Moscow State University, 119991, Moscow, Russia.
Dokl Biol Sci. 2021 Jan;496(1):30-33. doi: 10.1134/S0012496621010038. Epub 2021 Feb 26.
The study of the lophophore organization is of great importance for the reconstruction of lophophorate phylogeny and for understanding the evolutionary transformation in each phylum of Lophophorata. The innervation of the lophophore in ctenostome bryozoan Flustrellidra hispida was studied using immunocytochemistry and confocal laser scanning microscopy. It has been demonstrated that this species has an outer nerve ring giving rise to the tentacle nerves. The outer nerve ring was earlier described in some ctenostomates and cyclostomates, but not as connected with nerves. The discovered feature of lophophore innervation in F. hispida suggests the evolutionary transformation from a hypothetical phoronida-like ancestor lophophore bearing a prominent outer nerve ring with numerous tentacle nerves emanating from it, to the complex bell-shaped lophophore of F. hispida with a well-pronounced outer nervous ring bearing a few tentacle nerves. The next one in this hypothetical row is the lophophore of the other ctenostomates and some cyclostomates with no ring-nerve connection and cheilostomates lophophore with no outer nerve ring at all.
研究担轮结构对于重构担轮动物系统发生和理解每个担轮动物门的进化转变非常重要。使用免疫细胞化学和共聚焦激光扫描显微镜研究了栉水母类石珊瑚 Flustrellidra hispida 的担轮神经支配。结果表明，该物种具有外神经环，其产生触手神经。外神经环在一些栉水母类和环口类中已有描述，但并未与神经相连。在 F. hispida 中发现的担轮神经支配特征表明，从具有突出的外神经环和许多从其发出的触手神经的假设栉水母类祖先担轮，进化为具有明显外神经环和少数触手神经的复杂钟形担轮。在这个假设的进化序列中，接下来是其他栉水母类和一些环口类的担轮，它们没有环神经连接，而唇口类的担轮则完全没有外神经环。
