Biomedical subjects

Richard Morgan

Publications and source records attributed to Richard Morgan.

7 recordsLinked to original sources

PubMed2003

TALE class homeodomain gene Irx5 is an immediate downstream target for Hoxb4 transcriptional regulation.

The Hox genes are a family of homeodomain-containing transcription factors that determine anteroposterior identity early on in development. Although much is now known about their regulation and function, very little is known of their effector (downstream target) genes. Here, we show that the TALE class homeodomain transcription factor Irx5 is a direct, positively regulated target of Hoxb4.

Animals↗

PubMed2003

Flamingo, a cadherin-type receptor involved in the Drosophila planar polarity pathway, can block signaling via the canonical wnt pathway in Xenopus laevis.

The Flamingo gene encodes a seven-pass transmembrane receptor of the cadherin super family and is one of a growing number of components identified as being necessary for the establishment of planar polarity in the Drosophila wing. Although vertebrate homologues of Flamingo have been identified in both man and mice, no function has as yet been ascribed to them. Here, we report the cloning of the Xenopus homologue of Flamingo (XFmi). XFmi is expressed in the dorsal ectoderm during gastrulation and in the forebrain and midbrain subsequently. We show that ectopic expression of the murine Flamingo gene can prevent the wnt mediated posteriorisation of the neural plate by interfering with the canonical wnt signalling pathway.

Animals↗

PubMed2002

A common element in epidermal expression?

Members of an epidermally expressed gene cluster on human chromosome 21 each contain a short sequence similar to an element that can drive ectoderm-specific gene expression.

Cell Differentiation↗

PubMed2002

The small GTPase Rap1 is an immediate downstream target for Hoxb4 transcriptional regulation.

The Hox genes are a family of homeodomain-containing transcription factors which determine anteroposterior identity early on in development. Although a lot is now known about their regulation and function, very little is known of their effector (downstream target) genes. Here we show that the small GTPase Rap1 is a direct, negatively regulated target of Hoxb4 and is excluded from Hoxb4 expressing cells.

Animals↗

PubMed2002

Hoxc-8 expression shows left-right asymmetry in the posterior lateral plate mesoderm.

XHoxc-8 is the Xenopus homologue of the mouse Hoxc-8 gene, a homeodomain-containing transcription factor that is expressed in the posterior neural tube and adjacent tissues. Although XHoxc-8 has a very similar expression pattern to the Hoxc-8 gene in other species, it also displays distinct left/right asymmetry at later stages of development, being expressed in the posterior lateral mesoderm only on the left-hand side of the embryo.

Animals↗

PubMed2002

The circadian gene Clock is required for the correct early expression of the head specific gene Otx2.

The circadian cycle is a universal molecular mechanism for imposing cyclical control on cellular processes. Here we have examined the role of one of the crucial circadian genes, Clock, in early Xenopus development. We show that a dominant negative version of Clock can block the function of the endogenous Clock gene. Doing so during early development reduces Otx2 expression in a highly specific manner and results in anterior defects. Together with previous work (Green et al. (2001) Mech. Dev. 105-110), these results suggest that a positive regulatory loop exists between Clock and Otx2.

Animals↗

PubMedDate not supplied

Depression and anxiety impair health-related quality of life and are associated with increased costs in general medical inpatients.

Two hundred sixty-three consecutive medical inpatients were studied to assess whether depression and anxiety are associated with increased costs and reduced health-related quality of life. Seventy-three (27.8%) had depressive/anxiety disorders, 107 were "subthreshold" cases, and 83 were controls. After adjustment for severity of physical illness, using the Duke Severity of Illness Scale, cases and subthreshold cases incurred greater mean health care costs than controls over the follow-up period: $8,541 (SE = $605) versus $5,857 (SE = $859), P = 0.012. There was significant impairment of health-related quality of life (SF36 scores) in cases and, to a lesser extent, in subthreshold cases compared to controls. This impairment persisted at follow-up, as did anxiety and depression, indicating the need for future intervention studies.

Adult↗