Impacts of a newly identified behaviour-altering trematode on its host amphipod: from the level of gene expression to population.
Changes to host behaviour induced by some trematode species, as a means of increased trophic transmission, represents one of the seminal examples of host manipulation by a parasite. The amphipod Echinogammarus marinus (Leach, 1815) is infected with a previously undescribed parasite, with infected individuals displaying positive phototaxic and negative geotaxic behaviour. This study reveals that the unknown parasite encysts in the brain, nerve cord and the body cavity of E. marinus, and belongs to the Microphallidae family. An 18 month population study revealed that host abundance significantly and negatively correlated with parasite prevalence. Investigation of the trematode's influence at the transcriptomic level revealed genes with putative neurological functions, such as serotonin receptor 1A, an inebriated-like neurotransmitter, tryptophan hydroxylase and amino acid decarboxylase, present consistent altered expression in infected animals. Therefore, this study provides one of the first transcriptomic insights into the neuronal gene pathways altered in amphipods infected with a trematode parasite associated with changes to its host's behaviour and population structure.
Institute of Marine Sciences,School of Biological Sciences,University of Portsmouth,Ferry Road,Portsmouth,Hampshire,PO4 9LY,UK.
Yasmin
Y
Guler
Institute of Marine Sciences,School of Biological Sciences,University of Portsmouth,Ferry Road,Portsmouth,Hampshire,PO4 9LY,UK.
Stephen
S
Short
Institute of Marine Sciences,School of Biological Sciences,University of Portsmouth,Ferry Road,Portsmouth,Hampshire,PO4 9LY,UK.
Amaia
A
Green Etxabe
Institute of Marine Sciences,School of Biological Sciences,University of Portsmouth,Ferry Road,Portsmouth,Hampshire,PO4 9LY,UK.
Christopher M
CM
Sherhod
Cardiff School of Biosciences, Biological Sciences Building,Museum Avenue, Cardiff, CF10 3AT,UK.
Peter
P
Kille
Institute of Marine Sciences,School of Biological Sciences,University of Portsmouth,Ferry Road,Portsmouth,Hampshire,PO4 9LY,UK.
Alex T
http://orcid.org/0000-0001-5202-546X
AT
Ford
D000049:Acanthocephala / Q000502:physiology; D033304:Amphipoda / Q000235:genetics / Q000254:growth & development / Q000469:parasitology* / Q000502:physiology; D000818:Animals; D001483:Base Sequence; D001522:Behavior, Animal; D018509:DNA, Helminth / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006790:Host-Parasite Interactions; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012621:Seasons; D017422:Sequence Analysis, DNA / Q000662:veterinary; D014200:Trematoda / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology
D018509:DNA, Helminth; D004275:DNA, Ribosomal
amphipods; host behaviour; neurological genes; parasitic-manipulation; serotonin