Evolution of mating tactics and reproductive strategies in protozoan parasites
Lead Research Organisation:
University of Edinburgh
Department Name: Inst of Evolutionary Biology
Abstract
The Phylum Apicomplexa (Protozoa) includes some of the most serious pathogens of livestock and humans. Despite extensive funding efforts, we understand remarkably little about the strategies they have evolved in order to maximise their reproductive success. These parasites, including malaria (Plasmodium) parasites, must undergo a round of sexual reproduction inside their vectors in order to transmit to new hosts. Once inside a vector's blood meal, sexual stages rapidly differentiate into gametes and fertilisation between male and female gametes occurs. However, a blood meal is a very harsh environment to be mating in, as blood is rapidly cooling and clotting. This also exposes gametes to both their host's immune factors and their vector's digestive chemicals. Consequently, male sexual stages have a maximum of 20 minutes to exit their red blood cells, differentiate into gametes and find females to fertilise. Furthermore, unlike most other male animals, male malaria parasites can only produce a maximum of eight gametes. This makes the mating system of malaria parasites very novel, yet, there is remarkably little data available and important questions remain unanswered. This proposal will discover how mating between malaria parasites is influenced by host immune factors, ask whether males randomly search for females or can home in on their location, and will investigate how co infecting species of malaria parasite maintian their species identity. A greater understanding of how and why organisms adopt the strategies we observe provides fundamental insights into the process of adaptation, as well as having valuable practical applications in areas ranging from medical science to conservation. Given the medical and economic importance of malaria parasites and the drive to develop transmission blocking vaccines and intervention strategies, understanding this process from an evolutionary and ecological perspective is of crucial importance.
Organisations
People |
ORCID iD |
Sarah Reece (Principal Investigator) |
Publications
Shuker DM
(2007)
Information use in space and time: sex allocation behaviour in the parasitoid wasp Nasonia vitripennis.
in Animal behaviour
Savill NJ
(2009)
Quantitative analysis of mechanisms that govern red blood cell age structure and dynamics during anaemia.
in PLoS computational biology
Reece S
(2007)
Lethal male-male combat in the parasitoid Melittobia acasta: are size and competitive environment important?
in Animal Behaviour
Ramiro RS
(2011)
Sex and death: the effects of innate immune factors on the sexual reproduction of malaria parasites.
in PLoS pathogens
Innocent TM
(2007)
Lethal combat and sex ratio evolution in a parasitoid wasp.
in Behavioral ecology : official journal of the International Society for Behavioral Ecology
Drew DR
(2007)
Development of reverse-transcription PCR techniques to analyse the density and sex ratio of gametocytes in genetically diverse Plasmodium chabaudi infections.
in Molecular and biochemical parasitology
Culleton RL
(2011)
Strain-specific immunity induced by immunization with pre-erythrocytic stages of Plasmodium chabaudi.
in Parasite immunology
Augustijn KD
(2007)
Functional characterization of the Plasmodium falciparum and P. berghei homologues of macrophage migration inhibitory factor.
in Infection and immunity