O'Hara E B, Timberlake W E
Department of Genetics, University of Georgia, Athens 30602.
Genetics. 1989 Feb;121(2):249-54. doi: 10.1093/genetics/121.2.249.
We investigated the molecular organization of the region of Aspergillus nidulans chromosome I containing yA, a gene encoding the developmentally regulated enzyme conidial laccase. DNA fragments were identified that complemented the yA2 mutation and were shown to correspond to yA by genetic mapping and gene disruption experiments. The molecular map of the region was oriented to the genetic map by testing DNA fragments for their ability to complement a mutation in the tightly linked adE gene. The yA gene codes for a 2200 nucleotide mRNA that is present at low levels in vegetative cells and mature conidia, but accumulates to high levels in sporulating cultures. yA mRNA appears shortly after differentiation of sporogenous phialide cells. It accumulates in two developmentally abnormal mutant strains that produce phialides but is absent from two mutant strains that do not produce phialides. Thus, yA transcription is probably restricted to phialides. This result is discussed in relationship to the physiological roles played by phialides in spore differentiation.
我们研究了构巢曲霉染色体I上包含yA的区域的分子组织，yA是一个编码发育调控酶分生孢子漆酶的基因。鉴定出了能互补yA2突变的DNA片段，并通过遗传作图和基因破坏实验表明其与yA相对应。通过检测DNA片段互补紧密连锁的adE基因突变的能力，将该区域的分子图谱与遗传图谱进行了定位。yA基因编码一种2200个核苷酸的mRNA，其在营养细胞和成熟分生孢子中含量较低，但在产孢培养物中积累到较高水平。yA mRNA在产孢瓶梗细胞分化后不久出现。它在两种产生瓶梗的发育异常突变菌株中积累，但在两种不产生瓶梗的突变菌株中不存在。因此，yA转录可能仅限于瓶梗。结合瓶梗在孢子分化中所起的生理作用对这一结果进行了讨论。
