HoxA and HoxD expression in a variety of vertebrate body plan features reveals an ancient origin for the distal Hox program
HoxA and HoxD expression in a variety of vertebrate body plan features reveals an ancient origin for the distal Hox program
复制标题
DOI：
10.1186/2041-9139-5-44
复制
发表时间：
2014-11-19
期刊：
影响因子：
4.1
通讯作者：
Crow, Karen D.
中科院分区：
文献类型：
--
作者：
Archambeault, Sophie;Taylor, Julia Ann;Crow, Karen D.
背景：Hox基因是动物中轴发育过程中的主要调控基因，在中轴发育过程中起着重要的位置调控作用。由于它们在有颌脊椎动物中复杂的调节和身体平面特征的特异性，关于它们的协调表达模式的发现引起了人们的强烈兴趣。例如，后HoxD基因切换到一个倒置的共线表达模式在小鼠autopod，其中HoxD 13切换从一个更受限制的结构域相对于其相邻的基因簇。我们将此程序称为“远端相”（DP）表达模式，因为它发生在成对鳍和肢的远端区域，并且由HoxD簇上游5'区域中的元件独立调节。然而，很少有类群已经评估了这种模式，大多数研究都集中在胸鳍的形态发生，这发生在相对早期的development.Results：在这里，我们首次证明，DP的表达模式发生与后HoxA基因，因此并不完全与HoxD基因簇。此外，DP Hox表达并不局限于成对的鳍和四肢，而是发生在各种身体平面特征中，包括白鲟触须-从第一下颌弓（前“Hox无区”）和排气口（类似于尿道的中间结构）发育的感觉装饰物。我们发现DP表达的HoxD 13和HoxD 12在白鲟须，我们提出的第一个证据DP表达的HoxA基因在后肠和通风口的三条鳍鱼。HoxA DP的表达模式是预测的最近发现的一个共享的5'监管架构中的HoxA和HoxD集群，但以前没有观察到在任何身体计划feature.Conclusions：Hox DP的表达模式似乎是一个古老的模块，已增选在各种结构装饰的脊椎动物bauplan。该模块提供了一个共享的遗传程序，暗示了在脊椎动物形态多样性的进化中发挥了重要作用的各种远端细长结构的深层同源性
Background: Hox genes are master regulatory genes that specify positional identities during axial development in animals. Discoveries regarding their concerted expression patterns have commanded intense interest due to their complex regulation and specification of body plan features in jawed vertebrates. For example, the posterior HoxD genes switch to an inverted collinear expression pattern in the mouse autopod where HoxD13 switches from a more restricted to a less restricted domain relative to its neighboring gene on the cluster. We refer to this program as the 'distal phase' (DP) expression pattern because it occurs in distal regions of paired fins and limbs, and is regulated independently by elements in the 5' region upstream of the HoxD cluster. However, few taxa have been evaluated with respect to this pattern, and most studies have focused on pectoral fin morphogenesis, which occurs relatively early in development.Results: Here, we demonstrate for the first time that the DP expression pattern occurs with the posterior HoxA genes, and is therefore not solely associated with the HoxD gene cluster. Further, DP Hox expression is not confined to paired fins and limbs, but occurs in a variety of body plan features, including paddlefish barbels - sensory adornments that develop from the first mandibular arch (the former 'Hox-free zone), and the vent (a medial structure that is analogous to a urethra). We found DP expression of HoxD13 and HoxD12 in the paddlefish barbel; and we present the first evidence for DP expression of the HoxA genes in the hindgut and vent of three ray-finned fishes. The HoxA DP expression pattern is predicted by the recent finding of a shared 5' regulatory architecture in both the HoxA and HoxD clusters, but has not been previously observed in any body plan feature.Conclusions: The Hox DP expression pattern appears to be an ancient module that has been co-opted in a variety of structures adorning the vertebrate bauplan. This module provides a shared genetic program that implies deep homology of a variety of distally elongated structures that has played a significant role in the evolution of morphological diversity in vertebrates