Immune priming and pathogen resistance in ant queens.

Area of Science:

• Insect immunology
• Evolutionary biology
• Life-history theory

Background:

• Invertebrates can develop resistance to pathogens after non-lethal exposure, a phenomenon known as immune priming.
• The prevalence, mechanisms, and adaptive significance of immune priming are still debated.
• Life-history theory suggests long-lived species may exhibit greater immune priming and investment.

Purpose of the Study:

• To investigate immune priming and pathogen resistance in ant queens, known for their long lifespans.
• To determine if mating status influences immune priming and resistance in ant queens.
• To explore species-specific differences in immune responses within ant queens.

Main Methods:

• Exposure of virgin and mated ant queens (Lasius niger, Formica selysi) to a low dose of Beauveria bassiana.
• Subsequent challenge with a high dose of the same entomopathogenic fungus.
• Comparison of pathogen resistance between virgin and mated queens, and across species.

Main Results:

• Evidence of immune priming was found in naturally mated Lasius niger queens.
• No immune priming was observed in virgin L. niger queens or in either virgin or mated Formica selysi queens.
• Mated queens of both species demonstrated higher pathogen resistance than virgin queens, suggesting mating up-regulates immunity.

Conclusions:

• Immune priming in ant queens is influenced by mating status and species.
• Mating appears to enhance the immune system in ant queens, increasing pathogen resistance.
• Ant queens can allocate resources to both reproduction and immunity, supported by worker care.