Trivett Melanie K, Potter Ian C, Power Glenn, Zhou Hong, Macmillan David L, Martin T John, Danks Janine A
St. Vincent's Institute of Medical Research, 41 Victoria Parade, Fitzroy, Victoria 3065, Australia.
Dev Genes Evol. 2005 Nov;215(11):553-63. doi: 10.1007/s00427-005-0015-x. Epub 2005 Nov 4.
This study explored the distribution of parathyroid hormone-related protein (PTHrP) and its mRNA in tissues of the lamprey Geotria australis, a representative of one of the two surviving groups of an early and jawless stage in vertebrate evolution. For this purpose, antibodies to N-terminal and mid-molecule human PTHrP were used to determine the locations of the antigen. Sites of mRNA production were demonstrated by in situ hybridisation with a digoxigenin-labelled riboprobe to exon VI of the human PTHrP gene. The results revealed that antigen and its mRNA were widely distributed among similar sites of tissue localisation to those described for mammalian and avian species. However, some novel sites of localisation, such as in the gill and notochord, were also found. Some differences in PTHrP localisation were noted among individuals at different intervals of the life cycle, indicating that the distributions of PTHrP, and possibly its roles, change with the stage of development in this species. The widespread tissue distribution in G. australis implies diverse physiological roles for this protein. The presence of PTHrP in the lamprey, a representative of a group of vertebrates, which apparently evolved over 540 million years ago, strongly suggests that it is a protein of ancient origin. In addition, the successful use of antibodies and probes based on the human sequence in the lamprey also provides evidence that the PTHrP molecule may have been conserved from lampreys through to humans.
本研究探讨了甲状旁腺激素相关蛋白（PTHrP）及其mRNA在澳大利亚七鳃鳗组织中的分布情况。澳大利亚七鳃鳗是脊椎动物进化早期无颌阶段现存的两个类群之一的代表。为此，使用针对人PTHrP N端和中间分子的抗体来确定抗原的位置。通过用地高辛标记的核糖探针与人PTHrP基因外显子VI进行原位杂交，来证明mRNA的产生位点。结果显示，抗原及其mRNA在与哺乳动物和鸟类所描述的相似组织定位位点中广泛分布。然而，也发现了一些新的定位位点，如鳃和脊索中。在生命周期不同阶段的个体之间，观察到PTHrP定位存在一些差异，这表明在该物种中，PTHrP的分布及其可能的作用会随着发育阶段而变化。澳大利亚七鳃鳗中广泛的组织分布意味着该蛋白具有多种生理作用。PTHrP存在于七鳃鳗（一种显然在5.4亿多年前就已进化的脊椎动物类群的代表）中，这有力地表明它是一种起源古老的蛋白。此外，基于人类序列的抗体和探针在七鳃鳗中的成功应用也提供了证据，表明PTHrP分子可能从七鳃鳗到人类一直都得到了保守。
