Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00350 Helsinki, Finland.
Department of Mathematics and Statistics, Faculty of Science, University of Helsinki, 00560 Helsinki, Finland.
Viruses. 2023 Dec 14;15(12):2431. doi: 10.3390/v15122431.
Sporulation is a finely regulated morphogenetic program important in the ecology and epidemiology of . Exogenous elements disrupting sporulation-associated genes contribute to sporulation regulation and introduce diversity in the generally conserved sporulation programs of endospore formers. We identified a novel prophage-like DNA segment, termed the element, inserted within , encoding a sporulation-specific cysteine protease, in an environmental isolate of . Bioinformatic analysis revealed that the genetic structure of the element resembles previously reported mobile intervening elements associated with sporulation genes. Within a pure culture, we observed two subpopulations of cells with the element either integrated into the locus or excised as a circular DNA molecule. The dynamics between the two observed conformations of the element was growth-phase dependent and likely mediated by recombination events. The element was not required for sporulation by but triggered an earlier entry into sporulation than in a related isolate lacking this element. So far, the element has not been found in any other strains or other endospore-forming species. It remains to be demonstrated what kind of competitive edge it provides for survival and persistence.
sporulation 是一种精细调控的形态发生程序，在 的生态学和流行病学中很重要。破坏与孢子形成相关的基因的外源元素有助于孢子形成的调节，并在通常保守的内生孢子形成者的孢子形成程序中引入多样性。我们在 的环境分离株中鉴定出一个新的原噬菌体样 DNA 片段，称为 元件，插入 编码一个孢子特异性半胱氨酸蛋白酶的基因中。生物信息学分析表明， 元件的遗传结构类似于以前报道的与孢子形成基因相关的可移动中间元件。在纯 培养物中，我们观察到两种细胞亚群， 元件要么整合到 基因座中，要么作为环状 DNA 分子被切除。两种观察到的 元件构象之间的动态变化与生长阶段有关，可能由重组事件介导。 元件不是 形成孢子所必需的，但比缺乏该元件的相关分离株更早地进入孢子形成阶段。到目前为止，尚未在其他 菌株或其他内生孢子形成物种中发现 元件。它为 生存和持续提供了什么样的竞争优势还有待证明。
