Comparative gene expression analyses reveal heterochrony for Sox9 expression in the cranial neural crest during marsupial development.
Comparative gene expression analyses reveal heterochrony for Sox9 expression in the cranial neural crest during marsupial development.
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比较基因表达分析揭示了有袋动物发育过程中颅神经嵴中 Sox9 表达的异时性。
DOI：
10.1111/ede.12083
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发表时间：
2014
影响因子：
2.9
通讯作者：
Suzuki K.
中科院分区：
文献类型：
--
作者：
Wakamatsu Y;Nomura T;Osumi N;Suzuki K.
与胎盘哺乳动物相比，有袋类动物的妊娠期较短，新生儿也相对不成熟。尽管有这些特征，有袋动物的新生儿必须从产道到乳头，吮吸和消化乳汁才能完成发育。因此，有袋类新生动物的某些器官和组织，如爬行用的前肢和爬行用的颚部，必须在早期发育。先前的报道表明，颅神经嵴（CNC）细胞，作为颌骨元件的外胚间充质的来源，与其他啮齿动物模型（如小鼠）相比，在灰色短尾负鼠（Monodelphis arctica）中显着早期产生。在这项研究中，我们研究了已知对神经嵴形成重要的基因，如BMP 2/BMP 4（神经嵴诱导剂），Pax 7（神经边界指定符），Snail 1和Sox 9/Sox 10（神经嵴指定符）在Monodelphis arctica中的表达，并与小鼠，鸡和壁虎胚胎中的表达模式进行了比较。在这些基因中，Sox 9的表达在迁移前的CNC细胞中早期和广泛地开启，并且在颅蓝负鼠胚胎的外胚间充质中持续存在。相比之下，Sox 9表达在其他动物的CNC细胞中在迁移的早期阶段减少。比较Pax 7和Sox 9表达的起始时间发现，Sox 9在前瞻性CNC中的表达比在负鼠中的Pax 7表达更早且更广泛，这表明边界特化和神经嵴特化的顺序发生了改变。这项研究为了解有袋动物CNC细胞和颌骨成分异时发育的分子基础提供了第一条线索。
Compared to placental mammals, marsupials have short gestation period, and their neonates are relatively immature. Despite these features, marsupial neonates must travel from the birth canal to the teat, suckle and digest milk to complete development. Thus, certain organs and tissues of marsupial neonates, such as forelimbs to crawl and jaw elements to suckle, must develop early. Previous reports showed that cranial neural crest (CNC) cells, as the source of ectomesenchyme of jaw elements, are generated significantly early in gray short‐tailed opossum (Monodelphis domestica) compared to other amniote models, such as mouse. In this study, we examined the expression of genes known to be important for neural crest formation, such asBMP2/BMP4(neural crest inducer),Pax7(neural border specifier),Snail1andSox9/Sox10(neural crest specifier) inMonodelphis domestica, and compared the expression patterns with those in mouse, chicken, and gecko embryos. Among those genes, the expression ofSox9was turned on early and broadly in the premigratory CNC cells, and persisted in the ectomesenchyme of the cranialanlagenin opossum embryos. In contrast,Sox9expression diminished in the CNC cells of other animals at the early phase of migration. Comparison of the onset ofPax7andSox9expression revealed thatSox9expression in the prospective CNC was earlier and broader thanPax7expression in opossum, suggesting that the sequence of border specification and neural crest specification is altered. This study provides the first clue for understanding the molecular basis for the heterochronic development of the CNC cells and jaw elements in marsupials.