Analysis of hoxa11 and hoxa13 expression during patternless limb regeneration in Xenopus.
Analysis of hoxa11 and hoxa13 expression during patternless limb regeneration in Xenopus.
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DOI：
10.1016/j.ydbio.2009.11.026
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发表时间：
2010-02
影响因子：
2.7
通讯作者：
Shiro Ohgo;A. Itoh;Makoto Suzuki;A. Satoh;H. Yokoyama;K. Tamura
中科院分区：
文献类型：
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作者：
Shiro Ohgo;A. Itoh;Makoto Suzuki;A. Satoh;H. Yokoyama;K. Tamura
在肢体再生过程中，无尾纲蝌蚪和尾纲两栖动物产生模式组织、多能、间充质囊胚细胞，这些细胞产生了缺失肢体的复制品，包括三维模式。为了促进其他脊椎动物不可再生肢体的再生，阐明能够再生肢体模式的胚母细胞和不能再生肢体模式的胚母细胞之间的分子差异是很重要的。在非洲爪蟾小蛙（变形后不久）中，被截肢的肢体产生的胚母细胞不能产生适当的图案，导致无图案的再生，即尖刺，无论截肢程度如何。我们发现，尽管随后的近端-远端模式（包括hoxa11和hoxa13表达域的分离）被破坏，但在小胚中hoxa11和hoxa13的重新表达是开始的。我们还观察到EphA4基因在小胚中表达缺失和位置依赖性细胞分选失败，这与hoxa11和hoxa13表达的改变有关。定量分析hoxa11和hoxa13的表达发现，与蝌蚪囊胚相比，hoxa13在青蛙囊胚中的转录水平降低。此外，sox9（一种重要的软骨分化调节剂）的表达在无模式囊胚中比在蝌蚪囊胚中更早被检测到。这些结果表明，适当的空间、时间和数量的基因表达是胚母细胞模式再生的必要条件。
During limb regeneration, anuran tadpoles and urodele amphibians generate pattern-organizing, multipotent, mesenchymal blastema cells, which give rise to a replica of the lost limb including patterning in three dimensions. To facilitate the regeneration of nonregenerative limbs in other vertebrates, it is important to elucidate the molecular differences between blastema cells that can regenerate the pattern of limbs and those that cannot. In Xenopus froglet (soon after metamorphosis), an amputated limb generates blastema cells that do not produce proper patterning, resulting in a patternless regenerate, a spike, regardless of the amputation level. We found that re-expression of hoxa11 and hoxa13 in the froglet blastema is initiated although the subsequent proximal–distal patterning, including separation of the hoxa11 and hoxa13 expression domains, is disrupted. We also observed an absence of EphA4 gene expression in the froglet blastema and a failure of position-dependent cell sorting, which correlated with the altered hoxa11 and hoxa13 expression. Quantitative analysis of hoxa11 and hoxa13 expression revealed that hoxa13 transcript levels were reduced in the froglet blastema compared with the tadpole blastema. Moreover, the expression of sox9, an important regulator of chondrogenic differentiation, was detected earlier in patternless blastemas than in tadpole blastemas. These results suggest that appropriate spatial, temporal, and quantitative gene expression is necessary for pattern regeneration by blastema cells.