated from fission yeasts, namely wos2, which is able to suppress the lethal effects of the overexpression of wee1. The sequence of wos2 showed no similarity to any known gene. The protein sequence showed some guanine rich domains, present in chaperons and heat shock proteins, suggesting that this may function as a protein kinase modulator.
Funding SchemeCSC - Cost-sharing contracts
DD1 4HN Dundee
OX1 3QU Oxford