Horwitz B A, Sharon A, Lu S W, Ritter V, Sandrock T M, Yoder O C, Turgeon B G
Department of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Fungal Genet Biol. 1999 Feb;26(1):19-32. doi: 10.1006/fgbi.1998.1094.
A Galpha subunit-encoding gene (CGA1) was cloned from Cochliobolus heterostrophus, a heterothallic foliar pathogen of corn. The deduced amino acid sequence showed similarity to Galpha proteins from other filamentous fungi and suggested that CGA1 is a member of the Galphai class. cga1 mutants had reduced ability to form appressoria on glass surfaces and on corn leaves; mutants nevertheless caused lesions on corn plants like those of wild type. cga1 mutants were female sterile; sexual development was completely abolished when the mutant allele was homozygous in a cross. Ascospores produced in crosses heterozygous at Cga1 were all wild type. The signal transduction pathway represented by CGA1 appears to be involved in developmental pathways leading to either appressorium formation or mating; in sexual development CGA1 is required for both fertility and ascospore viability.
从玉米的异宗配合叶部病原菌玉米大斑病菌（Cochliobolus heterostrophus）中克隆到了一个编码Gα亚基的基因（CGA1）。推导的氨基酸序列与其他丝状真菌的Gα蛋白具有相似性，表明CGA1是Gαi类的成员。cga1突变体在玻璃表面和玉米叶片上形成附着胞的能力降低；然而，突变体仍能像野生型一样在玉米植株上引起病斑。cga1突变体雌性不育；当突变等位基因在杂交中纯合时，有性发育完全被阻断。在Cga1位点杂合的杂交中产生的子囊孢子均为野生型。由CGA1代表的信号转导途径似乎参与了导致附着胞形成或交配的发育途径；在有性发育中，CGA1对育性和子囊孢子活力都是必需的。
