Dasen J S, Rosenfeld M G
Howard Hughes Medical Institute, Cellular and Molecular Medicine, University of California, San Diego, CA, USA.
Curr Opin Cell Biol. 1999 Dec;11(6):669-77. doi: 10.1016/s0955-0674(99)00034-4.
The development of the pituitary gland has provided an instructive model system for exploring the mechanisms by which differentiated cell types arise from a common primordium in response to extrinsic and intrinsic signals. Recent studies have established that organ commitment, early patterning, proliferation and positional determination of cell types in the developing pituitary are mediated through the integral actions of multiple signaling gradients acting on an initially uniform ectodermal cell population. Studies of the cell-autonomous transcriptional mediators of the transient signaling events have also provided insight into the molecular mechanisms by which overlapping patterns of transcription factor expression can positionally specify pituitary cell lineages. There is emerging evidence for a morphogenetic code for the development of the pituitary gland based on the cooperative and opposing actions of multiple signaling gradients, mediated by corresponding expression patterns of temporally and spatially induced transcription factors.
垂体的发育为探索分化细胞类型如何从共同原基响应外在和内在信号而产生的机制提供了一个具有启发性的模型系统。最近的研究表明，发育中的垂体中细胞类型的器官定向、早期模式形成、增殖和位置确定是通过作用于最初均匀的外胚层细胞群体的多个信号梯度的整合作用介导的。对瞬时信号事件的细胞自主转录介质的研究也深入了解了转录因子表达的重叠模式能够在位置上指定垂体细胞谱系的分子机制。基于多个信号梯度的协同和拮抗作用，由时空诱导转录因子的相应表达模式介导，有新的证据表明存在垂体发育的形态发生密码。
