van de Rhee M D, Mendes O, Werten M W, Huizing H J, Mooibroek H
DLO-Institute for Agrotechnological Research (ATO-DLO), Wageningen, The Netherlands.
Curr Genet. 1996 Jul 31;30(2):166-73. doi: 10.1007/s002940050116.
Homologous integration was studied in the common mushroom, Agaricus bisporus, using a plasmid (pHAG3-1) carrying the hygromycin-resistance gene and a 3.2-kb genomic fragment from A. bisporus. Homologous integration was found in 30-60% of the transformants obtained with pHAG3-1 linearized at three different positions within the homologous sequence, generating either blunt, 5'- or 3'-protruding ends. The genomic fragment was found to contain two homologous open reading frames in tandem, which showed 60% similarity to exo-beta-1,3-glucanases from Saccharomyces cerevisiae and Candida albicans. The level of the corresponding mRNA is low in the vegetative mycelium and relatively high in fruiting bodies. In the vegetative mycelium of a transformant with tandemly integrated pHAG3-1 plasmids at the homologous position, exoglucanase mRNA was strongly increased without any apparent effect on growth rate or morphology.
利用携带潮霉素抗性基因的质粒（pHAG3 - 1）和双孢蘑菇的一个3.2 kb基因组片段，在双孢蘑菇中研究了同源整合。在用在同源序列内三个不同位置线性化的pHAG3 - 1获得的转化体中，30% - 60%发现了同源整合，产生平端、5' - 或3' - 突出端。发现该基因组片段包含两个串联的同源开放阅读框，与酿酒酵母和白色念珠菌的外切β - 1,3 - 葡聚糖酶显示出60%的相似性。相应mRNA的水平在营养菌丝体中较低，在子实体中相对较高。在同源位置串联整合有pHAG3 - 1质粒的转化体的营养菌丝体中，外切葡聚糖酶mRNA强烈增加，而对生长速率或形态没有任何明显影响。
