Involvement of the zebrafish trrap gene in craniofacial development

Area of Science:

• Developmental Biology
• Genetics
• Molecular Biology

Background:

• Trrap (transformation/transcription domain-associated protein) is a key component of histone acetyltransferase (HAT) complexes involved in gene transcription and DNA repair.
• The specific developmental roles of Trrap in vertebrates remain largely uncharacterized.
• Human TRRAP gene mutations are linked to developmental disorders like microcephaly and facial dysmorphisms.

Purpose of the Study:

• To investigate the physiological functions of Trrap during vertebrate development.
• To establish and characterize trrap gene-knockout zebrafish as a model for human TRRAP-related disorders.

Main Methods:

• Generation of trrap gene-knockout zebrafish.
• Phenotypic analysis of trrap mutants, including morphological assessments (head and eye size, pharyngeal arch development, tooth mineralization).
• Whole-mount in situ hybridization to examine gene expression patterns (dlx3, dlx2b) in developing pharyngeal arches.

Main Results:

• Trrap zebrafish mutants displayed significantly smaller heads and eyes compared to wild-type siblings.
• Reduced size of ventral pharyngeal arches and impaired tooth mineralization were observed in trrap mutants.
• Expression of dlx3 was restricted, and dlx2b was diminished in the pharyngeal arches of trrap mutants.

Conclusions:

• Trrap plays a crucial role in vertebrate craniofacial and dental development.
• Trrap zebrafish mutants serve as a valuable model organism for studying human disorders caused by TRRAP gene mutations.
• The study elucidates specific developmental defects associated with Trrap loss-of-function, providing insights into its physiological importance.