海马中特异性敲除Dicer1蛋白的小鼠的构建和表型

目的：在小鼠海马中特异性敲除RNA酶Ⅲ酶（RNAase Ⅲenzyme）Dicer1,并初步观察Dicer1在小鼠海马的生长发育中起到的基本作用。方法：用在海马中特异性表达Cre酶的Frizzled9-CreERTM小鼠和Dicer1（flox/flox）小鼠交配,得到Dicer1（flox/＋）;Frizzled9-CreERTM小鼠,并再次与Dicer1（flox/flox）交配,得到Dicer1（flox/flox）;Frizzled9-CreERTM小鼠,用他莫昔芬（TM）诱导Cre酶的表达,使Dicer1在海马中特异性敲除,观察小鼠的表型。结果：TM诱导的Dicer1全敲的小鼠出生率低,大部分在出生后40天左右死亡,海马中CA3区域变薄,猜测与海马中缺乏Dicer1酶有关。结论：Dicer1是miRNA产生过程中的重要因素,在海马中敲除Dicer1后影响小鼠发育,小鼠易猝死。

Generation of Dicer1 Conditional Null Allele in the Hippocampus in Mouse

Objective： Dicer1（RNAase III enzyme） was knocked out in a spatial or temporal-specific manner in the hippocampus,and preliminary observations were conducted to find out the role that Dicer1 played in the growth and development of the mouse hippocampus.Methods： The Frizzled9-CreERTM mice in which Cre enzyme was exclusively detected in the hippocampus bred with Dicer1（flox/flox） mouse to obtain Dicer1（flox/＋）;Frizzled9-CreERTM mice,then bred with the Dicer1（flox / flox） mouse again to obtain Dicer1（flox/flox）;Frizzled9-CreERTM mice.Using tamoxifen（TM） to induce the expression of Cre enzyme,Dicer1 was specifically knocked out in the hippocampus in mice then observed the phenotype of mice.Results： The TM induced Dicer1 Conditional Null Allele in the Hippocampus almost died about 40 days after birth;the CA3 region in the hippocampus was thinner.It was probably caused by the lack of Dicer1 enzyme in the hippocampus.Conclusion： Dicer1 plays an important role in the production of miRNA.Hippocampus without Dicer 1 cannot develop or grow normally and sudden death is more like to happen.