PT  - JOURNAL ARTICLE
AU  - Liat Ravid Lustig
AU  - Abhishek Sampath Kumar
AU  - Till Schwämmle
AU  - Ilona Dunkel
AU  - Gemma Noviello
AU  - Raha Weigert
AU  - Guido Pacini
AU  - René Buschow
AU  - Afrah Ghauri
AU  - Maximilian Stötzel
AU  - Lars Wittler
AU  - Alexander Meissner
AU  - Edda G. Schulz
TI  - GATA transcription factors drive initial Xist upregulation after fertilization through direct activation of a distal enhancer element
AID  - 10.1101/2022.08.02.502458
DP  - 2022 Jan 01
TA  - bioRxiv
PG  - 2022.08.02.502458
4099  - http://biorxiv.org/content/early/2022/08/03/2022.08.02.502458.short
4100  - http://biorxiv.org/content/early/2022/08/03/2022.08.02.502458.full
AB  - To ensure dosage compensation for X-linked genes between the sexes, one X chromosome is silenced during early embryonic development of female mammals. This process of X-chromosome inactivation (XCI) is initiated through upregulation of the RNA Xist from one X chromosome shortly after fertilization. Xist then mediates chromosome-wide gene silencing in cis and remains expressed in all cell types except the germ line and the pluripotent state, where XCI is reversed. The factors that drive Xist upregulation and thereby initiate XCI remain however unknown. We identify GATA transcription factors as potent Xist activators and demonstrate that they are essential for the activation of Xist in mice following fertilization. Through a pooled CRISPR activation screen we find that GATA1 can drive ectopic Xist expression in murine embryonic stem cells (mESCs). We demonstrate that all GATA factors can activate Xist directly via a GATA-responsive regulatory element (RE79) positioned 100 kb upstream of the Xist promoter. Additionally, GATA factors are essential for the induction of XCI in mouse preimplantation embryos, as simultaneous deletion of three members of the GATA family (GATA1/4/6) in mouse zygotes effectively prevents Xist upregulation. Thus, initiation of XCI and possibly its maintenance in distinct lineages of the preimplantation embryo is ensured by the combined activity of different GATA family members, and the absence of GATA factors in the pluripotent state likely contributes to X reactivation. We thus describe a form of regulation in which the combined action of numerous tissue-specific factors can achieve near-ubiquitous expression of a target gene.Competing Interest StatementThe authors have declared no competing interest.