Hydroxyproline‐rich glycoproteins (HRGPs) constitute a major group of proteins of the extracellular matrix (ECM). The multicellular green alga Volvox carteri is a suitable model organism in which to study the evolutionary transition to multicellularity, including the basic principles and characteristics of an ECM. In Volvox, the ECM is dominated by a single HRGP family: the pherophorins. Our inventory amounts to 117 pherophorin‐related genes in V. carteri. We focused on a pherophorin with an unexpected characteristic: pherophorin‐S is a soluble, non‐cross‐linked ECM protein. Using transformants expressing a YFP‐tagged pherophorin‐S we observed the synthesis and secretion of pherophorin‐S by somatic cells in vivo, and we then traced the protein during its conspicuous migration to the ECM around prehatching juveniles and its localized concentration there. Our results provide insights into how an ECM zone surrounding the progeny is remotely affected by distantly located parental somatic cells. In view of the properties and migration of pherophorin‐S, we conclude that pherophorin‐S is likely to act as an ECM plasticizer to allow for dynamic ECM remodeling.

中文翻译：

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信息素S的靶向迁移表明Volvox Carteri中广泛的细胞外基质动力学。

富含羟脯氨酸的糖蛋白（HRGP）构成了细胞外基质（ECM）的主要蛋白质组。多细胞绿藻Volvox Carteri是一种合适的模型生物，可在其中研究向多细胞性的进化过渡，包括ECM的基本原理和特征。在Volvox中，ECM由单个HRGP家族控制：信息素。我们的清单中有117种与信息素相关的V. Carteri相关基因。我们重点研究了具有非预期特征的信息素：信息素S是一种可溶的，非交联的ECM蛋白。使用表达YFP标签的pherophorin-S的转化子，我们观察到体细胞在体内合成和分泌pherophorin-S，然后我们在孵化前幼体周围的明显迁移及其附近的浓度期间追踪了该蛋白质。我们的结果提供了远见的亲代体细胞如何远程影响子代周围的ECM区的见解。考虑到信息素的性质和迁移，我们得出结论，信息素S可能充当ECM增塑剂，以实现动态ECM重塑。