Study on Maternal Environmental Factors for Cleft Lip and/or Palate by Transplanting Fertilized Ova

目的：在糖皮质激素（GCS）诱导小鼠腭裂的研究中，已知存在应变差异。虽然原因被指出是胎儿的遗传因素，但一份报告也指出了母亲的因素。以往的研究使用的是正常的交配小鼠。胎儿遗传因素和母系因素混合，母系因素在不同菌株间的检测比较困难。本研究通过分离遗传因素和母性因素的受精卵移植对母性因素进行了研究。材料与方法：受精卵供体选用gcs致腭裂发生率高的鼠系ddY小鼠。受体选用gcs致腭裂发生率较低的ddY小鼠和C57BL/6J小鼠。以正常交配的ddY小鼠组、C57BL/6J小鼠组为实验-1、GCS未处理组和受精卵转移小鼠组为实验-2、GCS处理组和受精卵转移小鼠为实验-3。于妊娠第11天给予右美托咪唑治疗，妊娠第18天观察各组腭裂发生率。这些数据是通过费雪精确检验来分析的。结果：实验1组ddY小鼠腭裂发生率为96%，C57BL/6J小鼠为20%。实验2组腭裂发生率均为0%。实验3组ddY小鼠受精卵移植组腭裂发生率为95%，C57BL/6J小鼠移植组腭裂发生率为29%。实验1组小鼠gcs -腭裂发生率与正常妊娠小鼠C57BL/6J有显著性差异。实验3组的腭裂均为GCS所致，因为实验2组未见腭裂发生。gcs诱发的腭裂是由于母体代谢能力的差异而发生的，被认为与母体因素密切相关。少

Purpose : Existence of strain difference has been known in the study of glucocorticoids(GCS)-induced cleft palate mouse. Although the cause was pointed out to be fetsuse's genetic factors, a report also suggested maternal al factors. Past study used normal mating mouse. Fetal genetic factors and maternal factors were mixed, it was difficult to examine maternal factors among the different strains. In this study, we examined the maternal factors by fertilized ovum transfer that separated genetic factors and maternal factors.Materials and Methods : For donors of fertilized ovum, we used ddY mouse as the strain shows high occurrence rate of GCS-induced cleft palate. For receipient, we used ddY mice and C57BL/6J mice which have a lower occurrence rate of GCS-induced cleft palate. Occurrence rates were compared to normal mating ddY mouse group, C57BL/6J mouse group as experimental-1, GCS untreated groups with fertilized ovum transferred mouse group as experimental-2, and GCS treated groups w … More ith fertilized ovum transferred mice as experimental-3. Dex was treated in gestation day 11 and each group was observed in gestation day 18 and analyzed for occurrence rate of cleft palate. The data were analyzed by Fisher's exact test.Results : In experimental-1 group, the occurrence rate of cleft palate in ddY mouse was 96%, and in C57BL/6J mouse was20%. In experimental-2 group, the occurrence rate of cleft palate in both groups was 0%. In experimental-3 group, the occurrence rate of cleft palate in the group in which ddY mouse's fertilized ovum was transfered to the same strain showed 95%, and the group transfered to C57BL/6J mouse showed 29%. In experimental-1 group, the occurrence rates of GCS-indced cleft palate between ddY and C57BL/6J mouse by normal gestation were significantly different. The cleft palates of the experimental-3 group were assumed to be all induced by GCS because no occurrence of cleft palate was seen in the experimental-2 group. GCS-induced cleft palate was occurred by difference of metabolism ability at the mother's body and it was considered to be related strongly by maternal factors. Less