The developing mouse thyroid: Embryonic vessel contacts and parenchymal growth pattern during specification, budding, migration, and lobulation
The developing mouse thyroid: Embryonic vessel contacts and parenchymal growth pattern during specification, budding, migration, and lobulation
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DOI：
10.1002/dvdy.20653
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发表时间：
2006-02-01
影响因子：
2.5
通讯作者：
Nilsson, M
中科院分区：
文献类型：
--
作者：
Fagman, H;Andersson, L;Nilsson, M
正常小鼠甲状腺发育已被修订，以确定关键的形态发生事件。早期甲状腺原基在发育和出芽时与主动脉囊内皮相结合。在甲状腺芽脱离咽内胚层后，血管接触消失，但在腺分裂形成两个叶之前恢复。沿第三咽部弓动脉的方向发生实质的横向扩张。表达Titf1/Nkx2.1的甲状腺前体细胞直到迁移阶段才会增殖，这意味着祖细胞可能是从甲状腺抗原位外募集的。早期分叶包括整个鳃末体被生长的中线甲状腺吞噬。同时，在C细胞分化之前，鳃末体上皮的增殖被抑制。在卵泡发生前，甲状腺叶肿大使人想起芽枝样生长模式。提示甲状腺诱导信号起源于胚胎血管，这为甲状腺发育不良的概念新发病机制提供了思路。
Normal mouse thyroid development has been revised to identify critical morphogenetic events. The early thyroid primordium associates with the aortic sac endothelium at the time of specification and budding. The vascular contact is lost after the thyroid buds from the pharyngeal endoderm, but is resumed before the gland divides to form two lobes. Lateral expansion of parenchyma takes place along the course of the third pharyngeal arch arteries. Thyroid precursor cells expressing Titf1/Nkx2.1 do not proliferate until the migration stage, implicating that progenitors likely are recruited from outside the thyroid placode. Early lobulation involves engulfment of the entire ultimobranchial bodies by the growing midline thyroid. At the same time, proliferation of the ultimobranchial body epithelium is silenced preceding the differentiation of C cells. Before folliculogenesis, thyroid lobe enlargement is reminiscent of a budding-branching-like growth pattern. It is suggested that thyroid inductive signals arise from embryonic vessels, and that this provides ideas to conceptually new pathogenetic mechanisms of thyroid dysgenesis.