BACKGROUND Apogamy is a unique asexual reproduction in the ferns, in which somatic cells of gametophytes go through dedifferentiation and then differentiate into haploid sporophytes bypassing fertilization. Restricted to the lack of genomic information, molecular mechanisms of apogamy have remained unclear. Comparative transcriptome analysis was conducted at six stages between sexual reproduction and apogamy in the fern Adiantum reniforme var. sinense, in an effort to identify genes and pathways that might initiate the asexual reproduction. RESULTS Approximately 928 million high-quality clean reads were assembled into 264,791 unigenes with an average length of 615 bp. A total of 147,865 (55.84%) unigenes were successfully annotated. Differential genes expression analysis indicated that transcriptional regulation was more active in the early stage of apogamy compared to sexual reproduction. Further comparative analysis of the enriched pathways between the early stages of the two reproductive modes demonstrated that starch and sucrose metabolism pathway responsible for cell wall was only significantly enriched in asexual embryonic cell initiation. Furthermore, regulation of plant hormone related genes was more vigorous in apogamy initiation. CONCLUSION These findings would be useful for revealing the initiation of apogamy and further understanding of the mechanisms related to asexual reproduction.

中文翻译：

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羊肚菌两个生殖模式的比较转录组分析。sinense的目标是探索无配偶的可能机制。

背景技术配子融合是蕨类植物中一种独特的无性繁殖，配子体的体细胞经历去分化，然后绕过受精过程分化为单倍体孢子体。由于缺乏基因组信息，无配子融合的分子机制仍不清楚。在蕨形铁线蕨变种中，在有性生殖和无性生殖之间的六个阶段进行了比较转录组分析。sinense，旨在识别可能引发无性繁殖的基因和途径。结果大约928百万个高质量的纯净读段被组装成264,791个单基因，平均长度为615 bp。总共成功注释了147,865（55.84％）个单基因。差异基因表达分析表明，与有性生殖相比，在单性配子的早期转录调控更为活跃。两种生殖模式早期阶段之间的富集途径的进一步比较分析表明，负责细胞壁的淀粉和蔗糖代谢途径仅在无性胚胎细胞启动中显着富集。此外，植物配体相关基因的调控在无配子形成的初期更为活跃。结论这些发现对于揭示无配偶的起源和进一步了解与无性生殖有关的机制是有用的。两种生殖模式早期阶段之间的富集途径的进一步比较分析表明，负责细胞壁的淀粉和蔗糖代谢途径仅在无性胚胎细胞启动中显着富集。此外，植物配偶体相关基因的调控在无性生活中起着更强的作用。结论这些发现对于揭示无配偶的起源和进一步了解与无性生殖有关的机制是有用的。两种生殖模式早期阶段之间的富集途径的进一步比较分析表明，负责细胞壁的淀粉和蔗糖代谢途径仅在无性胚胎细胞启动中显着富集。此外，植物配偶体相关基因的调控在无性生活中起着更强的作用。结论这些发现对于揭示无配偶的起源和进一步了解与无性生殖有关的机制是有用的。