Antigenic diversity in malaria parasites is maintained on extrachromosomal DNA

Emily R Ebel; Bernard Y Kim; Marina McDew-White; Elizabeth S Egan; Timothy J C Anderson; Dmitri A Petrov

doi:10.1101/2023.02.02.526885

Antigenic diversity in malaria parasites is maintained on extrachromosomal DNA

bioRxiv [Preprint]. 2023 Feb 2:2023.02.02.526885. doi: 10.1101/2023.02.02.526885.

Authors

Emily R Ebel^{1

2

3}, Bernard Y Kim¹, Marina McDew-White^{4

5}, Elizabeth S Egan^{2

3

6}, Timothy J C Anderson⁴, Dmitri A Petrov^{1

6}

Affiliations

¹ Department of Biology, Stanford University, Stanford, CA, USA.
² Department of Pediatrics, School of Medicine, Stanford University, Stanford, CA, USA.
³ Department of Microbiology and Immunology, School of Medicine, Stanford University, Stanford, CA, USA.
⁴ Disease Intervention and Prevention Program, Texas Biomedical Research Institute, San Antonio, TX, USA.
⁵ Present address: Host Pathogen Interaction Program, Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA.
⁶ Chan Zuckerberg Biohub, San Francisco, CA, USA.

Abstract

Sequence variation among antigenic var genes enables Plasmodium falciparum malaria parasites to evade host immunity. Using long sequence reads from haploid clones from a mutation accumulation experiment, we detect var diversity inconsistent with simple chromosomal inheritance. We discover putatively circular DNA that is strongly enriched for var genes, which exist in multiple alleles per locus separated by recombination and indel events. Extrachromosomal DNA likely contributes to rapid antigenic diversification in P. falciparum.

Publication types

Preprint

Grants and funding

P51 OD011133/OD/NIH HHS/United States