Postnikova Anna, Tello Julissa, Alvarez Maristhela, Lee Grace, Ali Ilhan, Field Christine M, Mitchison Timothy J, Ragkousi Katerina
Department of Biology, Amherst College, Amherst, MA 01002, USA.
Department of Systems Biology, Harvard Medical School, Boston, MA, USA.
bioRxiv. 2025 Aug 4:2025.08.03.668367. doi: 10.1101/2025.08.03.668367.
Assembly of cells into epithelial layers marks the early steps of tissue organization and embryonic development in most animals. Although several conserved proteins are known to be essential for epithelialization in bilaterians, it is unclear whether these are sufficient to drive epithelial organization in all metazoans. Using proteomics and knockdown approaches in embryos of the early-branching sea anemone , we identified the neural cell adhesion molecule NCAM2 to be essential for organization of the primary epithelial layer. NCAM2 belongs to the immunoglobulin family of cell adhesion molecules with roles in inter-cellular adhesion and signaling. In this work, we show that NCAM2 is enriched at the apical cell junctions and is required for epithelial cell identity. Importantly, embryos depleted for NCAM2 fail to gastrulate. Both whole-embryo germ layer patterning and tissue changes required for gastrulation are impaired. Together, our data show that in NCAM2 is required for both epithelial and germ layer organization.
细胞组装成上皮层标志着大多数动物组织形成和胚胎发育的早期阶段。尽管已知几种保守蛋白对两侧对称动物的上皮形成至关重要，但尚不清楚这些蛋白是否足以驱动所有后生动物的上皮组织形成。通过在早期分支的海葵胚胎中使用蛋白质组学和基因敲除方法，我们确定神经细胞黏附分子NCAM2对初级上皮层的组织形成至关重要。NCAM2属于细胞黏附分子的免疫球蛋白家族，在细胞间黏附和信号传导中发挥作用。在这项研究中，我们表明NCAM2在顶端细胞连接处富集，并且是上皮细胞特性所必需的。重要的是，缺乏NCAM2的胚胎无法进行原肠胚形成。原肠胚形成所需的全胚胎胚层模式和组织变化均受到损害。总之，我们的数据表明NCAM2对于上皮组织和胚层组织都是必需的。
