MUTATIONS IN SACCHAROMYCES-CEREVISIAE THAT BLOCK MEIOTIC PROPHASE CHROMOSOME METABOLISM AND CONFER CELL-CYCLE ARREST AT PACHYTENE IDENTIFY 2 NEW MEIOSIS-SPECIFIC GENES SAE1 AND SAE3
Ahz. Mckee et N. Kleckner, MUTATIONS IN SACCHAROMYCES-CEREVISIAE THAT BLOCK MEIOTIC PROPHASE CHROMOSOME METABOLISM AND CONFER CELL-CYCLE ARREST AT PACHYTENE IDENTIFY 2 NEW MEIOSIS-SPECIFIC GENES SAE1 AND SAE3, Genetics, 146(3), 1997, pp. 817-834
Two new meiosis-specific genes, SAE1 and SAE3 have been identified in
a screen for mutations that confer an intermediate block in meiotic pr
ophase. Such mutations confer a block to spore formation that is circu
mvented by addition of a mutation that eliminates meiotic recombinatio
n initiation and other aspects of chromosome metabolism, i.e., spo11.
We show that sae1-1 and sae3-1 mutations each confer a distinct defect
in meiotic recombination. sae1-1 produces recombinants but very slowl
y and ultimately to less than half the wild-type level; sae3-1 makes p
ersistent hyper-resected meiotic double-strand breaks and has a severe
defect in formation of recombinants. Both mutants arrest at the pachy
tene stage of meiotic prophase, sae1-1 temporarily and sae3-1 permanen
tly. The phenotypes conferred by sae3-1 are similar to those conferred
by mutation of the yeast RecA homologue DMC1, suggesting that SAE3 an
d DMC1 act at the same step(s) of chromosome metabolism. These results
provide further evidence that intermediate blocks to prophase chromos
ome metabolism cause cell-cycle arrest. SAE1 encodes a 208-residue pro
tein homologous to vertebrate mRNA cap-binding protein 20. SAE3 corres
ponds to a meiosis-specific RNA encoding an unusually short open readi
ng frame of 50 codons.