Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa

<h4>Background</h4> <p>Gene copy number variants (CNVs), which consist of deletions and amplifications of single or sets of contiguous genes, contribute to the great diversity in the Plasmodium falciparum genome. In vitro studies in the laboratory have revealed their important rol...

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Main Authors: Simam, J, Rono, M, Ngoi, J, Nyonda, M, Mok, S, Marsh, K, Bozdech, Z, Mackinnon, M
Format: Journal article
Language:English
Published: BioMed Central 2018
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author Simam, J
Rono, M
Ngoi, J
Nyonda, M
Mok, S
Marsh, K
Bozdech, Z
Mackinnon, M
author_facet Simam, J
Rono, M
Ngoi, J
Nyonda, M
Mok, S
Marsh, K
Bozdech, Z
Mackinnon, M
author_sort Simam, J
collection OXFORD
description <h4>Background</h4> <p>Gene copy number variants (CNVs), which consist of deletions and amplifications of single or sets of contiguous genes, contribute to the great diversity in the Plasmodium falciparum genome. In vitro studies in the laboratory have revealed their important role in parasite fitness phenotypes such as red cell invasion, transmissibility and cytoadherence. Studies of natural parasite populations indicate that CNVs are also common in the field and thus may facilitate adaptation of the parasite to its local environment.</p> <h4>Results</h4> <p>In a survey of 183 fresh field isolates from three populations in Eastern Africa with different malaria transmission intensities, we identified 94 CNV loci using microarrays. All CNVs had low population frequencies (minor allele frequency &lt; 5%) but each parasite isolate carried an average of 8 CNVs. Nine CNVs showed high levels of population differentiation (FST &gt; 0.3) and nine exhibited significant clines in population frequency across a gradient in transmission intensity. The clearest example of this was a large deletion on chromosome 9 previously reported only in laboratory-adapted isolates. This deletion was present in 33% of isolates from a population with low and highly seasonal malaria transmission, and in &lt; 9% of isolates from populations with higher transmission. Subsets of CNVs were strongly correlated in their population frequencies, implying co-selection.</p> <h4>Conclusions</h4> <p>These results support the hypothesis that CNVs are the target of selection in natural populations of P. falciparum. Their environment-specific patterns observed here imply an important role for them in conferring adaptability to the parasite thus enabling it to persist in its highly diverse ecological environment.</p>
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spelling oxford-uuid:4d6c6965-48b0-4652-8658-71e6d25c12f62022-03-26T15:55:30ZGene copy number variation in natural populations of Plasmodium falciparum in Eastern AfricaJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:4d6c6965-48b0-4652-8658-71e6d25c12f6EnglishSymplectic Elements at OxfordBioMed Central2018Simam, JRono, MNgoi, JNyonda, MMok, SMarsh, KBozdech, ZMackinnon, M <h4>Background</h4> <p>Gene copy number variants (CNVs), which consist of deletions and amplifications of single or sets of contiguous genes, contribute to the great diversity in the Plasmodium falciparum genome. In vitro studies in the laboratory have revealed their important role in parasite fitness phenotypes such as red cell invasion, transmissibility and cytoadherence. Studies of natural parasite populations indicate that CNVs are also common in the field and thus may facilitate adaptation of the parasite to its local environment.</p> <h4>Results</h4> <p>In a survey of 183 fresh field isolates from three populations in Eastern Africa with different malaria transmission intensities, we identified 94 CNV loci using microarrays. All CNVs had low population frequencies (minor allele frequency &lt; 5%) but each parasite isolate carried an average of 8 CNVs. Nine CNVs showed high levels of population differentiation (FST &gt; 0.3) and nine exhibited significant clines in population frequency across a gradient in transmission intensity. The clearest example of this was a large deletion on chromosome 9 previously reported only in laboratory-adapted isolates. This deletion was present in 33% of isolates from a population with low and highly seasonal malaria transmission, and in &lt; 9% of isolates from populations with higher transmission. Subsets of CNVs were strongly correlated in their population frequencies, implying co-selection.</p> <h4>Conclusions</h4> <p>These results support the hypothesis that CNVs are the target of selection in natural populations of P. falciparum. Their environment-specific patterns observed here imply an important role for them in conferring adaptability to the parasite thus enabling it to persist in its highly diverse ecological environment.</p>
spellingShingle Simam, J
Rono, M
Ngoi, J
Nyonda, M
Mok, S
Marsh, K
Bozdech, Z
Mackinnon, M
Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title_full Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title_fullStr Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title_full_unstemmed Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title_short Gene copy number variation in natural populations of Plasmodium falciparum in Eastern Africa
title_sort gene copy number variation in natural populations of plasmodium falciparum in eastern africa
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