Hoxgenes in time and space during vertebrate body formation

Abstract

Vertebrae display distinct morphological features at different levels of the body axis. Links between collinear Hox gene activation and the progressive mode of body axis elongation have provided a fascinating blueprint of the mechanisms for establishing these morphological identities. In this review, we first discuss the regulation and possible role of collinear Hox gene activation during body formation and then highlight the direct role of Hox genes in controlling cellular movements during gastrulation, therefore contributing to body formation. Additional related research aspects, such as imaging of chromatin regulation, roles of micro RNAs and evolutional findings are also discussed.

HOX transcription factors are potential therapeutic targets in non-small-cell lung cancer (targeting HOX genes in lung cancer)

“…These findings suggest that the interaction between HOX and PBX proteins is a potential therapeutic target in NSCLC. The HOX genes are a family of homeodomain-containing transcription factors that determine the identity of cells and tissues in early development (Iimura and Pourquié, 2007), and also have key regulatory roles in adult haematopoietic stem cells and their descendants (Abramovich and Humphries, 2005). In addition, HOX genes are often overexpressed in malignant cells and are known to act as oncogenes in some haematopoietic malignancies (Eklund, 2007).…”

Direct control of Hoxd1 and Irx3 expression by Wnt/beta-catenin signaling during anteroposterior patterning of the neural axis in Xenopus

“…The Hoxd1 homeobox gene belongs to the highly conserved family of Hox genes that are expressed in colinear fashion and establish a complex developmental regulatory system that provides cells with specific positional identities on the AP axis (Deschamps et al, 1999, Duboule, 1998, Iimura and Pourquie, 2007, McGinnis and Krumlauf, 1992. In Xenopus, Hoxd1 is first expressed in the ventrolateral mesoderm and later in the posterior ectoderm, presumptive hindbrain and its associated neural crest (McNulty et al, 2005).…”

“…Extensive evidence has been obtained to implicate the FGF, Wnt, and retinoic acid (RA) signaling pathways in the caudalization of the neural axis (Durston et al, 1997, Gamse and Sive, 2000, Gavalas and Krumlauf, 2000, Gomez-Skarmeta et al, 2003. In function of the combined activity of these factors boundaries of Hox gene expression are established along the AP axis, which in the neural plate have been suggested to be involved in establishing different identities in the hindbrain and spinal cord (Deschamps et al, 1999, Iimura and Pourquie, 2007, McGinnis and Krumlauf, 1992. Also other homeodomain containing transcription factors are induced in specific domains along the AP axis, including Cdx genes and transcription factors that pattern the tissue rostral from the most anterior expressed Hox genes (Deschamps et al, 1999).…”

MicroRNAs in brain function and disease

“…The mechanisms behind neural patterning might involve miRNAs on various levels. Development of the anteriorposterior axis of the CNS, for example, is regulated by homeobox (Hox) genes, which are in turn targeted by miRNAs [27,28]. Studies in zebrafish deficient in the Dicer protein (and therefore devoid of functional miRNAs) revealed organizational defects during the formation of the embryonic neural plate and during its transformation into the neural tube in the knockout animals [29••].…”