Department of Biochemistry, University of Turku, FI-20014 Turku, Finland.
Department of Chemistry, Faculty of Science, Sohag University, Sohag 82524, Egypt.
Toxins (Basel). 2020 Jan 16;12(1):56. doi: 10.3390/toxins12010056.
Aflatoxins (AF) are highly toxic compounds produced by section . They spoil food crops and present a serious global health hazard to humans and livestock. The aim of this study was to examine the phylogenetic relationships among aflatoxigenic and non-aflatoxigenic isolates. A polyphasic approach combining phylogenetic, sequence, and toxin analyses was applied to 40 section isolates collected from eight countries around the world (USA, Philippines, Egypt, India, Australia, Indonesia, China, and Uganda). This allows one to pinpoint the key genomic features that distinguish AF producing and non-producing isolates. Based on molecular identification, 32 (80%) were identified as three (7.5%) as three (7.5%) as and one (2.5%) as Toxin analysis showed that 22 (55%) isolates were aflatoxigenic. The majority of the toxic isolates (62.5%) originated from Egypt. The highest aflatoxin production potential was observed in an isolate which is originally isolated from the Philippines. DNA-based molecular markers such as random amplified polymorphic DNA (RAPD) and inter-simple sequence repeats (ISSR) were used to evaluate the genetic diversity and phylogenetic relationships among these 40 isolates, which were originally selected from 80 isolates. The percentage of polymorphic bands in three RAPD and three ISSR primers was 81.9% and 79.37%, respectively. Analysis of molecular variance showed significant diversity within the populations, 92% for RAPD and 85% for ISSR primers. The average of Polymorphism Information Content (PIC), Marker Index (MI), Nei's gene diversity (H) and Shannon's diversity index (I) in ISSR markers are higher than those in RAPD markers. Based on banding patterns and gene diversities values, we observed that the ISSR-PCR provides clearer data and is more successful in genetic diversity analyses than RAPD-PCR. Dendrograms generated from UPGMA (Unweighted Pair Group Method with Arithmetic Mean) cluster analyses for RAPD and ISSR markers were related to the geographic origin.
黄曲霉毒素（AF）是由 科产生的剧毒化合物。它们会使粮食作物变质，并对人类和牲畜的健康造成严重的全球性危害。本研究的目的是研究产毒和非产毒 菌株之间的系统发育关系。应用结合了系统发育、序列和毒素分析的多相方法，对来自全球 8 个国家（美国、菲律宾、埃及、印度、澳大利亚、印度尼西亚、中国和乌干达）的 40 个 科分离株进行了研究。这使得人们能够确定区分产毒和非产毒分离株的关键基因组特征。根据分子鉴定，32 株（80%）被鉴定为 3 株（7.5%）为 3 株（7.5%）为 ，一株（2.5%）为 。毒素分析表明，22 株（55%）分离株为产毒株。有毒分离株的大多数（62.5%）来自埃及。产毒能力最高的分离株是一株原本从菲律宾分离的 。随机扩增多态性 DNA（RAPD）和简单序列重复间（ISSR）等基于 DNA 的分子标记被用于评估这 40 株分离株的遗传多样性和系统发育关系，这些分离株最初是从 80 株分离株中选择的。在三个 RAPD 和三个 ISSR 引物中，多态性带的百分比分别为 81.9%和 79.37%。分析显示，群体内存在显著的多样性，RAPD 的为 92%，ISSR 的为 85%。ISSR 标记的多态信息含量（PIC）、标记指数（MI）、Nei 基因多样性（H）和 Shannon 多样性指数（I）的平均值均高于 RAPD 标记。基于带型和基因多样性值，我们观察到 ISSR-PCR 提供的数据更清晰，在遗传多样性分析中比 RAPD-PCR 更成功。基于 UPGMA（算术平均非加权对组法）聚类分析的 RAPD 和 ISSR 标记生成的系统发育树与地理起源有关。
