Kapron-Brás C M, Trasler D G
Teratology. 1984 Aug;30(1):143-50. doi: 10.1002/tera.1420300118.
Homozygotes for the splotch (Sp) mutation in the mouse have spina bifida, whereas the heterozygotes have a white belly spot but otherwise appear normal. Spina bifida can be induced by maternal treatment with retinoic acid. Female SWV strain mice were treated intraperitoneally with retinoic acid suspended in peanut oil 8 days/12 hours after they had been mated to either Sp/+ or +/+ males. Probit analysis of the dose-response data suggests that the presence of the Sp gene causes an increased susceptibility of the embryo to the spina bifida-causing effects of retinoic acid. To study the nature of this increase litters were obtained on gestation day 9 from untreated SWV females mated as above. The mean length of the posterior neuropore (the length of the posterior neural tube that has not yet closed) was determined for each somite number between 14 and 26 and was found to be significantly greater in embryos from the Sp/+ cross. This delay of closure of the neural tube in Sp/+ cross embryos could explain the observed increase in their susceptibility to retinoic acid.
小鼠中斑点（Sp）突变的纯合子患有脊柱裂，而异合子有白色腹部斑点，但其他方面看起来正常。脊柱裂可由母体用视黄酸治疗诱发。雌性SWV品系小鼠在与Sp/+或+/+雄性交配后8天/12小时，腹腔注射悬浮在花生油中的视黄酸。剂量反应数据的概率分析表明，Sp基因的存在会使胚胎对视黄酸导致脊柱裂的作用敏感性增加。为了研究这种增加的性质，在妊娠第9天从未经处理的如上所述交配的SWV雌性小鼠获得窝仔。确定了14至26之间每个体节数的后神经孔平均长度（尚未闭合的后神经管长度），发现Sp/+杂交的胚胎中该长度明显更长。Sp/+杂交胚胎中神经管闭合的延迟可以解释观察到的它们对视黄酸敏感性的增加。
