Corporate Banner
Satellite Banner
RNAi
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

“Junk DNA” Drives Embryonic Development

Published: Thursday, December 06, 2012
Last Updated: Thursday, December 06, 2012
Bookmark and Share
An embryo is an amazing thing. From just one initial cell, an entire living, breathing body emerges, full of working cells and organs.

It comes as no surprise that embryonic development is a very carefully orchestrated process—everything has to fall into the right place at the right time. Developmental and cell biologists study this very thing, unraveling the molecular cues that determine how we become human.

“One of the first, and arguably most important, steps in development is the allocation of cells into three germ layers—ectoderm, mesoderm, and endoderm—that give rise to all tissues and organs in the body,” explains Mark Mercola, Ph.D., professor and director of Sanford-Burnham’s Muscle Development and Regeneration Program in the Sanford Children’s Health Research Center.

In a study published November 14 in the journal Genes & Development, Mercola and his team, including postdoctoral researcher Alexandre Colas, Ph.D., and Wesley McKeithan, discovered that microRNAs play an important role in this cell- and germ layer-directing process during development.

MicroRNA: one man’s junk is another’s treasure

MicroRNAs are small pieces of genetic material similar to the messenger RNA that carries protein-encoding recipes from a cell’s genome out to the protein-building machinery in the cytoplasm.  Only microRNAs don’t encode proteins. So, for many years, scientists dismissed the regions of the genome that encode these small, non-protein coding RNAs as “junk.”

We now know that microRNAs are far from junk. They may not encode their own proteins, but they do bind messenger RNA, preventing their encoded proteins from being constructed. In this way, microRNAs play important roles in determining which proteins are produced (or not produced) at a given time.

MicroRNAs are increasingly recognized as an important part of both normal cellular function and the development of human disease.

So, why not embryonic development, too?

Directing cellular traffic

To pinpoint which—if any—microRNAs influence germ layer formation in early embryonic development, Mercola and his team individually studied most (about 900) of the microRNAs from the human genome. They tested each microRNA’s ability to direct formation of mesoderm and endoderm from embryonic stem cells. In doing so, they discovered that two microRNA families—called let-7 and miR-18—block endoderm formation, while enhancing mesoderm and ectoderm formation.

The researchers confirmed their finding by artificially blocking let-7 function and checking to see what happened. That move dramatically altered embryonic cell fate, diverting would-be mesoderm and ectoderm into endoderm and underscoring the microRNA’s crucial role in development.

But they still wanted to know more…how do let-7 and miR-18 work? Mercola’s team went on to determine that these microRNAs direct mesoderm and ectoderm formation by dampening the TGFβ signaling pathway. TGFβ is a molecule that influences many cellular behaviors, including proliferation and differentiation. When these microRNAs tinker with TGFβ activity, they send cells on a certain course—some go on to become bone, others brain.

“We’ve now shown that microRNAs are powerful regulators of embryonic cell fate,” Mercola says. “But our study also demonstrates that screening techniques, combined with systems biology, provide a paradigm for whole-genome screening and its use in identifying molecular signals that control complex biological processes.”


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,200+ scientific posters on ePosters
  • More than 4,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.


Scientific News
Contagious Cancers Are Spreading in Shellfish
Direct transmission of cancer among some marine animals may be more common than once thought, suggests a new study published in Nature by researchers at Columbia University Medical Center (CUMC).
Contagious Cancers Are Spreading in Shellfish
Direct transmission of cancer among some marine animals may be more common than once thought, suggests a new study published in Nature by researchers at Columbia University Medical Center (CUMC).
Fix for 3-Billion-Year-Old Genetic Error
Researchers at The University of Texas at Austin have developed a fix that allows RNA to accurately proofread for the first time.
Revealing the Genetic Causes of Bowel Cancer
A landmark study has given the most detailed picture yet of the genetics of bowel cancer — the UK's fourth most common cancer.
Self-Assembling Protein Shell for Drug Delivery
Made-to-order nano-cages open possibilities of shipping cargo into living cells or fashioning small chemical reactors.
Fighting Resistant Blood Cancer Cells
Biologists present new findings on chronic myeloid leukemia and possible therapeutic approaches.
Tumor Cells Develop Predictable Characteristics
Scientists have discovered that cancer cells at the edge of a tumor that are close to the surrounding environment are predictably different from the cells within the interior of the tumor.
Guided Chemotherapy Missiles
Latching chemotherapy drugs onto proteins that seek out tumors could provide a new way of treating tumors in the brain or with limited blood supply that are hard to reach with traditional chemotherapy.
Solutions for Biotherapeutic Characterization
Innovation to speed the routine.
What Makes a Good Scientist?
It’s the journey, not just the destination that counts as a scientist when conducting research.
SELECTBIO

SELECTBIO Market Reports
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,200+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!