Welcome to The Visible Embryo

Home- - -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- News Alerts -Contact

Welcome to The Visible Embryo, a comprehensive educational resource on human development from conception to birth.

The Visible Embryo provides visual references for changes in fetal development throughout pregnancy and can be navigated via fetal development or maternal changes.

The National Institutes of Child Health and Human Development awarded Phase I and Phase II Small Business Innovative Research Grants to develop The Visible Embryo. Initally designed to evaluate the internet as a teaching tool for first year medical students, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than ' million visitors each month.


WHO International Clinical Trials Registry Platform
The World Health Organization (WHO) has created a new Web site to help researchers, doctors and patients obtain reliable information on high-quality clinical trials. Now you can go to one website and search all registers to identify clinical trial research underway around the world!



Home

History

Bibliography

Pregnancy Timeline

Prescription Drug Effects on Pregnancy

Pregnancy Calculator

Female Reproductive System

Contact The Visible Embryo

News Alerts Archive

Disclaimer: The Visible Embryo web site is provided for your general information only. The information contained on this site should not be treated as a substitute for medical, legal or other professional advice. Neither is The Visible Embryo responsible or liable for the contents of any websites of third parties which are listed on this site.
Content protected under a Creative Commons License.

No dirivative works may be made or used for commercial purposes.

Return To Top Of Page
Pregnancy Timeline by SemestersFemale Reproductive SystemFertilizationThe Appearance of SomitesFirst TrimesterSecond TrimesterThird TrimesterFetal liver is producing blood cellsHead may position into pelvisBrain convolutions beginFull TermWhite fat begins to be madeWhite fat begins to be madeHead may position into pelvisImmune system beginningImmune system beginningPeriod of rapid brain growthBrain convolutions beginLungs begin to produce surfactantSensory brain waves begin to activateSensory brain waves begin to activateInner Ear Bones HardenBone marrow starts making blood cellsBone marrow starts making blood cellsBrown fat surrounds lymphatic systemFetal sexual organs visibleFinger and toe prints appearFinger and toe prints appearHeartbeat can be detectedHeartbeat can be detectedBasic Brain Structure in PlaceThe Appearance of SomitesFirst Detectable Brain WavesA Four Chambered HeartBeginning Cerebral HemispheresEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterDevelopmental Timeline
Click weeks 0 - 40 and follow fetal growth
Google Search artcles published since 2007
 
Home--History--Bibliography- -Pregnancy Timeline- Prescription Drugs/Pregnancy- Pregnancy Calculator - Reproductive System- -News Alerts

April 17, 2012--------News Archive Return to: News Alerts

WHO Child Growth Charts

What Is Your BMI?

       

Two Genes Essential for Placental Development

The absence of two genes, E2f7 and E2f8, in stem cells results in a placenta made up of overcrowded and poorly organized cells that cannot properly transport oxygen and nutrients or support normal embryo development

Two particular repressor genes in a family of regulatory genes are vital for controlling cell proliferation during development of the placenta, according to a new study by researchers with the Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James).

The two genes are called E2f7 and E2f8. Their absence in stem cells results in a placenta made up of overcrowded and poorly organized cells that cannot properly transport oxygen and nutrients or support normal embryonic development.

When placental stem cells were also missing a third gene, the activating gene called E2f3a, the placental defects were corrected and embryos carried to birth.

The findings, published in the journal Developmental Cell, shows at the molecular level how these E2Fs control cell proliferation in intact animals, the researchers say.

"The findings provide insight into the role of these two repressor genes," says principal investigators Gustavo Leone, associate professor of Medicine and associate director of Basic Research.


The E2F family of genes is thought to play
a crucial role in regulating cell proliferation.

It is unclear how these genes carry out their function
and interact with one another in intact animals.

This study shows that two E2F repressor genes are essential
for a functional placenta and for balancing
the effect of an E2F activator gene.


The two genes belong to a family of regulatory genes that, in humans, has eight members.

They are all believed to activate or suppress other genes to control cell division and proliferation in both normal and cancer cells. But which genes they regulate and how they interact with one another in living animals is poorly understood.

"E2F regulatory genes have been thought to be important for a long time, but with so many of them, it's been hard to tell which one is doing what," Leone says.

"Here, we show that the repressors E2f7 and E2f8 are essential for the development of an intact, functional, placenta, and that they balance out the effects of the activating gene E2f3a," Leone says. "Because these two repressors are important for proliferation, they may also play an important role in suppressing tumor development."

For this study, Leone and his colleagues used animal models that lacked one or more of the three E2F genes in trophoblast stem cells, which give rise to the placenta.

Earlier work led by Leone has shown that in some cases, an E2F gene can be an activator in some tissues and a repressor in others.

Original article: http://www.eurekalert.org/pub_releases/2012-04/osum-trg041212.php