The function of the coding sequences for the putative pheromone precursors in Podospora anserina is restricted to fertilization
The function of the coding sequences for the putative pheromone precursors in Podospora anserina is restricted to fertilization
复制标题
DOI：
10.1128/ec.4.2.407-420.2005
复制
发表时间：
2005-02-01
期刊：
影响因子：
--
通讯作者：
Debuchy, R
中科院分区：
文献类型：
--
作者：
Coppin, E;de Renty, C;Debuchy, R
我们克隆了柄孢壳菌（Podospora anserina）的信息素前体基因，以阐明它们在这种真菌生物学中的作用。mfp基因编码一个由24个氨基酸组成的多肽，其末端为CAAX基序，这是真菌脂肽信息素前体的特征，类似于酿酒酵母（Saccharomyces cerevisiae）的a - 因子前体。mfm基因编码一个由221个氨基酸组成的多肽，它与酿酒酵母的a - 因子前体相关，并包含两个13个残基的重复序列，推测其对应于成熟信息素。我们通过基因置换删除了mfp和mfm的编码序列。这些突变特异性地影响雄性育性，而不损害雌性育性和营养生长。雄性缺陷具有交配型特异性：mat + Δmfp和mat - Δmfm突变体产生在受精过程中无活性的雄性细胞，而mat - Δmfp和mat + Δmfm突变体表现出正常的雄性育性。遗传学数据表明，mfp和mfm在mat + 和mat - 营养菌丝中均以低水平转录。Northern杂交分析表明，它们的转录在小分生孢子中受交配型诱导（mfp由mat + 诱导，mfm由mat - 诱导）。我们通过信息素前体基因的互补和瞬时表达来触发受精，成功地使交配型相反的Δmfp Δmfm菌株杂交。这些杂交是可育的，这表明一旦受精发生，信息素前体基因对于有性生殖周期的完成是不必要的。最后，我们表明组成型转录的gpd::mfm和gpd::mfp构建体在转录后水平上被非同源交配型抑制。
We cloned the pheromone precursor genes of Podospora anserina in order to elucidate their role in the biology of this fungus. The mfp gene encodes a 24-amino-acid polypeptide finished by the CAAX motif, characteristic of fungal lipopeptide pheromone precursors similar to the a-factor precursor of Saccharomyces cerevisiae. The mfm gene encodes a 221-amino-acid polypeptide, which is related to the S. cerevisiae a-factor precursor and contains two 13-residue repeats assumed to correspond to the mature pheromone. We deleted the mfp and mfm coding sequence by gene replacement. The mutations specifically affect male fertility, without impairing female fertility and vegetative growth. The male defect is mating type specific: the mat+ Deltamfp and mat- Deltamfm mutants produce male cells inactive in fertilization whereas the mat- Deltamfp and mat+ Deltamfm mutants show normal male fertility. Genetic data indicate that both mfp and mfm are transcribed at a low level in mat+ and mat- vegetative hyphae. Northern-blot analysis shows that their transcription is induced by the mating types in microconidia (mfp by mat+ and mfm by mat-). We managed to cross Deltamfp Deltamfm strains of opposite mating type, by complementation and transient expression of the pheromone precursor gene to trigger fertilization. These crosses were fertile, demonstrating that once fertilization occurs, the pheromone precursor genes are unnecessary for the completion of the sexual cycle. Finally, we show that the constitutively transcribed gpd::mfm and gpd::mfp constructs are repressed at a posttranscriptional level by the noncognate mating type.