The evolution of ADAM gene family in eukaryotes

Area of Science:

• Evolutionary biology
• Genomics
• Molecular biology

Background:

• The ADAM (A Disintegrin And Metalloprotease) gene family encodes proteins involved in cell adhesion and proteolysis.
• ADAM proteins are implicated in various diseases, including cancers.
• While twenty ADAM genes exist in humans, their evolutionary history remains largely unexplored.

Purpose of the Study:

• To investigate the evolutionary origins and expansion of the ADAM gene family across eukaryotes.
• To identify key periods of gene duplication and loss within the ADAM family's history.

Main Methods:

• Comparative genomic analysis of ADAM gene repertoires in a wide range of eukaryotic genomes.
• Phylogenetic analysis to trace the duplication and loss events of ADAM genes.

Main Results:

• ADAM genes are present in early-branching green algae (Mamiellophyceae), indicating their origin in the last common eukaryotic ancestor.
• Significant expansion of the ADAM gene family occurred in early metazoans and prominently during early vertebrate evolution.
• The majority of mammalian ADAM gene diversity can be attributed to duplications in early bony fish.
• Evidence suggests early loss of ADAM genes during green plant evolution.

Conclusions:

• ADAM genes are ancient, predating the divergence of plants, fungi, and animals.
• Vertebrate evolution, particularly in early fish, was a critical period for ADAM gene family expansion.
• The evolutionary trajectory of ADAM genes involves early origins, significant expansion in metazoans and vertebrates, and subsequent loss in certain lineages like green plants.