A first step towards a molecular analysis of meiosis in any organism, is the cloning of meiosis specific genes from that organism. In order to clone genes involved in meiosis in the filamentous fungus A. nidulans several different strategies can be followed. The strategy that will be discussed here, is transformation complementation of mutants defective in meiosis. In A. nidulans two classes of such mutants exist. The first class consists of mutants that are both defective in the repair of DNA damage as well as in meiosis. Mutants in the A. nidulans uvsC gene have such a phenotype. We will describe the cloning of the uvsC gene of A. nidulans by transformation complementation of an A. nidulans uvsCII4 mutant. Sequence analysis of the smallest fragment still giving full complementation, revealed strong homology of the predicted protein sequence with all known RAD51 homologs. The second class are meiosis specific mutants. Since these were not already available in A. nidulans, we have set up a screening to isolate such mei mutants. One of them, meiAl, has been cytologically characterized and seems to be blocked at one of the later stages of the first meiotic division. We will report the cloning and characterization of the corresponding wild type meiA gene, which we are currently undertaking.
Full conference title:
3rd EUROPEAN CONFERENCE ON FUNGAL GENETICS
- ECFG 3rd (1996)