Mouse-chick chimera: an experimental system for study of somite development

Area of Science:

• Developmental biology
• Comparative embryology
• Stem cell biology

Background:

• Mammalian embryonic development is difficult to study directly due to uterine implantation.
• Lower vertebrate models are often used to understand mammalian somite development.
• In ovo grafting offers a method to study mammalian embryonic development.

Purpose of the Study:

• To investigate the developmental potential of mouse somites in a chick embryo environment.
• To examine the contribution of transplanted mouse somites to muscle formation in chick embryos.
• To explore the interaction between mouse neural tissue and somites in host myogenesis.

Main Methods:

• Unilateral replacement of chick somites with mouse fetal somites in ovo.
• Utilizing a LacZ transgenic mouse strain for lineage tracing.
• Transplantation of fetal mouse neural primordium into chick embryos.

Main Results:

• Mouse somites differentiated into dermis, cartilage, and skeletal muscle within the chick embryo.
• Implanted mouse muscle cells migrated into the chick host limb.
• Mouse myotome-derived muscle cells formed neuromuscular connections with chick motor axons.
• Mouse neural tube transplantation supported myogenesis in host somites.

Conclusions:

• Mouse somites can develop and integrate into chick embryos, contributing to muscle formation.
• Mouse neural tissue plays a role in maintaining myogenesis within developing somites.
• This chick-mouse chimera model is valuable for studying somitogenesis and myogenesis.
• Future studies using knockout mouse strains will elucidate molecular mechanisms of somitogenesis.