Department of Molecular Embryology, Institute of Anatomy and Cell Biology, Faculty of Medicine, University Freiburg, 79104 Freiburg, Germany.
Int J Mol Sci. 2023 Apr 29;24(9):8052. doi: 10.3390/ijms24098052.
Vision is likely our most prominent sense and a correct development of the eye is at its basis. Early eye development is tightly connected to the development of the forebrain. A single eye field and the prospective telencephalon are situated within the anterior neural plate (ANP). During normal development, both domains are split and consecutively, two optic vesicles and two telencephalic lobes emerge. If this process is hampered, the domains remain condensed at the midline. The resulting developmental disorder is termed holoprosencephaly (HPE). The typical ocular finding associated with intense forms of HPE is cyclopia. However, also anophthalmia and coloboma can be associated with HPE. Here, we report that a correct balance of Bone morphogenetic proteins (BMPs) and their antagonists are important for forebrain and eye field cleavage. Experimental induction of a BMP ligand results in a severe form of HPE showing anophthalmia. We identified a dysmorphic forebrain containing retinal progenitors, which we termed crypt-oculoid. Optic vesicle evagination is impaired due to a loss of and, consecutively, of . Our data further suggest that the subduction of prospective hypothalamic cells during neurulation and neural keel formation is affected by the induction of a BMP ligand.
视觉可能是我们最突出的感觉，而眼睛的正常发育是其基础。早期的眼睛发育与前脑的发育密切相关。一个单一的眼区和未来的端脑位于前神经板（ANP）内。在正常发育过程中，这两个区域都会分裂，随后形成两个视泡和两个端脑叶。如果这个过程受阻，这些区域就会在中线处保持凝结。由此产生的发育障碍被称为前脑无裂畸形（HPE）。与 HPE 强烈形式相关的典型眼部发现是独眼畸形。然而，无眼症和眼眶裂也可能与 HPE 相关。在这里，我们报告说，骨形态发生蛋白（BMPs）及其拮抗剂之间的正确平衡对于前脑和眼区分裂是很重要的。实验诱导 BMP 配体的表达会导致严重的 HPE 表现为无眼症。我们鉴定出一个形态异常的前脑，其中包含视网膜祖细胞，我们将其命名为隐眼-眼窝。由于 和 的缺失，视泡外凸受到损害，随后 也缺失。我们的数据进一步表明，在神经胚形成和神经龙骨形成过程中，下丘脑细胞的俯冲受到 BMP 配体诱导的影响。
