HOME ABOUT CONTACT AVAILABLE ISSUES SUBSCRIBE MEDIA & ADS CONFERENCE CALENDAR
LATEST UPDATES » Volume 20, No. 5, May 2016 – Healthcare Systems & Policies in Asia       » Understanding Healthcare Policies in the Philippines: Cancer Care       » Young Innovators under 35       » Healthcare Cost Effectiveness in Singapore       » ASLAN Pharmaceuticals Opens China Office       » A Journey Inside the Human Body       » Treatment Brings New Hope for Patients Suffering From Fatal Lung Disease      
BIOBOARD - JAPAN
‘Tug of war’ method to measure the copy number limits of all genes in budding yeast
Professor Hisao Moriya and colleagues at Okayama University used their ‘tug of war method to measure the copy number limits of all protein-coding genes in yeast—the first time ever for any organisms.

Over-expression of proteins due to the increase in the gene-copy numbers is considered to be the cause of pathologies of diseases such as Down syndrome and cancer, which involve chromosomal abnormality. However, the causal genes and thus the mechanisms directly involved in their pathologies are not clear, because gross rearrangements of the number of chromosomes, which contain a large number of genes, occur in these diseases.

The research group of associate professor Hisao Moriya previously developed an experimental technology designated “genetic Tug-Of-War (gTOW)” to measure how much the copy number of a gene can increase without disrupting the cellular function (the copy number limit of a gene).

The group uses the budding yeast Saccharomyces cerevisiae as the simplest model eukaryote, which basically has the same cellular structure as human cells. Using the gTOW method, the group recently has measured the copy number limits of all protein-coding genes (about 6000 genes) in S. cerevisiae, as the first time ever for any organisms.

As a result, the group first discovered that >80% of the genes have the copy number limits >100. This indicates that the cellular system is surprisingly robust against the increase in the copy numbers of most genes. The group also identified 115 genes with the copy number limits of 10 or less (here we designate these genes “dosage sensitive genes). Identified genes significantly contained genes involved in cytoskeletal organization and intracellular transport. They also tended to encode proteins relatively abundant in the cell, and proteins function as complexes with other proteins.

From these characteristics, the group assumed that the burden of the turnover of unnecessary proteins toward basic cellular functions (protein burden), and the dosage imbalance within protein complexes (stoichiometry imbalance) caused the strong adverse effects produced by the dosage sensitive genes. With additional gTOW experiments, the group further confirmed these assumptions were true. Finally the group proposed a hypothesis that the dosage balances of dosage sensitive genes determine the composition of chromosomes. The hypothesis explains how compositions of chromosomes of current organisms have been determined during evolution, and how they are stably maintained.

To understand what happens when the copy number of a dosage sensitive gene increases in yeast is to understand the pathologies of Down syndrome and cancer, in which the increase in chromosome numbers are involved. In addition, it is known that malignant cancer cells can avoid the adverse effects brought by the increase in the number of chromosomes. The group believes that the mechanisms to avoid the adverse effects are revealed by identifying the mutants that tolerate the copy number increases of the dosage sensitive genes
in yeast.

Source: Okayama University,
Planning and Public Information Division

Click here for the complete issue.

NEWS CRUNCH  
news World Immunisation Week 2016
news IoT Asia 2016 Delivers Actionable Solutions for a Sustainable IoT Ecosystem in Asia
news Lite-On presents a new Biomedical Research and Development Centre in Singapore
PR NEWSWIRE  
Asia Pacific Biotech News
EDITORS' CHOICE  
COLUMNS  
APBN Editorial Calendar 2016
January:
Guest Editorial - Biotechnology In Korea
February:
Guest Editorial - Biomedical Research Governance
March:
Guest Editorial - Life-Saving Opportunities: A Guide to Regenerative Medicine
April:
Leading-Edge ONCOLOGY
May:
Healthcare Systems & Policies in Asia
June:
Medical Devices and Digital Health Technology
July:
Water Technology
August:
Guest Editorial - Antibody Informatics In Japan
September:
Infectious Diseases
October:
Medical Tourism
November:
Biomedical Imaging Technology
December:
Food Technology
Editorial calendar is subjected to changes.
– Editor: Carmen, Jia Wen Loh
MAGAZINE TAGS
About Us
Events
Available issues
Editorial Board
Letters to Editor
Instructions to Authors
Advertise with Us
CONTACT
World Scientific Publishing Co. Pte. Ltd.
5 Toh Tuck Link, Singapore 596224
Tel: 65-6466-5775
Fax: 65-6467-7667
» Editorial Enquiries: biotech_edit@wspc.com
» For Subscriptions, Advertisements &
   Media Partnerships Enquiries:
   Ms PoPo Kwok or Ms Sok Ching Lim/td>
Copyright© 2015 World Scientific Publishing Co Pte Ltd  •  Privacy Policy