Mechanisms of endoderm formation in a cartilaginous fish reveal ancestral and homoplastic traits in jawed vertebrates.
Mechanisms of endoderm formation in a cartilaginous fish reveal ancestral and homoplastic traits in jawed vertebrates.
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DOI：
10.1242/bio.20148037
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发表时间：
2014-10-31
期刊：
影响因子：
2.4
通讯作者：
Mazan S
中科院分区：
文献类型：
--
作者：
Godard BG;Coolen M;Le Panse S;Gombault A;Ferreiro-Galve S;Laguerre L;Lagadec R;Wincker P;Poulain J;Da Silva C;Kuraku S;Carre W;Boutet A;Mazan S
为了深入了解卵黄增加对内胚层发育的影响，我们分析了猫鲨S. canicula（一种具有端粒卵和独特卵黄囊的物种）内胚层形成的机制。我们发现，在这个物种中，内胚层标记在两个不同的组织中表达，深层间充质，位于上皮样浅层之下的深层卵裂球的间充质群体，已经在囊胚早期阶段被指定，以及在原胚形成开始时出现在囊胚后缘的内包皮层。深层间质的形成涉及细胞在原肠胚形成之前由浅层内化，通过一个暗示侵入的运动。这些细胞运动不仅发生在后缘，在那里大量内化发生在内化开始之前，而且也发生在胚皮的中心，在那里单细胞内化盛行。与相邻的内纠缠间质一样，后深层间质在淋巴结/激活素信号的控制下表达前间质标记物。脊椎动物间的比较支持这样的结论，即猫鲨的内胚层在两个不同的时间阶段被指定，就像所有主要的骨鱼类谱系一样，这与颌口动物内胚层的双阶段模式的古老起源一致。他们还强调了与羊膜的意想不到的相似之处，例如在原肠形成之前，细胞从浅层侵入。这些相似性可能对应于羊膜动物和软骨鱼分别固定的同塑性状，并与蛋黄质量的增加有关。
In order to gain insight into the impact of yolk increase on endoderm development, we have analyzed the mechanisms of endoderm formation in the catshark S. canicula, a species exhibiting telolecithal eggs and a distinct yolk sac. We show that in this species, endoderm markers are expressed in two distinct tissues, the deep mesenchyme, a mesenchymal population of deep blastomeres lying beneath the epithelial-like superficial layer, already specified at early blastula stages, and the involuting mesendoderm layer, which appears at the blastoderm posterior margin at the onset of gastrulation. Formation of the deep mesenchyme involves cell internalizations from the superficial layer prior to gastrulation, by a movement suggestive of ingressions. These cell movements were observed not only at the posterior margin, where massive internalizations take place prior to the start of involution, but also in the center of the blastoderm, where internalizations of single cells prevail. Like the adjacent involuting mesendoderm, the posterior deep mesenchyme expresses anterior mesendoderm markers under the control of Nodal/activin signaling. Comparisons across vertebrates support the conclusion that endoderm is specified in two distinct temporal phases in the catshark as in all major osteichthyan lineages, in line with an ancient origin of a biphasic mode of endoderm specification in gnathostomes. They also highlight unexpected similarities with amniotes, such as the occurrence of cell ingressions from the superficial layer prior to gastrulation. These similarities may correspond to homoplastic traits fixed separately in amniotes and chondrichthyans and related to the increase in egg yolk mass.
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影响因子：
--
作者：
Hardy KM;Yatskievych TA;Konieczka J;Bobbs AS;Antin PB
通讯作者：
Antin PB
影响因子：
3.7
作者：
Coolen M;Nicolle D;Plouhinec JL;Gombault A;Sauka-Spengler T;Menuet A;Pieau C;Mazan S
通讯作者：
Mazan S
影响因子：
4.6
作者：
Mesnard, Daniel;Guzman-Ayala, Marcela;Constam, Daniel B.
通讯作者：
Constam, Daniel B.
影响因子：
2.7
作者：
Plouhinec, JL;Leconte, L;Saule, S
通讯作者：
Saule, S
影响因子：
4.6
作者：
Luxardi, Guillaume;Marchal, Leslie;Kodjabachian, Laurent
通讯作者：
Kodjabachian, Laurent