Yokoyama M, Hasegawa T, Nomura T, Katsuki M
Central Institute for Experimental Animals, Kanagawa, Japan.
Exp Anim. 1995 Apr;44(2):145-50. doi: 10.1538/expanim.44.145.
We attempted to convert the genetic background of transgenic (Tg) mice in a short period of time by applying in vitro fertilization techniques. Tg mice were obtained by injecting human interleukin-2 (hIL-2) gene into the fertilized eggs of the C57BL/6N strain. These Tg mice were back-crossed 8 times to the inbred C3H/HeN strain using the hIL-2 gene as the genetic selection marker. In order to shorten the length of the back-crossing time, in vitro fertilization was performed with eggs collected from immature Tg females and spermatozoa from mature C3H/HeN males, and successfully fertilized eggs (2-cell stage) were transferred to pseudopregnant recipients to obtain the offspring of next generation. When no offspring were obtained through the procedures using immature Tg females, in vitro fertilization was performed with mature Tg males and mature C3H/HeN females to continue successive back-crosses. With this method, it was possible to perform 8 successive back-crosses in 18 months.
我们试图通过应用体外受精技术在短时间内改变转基因（Tg）小鼠的遗传背景。通过将人白细胞介素-2（hIL-2）基因注入C57BL/6N品系的受精卵中获得Tg小鼠。这些Tg小鼠以hIL-2基因为遗传选择标记与近交系C3H/HeN品系回交了8次。为了缩短回交时间，用从未成熟Tg雌性小鼠采集的卵子和成熟C3H/HeN雄性小鼠的精子进行体外受精，并将成功受精的卵子（2细胞期）移植到假孕受体中以获得下一代后代。当通过使用未成熟Tg雌性小鼠的程序未获得后代时，用成熟Tg雄性小鼠和成熟C3H/HeN雌性小鼠进行体外受精以继续连续回交。用这种方法，可以在18个月内进行8次连续回交。
