engleski

Differentiation of mouse egg-cylinders cultured in vitro

Mammalian embryo culture systems are used for studying normal and abnormal embryo development1, 2. In present study postimplantation mouse embryos without extraembryonic parts were cultivated in vitro to determine sequence of appearance of various tissues and the time needed for their differentiation. Embryonic development in vitro was compared with development in vivo. Gastrulating CD1 mouse embryos E7.5 were cultivated in Dulbecco's Modified Eagle Medium with 20% foetal bovine serum. After 1, 2, 3, 4, 7, and 14 days explants were taken for histology and serial semithin sections were prepared and analysed by light microscopy. After 3 days of culture neural (Fig 1.) and surface epithelium, and columnar epithelium corresponding to the primitive gut was present in the explants. From fourth till seventh day the neuroepithelium with noticeable basal lamina formed small cysts in the mesenchyme. After 14 days of culture more differentiated derivatives of all three germ layers were present. Among others, stratified squamous epithelium, cartilage with perichondrium and pseudostratified columnar epithelium with ciliae and goblet cells were observed. The present findings indicate that after cultivation of gastrulating mouse embryos, structures like neuroepithelium and primitive gut were observed two days later than in vivo. Although we used significantly lower percentage of serum than in previous studies, after two-weeks of culture all main tissue types were present.

mouse embryo; culture in vitro; differentiation

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