Biotechnological study to know the effects of genetic and matemal factors on craniofacial growth in mice.

为了研究遗传和环境因素对体外小鼠胚胎着床前发育的相对影响程度，我们从5个近交系小鼠（DDD/QDJ、C3H/ QDJ、C57BL/6J Sea、DBA/1J Sea和BALB/C Sea）的输卵管中收集两细胞期胚胎，培养至囊胚膨大期72小时。计算每个受体和每个品系的受精率和存活率。对这两个比率进行的Student-Newman-Keuls测试显示出显著的种间差异，而对遗传和环境影响对胚胎着床前发育的相对重要性进行的方差分析显示，这两个比率的遗传决定程度都很低。由此可见，环境对小鼠体外胚胎着床前发育的影响更为重要。应用胚胎移植和头孢他汀，研究了胚胎移植对小鼠颅面胚胎发育的影响和子宫内对颅面胚胎发育的影响。将DDD株胚胎移植到3株受体（DDD、C57BL和DBA）中。移植胚胎发育的新生子代在分娩后进行了头位测量观察。新生儿背腹侧颅面大小采用背腹侧脑电图x、y坐标值计算。统计分析显示，移植组与非移植组的颅面大小组间差异显著，三种受术者的颅面大小组间差异显著。因此，揭示了胚胎移植技术可能延缓移植胚胎颅面复合体的产前发育，并且三种受体通过各自的子宫内环境作为产前母体效应对移植胚胎颅面复合体的产前发育贡献不均衡。这些结果表明，受体子宫内环境对小鼠胚胎颅面复合体的产前发育起重要作用。少

To examine the degree of the relative contribution of genetic and environmental effects to preimplantation development of mouse embryo in vitro, two-cell stage embryos collected from oviducts of five strains of inbred mice(DDD/QDJ, C3H/ QDJ, C57BL/6J Sea,DBA/1J Sea, and BALB/C Sea) were cultivated up to the stage of expanded blasytocyst for seventy two hours. Both fertility and survival rates were calculated in each recipient and also in each strain. A Student-Newman-Keuls test for both rates showed a significant interstrain difference and an analysis of variance done to estimate the relative importance of genetic and environmental effects on the preimplantation development of embryo showed a low degree of genetic determination for both rates. It was thus possible to conclude that the environmental effect played a more important role on preimplantation development of mouse embryo in vitro.Embryo transfer effect and intra-uterine effect of dam on prenatal development of craniofacial com … More plex of mice embryos were investigated with use of embryo transfer and cephalostat. DDD strain embryos were transferred to the three strains of recipients (DDD, C57BL and DBA). The cephalometric observation of newborn offspring developed from transferred embryos was performed just after parturition. Dorso-ventral craniofacial size of newborn offspring was calculated using values of X-and Y-coordinates on dorso-ventral cephalogram. Statistical analysis showed that a significant inter-group difference in craniofacial size between transferred and non-transferred groups as well as a significant inter-strain difference among those of the three strains of recipients were observed. Thus, it was disclosed that embryo transfer technique might retard the prenatal development of craniofacial complex of transferred embryo and that the three strains of recipients contributed unequally to the prenatal development of craniofacial complex of transferred embryo through each of their intra-uterine environment as a prenatal matemal effect. These results indicated that the intra-uterine environment of recipient played an important role in the prenatal development of craniofacial complex of mice embryo. Less