CNRS, Aix Marseille Université, Marseille, France.
Dev Dyn. 2014 Jan;243(1):192-200. doi: 10.1002/dvdy.24081. Epub 2013 Nov 28.
Hox genes encode transcription factors playing important role in segment specific morphogenesis along the anterior posterior axis. Most work in the Hox field aimed at understanding the basis for specialised Hox functions, while little attention was given to Hox common function. In Drosophila, genes of the Bithorax complex [Ultrabithorax (Ubx), abdominalA (abdA), and AbdominalB (AbdB)] all promote abdominal identity. While Ubx and AbdA share extensive sequence conservation, AbdB is highly divergent, questioning how it can perform similar functions as Ubx and AbdA.
In this study, we investigate the genetic requirement for the specification of abdominal-type denticles by Ubx, AbdA, and AbdB. The impact of ectopic expression of Hox proteins in embryos mutant for Exd as well as of Wingless or Hedgehog signaling involved in intrasegmental patterning was analyzed. Results indicated that Ubx and AbdA do not require Exd, Wg, and Hh activity for specifying abdominal-type denticles, while AbdB does.
Our results support that distinct regulatory mechanisms underlie Ubx/AbdA- and AbdB-mediated specification of abdominal-type denticles, highlighting distinct strategies for achieving a similar biological output. This suggests that common function performed by distinct paralogue Hox proteins may also rely on newly acquired property, instead of conserved/ancestral properties.
Hox 基因编码转录因子，在沿前后轴的特定节段形态发生中发挥重要作用。Hox 领域的大多数工作旨在了解专门的 Hox 功能的基础，而很少关注 Hox 的常见功能。在果蝇中，双胸复合体[Ultrabithorax (Ubx)、腹部 A (abdA)和 AbdominalB (AbdB)]的基因都促进腹部身份。虽然 Ubx 和 AbdA 具有广泛的序列保守性，但 AbdB 高度分化，这使得它如何能够执行与 Ubx 和 AbdA 类似的功能成为一个问题。
在这项研究中，我们研究了 Ubx、AbdA 和 AbdB 对腹部型齿的指定的遗传要求。分析了 Hox 蛋白在 Exd 突变胚胎中的异位表达以及参与节内模式形成的 Wingless 或 Hedgehog 信号的影响。结果表明，Ubx 和 AbdA 不需要 Exd、Wg 和 Hh 活性来指定腹部型齿，而 AbdB 需要。
我们的结果支持 Ubx/AbdA- 和 AbdB-介导的腹部型齿指定的不同调节机制，突出了实现相似生物学输出的不同策略。这表明，不同的 Hox 蛋白的相似的功能也可能依赖于新获得的特性，而不是保守/祖先的特性。
