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1-9 days old, found that the epithelium of their control explants
preserved the typical prepuberal state throughout the 3-day culture
period. The absence of spontaneous keratinization may be related to
the age of the animal from which the explants are derived. In the
cultures from the older animals this process may have been promoted
by a longer exposure to oestrogenic hormones before explantation.
FIG. 17. Vaginal explant from a 2-week mouse grown for 3 days in medium without added
hormones. The epithelium consists of one row of basal and one row of transitional cells each,
and precornified cells covered by a layer of keratin..PAS, after diastase digestion, x 500.
FIG. 18. Similar vaginal explant grown for 3 days in medium containing 2 /xg/ml of oestrone.
Note the greater number of cells and increased amount of keratin as compared with Fig. 17.
PAS, after diastase digestion, x 500.