Featured Research

from universities, journals, and other organizations

How Embryos Regulate Vitamin A Derivatives: Too Much Or Too Little Linked To Birth Defects

Date:
November 24, 2007
Source:
University of California - Irvine
Summary:
Human embryos that get too much or too little retinoic acid, a derivative of Vitamin A, can develop into babies with birth defects. New research shows for the first time how embryonic cells may regulate levels of retinoic acid, giving scientists insight into how it acts as a signal between cells to control development of the brain, limbs and many other tissues in embryos.

Zebrafish.
Credit: Photo by Lukas Roth

Human embryos that get too much or too little retinoic acid, a derivative of Vitamin A, can develop into babies with birth defects. New research at UC Irvine shows for the first time how embryonic cells may regulate levels of retinoic acid, giving scientists insight into how it acts as a signal between cells to control development of the brain, limbs and many other tissues in embryos.

Thomas Schilling, Richard White, Qing Nie and Arthur Lander of UCI studied the behavior of retinoic acid in zebrafish embryos, which often are used in genetic studies as models for human development because the transparent embryos are easy to examine and develop rapidly. The zebrafish genome also has been completely sequenced.

Retinoic acid is important to human health. In addition to its vital role in embryo development, it is used to treat patients with certain types of leukemia, and it is included in many acne medications because of its profound effects on skin cells. Vitamin A is found naturally in many foods, including liver, carrots, broccoli, kale and sweet potatoes.

"Vitamin A in the diet gets converted into retinoic acid, which scientists have known since the 1960s has amazing effects on cells and tissues," said Schilling, associate professor of developmental and cell biology at UC Irvine. "If you don't get enough Vitamin A in your diet -- or if you get too much -- your body compensates for that. Our study helps explain how this regulation occurs."

Within a certain range, cells can regulate levels of retinoic acid. Schilling and his colleagues found that if the level becomes too high, an enzyme called cyp26a1 degrades the excess and brings it back to normal. When levels drop too low, proteins called fibroblast growth factors, or FGFs, stop the retinoic acid from degrading as rapidly.

"Those two things work together to keep the whole system adjusted to the right level," Schilling said. "Retinoic acid induces its own degradation, and FGFs, also present in the embryo, have the opposite effect by inhibiting retinoic acid degradation."

Zebrafish embryos used in this study were genetically engineered to be unable to make enough retinoic acid. The UCI scientists implanted tiny retinoic acid-soaked beads, which gradually released retinoic acid into the embryos. Using genetically altered fish embryos in which cells become fluorescent in response to retinoic acid when illuminated with an ultraviolet light, the scientists tracked how the retinoic acid moved within the embryos. This study is among the first to examine the distribution of retinoic acid.

These data were analyzed in a mathematical model based on the different biological components of the embryo. This type of collaboration between biologists and mathematicians is key to understanding how signals work and act together in complex biological systems.

Previously, scientists focused on where retinoic acid is made within an embryo, "but now we're hoping the results of our study will shift the focus of research to how the degradation of retinoic acid is controlled," Schilling said. Hopefully this someday will help scientists better predict how retinoic acid behaves in the human body, leading to more effective drug treatments.

Citation: White RJ, Nie Q, Lander AD, Schilling TF (2007) Complex regulation of cyp26a1 creates a robust retinoic acid gradient in the zebrafish embryo. PLoS Biol 5(11): e304. doi:10.1371/journal.pbio.0050304.

This study was funded by the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of California - Irvine. Note: Materials may be edited for content and length.


Cite This Page:

University of California - Irvine. "How Embryos Regulate Vitamin A Derivatives: Too Much Or Too Little Linked To Birth Defects." ScienceDaily. ScienceDaily, 24 November 2007. <www.sciencedaily.com/releases/2007/11/071119214004.htm>.
University of California - Irvine. (2007, November 24). How Embryos Regulate Vitamin A Derivatives: Too Much Or Too Little Linked To Birth Defects. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2007/11/071119214004.htm
University of California - Irvine. "How Embryos Regulate Vitamin A Derivatives: Too Much Or Too Little Linked To Birth Defects." ScienceDaily. www.sciencedaily.com/releases/2007/11/071119214004.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com
How to Master Motherhood With the Best Work/Life Balance

How to Master Motherhood With the Best Work/Life Balance

TheStreet (Apr. 22, 2014) In the U.S., there are more than 11 million couples trying to conceive at any given time. From helping celebrity moms like Bethanny Frankel to ordinary soon-to-be-moms, TV personality and parenting expert, Rosie Pope, gives you the inside scoop on mastering motherhood. London-born entrepreneur Pope is the creative force behind Rosie Pope Maternity and MomPrep. She explains why being an entrepreneur offers the best life balance for her and tips for all types of moms. Video provided by TheStreet
Powered by NewsLook.com
Catching More Than Fish: Ugandan Town Crippled by AIDS

Catching More Than Fish: Ugandan Town Crippled by AIDS

AFP (Apr. 22, 2014) The village of Kasensero on the shores of Lake Victoria was where HIV-AIDS was first discovered in Uganda. Its transient population of fishermen and sex workers means the nationwide programme to combat the virus has had little impact. Duration: 02:30 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins