GreenAnt · Nature of a Greenbeard Gene in the Fire Ant
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-09-01 → 2021-09-26
- EU contribution
- €203,149
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Nature of a Greenbeard Gene in the Fire Ant
Genes generally spread in populations by increasing the survival and/or reproductive success of the carrier organism. However, some genetic elements gain a transmission advantage without increasing the host organism’s fitness. Such pieces of DNA –called « selfish » genetic elements (SGEs)– induce intragenomic conflicts, which have far-reaching consequences on the evolution of genomes and organisms. Greenbeard genes are a special type of SGEs, which achieve a transmission bias by increasing the fitness of other individuals also carrying the greenbeard gene. Such phenotype, known as a "Greenbeard effect", can only occur if a gene or a group of tightly linked genes produce 1: a conspicuous phenotype, 2: the ability to recognize this phenotype, allowing the bearer individual to discriminate carriers from non-carriers and 3: a nepotistic behavior in favor of carriers. Because of these requirements, Greenbeard effects have been presumed to be rare in nature. The first identified Greenbeard genetic element was identified in the fire ant Solenopsis invicta. In this species, the Greenbeard effect is produced by a single Mendelian genomic element: the Social b (Sb) supergene. Sb-bearer workers kill non-bearer queens (SB/SB) to replace them by carrying-queens (SB/Sb). The objective of the project GreenAnt is to take advantage of the fire ant Greenbeard system to identify and characterize the genetic elements involved in this SGE. The aim of my project is to determine how workers discriminate Greenbeard-carrier queens from non-carriers.
Data: CORDIS, © European Union
Project objective
Greenbeard genes are selfish genetic elements (SGEs) that favor their own transmission by increasing the fitness of other carrying individuals. Such a phenotype, can only occur if a gene or a group of tightly linked genes produce (1) a conspicuous phenotype, (2) the ability to recognize this phenotype, allowing the bearer individual to discriminate carriers from non-carriers and (3) a nepotistic behavior in favor of carriers. These extraordinary SGEs can have profound evolutionary consequences on genomes and social behavior. The first identified Greenbeard haplotype was in the fire ant Solenopsis invicta. In this species, the Social b (Sb) supergene, an 11 Mb non-recombining region is associated with a Greenbeard effect. Discriminating on cuticular chemical profiles, carrier ant workers spread the Sb supergene by killing non-bearer queens. In this project I aim to identify the genetic basis of the queen-discrimination ability of Greenbeard-carrier ant workers. I will first compare the molecular evolution of the Sb supergene with the non-driving homologous haplotype over multiple bearer and outgroup species. Then I will compare patterns of expression of Sb supergene genes in antennae and brains between workers. Lastly, I will functionally validate candidate genes by genetically altering their sequence in workers. I will assay the impact of the knock out on the Greenbeard effect by testing the queen-discrimination ability of transformed workers. Using this combination of techniques and analyses, the GreenAnt project will tackle the molecular basis and evolution of Greenbeard genes in metazoan organisms.
Original text from CORDIS.
Participants
- UNIVERSITE DE LAUSANNE · LAUSANNECoordinatorSwitzerland
Links
Data: CORDIS, © European Union