Runner M N
Anat Rec. 1984 Jul;209(3):399-406. doi: 10.1002/ar.1092090320.
The 11.5-day twin mice reported here support one of the classically described mechanisms for mammalian monozygotic twinning: subdivision of the blastocyst inner cell mass at the stage of proamnion cavitation. This particular method for monozygotic twinning has the attraction of providing a hypothesis for mirror image translocation of asymmetric traits. Monozygotic twins in laboratory rodents at or near parturition have not been identified and only two prior descriptions, for 7.5- and 9.5-day mouse embryos, have been found in the literature. Experimentally induced twins having identical heredity, i.e., clones, would enable study of heritable and environmental regulation of the components of discordance. A set of twin mouse embryos at 11.5 days of gestation within a common yolk sac, and with shared vitelline and allantoic circulations, provides direct evidence that monozygotic twin mice can survive rotation within the common yolk sac and suggests a reasonable probability that they can survive to term.
本文报道的11.5天龄的双胎小鼠支持经典描述的哺乳动物单卵双胎形成机制之一：在羊膜腔形成阶段囊胚内细胞团的分裂。这种单卵双胎形成的特殊方式具有吸引力，它为不对称性状的镜像易位提供了一种假说。在实验室啮齿动物中，接近或在分娩时的单卵双胎尚未被识别，并且在文献中仅发现了两篇关于7.5天和9.5天龄小鼠胚胎的先前描述。实验诱导的具有相同遗传的双胞胎，即克隆体，将能够研究不一致成分的遗传和环境调控。一组妊娠11.5天的双胎小鼠胚胎位于共同的卵黄囊内，并共享卵黄和尿囊循环，这直接证明了单卵双胎小鼠能够在共同卵黄囊内旋转存活，并表明它们有合理的概率存活至足月。
