Jiang An, Zhang Wei, Wei Jiankai, Liu Penghui, Dong Bo
Fang Zongxi Center, MoE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
Laoshan Laboratory, Qingdao 266237, China.
Biology (Basel). 2023 Feb 3;12(2):245. doi: 10.3390/biology12020245.
The endostyle is a pharyngeal organ with an opening groove and cilia in invertebrate chordates (amphioxus and ascidian) and cyclostomate (lamprey), serving as a filter-feeding tract and thyroid-secreting location. Emerging evidence implies its complex cellular composition and potentially versatile functions. Multiple cell types in the endostyle have been thought to be progenitors of complex organs in advanced vertebrates. To describe the expression profile and the potential functions, bulk RNA sequencing on the endostyle in ascidian was conducted and distinct markers were selected by multileveled comparative analysis. Transcriptional data assay and qRT-PCR-verified results showed the regional expression patterns of Hox genes in the longitudinal axis. Organ-specific markers of the endostyle was proposed by comparing expression with the main organs of the ascidian. A cross-species transcriptional profile projection between the endostyle and organs from and indicates a robust homogenous relationship to the thyroid and digestive system of the endostyle. The high similarity between the endostyle and the head kidney in zebrafish/the bone marrow in human implies uniquely profound functions of the pharyngeal organ in proto-vertebrates. Our result revealed that the transcriptional profile of the human parathyroid gland was similar to the ascidian endostyle, indicating the evolutionary origin of vertebrate hormone secretion organs.
内柱是无脊椎动物脊索动物（文昌鱼和海鞘）以及圆口纲动物（七鳃鳗）中具有开口沟和纤毛的咽器官，充当滤食通道和甲状腺分泌部位。新出现的证据表明其细胞组成复杂且功能可能具有多样性。内柱中的多种细胞类型被认为是高等脊椎动物复杂器官的祖细胞。为了描述其表达谱和潜在功能，对海鞘的内柱进行了批量RNA测序，并通过多层次比较分析选择了不同的标记物。转录数据测定和qRT-PCR验证结果显示了Hox基因在纵轴上的区域表达模式。通过与海鞘的主要器官比较表达情况，提出了内柱的器官特异性标记物。内柱与来自[未提及的物种1]和[未提及的物种2]的器官之间的跨物种转录谱投影表明，内柱与甲状腺和消化系统存在很强的同源关系。海鞘的内柱与斑马鱼的头肾/人类的骨髓高度相似，这意味着原脊椎动物中咽器官具有独特而深远的功能。我们的结果表明，人类甲状旁腺的转录谱与海鞘内柱相似，这表明了脊椎动物激素分泌器官的进化起源。
