In:
eLife, eLife Sciences Publications, Ltd, Vol. 4 ( 2015-07-15)
Abstract:
Single-celled parasites cause many severe diseases in humans and animals. The apicomplexans form probably the most successful group of these parasites and include the parasites that cause malaria. Apicomplexans infect a broad range of hosts, including humans, reptiles, birds, and insects, and often have complicated life cycles. For example, the malaria-causing parasites spread by moving from humans to female mosquitoes and then back to humans. Despite significant differences amongst apicomplexans, these single-celled parasites also share a number of features that are not seen in other living species. How and when these features arose remains unclear. It is known from previous work that apicomplexans are closely related to single-celled algae. But unlike apicomplexans, which depend on a host animal to survive, these algae live freely in their environment, often in close association with corals. Woo et al. have now sequenced the genomes of two photosynthetic algae that are thought to be close living relatives of the apicomplexans. These genomes were then compared to each other and to the genomes of other algae and apicomplexans. These comparisons reconfirmed that the two algae that were studied were close relatives of the apicomplexans. Further analyses suggested that thousands of genes were lost as an ancient free-living algae evolved into the apicomplexan ancestor, and further losses occurred as these early parasites evolved into modern species. The lost genes were typically those that are important for free-living organisms, but are either a hindrance to, or not needed in, a parasitic lifestyle. Some of the ancestor's genes, especially those that coded for the building blocks of flagella (structures which free-living algae use to move around), were repurposed in ways that helped the apicomplexans to invade their hosts. Understanding this repurposing process in greater detail will help to identify key molecules in these deadly parasites that could be targeted by drug treatments. It will also offer answers to one of the most fascinating questions in evolutionary biology: how parasites have evolved from free-living organisms.
Type of Medium:
Online Resource
ISSN:
2050-084X
DOI:
10.7554/eLife.06974.001
DOI:
10.7554/eLife.06974.002
DOI:
10.7554/eLife.06974.003
DOI:
10.7554/eLife.06974.004
DOI:
10.7554/eLife.06974.005
DOI:
10.7554/eLife.06974.006
DOI:
10.7554/eLife.06974.007
DOI:
10.7554/eLife.06974.008
DOI:
10.7554/eLife.06974.014
DOI:
10.7554/eLife.06974.009
DOI:
10.7554/eLife.06974.010
DOI:
10.7554/eLife.06974.011
DOI:
10.7554/eLife.06974.012
DOI:
10.7554/eLife.06974.013
DOI:
10.7554/eLife.06974.015
DOI:
10.7554/eLife.06974.016
DOI:
10.7554/eLife.06974.017
DOI:
10.7554/eLife.06974.018
DOI:
10.7554/eLife.06974.019
DOI:
10.7554/eLife.06974.020
DOI:
10.7554/eLife.06974.021
DOI:
10.7554/eLife.06974.022
DOI:
10.7554/eLife.06974.023
DOI:
10.7554/eLife.06974.024
DOI:
10.7554/eLife.06974.034
DOI:
10.7554/eLife.06974.025
DOI:
10.7554/eLife.06974.026
DOI:
10.7554/eLife.06974.027
DOI:
10.7554/eLife.06974.028
DOI:
10.7554/eLife.06974.029
DOI:
10.7554/eLife.06974.030
DOI:
10.7554/eLife.06974.031
DOI:
10.7554/eLife.06974.032
DOI:
10.7554/eLife.06974.033
Language:
English
Publisher:
eLife Sciences Publications, Ltd
Publication Date:
2015
detail.hit.zdb_id:
2687154-3
