REGULATION OF GENE-EXPRESSION DURING MEIOSIS IN SACCHAROMYCES-CEREVISIAE - SPR3 IS CONTROLLED BY BOTH ABFI AND A NEW SPORULATION CONTROL ELEMENT

The SPR3 gene encodes a sporulation-specific homolog of the yeast Cdc3 /10/11/12 family of bud neck filament proteins, It is expressed specif ically during meiosis and sporulation in Saccharomyces cerevisiae. Ana lysis of the sporulation-specific regulation of SPR3 has shown that it is strongly activated under sporulating conditions but shows low leve ls of expression under nonsporulating conditions. A palindromic sequen ce located near the TATA box is essential to the developmental regulat ion of this gene and is the only element directly activating SPR3 at t he right time during sporulation, Within the palindrome is a 9-bp sequ ence, gNCRCAAA(A/T) (midsporulation element [MSE]), found in the known control regions of three other sporulation genes. A previously identi fied ABFI element is also needed for activation, The MSE has been show n to activate a heterologous promoter (CYC1) in a sporulation-specific manner. Related sequences, including an association of MSE and ABFI e lements, have been found upstream of other genes activated during the middle stage of S. cerevisiae sporulation, One group of these may be i nvolved in spore coat formation or maturation.