Khuansuwan Sataree, Clanton Joshua A, Dean Benjamin J, Patton James G, Gamse Joshua T
Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA.
Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA
Development. 2016 Jul 15;143(14):2641-50. doi: 10.1242/dev.131680. Epub 2016 Jun 17.
The zebrafish pineal complex consists of four cell types (rod and cone photoreceptors, projection neurons and parapineal neurons) that are derived from a single pineal complex anlage. After specification, parapineal neurons migrate unilaterally away from the rest of the pineal complex whereas rods, cones and projection neurons are non-migratory. The transcription factor Tbx2b is important for both the correct number and migration of parapineal neurons. We find that two additional transcription factors, Flh and Nr2e3, negatively regulate parapineal formation. Flh induces non-migratory neuron fates and limits the extent of parapineal specification, in part by activation of Nr2e3 expression. Tbx2b is positively regulated by Flh, but opposes Flh action during specification of parapineal neurons. Loss of parapineal neuron specification in Tbx2b-deficient embryos can be partially rescued by loss of Nr2e3 or Flh function; however, parapineal migration absolutely requires Tbx2b activity. We conclude that cell specification and migration in the pineal complex are regulated by a network of at least three transcription factors.
斑马鱼松果体复合体由四种细胞类型（视杆和视锥光感受器、投射神经元和松果旁神经元）组成，这些细胞类型源自单个松果体复合体原基。在细胞特化后，松果旁神经元单向迁移，远离松果体复合体的其他部分，而视杆、视锥和投射神经元则不迁移。转录因子Tbx2b对松果旁神经元的正确数量和迁移都很重要。我们发现另外两个转录因子Flh和Nr2e3对松果旁神经元的形成起负调控作用。Flh诱导非迁移性神经元命运，并限制松果旁神经元特化的程度，部分是通过激活Nr2e3的表达来实现的。Tbx2b受Flh的正向调控，但在松果旁神经元特化过程中与Flh的作用相反。在Tbx2b缺陷型胚胎中，松果旁神经元特化的缺失可通过Nr2e3或Flh功能的缺失得到部分挽救；然而，松果旁神经元的迁移绝对需要Tbx2b的活性。我们得出结论，松果体复合体中的细胞特化和迁移受至少三种转录因子组成的网络调控。
