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[Contribution to hair medulla study (author's transl)]
Annales De Dermatologie Et De Venereologie
|January 1, 1981
Summary
This study reveals the complex anatomical structure of hair medullary cells across mammal genera. We observed distinct evolutionary changes in medullary cell composition, from amorphous to granular or fibrillar structures.
Area of Science:
- Anatomy
- Cell Biology
- Mammalogy
Context:
- Hair morphology and development are crucial for understanding mammalian evolution.
- Previous research indicated amorphous medullary cell cytoplasm and microfibril formation in the inner root sheath.
- Medulla and inner root sheath are characterized by low sulfur content and high citrulline, with specific protein cross-linking.
Purpose:
- To elucidate the anatomical features of hair medullary cells.
- To investigate the evolutionary patterns of these features across different mammal genera.
- To correlate medullary cell structure with biochemical composition.
Summary:
- Utilizing scanning electron microscopy (SEM) and transmission electron microscopy (TEM), this study provides detailed anatomical and ultrastructural observations of hair medullary cells.
- The research highlights the complexity and evolutionary development of medullary cells, contrasting with previous assumptions.
- Observations reveal variations in medullary cell content, ranging from amorphous to biphasic (granular) in higher mammals, and containing macro- and microfibrils in humans and anthropoids.
Impact:
- The findings enhance our understanding of hair cell differentiation and evolution in mammals.
- Identifies similarities between medullary microfibrils and those in the inner root sheath.
- Explains the presence of citrulline and epsilon(gamma-glutamyl)lysine bonds in medullary cells, linking structure to biochemistry.