Histological and Biochemical Observations of Developing Enameloid of the Sea Bream

¹ Departments of Anatomy and Biochemistry, School of Dental Medicine, Tsurumi University, Tsurumi-ku, Yokohama 230, Japan

In order to study changes in the enameloid matrix of the Sea Bream during the course of its development, we selected the developmental tooth germs of this fish as representative of three different developmental stages: " chalk-like", " cheese-like", and " soft" enameloid. The protein, calcium, and phosphate contents of each sample were analyzed. The changes of the total protein content in each sample suggest that a major part of the proteins decreased during maturation, although newly formed enameloid of the Sea Bream contains collagen and noncollagenous proteins. The existence of proteolytic activity was examined by placement of undemineralized cryostat sections of unfixed tooth germs on exposed and processed photographic films and then incubation for 30 min in a water-saturated atmosphere at 37 ° C. Proteolytic activity could be detected in the enameloid matrix, which appeared to be in a " cheese-like" stage. It is suggested that proteolytic enzymes play an important role in the removal of proteins during the maturation of enameloid, although the detailed mechanism of the process is still obscure.

Note:

We are grateful to Dr. R. W. Fearnhead for his kind advice.

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