Summary

RMgm-1475
Malaria parasiteP. berghei
Genotype
Genetic modification not successful
DisruptedGene model (rodent): PBANKA_0504100; Gene model (P.falciparum): PF3D7_1019900; Gene product: autophagy-related protein 8 (ATG8)
PhenotypeNo phenotype has been described
Last modified: 5 July 2016, 17:10
  *RMgm-1475
Successful modificationThe gene/parasite could not be changed/generated by the genetic modification.
The following genetic modifications were attempted Gene disruption
Number of attempts to introduce the genetic modification 3
Reference (PubMed-PMID number) Reference 1 (PMID number) : 27353755
Parent parasite used to introduce the genetic modification
Rodent Malaria ParasiteP. berghei
Parent strain/lineP. berghei ANKA
Name parent line/clone Not applicable
Other information parent line
Attempts to generate the mutant parasite were performed by
Name PI/ResearcherVoss C; Sinnis P; Coppens I
Name Group/DepartmentDepartment of Molecular Microbiology and Immunology, Malaria Research Institute
Name InstituteJohns Hopkins University Bloomberg School of Public Health
CityBaltimore, Maryland
CountryUSA

  Disrupted: Mutant parasite with a disrupted gene
Details of the target gene
Gene Model of Rodent Parasite PBANKA_0504100
Gene Model P. falciparum ortholog PF3D7_1019900
Gene productautophagy-related protein 8
Gene product: Alternative nameATG8
Details of the genetic modification
Inducable system usedNo
Additional remarks inducable system
Type of plasmid/construct usedunknown
PlasmoGEM (Sanger) construct/vector usedNo
Modified PlasmoGEM construct/vector usedNo
Plasmid/construct map
Plasmid/construct sequence
Restriction sites to linearize plasmid
Partial or complete disruption of the geneUnknown
Additional remarks partial/complete disruption
Selectable marker used to select the mutant parasiteunknown
Promoter of the selectable markerunknown
Selection (positive) procedureunknown
Selection (negative) procedureNo
Additional remarks genetic modificationThe negative attempts to disrupt the atg8 gene indicates an essential role of ATG8 for blood stage development/multiplication.

no details are provided in the paper for the construct used in attempts to disrupt the gene.

See also RMgm-1476 for a P. berghei mutant over-expressing ATG8.

Autophagy is the archetypal disposal pathway for keeping the cell interior clean of disused and superfluous organelles In contrast to mammalian cells and yeast that contain ~40 autophagy-related genes (ATG), the malaria parasite contains ~15 orthologs of ATG identified by in silico comparative studies: those whose products are required for vesicle expansion and completion are present, while genes involved in induction of autophagy and cargo packaging are mostly absent. All the components of the ubiquitin-like ATG8 system, which are involved in autophagosome formation, are expressed by Plasmodium. Coexpression of PbATG8, PbATG3, and PbATG7 is upregulated during early sporozoite differentiation in liver cells. In liver forms of P. berghei, PbATG8 localizes to a network of vesicles and tubules that align along the apicoplast, a relict plastid organelle, as well as to numerous vesicles in the cytoplasm.
PbATG8 is preferentially distributed on the outermost membranes of the apicoplast. ATG8 expressed in the related apicomplexan parasite Toxoplasma gondii is also localized to the apicoplast, and it seems to be involved in the maintenance of this organelle and proper segregation between daughter cells during replication.
A mutant over-expressing PbATG8 (RMgm-1476) showed poor development into late liver stages and production of small merosomes that contain immature merozoites unable to initiate a blood infection. Based on these observations it has been proposed that that Plasmodium ATG8 is a key effector in the development of merozoites by controlling microneme clearance and apicoplast proliferation and that dysregulation in ATG8 levels is detrimental for malaria infectivity.
Additional remarks selection procedure
Primer information: Primers used for amplification of the target sequences  Click to view information
Primer information: Primers used for amplification of the target sequences  Click to hide information
Sequence Primer 1
Additional information primer 1
Sequence Primer 2
Additional information primer 2
Sequence Primer 3
Additional information primer 3
Sequence Primer 4
Additional information primer 4
Sequence Primer 5
Additional information primer 5
Sequence Primer 6
Additional information primer 6