Evolutionary relationships of the gut hormones

Area of Science:

• Comparative physiology
• Evolutionary biology
• Neuroendocrinology

Background:

• Peptides homologous to mammalian gut hormones are widely distributed in various tissues, including the brain, nerves, and invertebrate systems.
• This dual distribution suggests an ancient evolutionary origin, potentially predating the divergence of major vertebrate groups.

Purpose of the Study:

• To investigate the evolutionary history and functional conservation of gut hormones.
• To explore the co-evolution of gut peptides and their receptor mechanisms across different species.

Main Methods:

• Comparative sequence analysis of gut peptides across diverse species.
• Examination of functional similarities and differences in peptide roles in various organisms.
• Review of evidence for conserved functional residues and receptor mechanisms.

Main Results:

• Gut hormones and related peptides exhibit a broad distribution beyond the gut, including the central nervous system.
• Evolutionary analysis reveals gene duplication and divergence as key mechanisms in peptide evolution, with conserved functionally important residues.
• Evidence suggests distinct but related roles for peptides like secretin and vasoactive intestinal polypeptide (VIP) in regulating pancreatic function in mammals versus birds, respectively.

Conclusions:

• The widespread presence and conserved sequences of gut hormones point to their ancient origins and fundamental roles in vertebrate physiology.
• Evolutionary modifications in both peptide structure and target organ receptors have led to diversified functions across species, exemplified by secretin and VIP roles.