In vitro production of cat-restricted Toxoplasma pre-sexual stages by epigenetic reprogramming [ATAC-seq]

Here we show that AP2XII-1 and AP2XI-2, two transcription factors expressed in tachyzoites, a stage that causes acute toxoplasmosis, silence genes specific to merozoites, a developmental stage critical for sexual commitment and transmission to the next host, including humans. Their conditional and simultaneous depletion leads to a drastic change in the transcriptional program, promoting a complete transition from tachyzoites to merozoites. Pre-gametes produced in vitro are characterized by specific protein markers and undergo typical asexual endopolygenic division cycles. AP2XII-1 and AP2XI-2 bind DNA as heterodimers at merozoite promoters and recruit the epigenitors MORC and HDAC3, which in turn restrict the accessibility of chromatin to the transcriptional machinery. We report Tn5 transposase accessiblity data (ATAC-Sequencing) on the RHK80 AP2XII-1 mAID_AP2XI-2 mAID strain in an untreated condition (UT) and induced knockdown of both AP2s (IAA 24h)