Tenascin Mr 220,000 isoform expression correlates with corneal cell migration

Area of Science:

• Developmental Biology
• Extracellular Matrix Biology
• Molecular Biology

Background:

• Tenascin is an extracellular matrix glycoprotein involved in cell adhesion and migration.
• Chicken tenascin exists in three isoforms (ten220, ten200, ten190) generated by alternative splicing.
• Understanding tenascin isoform expression is crucial for comprehending developmental processes.

Purpose of the Study:

• To investigate the differential expression of chicken tenascin isoforms during embryonic development.
• To correlate tenascin isoform expression with specific developmental events, particularly cell migration.
• To characterize the molecular properties of cell migration-associated tenascin isoforms.

Main Methods:

• Development of specific monoclonal antibodies (mAb T17 for ten220, mAb T16 for all isoforms).
• Immunohistochemical analysis of tenascin isoform distribution in embryonic chicken tissues.
• Biochemical analysis of tenascin isoforms from tissue extracts.

Main Results:

• Ten220 expression strongly correlates with cell migration in the embryonic cornea, appearing before and disappearing after neural crest cell and fibroblast invasion.
• Ten190/200 isoforms are present in the corneal epithelium, lens, sclera, and remain near the endothelium and Bowman's membrane.
• A potential new tenascin isoform (Mr 210,000) was detected in brain extracts.

Conclusions:

• Tenascin isoform synthesis is tightly regulated during development.
• The ten220 isoform likely plays a functional role in facilitating cell migration.
• Alternative splicing of tenascin contributes to diverse functions during embryonic development.