Talk:Developmental Signals - Homeobox

From Embryology
Revision as of 20:39, 20 March 2012 by Z8600021 (talk | contribs)
About Discussion Pages  
Mark Hill.jpg
On this website the Discussion Tab or "talk pages" for a topic has been used for several purposes:
  1. References - recent and historic that relates to the topic
  2. Additional topic information - currently prepared in draft format
  3. Links - to related webpages
  4. Topic page - an edit history as used on other Wiki sites
  5. Lecture/Practical - student feedback
  6. Student Projects - online project discussions.
Links: Pubmed Most Recent | Reference Tutorial | Journal Searches

Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Cite this page: Hill, M.A. (2019, December 13) Embryology Developmental Signals - Homeobox. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Developmental_Signals_-_Homeobox


Search All Databases hox

UNSW Embryology - Molecular Notes | Musculoskeletal Notes


PMID 20485555 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0010600

2011

Evolution of anterior Hox regulatory elements among chordates

BMC Evol Biol. 2011 Nov 15;11:330.

Natale A, Sims C, Chiusano ML, Amoroso A, D'Aniello E, Fucci L, Krumlauf R, Branno M, Locascio A. Source Laboratory of Cellular and Developmental Biology, Stazione Zoologica Anton Dohrn, Villa Comunale, Naples, Italy. Abstract BACKGROUND: The Hox family of transcription factors has a fundamental role in segmentation pathways and axial patterning of embryonic development and their clustered organization is linked with the regulatory mechanisms governing their coordinated expression along embryonic axes. Among chordates, of particular interest are the Hox paralogous genes in groups 1-4 since their expression is coupled to the control of regional identity in the anterior nervous system, where the highest structural diversity is observed. RESULTS: To investigate the degree of conservation in cis-regulatory components that form the basis of Hox expression in the anterior nervous system, we have used assays for transcriptional activity in ascidians and vertebrates to compare and contrast regulatory potential. We identified four regulatory sequences located near the CiHox1, CiHox2 and CiHox4 genes of the ascidian Ciona intestinalis which direct neural specific domains of expression. Using functional assays in Ciona and vertebrate embryos in combination with sequence analyses of enhancer fragments located in similar positions adjacent to Hox paralogy group genes, we compared the activity of these four Ciona cis-elements with a series of neural specific enhancers from the amphioxus Hox1-3 genes and from mouse Hox paralogous groups 1-4. CONCLUSIONS: This analysis revealed that Kreisler and Krox20 dependent enhancers critical in segmental regulation of the hindbrain appear to be specific for the vertebrate lineage. In contrast, neural enhancers that function as Hox response elements through the action of Hox/Pbx binding motifs have been conserved during chordate evolution. The functional assays reveal that these Hox response cis-elements are recognized by the regulatory components of different and extant species. Together, our results indicate that during chordate evolution, cis-elements dependent upon Hox/Pbx regulatory complexes, are responsible for key aspects of segmental Hox expression in neural tissue and appeared with urochordates after cephalochordate divergence.

PMID 22085760


2009

Hedgehog signaling is dispensable for adult murine hematopoietic stem cell function and hematopoiesis

Cell Stem Cell. 2009 Jun 5;4(6):559-67.

Hofmann I, Stover EH, Cullen DE, Mao J, Morgan KJ, Lee BH, Kharas MG, Miller PG, Cornejo MG, Okabe R, Armstrong SA, Ghilardi N, Gould S, de Sauvage FJ, McMahon AP, Gilliland DG. Source Division of Hematology, Department of Medicine, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.

Abstract

We report the unexpected finding that loss of Hh signaling through conditional deletion of Smoothened (Smo) in the adult hematopoietic compartment has no apparent effect on adult hematopoiesis, including peripheral blood count, number or cell-cycle status of stem or progenitor cells, hematopoietic colony-forming potential, long-term repopulating activity in competitive repopulation assays, or stress response to serial 5-fluorouracil treatment. Furthermore, pharmacologic inhibition of Hh signaling with a potent and selective small molecule antagonist has no substantive effect on hematopoiesis in the mouse. In addition, Hh signaling is not required for the development of MLL-AF9-mediated acute myeloid leukemia (AML). Taken together, these data demonstrate that Hh signaling is dispensable for normal hematopoietic development and hematopoietic stem cell function, indicating that targeting of Hh signaling in solid tumors is not likely to result in hematopoietic toxicity. Furthermore, the Hh pathway may not be a compelling target in certain hematopoietic malignancies.

Comment in Cell Stem Cell. 2009 Jun 5;4(6):470-1.

PMID 19497284

2006

Hox transcription factors and their elusive mammalian gene targets

Heredity. 2006 Aug;97(2):88-96. Epub 2006 May 24.

Svingen T, Tonissen KF. Source Cell Biology Group, Eskitis Institute for Cell and Molecular Therapies and School of Biomolecular and Biomedical Science, Griffith University, Nathan, Queensland 4111, Australia.

Abstract

The Hox family of homeodomain transcription factors regulate numerous pathways during developmental and normal cellular processes. All Hox proteins recognise similar sequences in vitro yet display functional diversity in an in vivo environment. This review focuses on the transcriptional and functional specificity elicited by Hox proteins, giving an overview of homeodomain-DNA interactions and the gain of binding specificity through cooperative binding with cofactors. Furthermore, currently identified mammalian Hox target genes are presented, of which the most striking feature is that very few direct Hox targets have been identified. The direct targets participate in an array of cellular functions including organogenesis and cellular differentiation, cell adhesion and migration and cell cycle and apoptotic pathways. A further assessment of identified mammalian promoter targets and the contribution of bases outside the canonical recognition motif is given, highlighting roles they may play in either trans-activation or repression by Hox proteins.

PMID 16721389

The list contains likely Hox gene targets and the Hox protein responsible for the trans-regulatory effect. The (+/-) symbols represent either a positive or negative regulatory effect on the target gene and (?) symbol indicates an unknown effect. Also, note that although there is some experimental evidence to suggest all are likely direct gene targets, not all have been exclusively verified of being so through in vivo experiments. The corresponding reference(s) for each gene target is also shown.

</thead><tbody valign="top"></tbody>

Hox protein

+/-

Target

Species

Reference

Hoxa2-Six2Mouse

Kutejova et al (2005)

Hoxa5+p53Mouse

Raman et al (2000a)

HOXA5  Human 
HOXA5+Progesterone receptorHuman

Raman et al (2000b)

HOXA5+PleiotrophinHuman

Chen et al (2005)

HOXA5+IGFBP-1Human

Foucher et al (2002); Gao et al (2002)

HOXA10    
HOXB4    
Hoxa9-OsteopontinMouse

Shi et al (1999, 2001)

Hoxc8    
HOXA9+EphB4Human

Bruhl et al (2004)

HOXA10+p21Human

Bromleigh and Freedman (2000)

HOXA10+ beta 3-IntegrinHuman

Daftary et al (2002)

HOXA10-EMX2Human

Troy et al (2003)

Hoxa10+IGFBP-1Baboon

Kim et al (2003)

Hoxa13, Hoxd13+EphA7Mouse

Salsi and Zappavigna (2006)

HOXB1+COL5A2Human

Penkov et al (2000)

Hoxb3+TTF-1Rat

Guazzi et al (1994)

Hoxb5+SPI3Mouse

Safaei (1997)

Hoxb5+Flk1Mouse

Wu et al (2003)

HOXB7+BFGFHuman

Carè et al (1996)

Hoxb8-N-CAMMouse

Jones et al (1992)

Hoxb9+N-CAMMouse

Jones et al (1992)

Hoxc8?mgl-1Mouse

Tomotsune et al (1993)

Hoxc13-KeratinsMouse

Tkatchenko et al (2001)

Hoxd10, b6, b7, b9, c8+ReninMouse

Pan et al (2004)

2005

Developmental regulation of the Hox genes during axial morphogenesis in the mouse

Development. 2005 Jul;132(13):2931-42.

Deschamps J, van Nes J. Source Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands. jacqueli@niob.knaw.nl

Abstract

The Hox genes confer positional information to the axial and paraxial tissues as they emerge gradually from the posterior aspect of the vertebrate embryo. Hox genes are sequentially activated in time and space, in a way that reflects their organisation into clusters in the genome. Although this co-linearity of expression of the Hox genes has been conserved during evolution, it is a phenomenon that is still not understood at the molecular level. This review aims to bring together recent findings that have advanced our understanding of the regulation of the Hox genes during mouse embryonic development. In particular, we highlight the integration of these transducers of anteroposterior positional information into the genetic network that drives tissue generation and patterning during axial elongation.

PMID 15944185