Haviland M B, Essien F B
Department of Biological Sciences, Rutgers University, Piscataway, New Jersey 08855-1059.
J Exp Zool. 1990 Dec;256(3):342-6. doi: 10.1002/jez.1402560315.
The Axd mutation in the mouse acts by an unknown mechanism to cause lumbosacral open neural tube defects and a variety of tail anomalies. Retinoic acid (RA) plays a number of different physiological and developmental roles and has been shown to affect neurulation in mice and other species. Indeed, reports have shown that this biologically active compound (or its metabolites) at low dose can alter the incidence of neural tube defects (NTD) in curly-tail (ct), splotch (Sp), and delayed splotch (Spd) mice, strains that are genetically predisposed to such abnormalities. The aim of the present study was to determine if RA administered under similar conditions would affect the penetrance or expression of the Axd mutation or survival of Axd homozygotes. Axd/+ and +/+ dams were exposed to RA intraperitoneally (5 mg/kg) on D9 postcoitus. No difference in incidence or extent of neural tube defects or other axial anomalies was detected among embryos of Axd/+ dams given RA compared with those administered vehicle only. This finding is consistent with the diversity of gene-controlled steps required for neurulation and the differing sensitivities of specific mutants to rescue by extrinsic agents.
小鼠中的Axd突变通过未知机制导致腰骶部开放性神经管缺陷和多种尾部异常。视黄酸（RA）发挥多种不同的生理和发育作用，并且已被证明会影响小鼠和其他物种的神经胚形成。事实上，报告显示这种生物活性化合物（或其代谢物）在低剂量时可改变卷尾（ct）、斑点（Sp）和延迟斑点（Spd）小鼠中神经管缺陷（NTD）的发生率，这些品系在遗传上易患此类异常。本研究的目的是确定在类似条件下给予RA是否会影响Axd突变的外显率或表达，或Axd纯合子的存活。在交配后第9天，将Axd/+和+/+母鼠腹腔注射RA（5 mg/kg）。与仅给予赋形剂的母鼠相比，给予RA的Axd/+母鼠的胚胎在神经管缺陷或其他轴向异常的发生率或程度上未检测到差异。这一发现与神经胚形成所需的基因控制步骤的多样性以及特定突变体对外源剂拯救的不同敏感性一致。
