Genomic diversity of the human intestinal parasite Entamoeba histolytica.
BACKGROUND
Entamoeba histolytica is a significant cause of disease worldwide. However, little is known about the genetic diversity of the parasite. We re-sequenced the genomes of ten laboratory cultured lines of the eukaryotic pathogen Entamoeba histolytica in order to develop a picture of genetic diversity across the genome.


RESULTS
The extreme nucleotide composition bias and repetitiveness of the E. histolytica genome provide a challenge for short-read mapping, yet we were able to define putative single nucleotide polymorphisms in a large portion of the genome. The results suggest a rather low level of single nucleotide diversity, although genes and gene families with putative roles in virulence are among the more polymorphic genes. We did observe large differences in coverage depth among genes, indicating differences in gene copy number between genomes. We found evidence indicating that recombination has occurred in the history of the sequenced genomes, suggesting that E. histolytica may reproduce sexually.


CONCLUSIONS
E. histolytica displays a relatively low level of nucleotide diversity across its genome. However, large differences in gene family content and gene copy number are seen among the sequenced genomes. The pattern of polymorphism indicates that E. histolytica reproduces sexually, or has done so in the past, which has previously been suggested but not proven.
Institute of Integrative Biology, University of Liverpool, Biosciences building, Crown Street, Liverpool L69 7AH, UK.
Gareth D
GD
Weedall
C Graham
CG
Clark
Pia
P
Koldkjaer
Suzanne
S
Kay
Iris
I
Bruchhaus
Egbert
E
Tannich
Steve
S
Paterson
Neil
N
Hall
D001483:Base Sequence; D004748:Entamoeba histolytica / Q000235:genetics* / Q000472:pathogenicity*; D018628:Gene Dosage; D005819:Genetic Markers; D014644:Genetic Variation; D018503:Genome, Protozoan; D023281:Genomics / Q000379:methods; D006801:Humans; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*
D005819:Genetic Markers; D015800:Protozoan Proteins