Genome-wide identification of genes upregulated at the onset of gametocytogenesis in Plasmodium falciparum

Abstract

A genome-wide expression analysis was undertaken to identify novel genes specifically activated from early stages of gametocytogenesis in Plasmodium falciparum. A comparative analysis was conducted on sexually induced cultures of reference parasite clone 3D7 and its gametocyteless derivative clone F12. Competitive hybridisations on long-oligomer microarrays representing 4488 P. falciparum genes identified a remarkably small number of transcripts differentially produced in the two clones. Upregulation of the mRNAs for the early gametocyte markers Pfs16 and Pfg27 was however readily detected in 3D7, and such genes were used as reference transcripts in a comparative time course analysis of 3D7 and F12 parasites between 30 and 40 h post-invasion in cultures induced to enter gametocytogenesis. One hundred and seventeen genes had expression profiles which correlated to those of pfs16 and pfg27, and Northern blot analysis and published proteomic data identified those whose expression was gametocyte-specific. Immunofluorescence analysis with antibodies against two of these gene products identified two novel parasite membrane associated, sexual stage-specific proteins. One was produced from stage I gametocytes and the second showed peak production in stage II gametocytes. The two proteins were named Pfpeg-3 and Pfpeg-4, for P. falciparum proteins of early gametocytes.

The Puf-family RNA-binding protein PfPuf2 regulates sexual development and sex differentiation in the malaria parasitePlasmodium falciparum

“…As developmental decision for gametocytogenesis occurs during the formation of the asexual schizont (Bruce et al, 1990), it is important that regulatory genes are expressed in schizonts that are committed to sexual differentiation (Alano, 2007). Global analyses of gene expression by several groups have revealed relatively small numbers of genes showing evidence of upregulation after induction of sexual development (Eksi et al, 2005;Silvestrini et al, 2005;Young et al, 2005). Some early gametocyte genes are probably involved in host cell remodeling, since they are found to be exported to the parasitophorous vacuole and/or the cytoplasm of erythrocytes (Eksi et al, 2005;Lanfrancotti et al, 2007).…”

Stage independent chloroquine resistance and chloroquine toxicity revealed via spinning disk confocal microscopy

“…Several papers report a wide range of different N per schizont, but some of these merely repeat previous literature statements without significant additional data (eg. N= 6-32 [45], N= 16-32 [46,47], N= 8-32 [48,49], N= 8-24 [50,51], N= 3-24 [52]. With regard to these previous data, the methods used most often have been light microscopy on Giemsa labeled smears of dehydrated, fixed and flattened cells.…”

The development of malaria parasites in the mosquito midgut

“…2). Female osmiophilic bodies contain gametocyte‐specific proteins like Pg377 (Alano et al ., 1995; Severini et al ., 1999; Olivieri et al ., 2015), MDV‐1/Peg3 (Furuya et al ., 2005; Silvestrini et al ., 2005; Lanfrancotti et al ., 2007; Ponzi et al ., 2009) and GEST (gamete egress and sporozoite traversal; Talman et al ., 2011), which are discharged into the PV following gametocyte activation. Gametocytes lacking MDV‐1/Peg3 or GEST are impaired in egress and stuck within the PV (Ponzi et al ., 2009; Talman et al ., 2011).…”