交叉抚育经历对根田鼠体重发育的影响

Effects of cross-fostering during early postnatal period on body weight development in root vole(Microtus oeconomus)

为检验交叉抚育经历对根田鼠体重发育的可能影响,监测了雌雄亲生和寄养幼仔的体重生长。结果发现:在不同发育时期(2～70日龄),雄性亲生与寄养幼仔的体重没有差异;除第18和20日龄外,其它时期(2～16,25～70日龄)雌性亲生与寄养幼仔的体重没有差异;亲生和寄养幼仔在25日龄前两性体重差异不明显;25日龄后两性体重差异显著;随着日龄的增加,根田鼠的体重日增长率呈现下降趋势。这些结果表明交叉抚育经历对雄性个体的发育没有影响,对雌性体重发育可能存在短暂影响,但持续时间不长(3d≤T<9d);根田鼠亲生和寄养幼仔体重生长的性别差异均在25日龄前后形成。

The laboratory population of root vole （ Microtus oeconomus） was founded by cross-fostering method. In order to test the effects of fostering on body weight development, body weights of offspring and fostered offspring were measured respectively. The results showed that： There was no significant difference in male vole body weights during different developmental periods （2 -70 age in days）. There was no significant difference in female vole body weight during developmental periods （2 - 16, 25 -70 age in days） apart from 18 and 20 age in days. Before 25 age in days, there were no significant differences in body weight between male and female voles in offspring and fostered offspring separately. The differences of body weight between different sexes reached to the significant level from 25 ages in days. With the increase of age in days, the descendant tendencies of increasing ratio per day were evident among 4 groups of root voles. The regress equations were non-linear. It indicated that the fostering experience had transient influence （3d ≤ T 〈 9 d） on female rather than on male voles. Sexual dimorphisms of body weight were formed at the age of about 25 days in offspring and fostered offspring. Increasing ratio per day of 4 groups of root voles showed similarly descending tendency.