Mutant/mutation
The mutant contains a disrupted eefiab gene which is one of the two copies that are present in the genome (eefiaa and eefiab) and which encode the protein (eukaryotic) elongation factor 1 alpha (eEF1A). The disruption results in reduced production of eEF1A.
Plasmodium contain two eef1a genes with identical open reading frames linked head-to-head in the genome separated by a short 1 kb region (bidirectional promoter region) that drives the transcription of both genes. This mutant exhibited an unpredicted integration event. The eef1ab gene is disrupted, but these parasites contain an intergenic region that is inverted compared with the arrangement of the pbeef1a intergenic region of wt parasites (see also mutant 174 which also contains a disrupted eef1ab gene but with a normal organization of the intergenic region).

Protein (function)
Eukaryotic elongation factor 1A (eEF1A) is a highly abundant multifunctional protein that regulates components of protein synthesis and cell growth and is principally responsible for the transfer of amino-acylated tRNA to the ribosome A site. Plasmodium contain two eef1a genes with identical open reading frames linked head-to-head in the genome separated by a short 1 kb region (bidirectional promoter region) that drives the transcription of both genes.

Phenotype
The disruption of the eef1ab gene results in reduced production of eEF1A. Mutants can complete the vertebrate and mosquito phases of the life cycle, but  the blood stages of mutants show a small decrease in the proliferation rate in mice compared to wild type blood stages. The growth phase of the asexual blood stages is extended by up to 20%. Analysis of the cell cycle by flow cytometry as well as transcriptional analyses revealed that the duration of the S and M phases during schizogony and the number of daughter merozoites per schizont were not detectably affected, but that the G1 phase (development of the ring form into the mature trophozoite) is elongated.
Despite the lower proliferation rate of blood stages, the mutant parasites do induce cerebral complications in mice that are sensitive to experimental cerebral malaria (ECM).

Additional information
Mutants can complete the vertebrate and mosquito phases of the life cycle. However, possible (minor) effects of disruption of the eef1ab gene on (the cell cycle of) oocysts and liver stages have not been analysed in detail

Other mutants
RMgm-173: A mutant with disruption of the second copy of the eef1a gene, eef1aa
RMgm-174: An independent mutant with disruption of the eef1ab (without the inversion of the promoter region).