Pax6 is implicated in murine pituitary endocrine function
Pax6 is implicated in murine pituitary endocrine function
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DOI：
10.1385/endo:10:2:171
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发表时间：
1999-04-01
期刊：
影响因子：
3.7
通讯作者：
Roberts, VJ
中科院分区：
文献类型：
--
作者：
Bentley, CA;Zidehsarai, MP;Roberts, VJ
Pax6是一种进化上保守的转录因子，在小鼠和斑马鱼的胚胎垂体中表达，但其在垂体发育和内分泌功能中的作用尚未被描述。为了研究Pax6在体内的作用，我们检测了Pax6突变小鼠（Sey(Neu)）的垂体。Sey（new）突变纯合的小鼠出生时死亡；因此，我们通过分化的垂体细胞类型检测了肽激素的表达，以及胚胎垂体中间叶和前叶的发育标记物的表达，尽管这些肽激素的mRNA表达和其他垂体标记物的表达存在，但在胚胎期17.5的近交系ICR背景下，GH-和prl免疫阳性细胞出现严重下降。为了确定导致Pax6突变小鼠GH-和PRL免疫反应性降低的细胞或生理机制，我们检测了GH和PRL的血清水平，Pax6纯合突变小鼠在胚胎期17.5时的CH血清水平是对照组的五分之一，出生后0时PRL血清水平是对照组的三分之一，在胚胎期和新生儿期PRL血清水平非常低。在野生型和突变型组中均低于检测限。综上所述，这些数据表明Pax6对垂体分化并不是必需的，而可能是通过调节翻译或分泌机制来建立适当的新生儿GH和PRL的稳态水平。
Pax6, an evolutionarily conserved transcription factor, is expressed in the murine and zebrafish embryonic pituitary, but its role in pituitary development and endocrine function has not been described, To study the role of Pax6 in vivo, we examined Pax6 mutant mouse (Sey(Neu)) pituitaries. Mice homozygous for the Sey(Neu) mutation die at birth; therefore, we examined peptide hormone expression by the differentiated pituitary cell types as well as developmental marker expression in the intermediate and anterior lobes of the embryonic pituitary, GH- and PRL-immunopositive cells appear severely decreased in an outbred ICR background at embryonic d 17.5, although mRNA expression of these peptide hormones is present, as is expression of other pituitary markers. This suggests that pituitary cell types are able to differentiate in mutant embryos, To identify the cellular or physiologic mechanism responsible for less GH- and PRL-immunoreactivity in Pax6 mutant mice, we tested serum levels of GH and PRL, Pax6 homozygous mutant mice have CH serum levels one fifth that of controls at embryonic d 17.5, and one-third that of controls at postnatal d 0, PRL serum levels, which are very low during embryonic and neonatal stages, were below assay detection limits in both the wild-type and mutant groups. Taken together, these data suggest that Pax6 is not essential for pituitary differentiation, but rather functions to establish appropriate neonatal homeostatic levels of GH and PRL, possibly through regulation of translational or secretory mechanisms.