Kusumoto K I, Yabe K, Nogata Y, Ohta H
National Food Research Institute, Ministry of Agriculture, Forestry, and Fisheries, Ibaraki, Japan.
Appl Microbiol Biotechnol. 1998 Jul;50(1):98-104. doi: 10.1007/s002530051262.
Part of the nucleotide sequence of the ver-1 homolog in each of two strains of Aspergillus oryzae, Aspergillus sojae, and Aspergillus flavus were compared with two homologs in Aspergillus parasiticus. The homologs in A. oryzae and A. sojae (non-aflatoxin-producers) exhibited an extremely high degree (93.8-99.8% for A. oryzae, and 96.0-99.5% for A. sojae) of sequence identify with that of A. flavus and A. parasiticus. No two strains within the same species, except A. sojae, were identical. No sequence fingerprint was found to distinguish between A. oryzae and A. flavus, or between A. sojae and A. parasiticus. The predicted partial amino acid sequences (181 amino acids) of the ver-1 homologs had at most two amino acid changes relative to A. parasiticus SYS-4 ver-1. Transcripts of ver-1 homologs in the strains of A. oryzae and A. sojae examined were not detected by the polymerase chain reaction coupled with reverse transcription. By Southern analysis, a total of 46 strains of A. oryzae were examined for the presence of the ver-1 homolog. The homolog was detected in 38 strains, but not in 8 strains. Morphologically, strains with and without the ver-1 homolog were indistinguishable. Thus, A. oryzae contains strains with and without a homolog of the aflatoxin biosynthetic gene ver-1.
对米曲霉、酱油曲霉和黄曲霉的两个菌株中ver-1同源物的部分核苷酸序列，与寄生曲霉中的两个同源物进行了比较。米曲霉和酱油曲霉（非黄曲霉毒素产生菌）中的同源物与黄曲霉和寄生曲霉的同源物表现出极高的序列同一性（米曲霉为93.8 - 99.8%，酱油曲霉为96.0 - 99.5%）。除酱油曲霉外，同一物种内的菌株之间不存在完全相同的情况。未发现可区分米曲霉和黄曲霉，或酱油曲霉和寄生曲霉的序列指纹。相对于寄生曲霉SYS-4 ver-1，ver-1同源物预测的部分氨基酸序列（181个氨基酸）最多有两个氨基酸变化。通过逆转录聚合酶链反应未检测到所检测的米曲霉和酱油曲霉菌株中ver-1同源物的转录本。通过Southern分析，对总共46株米曲霉检测了ver-1同源物的存在情况。在38株中检测到了该同源物，8株中未检测到。在形态学上，有和没有ver-1同源物的菌株无法区分。因此，米曲霉中既有含有黄曲霉毒素生物合成基因ver-1同源物的菌株，也有不含有该同源物的菌株。
