The haploid-diploid life cycle of the filamentous brown alga Ectocarpus involves alternation between two independent and morphologically distinct multicellular generations, the sporophyte and the gametophyte. Deployment of the sporophyte developmental program requires two TALE homeodomain transcription factors OUROBOROS and SAMSARA. In addition, the sporophyte generation has been shown to secrete a diffusible factor that can induce uni-spores to switch from the gametophyte to the sporophyte developmental program. Here, we determine optimal conditions for production, storage, and detection of this diffusible factor and show that it is a heat-resistant, high molecular weight molecule. Based on a combined approach involving proteomic analysis of sporophyte-conditioned medium and the use of biochemical tools to characterize arabinogalactan proteins, we present evidence that sporophyte-conditioned medium contains AGP epitopes and suggest that the diffusible factor may belong to this family of glycoproteins.

中文翻译：

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褐藻外果果中诱导配子体向孢子体转换的扩散因子的生化特征

丝状褐藻Ectocarpus的单倍体-二倍体生命周期涉及两个独立且形态不同的多细胞世代之间的交替，即孢子体和配子体。孢子体发育程序的部署需要两个 TALE 同源域转录因子 OUROBOROS 和 SAMSARA。此外，孢子体产生分泌一种可诱导单孢子从配子体转变为孢子体发育程序的扩散因子。在这里，我们确定了这种扩散因子的生产、储存和检测的最佳条件，并表明它是一种耐热的高分子量分子。基于包括孢子体条件培养基的蛋白质组学分析和使用生化工具来表征阿拉伯半乳聚糖蛋白的组合方法，