{"database":"GEO","file_versions":[{"headers":{"Content-Type":["application/json"]},"body":{"files":{"Other":["ftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE298nnn/GSE298024/"]},"type":"primary"},"statusCodeValue":200,"statusCode":"OK"}],"scores":null,"additional":{"omics_type":["Genomics"],"species":["Plasmodium falciparum"],"gds_type":["Genome binding/occupancy profiling by high throughput sequencing"],"full_dataset_link":["https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE298024"],"repository":["GEO"],"entry_type":["GSE"],"additional_accession":[]},"is_claimable":false,"name":"AP2-HS and a GDV1 regulatory feedback loop mediate environmental induction of sexual conversion in Plasmodium falciparum [H3K9me3 ChIP-seq]","description":"Transmission of Plasmodium spp. from a human host to a mosquito vector requires that some parasites abandon the asexual replicative cycle in the blood, associated with all clinical symptoms of malaria, and convert into non-replicative sexual precursors called gametocytes. The sexual conversion rate (i.e., the proportion of parasites that convert at each cycle) is variable, which enables parasites to adjust the balance between sexual and asexual development to the conditions of the human blood environment. Under some specific types of stress, parasites enhance sexual conversion rates to increase their relative investment in transmission. Sexual conversion is orchestrated by the master regulator AP2-G, a transcription factor of the ApiAP2 family. In Plasmodium falciparum, the species that produces the vast majority of human malaria cases and deaths, activation of ap2-g expression requires the GDV1 protein, which displaces heterochromatin from the ap2-g promoter. An antisense long noncoding RNA (lncRNA) encoded in the same locus as GDV1, named gdv1-as, is a negative regulator of GDV1 expression, but how the expression of this lncRNA is regulated or how specific types of stress enhance sexual conversion is not known. Here we show that environmental induction of sexual conversion is initiated by activation of gdv1 expression in a process dependent on the AP2-HS transcription factor, previously described as the activator of the malarial protective HS response. Next, GDV1 activates the expression of its own repressor, gdv1-as, by removing heterochromatin from its putative promoter. This positive-negative regulatory feedback loop limits GDV1 activation to a short burst of expression. This same mechanism operates for stimulation of sexual conversion by different environmental conditions, and AP2-HS is also needed for the activation of metabolic pathways that compensate depletion of phospholipid precursors. These findings provide new insight on the mechanisms underlying the fundamental developmental decision of malaria parasites and explain their plasticity to increase the investment in transmission when the conditions of the environment are unfavourable.","dates":{"publication":"2026/07/27"},"accession":"GSE298024","cross_references":{"GSM":["GSM9004780","GSM9004782","GSM9004781","GSM9004784","GSM9004783","GSM9004786","GSM9004785","GSM9004821","GSM9004788","GSM9004787","GSM9004820","GSM9004823","GSM9004789","GSM9004822","GSM9004825","GSM9004824","GSM9004816","GSM9004815","GSM9004818","GSM9004817","GSM9004819","GSM9004890","GSM9004892","GSM9004891","GSM9004894","GSM9004893","GSM9004896","GSM9004895","GSM9004898","GSM9004810","GSM9004897","GSM9004812","GSM9004779","GSM9004811","GSM9004814","GSM9004813","GSM9004805","GSM9004804","GSM9004807","GSM9004806","GSM9004809","GSM9004808","GSM9257749","GSM9004841","GSM9004840","GSM9004843","GSM9004842","GSM9004845","GSM9004844","GSM9004847","GSM9004846","GSM9004838","GSM9004837","GSM9004839","GSM9257751","GSM9257750","GSM9257752","GSM9004791","GSM9004790","GSM9004793","GSM9004792","GSM9004795","GSM9004794","GSM9915965","GSM9004830","GSM9004797","GSM9004796","GSM9004832","GSM9004799","GSM9004798","GSM9004831","GSM9915969","GSM9004834","GSM9915968","GSM9004833","GSM9004836","GSM9915967","GSM9004835","GSM9915966","GSM9004827","GSM9004826","GSM9004829","GSM9004828","GSM9257748","GSM9257747","GSM9257746","GSM9257745","GSM9004861","GSM9004860","GSM9004863","GSM9004862","GSM9004865","GSM9004864","GSM9004867","GSM9004866","GSM9004869","GSM9004868","GSM9004859","GSM9915972","GSM9915971","GSM9915970","GSM9004850","GSM9004852","GSM9004851","GSM9004854","GSM9004853","GSM9004856","GSM9004855","GSM9004858","GSM9004857","GSM9004849","GSM9004848","GSM9004881","GSM9004880","GSM9004883","GSM9004882","GSM9004885","GSM9004884","GSM9004887","GSM9004886","GSM9004801","GSM9004889","GSM9004888","GSM9004800","GSM9004803","GSM9004802","GSM9004870","GSM9004872","GSM9004871","GSM9004874","GSM9004873","GSM9004876","GSM9004875","GSM9004878","GSM9004877","GSM9004879"],"GPL":["21298","37248"],"GSE":["298024"],"taxon":["Plasmodium falciparum"]}}