SOME HISTOCHEMICAL OBSERVATIONS ON THE LIMB BUDS OF MOUSE EMBRYO
- VernacularTitle:对于小鼠胚胎肢芽的一些组织化学观察
- Author:
Tsokan CHANG
- Publication Type:Journal Article
- From:
Acta Anatomica Sinica
1955;0(03):-
- CountryChina
- Language:Chinese
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Abstract:
The limb buds of mouse embryos from 10-17 days were used for the study on the distribution of acid and alkaline phosphatases according to MacDonald's modification of lead nitrate and Danielli's modification of calcium cobalt methods respectively. McManus' modification of Hotchkiss' PAS was used for the demonstration of glycogen with control sections stained after diastase digestion. A modified diluted methyl green-pyronine method was used for the stain of nuclei acids. The reaction of both alkaline and acid phosphatases was weak in the limb buds of 2-3 mm embryos when they began to bulge out from the somatopleure. The reaction became stronger when the apical ectodermal thickening process in the limb buds of 3-4 mm embryos began. It increased further when the thickening reached its full development in 5-7 mm embryos. Since then the enzymes were weakened together with the thinning of the thickening. The ectoderm, particularly that in the shoulder region, had more glycogen granules than that of the apical ectodermal thickening. The ribonucleic acid took deeper stain in the thickening than that of the general ectodermal covering due to vacuolization of the latter. There were pyknotic nuclear fragments of different sizes in the thickening, more frequently in the regressional ones. They were considered to be in the process of autolysis. The staining reaction of phosphatases and ribonucleic acids was increased in the mesodermal cells around the cartilage primordia and in the premuscle masses. It was even more prominent when the perichondrial fibroblasts and myoblasts were in process of elongation. During chondrification, the phos- phatases and ribonucleic acid began to increase in precartilage stage, reached their maximum in the chondrocytes before hypertrophy and became decreas- sed in the hypertrophied cells. The glycogen granules in the fully developed muscle fibers were about the same as that of the myoblasts, but the phos- phatases and nucleic acid were decreased in the former. In general the changes were prominent in phosphatases than in ribonucleic acid and gly- cogen. The above phenomena lead one to correlate the increase of phosphatases and nucleic acid with embryonic differentiation. The increase of glycogen content may or may not follow the increase of either the phosphatases or ribonucleic acid. Their significance in embryonic development was discussed.
