Niklas Janz and colleagues have recently proposed that host-dependent groups (this works for parasites and for plant-eating insects that have specific plant host requirements) evolve through alternating episodes of increasing numbers of host species followed by isolation on restricted numbers of host species.
Competition has likely separated different species by host species as well as by host requirements within the same species, resulting in unique niches based on such characters as phloem thickness, tree defense chemistry, nutritional quality and water content [11].
(3) Does the island consist of a combination of genes showing different host requirements for expression?
Our results indicate the presence of common host requirements for DENV in mosquitoes and humans.
Additionally, there is still much to be discovered regarding the viral and host requirements for HP protein priming and the conformational dynamics of HP throughout viral replication.
Given the very distinct fundamental host requirements and the vastly different host niches occupied by these two genotypes, we were interested to identify to what degree this would be reflected in their respective gene profiles.
First, Gilbert and Webb limited their analysis to necrotrophic fungal pathogens that were easily grown on laboratory media, which might be expected to have less specific host requirements than many of the fungi (and other pests) in the current analysis.
Sciomyzids have three larval stages and most species exhibiting parasitoid behavior have very specific host requirements in the 1st and 2nd larval stage but become more generalized predators in the 3rd stage.
All these data suggest that massive gene losses may have occurred in Blattabacterium genomes soon after the transition from the free-living state to the intracellular life style, establishing an optimal genome to fulfill the host requirements, albeit minimized.
Various groups of avian haemosporidia can be transmitted by different primary vectors, each having unique habitat, climate, and host requirements, and understanding the evolutionary dynamics between pathogen, vector, and host components of a disease cycle is essential (Vander Wal et al. 2014).
