Thorea hispida exclusively inhabits freshwater environments and is characterized by a triphasic life history. In this study, the organelle genomes and transcriptomes of different life history stages of T. hispida were examined using next generation sequencing. The chloroplast and mitochondrial genomes of the chantransia stage were 175,747 and 25,411 bp in length, respectively. The chantransia stage was highly similar to the gametophyte stage based on comparisons of organelle genomes and phylogenetic reconstruction. Transcriptomic comparisons of two stages found that ribosome-related genes were the most up-regulated in the gametophyte stage of T. hispida. Seven meiosis-specific genes, including SPO11 initiator of meiotic double-stranded breaks(spo11), meiotic nuclear divisions 1(mnd1), RAD51 recombinase(rad51), mutS homolog 4(msh4), mutS homolog 5(msh5), REC8 meiotic recombination protein(rec8), and DNA helicase Mer3(mer3), were differentially regulated between the two life history stages. The organelle genomes and transcriptomes from T. hispida provided in this study will be valuable for future studies of freshwater red algae.

Thorea hispida只栖息在淡水环境中，以三相生活史为特征。在这项研究中，使用下一代测序检查了T. hispida不同生活史阶段的细胞器基因组和转录组。chantransia 阶段的叶绿体和线粒体基因组的长度分别为 175,747 和 25,411 bp。基于细胞器基因组和系统发育重建的比较，chantransia 阶段与配子体阶段高度相似。两个阶段的转录组比较发现，核糖体相关基因在T. hispida配子体阶段上调最多。七个减数分裂特异性基因，包括减数分裂双链断裂（spo11），减数分裂核分裂1（MND 1），RAD51重组酶（弧度51），mutS的同系物4（MSH 4），mutS的同系物5（MSH 5），REC8减数分裂重组蛋白（REC 8）和DNA解旋酶MER3（聚体3），在两个生活史阶段之间受到差异调节。本研究中提供的来自T. hispida的细胞器基因组和转录组对于未来淡水红藻的研究将是有价值的。