title: Hybridization and pre-zygotic reproductive barriers in Plasmodium.
abstract: Sexual reproduction is an obligate step in the life cycle of many parasites, including the causative agents of malaria (Plasmodium). Mixed-species infections are common in nature and consequently, interactions between heterospecific gametes occur. Given the importance of managing gene flow across parasite populations, remarkably little is understood about how reproductive isolation between species is maintained. We use the rodent malaria parasites P. berghei and P. yoelii to investigate the ecology of mixed-species mating groups, identify proteins involved in pre-zygotic barriers, and examine their evolution. Specifically, we show that (i) hybridization occurs, but at low frequency; (ii) hybridization reaches high levels when female gametes lack the surface proteins P230 or P48/45, demonstrating that these proteins are key for pre-zygotic reproductive isolation; (iii) asymmetric reproductive interference occurs, where the fertility of P. berghei gametes is reduced in the presence of P. yoelii and (iv) as expected for gamete recognition proteins, strong positive selection acts on a region of P230 and P47 (P48/45 paralogue). P230 and P48/45 are leading candidates for interventions to block malaria transmission. Our results suggest that depending on the viability of hybrids, applying such interventions to populations where mixed-species infections occur could either facilitate or hinder malaria control.
authors: Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK ramiroricardo@gmail.com.
authors: Ricardo S
authors: RS
authors: Ramiro
authors: Department of Parasitology, Leiden Malaria Research Group, LUMC, Albinusdreef 2, ZA Leiden 2333, The Netherlands.
authors: Shahid M
authors: SM
authors: Khan
authors: Department of Parasitology, Leiden Malaria Research Group, LUMC, Albinusdreef 2, ZA Leiden 2333, The Netherlands.
authors: Blandine
authors: B
authors: Franke-Fayard
authors: Department of Parasitology, Leiden Malaria Research Group, LUMC, Albinusdreef 2, ZA Leiden 2333, The Netherlands.
authors: Chris J
authors: CJ
authors: Janse
authors: Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK.
authors: Darren J
authors: DJ
authors: Obbard
authors: Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK Centre for Immunity, Infection and Evolution, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK Institute of Immunology and Infection Research, University of Edinburgh, Ashworth Laboratories, West Mains Road, Edinburgh EH9 3JT, UK.
authors: Sarah E
authors: SE
authors: Reece
mesh_terms: D019143:Evolution, Molecular; D051456:Gene Flow; D006824:Hybridization, Genetic; D008969:Molecular Sequence Data; D010962:Plasmodium berghei / Q000235:genetics* / Q000378:metabolism; D010967:Plasmodium yoelii / Q000235:genetics* / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D012098:Reproduction; D017422:Sequence Analysis, DNA
chemical_list: D015800:Protozoan Proteins
keywords: P230; P48/45; hybridization; malaria; reproductive isolation; transmission