REGULATION OF EXPRESSION AND FUNCTION OF NEUROPEPTIDES DURING DEVELOPMENT

局部相互作用在神经肽多样化中的作用 表型进行了研究，在发展爪蟾脑，使用原位 杂交组织化学 一种高度局部化的亲- 在垂体中观察到阿黑皮素（POMC）细胞， 前脑表明存在一个共同的POMC前体， 神经板的最前面 在另一种神经肽表型中， TRH，跨越成人前脑的模式，包括超过六个不同的 核心来自高度区域化的分散人口 胚胎学上因此，表型不同的神经元细胞的子集 在不同的前脑核团形成之前， 特定的神经元细胞命运可由细胞谱系或局部神经元细胞决定。 诱导 并对GnRH-I的发育表达进行了研究。 与POMC和TRH不同，GnRH-I被抑制直到变态高潮。 GnRH细胞在到达其最终位置后首次被检测到， 在幼虫后期的视前区。 非洲爪蟾的碎片 用PCR方法克隆了激素原转化酶基因PC 2， 在原位杂交中用作第二表型标记， 神经肽细胞 发现PC 2在一个高度定位的 区域特异性模式，包括TRH神经元。 的表达 一个新的LIM类同源异型盒基因家族的特征在于， 胚胎到成年爪蟾CNS。 发现Xlim-3基因是 在蛙松果体、垂体、后脑和视网膜中表达。 但 在垂体前叶的特定细胞亚群中不表达 或松果体。 Xlim-1在前脑后部的某些区域表达， 核和表达模式可能包括一些前脑细胞 表达TRH和GnRH，但不表达POMC。 LIM类同源盒 基因可能与脑细胞结构的特化有关 对应于单个脑核团，包括表达 特异性神经肽基因

The role of local interactions in the diversification of neuropeptide phenotypes was studied in developing Xenopus brain, using in situ hybridization histo-chemistry. A highly localized appearance of pro- opiomelanocortin (POMC) cells was observed in the pituitary and forebrain suggesting the existence of a common POMC precursor that is anterior most in the neural plate. In another neuropeptide phenotype TRH, the pattern spanning adult forebrain, comprising over six different nuclei arise from a dispersed population that is highly regionalized embryonically. Thus a subset of phenotypically distinct neuronal cells develops as a group before distinct forebrain nuclei form, arguing specific neuronal cell fates may be dictated by cell lineage or local induction. The developmental expression of GnRH-I was also studied. Unlike POMC and TRH, GnRH-I was suppressed until metamorphic climax. GnRH cells were first detected after they reached their final position in the preoptic area during the late larval period. A fragment of Xenopus PC2, a prohormone converting enzyme was cloned by PCR and the cDNA used in in situ hybridization as a second phenotypic marker for neuropeptide cells. PC2 was found to be expressed in a highly localized region specific pattern which included TRH neurons. The expression of a new LIM-class family of homeobox genes was characterized from embryo to adult Xenopus CNS. It was found that the Xlim-3 gene was expressed in frog pineal, pituitary, hindbrain and retina. However, it was not expressed in a specific subset of cells in the anterior pituitary or pineal. Xlim-1 was expressed in certain more posterior forebrain nuclei and the expression pattern could include some forebrain cells that express TRH and GnRH, but not POMC. The LIM-class homeobox genes may be involved in the specification of brain cytoarchitecture corresponding to individual brain nuclei including ones expressing specific neuropeptide genes.