Data from: Induction of sexual reproduction and genetic diversity in the cheese fungus Penicillium roqueforti

The emblematic fungus Penicillium roqueforti is used throughout the world as a starter culture in the production of blue-veined cheeses. Like other industrial filamentous fungi, P. roqueforti was thought to lack a sexual cycle. However, an ability to induce recombination is of great economic and fundamental importance, as it would make it possible to transform and improve industrial strains, promoting the creation of novel phenotypes and eliminating the deleterious mutations that accumulate during clonal propagation. We report here, for the first time, the induction of the sexual structures of P. roqueforti — ascogonia, cleistothecia and ascospores. The progeny of the sexual cycle displayed clear evidence of recombination. We also used the recently published genome sequence for this species to develop microsatellite markers for investigating the footprints of recombination and population structure in a large collection of isolates from around the world and from different environments. Indeed, P. roqueforti also occurs in silage, wood and human-related environments other than cheese. We found tremendous genetic diversity within P. roqueforti, even within cheese strains, and identified six highly differentiated clusters that probably predate the use of this species for cheese production. Screening for phenotypic and metabolic differences between these populations could guide future development strategies.

作为标志性真菌，娄地青霉（Penicillium roqueforti）在全球范围内被用作蓝纹奶酪生产的发酵起始菌种。与其他工业丝状真菌类似，娄地青霉此前被认为不存在有性生殖周期。然而，诱导重组的能力具有极高的经济与基础研究价值：它可实现工业菌株的遗传改造与性能优化，助力新型表型的创制，并清除无性繁殖过程中累积的有害突变。本研究首次报道了娄地青霉有性生殖结构的诱导：产囊体（ascogonia）、闭囊壳（cleistothecia）与子囊孢子（ascospores）。有性生殖产生的后代展现出明确的重组特征。本研究还依托该物种新近发布的基因组序列，开发了微卫星标记（microsatellite markers），用于分析全球不同环境来源的大量分离菌株中的重组痕迹与种群结构。事实上，娄地青霉除奶酪环境外，还广泛存在于青贮饲料、木材以及其他与人类活动相关的环境中。本研究在娄地青霉中发现了极高的遗传多样性，即便在奶酪来源的菌株中亦是如此；同时鉴定出6个高度分化的种群簇，其分化时间可能早于人类将该菌种用于奶酪生产的历史。对这些种群间的表型与代谢差异进行筛选，可为后续的研发策略提供指导。