For the production and rederivation of mouse strains, pseudopregnant female mice are used for embryo transfer and serve as surrogate mothers to support embryo development to term. Vasectomized males are commonly used to render pseudopregnancy in females, generated by surgical procedures associated with considerable pain and discomfort. Genetically modified mouse strains with a sterility phenotype provide a non-surgical replacement and represent an important application of the 3Rs (Replacement, Reduction, Refinement). However, the maintenance of such genetically modified mouse strains requires extensive breeding and genotyping procedures, which are regulated procedures under national legislation. As an alternative, we have explored the use of sterile male hybrids that result when two wild-type mouse subspecies, Mus musculus musculus and Mus musculus domesticus, interbreed. We find the male STUSB6F1 hybrid, resulting from the mating of female STUS/Fore with male C57BL/6J, ideally suited and demonstrate that its performance for the production of oviduct and uterine transfer recipients is indistinguishable when compared to surgically vasectomized mice. The use of these sterile hybrids avoids the necessity for surgical procedures or the breeding of sterile genetically modified lines and can be generated by the simple mating of two wild-type laboratory strains—a non-regulated procedure. Furthermore, in contrast with the breeding of genetically sterile mice, all male offspring are sterile and suitable for the generation of pseudopregnancy, allowing their efficient production with minimal breeding pairs.

对于小鼠品系的生产和再衍生，假孕雌性小鼠用于胚胎移植，并作为代孕母亲支持胚胎发育至足月。男性输精管切除术通常用于使女性假孕，这是由与相当大的疼痛和不适相关的外科手术产生的。具有不育表型的转基因小鼠品系提供了非手术替代品，并代表了 3Rs（替代、减少、细化）的重要应用。然而，维持这种转基因小鼠品系需要广泛的育种和基因分型程序，这是国家立法规定的程序。作为替代方案，我们已经探索了当两个野生型小鼠亚种时产生的不育雄性杂种的使用，Mus musculus musculus和Mus musculus domesticus杂交。我们发现雄性 STUSB6F1 杂交种是由雌性 STUS/Fore 与雄性 C57BL/6J 交配产生的，非常适合并证明其在生产输卵管和子宫转移受体方面的性能与手术输精管切除小鼠相比无法区分。使用这些不育杂种避免了外科手术的必要性或育种不育的转基因品系，并且可以通过两个野生型实验室菌株的简单交配来产生——这是一种不受管制的过程。此外，与遗传不育小鼠的繁殖相比，所有雄性后代都是不育的，适合假孕的产生，从而可以用最少的繁殖对进行有效生产。