The buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling.
The buccohypophyseal canal is an ancestral vertebrate trait maintained by modulation in sonic hedgehog signaling.
复制标题
DOI：
10.1186/1741-7007-11-27
复制
发表时间：
2013-03-28
期刊：
影响因子：
5.4
通讯作者：
Sharpe PT
中科院分区：
文献类型：
--
作者：
Khonsari RH;Seppala M;Pradel A;Dutel H;Clément G;Lebedev O;Ghafoor S;Rothova M;Tucker A;Maisey JG;Fan CM;Kawasaki M;Ohazama A;Tafforeau P;Franco B;Helms J;Haycraft CJ;David A;Janvier P;Cobourne MT;Sharpe PT
脑下垂体是由两种组织并置而成的：从间脑基底产生的神经外胚层，以及从口腔顶部向中枢神经系统内陷的口腔上皮。从口腔到达大脑的口腔内陷被称为Rathke囊，其尖端形成腺垂体，柄在发育的最早阶段后消失。在四足动物中，颅底的形成在垂体和口腔之间建立了一个明确的屏障;然而，许多灭绝和现存的脊椎动物物种在成年后保留了开放的颊垂体管，这是Rathke囊柄的遗迹。目前对这种结构的形成和功能知之甚少。在这里，我们已经调查的分子机制，推动形成的颊垂体管和它们的进化意义。我们发现，Rathke的邮袋位于边界区域划定的内胚层，神经嵴衍生的口腔间充质和脊索的前极限，使用CD 1，R26 R-Sox 17-Cre和R26 R-Wnt 1-Cre小鼠线。正如在小鼠胚胎碘染色后通过同步辐射X射线显微断层扫描所揭示的那样，在垂体形成期间，囊袋具有分叶状的三维结构，该结构包含下降的间脑。Polymorphism fl/fl; Wnt 1-Cre、Ofd 1-/-和Kif 3a-/-初级纤毛小鼠突变体具有异常的音刺猬（Shh）信号传导，并且都存在垂体前叶和前颅底中线结构的畸形。在Gas 1-/-小鼠中证实了Shh下游基因表达的变化。从进化的角度来看，持久性的buccohypophyseal管是所有脊椎动物的一个基本特征，它的维护在几个组是有关的特定形态的中线，可以涉及到调制Shh信号。这些结果提供了深入了解一个鲜为人知的祖先脊椎动物的结构。看来，开放的buccohypophyseal管依赖于Shh信号和调制在这条途径最有可能解释其持久性在胚胎发育。
The pituitary gland is formed by the juxtaposition of two tissues: neuroectoderm arising from the basal diencephalon, and oral epithelium, which invaginates towards the central nervous system from the roof of the mouth. The oral invagination that reaches the brain from the mouth is referred to as Rathke’s pouch, with the tip forming the adenohypophysis and the stalk disappearing after the earliest stages of development. In tetrapods, formation of the cranial base establishes a definitive barrier between the pituitary and oral cavity; however, numerous extinct and extant vertebrate species retain an open buccohypophyseal canal in adulthood, a vestige of the stalk of Rathke’s pouch. Little is currently known about the formation and function of this structure. Here we have investigated molecular mechanisms driving the formation of the buccohypophyseal canal and their evolutionary significance. We show that Rathke’s pouch is located at a boundary region delineated by endoderm, neural crest-derived oral mesenchyme and the anterior limit of the notochord, using CD1, R26R-Sox17-Cre and R26R-Wnt1-Cre mouse lines. As revealed by synchrotron X-ray microtomography after iodine staining in mouse embryos, the pouch has a lobulated three-dimensional structure that embraces the descending diencephalon during pituitary formation. Polarisfl/fl; Wnt1-Cre, Ofd1-/- and Kif3a-/- primary cilia mouse mutants have abnormal sonic hedgehog (Shh) signaling and all present with malformations of the anterior pituitary gland and midline structures of the anterior cranial base. Changes in the expressions of Shh downstream genes are confirmed in Gas1-/- mice. From an evolutionary perspective, persistence of the buccohypophyseal canal is a basal character for all vertebrates and its maintenance in several groups is related to a specific morphology of the midline that can be related to modulation in Shh signaling. These results provide insight into a poorly understood ancestral vertebrate structure. It appears that the opening of the buccohypophyseal canal depends upon Shh signaling and that modulation in this pathway most probably accounts for its persistence in phylogeny.
登录
查看更多内容
影响因子：
64.8
作者：
Davis, Samuel P.;Finarelli, John A.;Coates, Michael I.
通讯作者：
Coates, Michael I.
影响因子：
2.7
作者：
Bimonte, Sabrina;De Angelis, Amalia;Franco, Brunella
通讯作者：
Franco, Brunella
影响因子：
1.5
作者：
Engert, Silvia;Liao, W. Perry;Lickert, Heiko
通讯作者：
Lickert, Heiko
影响因子：
30.8
作者：
Ferrante, MI;Zullo, A;Franco, B
通讯作者：
Franco, B
影响因子：
3.5
作者：
Brugmann, Samantha A.;Allen, Nancy C.;Helms, Jill A.
通讯作者：
Helms, Jill A.