Three vertebrate hyaluronan synthases are expressed during mouse development in distinct spatial and temporal...

Area of Science:

• Developmental Biology
• Molecular Genetics
• Gene Expression Analysis

Background:

• Hyaluronan is a crucial glycosaminoglycan in vertebrate development.
• The hyaluronan synthase (Has) gene family encodes enzymes responsible for hyaluronan synthesis.
• Understanding the spatiotemporal expression of Has genes is vital for elucidating their developmental roles.

Purpose of the Study:

• To investigate the expression patterns of the mouse hyaluronan synthase (Has) gene family members (Has1, Has2, and Has3) during embryonic development.
• To determine the specific tissues and developmental stages where each Has gene is expressed.
• To analyze the potential overlapping and complementary roles of Has genes in mouse embryogenesis.

Main Methods:

• In situ hybridization was employed to detect Has gene transcripts in developing mouse embryos.
• Expression patterns were analyzed at various embryonic days (E), starting from E7.5.
• Specific attention was given to craniofacial, cardiac, skeletal, and appendage development.

Main Results:

• Has1 and Has2 were broadly expressed at embryonic day (E) 7.5.
• Has1 expression diminished after E8.5, while Has2 showed strong transient expression in branchial arches, craniofacial structures (palatal shelves, lens pit), heart, skeleton, and tail.
• Has3 transcripts appeared at E10.5 in the first branchial arch and showed complementary expression to Has2 in developing teeth, hair follicles, nasal cavity, and inner ear.

Conclusions:

• The Has gene family exhibits dynamic and distinct expression profiles during mouse development.
• Has2 plays a significant role in multiple developmental processes, including craniofacial and cardiac formation.
• Has3 expression patterns complement those of Has2 in specific ectodermal appendages and sensory organs, suggesting coordinated functions.