XML Feed for RxPG News   Add RxPG News Headlines to My Yahoo!   Javascript Syndication for RxPG News

Research Health World General
 
  Home
 
 Latest Research
 Cancer
 Psychiatry
 Genetics
 Surgery
 Aging
 Ophthalmology
 Gynaecology
 Neurosciences
 Pharmacology
 Cardiology
 Obstetrics
 Infectious Diseases
 Respiratory Medicine
 Pathology
 Endocrinology
 Immunology
 Nephrology
 Gastroenterology
 Biotechnology
 Radiology
 Dermatology
 Microbiology
 Haematology
 Dental
 ENT
 Environment
 Embryology
  Stem Cell Research
 Orthopedics
 Metabolism
 Anaethesia
 Paediatrics
 Public Health
 Urology
 Musculoskeletal
 Clinical Trials
 Physiology
 Biochemistry
 Cytology
 Traumatology
 Rheumatology
 
 Medical News
 Health
 Opinion
 Healthcare
 Professionals
 Launch
 Awards & Prizes
 
 Careers
 Medical
 Nursing
 Dental
 
 Special Topics
 Euthanasia
 Ethics
 Evolution
 Odd Medical News
 Feature
 
 World News
 Tsunami
 Epidemics
 Climate
 Business
 
 India
Search

Last Updated: Nov 18, 2006 - 12:32:53 PM

Embryology Channel
subscribe to Embryology newsletter

Latest Research : Embryology

   DISCUSS   |   EMAIL   |   PRINT
New mechanism potentially explain evolution of signalling pathways
Feb 8, 2006 - 11:19:00 AM, Reviewed by: Dr. Priya Saxena

The finding is the first clear demonstration of a major difference in the function of conserved signalling pathways between species.

 
Cancer researchers at the University of Helsinki, in trying to find a novel tumor suppressor gene, instead found an important evolutionary change that occurred in a key developmental signalling pathway. The finding suggests a potential mechanism for evolution of complex intercellular signalling pathways.

A relatively small number of evolutionary conserved genes are responsible for controlling the development of the diverse range of animal species. Most of these genes have been originally identified in fruit fly, based on the analysis of mutations that alter the body pattern of a developing embryo.

During embryonic development, cells regulate the growth and differentiation of each other by secreting extracellular signalling molecules (growth factors or morphogens), which bind to receptors present on the surface of other cells. The receptors in turn activate intracellular signalling pathway composed of proteins that relay the signal to the nucleus, activating specialized proteins called transcription factors. The transcription factors then affect expression of genes that induce cell growth and differentiation.

The signal transduction molecules and mechanisms of major developmental signalling pathways are thought to be evolutionary conserved between invertebrates and vertebrates in such a way that if a signalling pathway is present in a given organism, it includes all the major classes of components found in humans. Because of the lack of intermediate forms, the evolution of these complex signalling pathways is not understood in detail, and the emergence of signalling pathways with multiple specific and essential components has even been used as an argument against evolution.

Because multiple components of the Hedgehog (Hh) signalling pathway are defective in human cancers, Markku Varjosalo in Professor Jussi Taipale's laboratory (the University of Helsinki and National Public Health Institute of Finland) cloned the gene for mammalian homolog of a key regulator of fruit fly Hh signalling pathway, Costal-2. However, further analysis of the function of the mammalian gene revealed that it did not function as a Hh pathway regulator, let alone as the tumor suppressor gene the researchers had hoped for. Instead, together with a group led by Prof. Rune Toftg�rd and Dr. Stephan Teglund from Karolinska Institutet, the researchers found that another gene (Suppressor of Fused), which has a minor role in Hh signalling in fruit fly is critical for Hh pathway regulation in mammals.

The finding is the first clear demonstration of a major difference in the function of conserved signalling pathways between species. The results also show that multi-component pathways evolve, in part, by the insertion of novel proteins between existing pathway components. This insertion mechanism can potentially explain a challenging aspect of evolutionary biology regarding the emergence of signalling pathways with multiple specific components.
 

- Developmental Cell Journal
 

www.helsinki.fi

 
Subscribe to Embryology Newsletter
E-mail Address:

 



Related Embryology News

Faults in housekeeping genes regulating protein trafficking results in skeletal deformities
Neural stem cells derived from human embryonic stem cells carry abnormal gene expression
Neurons grown from embryonic stem cells restore function in paralyzed rats
New stem-cell findings can help the body to cure itself
Putting avian transgenics on a par with transgenic mice
Harvard to Create Human Embryonic Stem Cell Lines
Stem Cell Study for Patients with Heart Attack Damage Seeks to Regenerate Heart Muscle
Stem cells - An alternative to skin grafting?
Bone morphogenetic protein 6 (BMP-6) factor stimulates cartilage growth from stem cells
Doctors grow organ from patients' own cells


For any corrections of factual information, to contact the editors or to send any medical news or health news press releases, use feedback form

Top of Page

 

© Copyright 2004 onwards by RxPG Medical Solutions Private Limited
Contact Us