Ma E, Klempt N, Grossmann R, Ivell R, Kato Y, Ellendorff F
Institute for Animals Sciences and Animal Behaviour (FAL), Neustadt, Germany.
Exp Clin Endocrinol Diabetes. 1996;104(6):464-72. doi: 10.1055/s-0029-1211486.
The development of the anterior pituitary gland involves the proliferation and differentiation of ectodermal cells in Rathke's pouch to generate distinct cell types, each of which produces its corresponding trophic hormone. Studying pituitary development will therefore reveal novel aspects of organogenesis. In the present study, we examined by in situ hybridization the expression of genes for anterior pituitary hormones during development of the fetal pig pituitary. We found that the beta-subunit gene of thyroid-stimulating hormone (TSH beta) was first expressed at E40, (E = day of embryonal/fetal life), growth hormone (GH) mRNA appeared between E40 and E50, and the gonadotrophin genes (LH beta and FSH beta) were expressed at E50. The transcripts for TSH beta, LH beta and FSH beta were abundantly expressed at about E80, while GH mRNA continued to be richly expressed until after birth. The GH gene was first expressed in the mantle layer of the anterior lobe, while the TSH beta and gonadotrophin (LH beta and FSH beta) mRNAs were found in the central and the basal regions of the anterior lobe, respectively. All of these mRNAs (GH, TSH beta, LH beta, and FSH beta) remained concentrated until the end of gestation in the area where they first appeared. The distinctive pattern of developmental expression of these hormone genes in the fetal pig anterior pituitary makes this tissue an excellent system in which to study tissue-specific gene activation and regulation.
腺垂体的发育涉及拉特克囊中外胚层细胞的增殖和分化，以产生不同的细胞类型，每种细胞类型都产生其相应的促激素。因此，研究垂体发育将揭示器官发生的新方面。在本研究中，我们通过原位杂交检查了胎猪垂体发育过程中腺垂体激素基因的表达。我们发现促甲状腺激素β亚基基因（TSHβ）在胚胎第40天（E = 胚胎/胎儿期天数）首次表达，生长激素（GH）mRNA在胚胎第40天至第50天之间出现，促性腺激素基因（LHβ和FSHβ）在胚胎第50天表达。TSHβ、LHβ和FSHβ的转录本在大约胚胎第80天大量表达，而GH mRNA在出生后仍持续大量表达。GH基因首先在前叶的套层表达，而TSHβ和促性腺激素（LHβ和FSHβ）mRNA分别在前叶的中央和基部区域被发现。所有这些mRNA（GH、TSHβ、LHβ和FSHβ）在妊娠末期之前一直集中在它们最初出现的区域。这些激素基因在胎猪腺垂体中的独特发育表达模式使该组织成为研究组织特异性基因激活和调控的极佳系统。
