Sperm storage induces an immunity cost in ants

Research output: Contribution to journalJournal articleResearchpeer-review

Boris Baer, Sophie A O Armitage, Jacobus J Boomsma

Ant queens are among the most long-lived insects known. They mate early in adult life and maintain millions of viable sperm in their sperm storage organ until they die many years later. Because they never re-mate, the reproductive success of queens is ultimately sperm-limited, but it is not known what selective forces determine the upper limit to sperm storage. Here we show that sperm storage carries a significant cost of reduced immunity during colony founding. Newly mated queens of the leaf-cutting ant Atta colombica upregulate their immune response shortly after completing their nest burrow, probably as an adaptive response to a greater exposure to pathogens in the absence of grooming workers. However, the immune response nine days after colony founding is negatively correlated with the amount of sperm in the sperm storage organ, indicating that short-term survival is traded off against long-term reproductive success. The immune response was lower when more males contributed to the stored sperm, indicating that there might be an additional cost of mating or storing genetically different ejaculates.
Original languageEnglish
Issue number7095
Pages (from-to)872-5
Number of pages3
Publication statusPublished - 2006

Bibliographical note

Keywords: Animals; Ants; Ejaculation; Female; Fertilization; Fungi; Haplotypes; Immunity; Male; Models, Biological; Spermatozoa; Time Factors

ID: 9619778