生殖嵴定植前后鸡原始生殖细胞多能性基因的表达动态。
Expression dynamics of pluripotency genes in chicken primordial germ cells before and after colonization of the genital ridges.
机构信息
Department of Basic Science, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.
出版信息
Mol Reprod Dev. 2013 Oct;80(10):849-61. doi: 10.1002/mrd.22216. Epub 2013 Aug 2.
Mammalian species utilize an inductive mechanism of germ cell specification, diverting the fate of some of somatic cells toward pluripotency and germ-cell totipotency. It is not known if avian species utilize a similar mechanism nor if, analogous to mammalian primordial germ cells (PGCs), pluripotency genes are continuously upregulated in migrating and genital ridge-colonizing avian PGCs. Thus, this study was conducted to quantify and to analyze the expression profile of pluripotency genes at different stages of chicken PGCs development at Hamburger and Hamilton (HH) stage 14, when the majority of PGCs have entered into the bloodstream; at HH stage 18, when PGCs have resided for 8-12 hr in the bloodstream; and at HH stage 28, when the majority of PGCs are found in the genital ridge. The transcription for Oct4, Sox2, and Nanog continuously decreased from HH stage 14 to HH stage 28. In addition, equal amounts of total RNA could be isolated from chicken PGCs at each stage of development, indicating that the observed drop of transcription of pluripotency genes is not a consequence of transcriptional repression in general. Decreased expression for all three proteins was also observed at HH stage 28. Furthermore, in comparison to blood PGCs, those residing in the gonad have lost their full capacity for colony formation. Our results indicate that, in contrast to mammalian PGCs, chicken PGCs continuously downregulate the expression of pluripotency genes and show a progressive loss of pluripotency-associated features during different stages of germ-line migration.
哺乳动物物种利用一种诱导机制来指定生殖细胞的命运,使一些体细胞向多能性和生殖细胞全能性转变。目前还不清楚鸟类物种是否利用类似的机制,也不清楚类似于哺乳动物原始生殖细胞(PGC)的多能性基因是否在迁移和生殖嵴定殖的禽类 PGC 中持续上调。因此,本研究旨在定量分析和分析鸡 PGC 发育不同阶段的多能性基因表达谱,这些阶段在 Hamburger 和 Hamilton(HH)阶段 14 时,大多数 PGC 已经进入血液循环;在 HH 阶段 18 时,PGC 已经在血液中停留了 8-12 小时;在 HH 阶段 28 时,大多数 PGC 都存在于生殖嵴中。Oct4、Sox2 和 Nanog 的转录从 HH 阶段 14 到 HH 阶段 28 持续下降。此外,在发育的每个阶段都可以从鸡 PGC 中分离出等量的总 RNA,这表明观察到的多能性基因转录下降不是普遍转录抑制的结果。在 HH 阶段 28 时,这三种蛋白质的表达也明显下降。此外,与血液 PGC 相比,那些驻留在性腺中的 PGC 已经失去了形成菌落的全部能力。我们的结果表明,与哺乳动物 PGC 相反,鸡 PGC 不断下调多能性基因的表达,并在生殖系迁移的不同阶段表现出逐渐丧失与多能性相关的特征。