Barker Donna M, Beck Caroline W
Department of Zoology and Genetics Otago, University of Otago, New Zealand.
Dev Dyn. 2009 Jun;238(6):1366-78. doi: 10.1002/dvdy.21923.
Xenopus laevis tadpoles are capable of hindlimb regeneration, although this ability declines with age. Bmp signaling is one pathway known to be necessary for successful regeneration to occur. Using an inducible transgenic line containing an activated version of the Bmp target Msx1, we assessed the ability of this transcription factor to enhance regeneration in older limbs. Despite considerable evidence correlating msx1 expression with regenerative success in vertebrate regeneration models, we show that induction of msx1 during hindlimb regeneration fails to induce complete regeneration. However, we did observe some improvement in regenerative outcome, linked to morphological changes in the early wound epithelium and a corresponding increase in proliferation in the underlying distal mesenchyme, neither of which are maintained later. Additionally, we show that Msx1 is not able to rescue limb regeneration in a Bmp signalling-deficient background, indicating that additional Bmp targets are required for regeneration in anuran limbs. Developmental Dynamics 238:1366-1378, 2009. (c) 2009 Wiley-Liss, Inc.
非洲爪蟾蝌蚪能够再生后肢，尽管这种能力会随着年龄的增长而下降。骨形态发生蛋白（Bmp）信号传导是已知的成功再生所必需的一条途径。我们使用了一个含有Bmp靶标Msx1激活版本的可诱导转基因品系，评估了这种转录因子增强老年肢体再生的能力。尽管有大量证据表明在脊椎动物再生模型中msx1表达与再生成功相关，但我们发现后肢再生过程中msx1的诱导未能诱导完全再生。然而，我们确实观察到再生结果有一些改善，这与早期伤口上皮的形态变化以及下方远端间充质中增殖的相应增加有关，不过这两者在后期都没有持续。此外，我们表明Msx1无法在Bmp信号缺陷的背景下挽救肢体再生，这表明无尾两栖类肢体再生还需要其他Bmp靶标。《发育动力学》238:1366 - 1378，2009年。（c）2009威利 - 利斯出版公司。
