Guo Weinan, Nan Fangru, Liu Xudong, Liu Qi, Feng Jia, Xie Shulian
School of Life Science, Shanxi Key Laboratory for Research and Development of Regional Plants, Shanxi University, Taiyuan, 030006, China.
BMC Genomics. 2025 Feb 27;26(1):202. doi: 10.1186/s12864-025-11396-1.
The genus Virescentia is a significant member of the Batrachospermaceae, exhibiting distinctive life history characteristics defined by alternating generations. This group of taxa has specific environmental requirements for growth. This paper investigates Virescentia, which primarily thrives in freshwater environments, such as streams and springs, characterized by low light, low temperatures, and high dissolved oxygen levels. Currently, no laboratory simulations of their growth conditions have been reported in culture studies. Additionally, previous studies indicate that comparisons of photosynthetic strength across different life-history stages of the same species have not been conducted, mainly due to the challenges of simultaneously collecting algal strains at both life-history stages.
During the gametophyte stage, the chloroplast and mitochondrial genomes were measured at 184,899 bp and 26,867 bp, respectively. In the chantransia stage, the lengths of these genomes were 184,887 bp and 27,014 bp, respectively. A comparison of organellar genome covariation and phylogenetic reconstruction revealed that the chloroplast and mitochondrial genomes across different life history stages were highly conserved, with genetic distances of 0 and nucleotide variants of only 9-15 bp. The mitochondrial genome of gametophyte SXU-YN24005 was found to lack two tRNA-Leu (tag) genes compared to that of the chantransia strain. Additionally, a comparative analysis of KEGG pathway transcriptome data from the two life history stages showed that 33 genes related to the ribosomal pathway and 53 genes associated with the photosynthesis pathway exhibited a significant decline in expression during the gametophyte stage compared to the chantransia stage.
In this study, two samples of the same species at different life-history stages were collected from the same location for the first time. The analysis revealed a high degree of conservation between their organelle genomes. Additionally, transcriptome sequencing results indicated substantial differences in gene expression patterns between the two life-history stages. This research will provide reliable data to support the future histological database of freshwater red algae and will establish a theoretical basis for conserving rare and endangered species.
绿藻属是串珠藻科的重要成员，具有由世代交替定义的独特生活史特征。这一类群的分类单元对生长有特定的环境要求。本文研究主要生长在淡水环境中的绿藻属，这些环境如溪流和泉水，其特点是光照低、温度低和溶解氧水平高。目前，在培养研究中尚未报道对其生长条件进行实验室模拟。此外，先前的研究表明，尚未对同一物种不同生活史阶段的光合强度进行比较，主要是因为在两个生活史阶段同时收集藻类菌株存在挑战。
在配子体阶段，叶绿体和线粒体基因组的长度分别测定为184,899 bp和26,867 bp。在 Chantransia 阶段，这些基因组的长度分别为184,887 bp和27,014 bp。细胞器基因组共变和系统发育重建的比较表明，不同生活史阶段的叶绿体和线粒体基因组高度保守，遗传距离为0，核苷酸变异仅9 - 15 bp。与 Chantransia 菌株相比，发现配子体 SXU - YN24005 的线粒体基因组缺少两个 tRNA - Leu（tag）基因。此外，对两个生活史阶段的KEGG通路转录组数据进行比较分析表明，与核糖体通路相关的33个基因和与光合作用通路相关的53个基因在配子体阶段的表达与 Chantransia 阶段相比显著下降。
在本研究中，首次从同一地点收集了同一物种不同生活史阶段的两个样本。分析揭示了它们细胞器基因组之间的高度保守性。此外，转录组测序结果表明两个生活史阶段之间基因表达模式存在显著差异。本研究将提供可靠数据以支持未来淡水红藻的组织学数据库，并为保护珍稀濒危物种奠定理论基础。
