Martínez de Los Reyes Nuria, Flores-Borobia Inés, González-Brusi Leopoldo, Galiano-Cogolludo Beatriz, Marigorta Pilar, Toledano-Díaz Adolfo, Santiago-Moreno Julián, Bermejo-Álvarez Pablo, Ramos-Ibeas Priscila
Reproduction. 2025 Jun 10;170(1). doi: 10.1530/REP-25-0113. Print 2025 Jul 1.
GATA3 is a transcription factor exclusively expressed by the trophectoderm. In this paper, we demonstrate that although GATA3 ablation is dispensable for trophectoderm specification and blastocyst formation in sheep, its ablation negatively affects epiblast survival during post-hatching development, making the first such observation in non-rodent mammals.
Early embryo mortality represents a major challenge in livestock production, leading to significant economic losses. However, the molecular determinants underpinning early embryo development in these species remain poorly understood. GATA3 is a key transcription factor exclusively expressed by the trophectoderm (TE) in mammalian embryos. Although its ablation does not impede trophectoderm differentiation or blastocyst formation in mice, it is lethal at later developmental stages. Here, we aimed to investigate the role of GATA3 in ovine pre- and post-hatching development in vitro as well as during conceptus elongation in vivo. By generating GATA3 knockout (KO) embryos, we confirmed that GATA3 is dispensable for TE specification and blastocyst formation in ovine. GATA3 ablation did not impact developmental rates or TE development at post-hatching stages developed in vitro but it significantly reduced epiblast survival. Following embryo transfers to evaluate the effect of GATA3 ablation at later stages, the development of extraembryonic membranes (TE and hypoblast) during conceptus elongation was unaffected by GATA3 loss. However, a significantly reduced proportion of conceptuses developed an embryonic disc after GATA3 ablation. These findings indicate that GATA3 may play a previously unrecognised role in supporting epiblast development beyond the blastocyst stage in ovine.
GATA3是一种仅由滋养外胚层表达的转录因子。在本文中，我们证明，虽然GATA3缺失对于绵羊滋养外胚层特化和囊胚形成并非必需，但其缺失对孵化后发育期间上胚层存活有负面影响，这是在非啮齿类哺乳动物中的首次此类观察。
早期胚胎死亡是家畜生产中的一个主要挑战，会导致重大经济损失。然而，这些物种早期胚胎发育的分子决定因素仍知之甚少。GATA3是哺乳动物胚胎中仅由滋养外胚层（TE）表达的关键转录因子。虽然其缺失在小鼠中并不妨碍滋养外胚层分化或囊胚形成，但在后期发育阶段是致命的。在这里，我们旨在研究GATA3在绵羊体外孵化前后发育以及体内孕体伸长过程中的作用。通过生成GATA3基因敲除（KO）胚胎，我们证实GATA3对于绵羊的TE特化和囊胚形成并非必需。GATA3缺失对体外发育的孵化后阶段的发育速率或TE发育没有影响，但显著降低了上胚层存活率。在胚胎移植以评估GATA3缺失在后期的影响后，孕体伸长期间的胎膜（TE和下胚层）发育不受GATA3缺失的影响。然而，GATA3缺失后发育出胚胎盘的孕体比例显著降低。这些发现表明，GATA3可能在支持绵羊囊胚阶段之后的上胚层发育中发挥了以前未被认识到的作用。
