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
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 2,500+ scientific posters on ePosters
  • More than 3,700+ 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
Microscopic Fish are 3D-Printed to do More Than Swim
Researchers demonstrate a novel method to build microscopic robots with complex shapes and functionalities.
Inciting an Immune Attack on Cancer Cells
A new minimally invasive vaccine that combines cancer cells and immune-enhancing factors could be used clinically to launch a destructive attack on tumors.
Reprogramming Cancer Cells
Researchers on Mayo Clinic’s Florida campus have discovered a way to potentially reprogram cancer cells back to normalcy.
New Strategy for Combating Adenoviruses
Using an animal model they developed, Saint Louis University and Utah State university researchers have identified a strategy that could keep a common group of viruses called adenoviruses from replicating and causing sickness in humans.
Surprising Mechanism Behind Antibiotic-Resistant Bacteria Uncovered
Now, scientists at TSRI have discovered that the important human pathogen Staphylococcus aureus, develops resistance to this drug by “switching on” a previously uncharacterized set of genes.
Fat in the Family?
Study could lead to therapeutics that boost metabolism.
Imaging Software Could Speed Up Breast Cancer Diagnosis
Researchers use high speed optical microscopy of intact breast tissue specimens to analyze breast tissue.
A Metabolic Master Switch Underlying Human Obesity
Researchers find pathway that controls metabolism by prompting fat cells to store or burn fat.
Synthetic DNA Vaccine Against MERS Shows Promise
A novel synthetic DNA vaccine can, for the first time, induce protective immunity against the Middle East Respiratory Syndrome (MERS) coronavirus in animal species.
How Small RNA Helps Form Memories
In a new study, a team of scientists at Scripps Florida has found that a type of genetic material called "microRNA" (miRNA) plays surprisingly different roles in the formation of memory in animal models.
SELECTBIO

Skyscraper Banner
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
2,500+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!