Transcriptomics informed discovery of developmentally essential transcription factors

Area of Science:

• Cellular and Molecular Biology
• Developmental Biology
• Genetics

Background:

• Transcription factors (TFs) are crucial for cell differentiation but many TFs remain uncharacterized.
• Model organisms like Dictyostelia amoebas offer insights into TF function during multicellular development.
• Understanding orphan TFs is essential for a complete picture of gene regulatory networks.

Purpose of the Study:

• To classify orphan transcription factors (TFs) in Dictyostelia amoebas.
• To investigate the roles of somatically expressed TFs in multicellular development.
• To identify TFs involved in regulating cell differentiation and morphogenesis.

Main Methods:

• Deletion of seven somatically expressed TF genes in Dictyostelia amoebas.
• Analysis of developmental defects in TF knock-out mutants, including slug migration and fruiting body formation.
• Transcriptomic analysis and hierarchical clustering to identify gene expression patterns and functional relationships.

Main Results:

• Four TF knock-outs (ariA-, gtaJ-, mybAA-, mybM-) exhibited distinct developmental defects.
• mybAA- mutants showed impaired multicellular aggregation and fruiting body development, linked to autophagy genes.
• mybM- mutants displayed defects in slug migration and fruiting body morphogenesis, despite normal cell-type marker expression.

Conclusions:

• Transcriptomic data effectively guided the selection of TFs for functional studies.
• Specific TFs play critical roles in Dictyostelia amoebas' development, influencing migration, morphogenesis, and potentially autophagy.
• This study advances the functional classification of orphan transcription factors in a model organism.