Brennan H C, Nijjar S, Jones E A
Cell and Molecular Development Group, Department of Biological Sciences, Warwick University, Coventry CV4 7AL, USA.
Mech Dev. 1998 Jul;75(1-2):127-37. doi: 10.1016/s0925-4773(98)00094-x.
We have examined the timing of specification of the pronephric tubules and duct in Xenopus laevis by explanting the presumptive pronephric rudiments into blastula ectodermal wraps. We have established the time point of specification using the monoclonal antibody markers 3G8 and 4A6 which recognize antigens in pronephric tubule and duct, respectively. We show that, by experimental analysis in explants, kidney tubules are specified by stage 12.5 in the pronephric anlagen whereas pronephric duct is specified later between stages 13 and 14. Furthermore we show that signals involved in tubulogenesis of the pronephric tubules are normally received between stage 12.5 and 13. These experiments unambiguously pinpoint the timing of pronephros specification analyzed by explant experimentation to a developmental stage prior to that demonstrated for urodele amphibia, and provide an essential biological backdrop to a search for the molecular nature of pronephric inducers.
我们通过将推定的原肾原基植入囊胚外胚层包裹物中，研究了非洲爪蟾原肾小管和导管的特化时间。我们使用分别识别原肾小管和导管中抗原的单克隆抗体标记3G8和4A6确定了特化的时间点。我们通过外植体实验分析表明，在原肾原基中，肾小管在12.5期被特化，而原肾导管在13至14期之间较晚被特化。此外，我们表明参与原肾小管形成的信号通常在12.5期至13期之间被接收。这些实验明确地将通过外植体实验分析的原肾特化时间精确到比有尾两栖动物所证明的发育阶段更早的阶段，并为寻找原肾诱导物的分子性质提供了重要的生物学背景。
