A New Strategy for Constructing Mouse Models of Complex Diseases: Semi-cloning Technology Based on Sperm-like Haploid Embryonic Stem Cells

The development of haploid genetics has motivated studies on genome evolution and function, especially the technological advancements in recent years have prompted the birth of culture techniques for mammalian haploid embryonic stem cells (haESCs). Sperm-like haESCs are novel haESCs derived from mouse parthenogenetic blastocysts. Sperm-like haESCs only contain paternal genetic material, and their sex chromosome is the X chromosome. They can self-renew, differentiate, and proliferate in vitro for a long time. Furthermore, editing single or multiple genes using the CRISPR system is possible for sperm-like haESCs, which can replace sperms to fertilize oocytes. In contrast to traditional methods for constructing mouse models, such as pronuclear injection, cytoplasmic injection, and tetraploid complementation, by injecting sperm-like haESCs after gene editing into oocytes, semi-cloned mice with a definitive genotype can be obtained efficiently and stably without chimerism, and primary mice can be used for research. The mouse disease model based on multiple precisely edited genes obtained from sperm-like haESCs can explain the effect of multiple genes synergistic interaction at the level of biological individuals to completely simulate various pathological characteristics of complex human diseases that may be affected by multiple genes, and this model facilitates the exploration of novel diagnostic and therapeutic methods.