低氧诱导因子-1在小鼠胚胎神经胚形成阶段的发育学表达

为研究低氧诱导因子-1(HIF-1)在小鼠胚胎神经胚形成阶段的时空表达规律,探讨HIF-1在胚胎神经系统发生和发育过程中的作用。本研究以地高辛标记的HIF-1αcRNA为探针,采用全胚胎原位杂交技术,观察HIF-1α在神经胚形成阶段的表达规律。结果显示在E8.5d,整个鼠胚神经管的头端和尾端均可观察到HIF-1αmRNA的表达,此时表达较弱。在E9.5d,随着神经管的逐渐关闭,HIF-1αmRNA在前脑泡、第一鳃弓、第二鳃弓、后脑泡处急剧增多,并在发育中的眼部有较强的表达;此外在中脑泡以及心脏原基有较弱的表达。到E10.5d,阳性信号除在E9.5d检测到的部位继续富集外,在端脑、间脑、发育中的肢芽以及尾部也出现较强的HIF-1αmRNA的表达,且在心脏原基的表达亦进一步增强。E11.5d时在连合板、喙区、第一鳃弓、第二鳃弓、后脑、延脑、发育中的肢芽以及尾部末端可检测到HIF-1αmRNA的明显表达。以上结果提示HIF-1可能参与了小鼠神经胚形成的发育过程。

THE EXPRESSION OF HYPOXIA-INDUCIBLE FACTOR-1 IN THE NEURULATION OF DEVELOPING NERVOUS SYSTEM OF MOUSE

To investigate the spatio-temporal expression of hypoxia-inducible factor-1 (HIF-1) during murine neurulation and explore the role of HIF-1 in the embryonic development of the nervous system. The expression of HIF-1α mRNA in developing neural tube was examined by using Digoxigenin labeling HIF-1α cRNA probes and whole-mount embryo in situ hybridization. At E 8.5 d, expression of HIF-1α mRNA was weakly detected at the cranial portion and caudal end of the neural tube in mouse embryo. With closure of the neural tube the expression of HIF-1α mRNA was increased dramatically in the prosencephalon, branchial arch 1, branchial arch 2, and metencephalon at E 9.5 d. The highest level of HIF-1α mRNA was observed in the developing eyes, while the lowest was in the mesencephalon and primary heart. At E 10.5 d, besides the regions where positive signals were detected on E 9.5 d, HIF-1α mRNA was clearly observed in the telencephalon, diencephalons, developing limbs, and caudal regions. At E 11.5 d HIF-1α mRNA was strongly detected in the commissural plate, rostral region, branchial arches 1 and 2, metencephalon, myelencephalon, limbs, and terminal caudal region of the neural tube. The present results suggest that HIF-1 might be involved in the development of the mouse neurulation.