Osman G E, Jacobson D P, Li S W, Hood L E, Liggitt H D, Ladiges W C
Department of Molecular Biotechnology, University of Washington School of Medicine, Seattle 98195, USA.
Lab Anim Sci. 1997 Apr;47(2):167-71.
Production of fertilized oocytes and generation of transgenic mice is generally more efficient using F2 hybrid embryos than embryos from inbred mice. Most F2 hybrids are of the C57BL/6 background because of its genetic and embryologic features. However, our goal of developing a transgenic mouse model for rheumatoid arthritis necessitated using a susceptible mouse strain such as DBA/1. We prepared alpha and beta T-cell receptor (TCR) chain gene constructs and microinjected them into embryos from DBA/1, SWR, (DBA/1 x SWR)F1, and (SWR x DBA/1)F1 strains. We found SWR female mice to be prolific ovulators in response to exogenous hormones, with oocyte numbers comparable to those produced by (C57BL/6 x C3H)F1 female mice. Embryos from the (SWR x DBA/1)F1 or SWR strain were large and had prominent pronuclei, whereas (DBA/1 x SWR)F1 embryos were smaller and had less visible pronuclei, similar to those of DBA/1 embryos. Therefore, the pronuclear size and visibility are features of the SWR female mice and are independent of the genotype of the fertilizing spermatozoa. Resistance to lysis after co-injection of alpha beta TCR constructs and the efficiency of generating DNA-positive founders were comparable in SWR, (SWR x DBA/1)F1, and (C57BL6 x C3H)F2 embryos. Thus, the SWR mouse is another inbred strain, in addition to the FVB inbred strain, found to be highly suitable for propagation of transgenes. Furthermore, the SWR mouse is well defined genetically, and SWR females have a high ovulation rate, comparable to that of F1 hybrid mice.
与近交系小鼠的胚胎相比，使用F2杂交胚胎产生受精卵母细胞和生成转基因小鼠通常效率更高。由于其遗传和胚胎学特征，大多数F2杂交种具有C57BL/6背景。然而，我们开发类风湿性关节炎转基因小鼠模型的目标需要使用易感小鼠品系，如DBA/1。我们制备了α和βT细胞受体（TCR）链基因构建体，并将它们显微注射到DBA/1、SWR、（DBA/1×SWR）F1和（SWR×DBA/1）F1品系的胚胎中。我们发现SWR雌性小鼠对外源激素有良好的排卵反应，其卵母细胞数量与（C57BL/6×C3H）F1雌性小鼠产生的卵母细胞数量相当。（SWR×DBA/1）F1或SWR品系的胚胎较大，原核明显，而（DBA/1×SWR）F1胚胎较小，原核不太明显，类似于DBA/1胚胎。因此，原核大小和可见性是SWR雌性小鼠的特征，与受精精子的基因型无关。在共注射αβTCR构建体后，SWR、（SWR×DBA/1）F1和（C57BL6×C3H）F2胚胎对裂解的抗性以及产生DNA阳性奠基者的效率相当。因此，除了FVB近交系外，SWR小鼠是另一种被发现非常适合转基因繁殖的近交系。此外，SWR小鼠在基因上定义明确，SWR雌性小鼠的排卵率很高，与F1杂交小鼠相当。
