Welcome to The Visible Embryo

 

 

Home-- -History-- -Bibliography- -Pregnancy Timeline- --Prescription Drugs in Pregnancy- -- Pregnancy Calculator- --Female Reproductive System- -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 one million visitors each month.

Today, The Visible Embryo is linked to over 600 educational institutions and is viewed by more than 1 million visitors each month. The field of early embryology has grown to include the identification of the stem cell as not only critical to organogenesis in the embryo, but equally critical to organ function and repair in the adult human. The identification and understanding of genetic malfunction, inflammatory responses, and the progression in chronic disease, begins with a grounding in primary cellular and systemic functions manifested in the study of the early embryo.

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.

 

Pregnancy Timeline by SemestersFetal 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 HemispheresFemale Reproductive SystemEnd of Embryonic PeriodEnd of Embryonic PeriodFirst Thin Layer of Skin AppearsThird TrimesterSecond TrimesterFirst TrimesterFertilizationDevelopmental Timeline
CLICK ON weeks 0 - 40 and follow along every 2 weeks of fetal development
Google Search artcles published since 2007
 
 

Home | Pregnancy Timeline | News Alerts |News Archive Oct 25, 2013

 



Berkeley Lab researchers identified distant-acting transcriptional enhancers in the
developing craniofacial complex and studied them in detail in transgenic mice.

from video: Fine-tuning the Face with Enhancers Credit: image courtesy of Berkeley Lab

 







WHO Child Growth Charts

 

 

 

What is it about your face?

The human face is as unique as a fingerprint, no one else looks exactly like you. But what is it that makes facial morphology so distinct? Berkeley Lab researchers provide new insight into why each human face is unique.

Certainly genetics play a major role in the uniqueness of our face as evident in the similarities between parents and their children, but what is it in our DNA that fine-tunes the genetics so that siblings – especially identical twins - resemble one another but look different from unrelated individuals?


A new study by researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) has now shown that gene enhancers — regulatory sequences of DNA that turn-on or amplify the expression of a specific gene — are major players in craniofacial development.

"Our results suggest it is likely there are thousands of enhancers in the human genome that are somehow involved in craniofacial development. We don't know yet what all of these enhancers do, but we do know that they are out there and they are important for craniofacial development."

Axel Visel, geneticist, Berkeley Lab's Genomics Division, and study leader.


While some genetic defects responsible for craniofacial pathologies such as clefts of the lip or palate have been identified, genetic drivers of normal craniofacial variation have been poorly understood.

Visel is the corresponding author of a paper in the journal Science that describes this research. Previous work by Visel and his collaborators, in which they mapped gene enhancers in the heart, the brain and other organ systems demonstrated that gene enhancers can regulate their targets from across distances of hundreds of thousands of base pairs.

To learn whether gene enhancers can also have the same long-distance impact on craniofacial development, Visel and a multinational team of collaborators studied transgenic mice.


"We used a combination of epigenomic profiling, in vivo characterization of candidate enhancer sequences, and targeted deletion experiments to examine the role of distant-acting enhancers in the craniofacial development of our mice.

"This enabled us to identify complex regulatory landscapes, consisting of enhancers that drive spatially complex developmental expression patterns. Analysis of mouse lines in which individual craniofacial enhancers had been deleted revealed significant alterations of craniofacial shape, demonstrating the functional importance of enhancers in defining face and skull morphology."

Catia Attanasio, Lawrence Berkeley National Laboratory, Berkeley, CA, and lead author.


In all, Visel, Attanasio and their colleagues identified more than 4,000 candidate enhancer sequences predicted to be active in fine-tuning the expression of genes involved in craniofacial development. They then created genome-wide maps of these enhancers by pin-pointing their location in the mouse genome. They characterized in detail the activity of some 200 of these gene enhancers and deleted three of them.

A majority of the enhancer sequences identified and mapped are at least partially conserved between humans and mice, and many are located in human chromosomal regions associated with normal facial morphology or craniofacial birth defects.


"Knowing about the existence of these enhancers, which are inherited from parents to their children just like genes, knowing their exact location in the human genome, and knowing their general activity pattern in craniofacial development should facilitate a better understanding of the connection between genetics and human craniofacial morphology.

"Our results also offer an opportunity for human geneticists to look for mutations specifically in enhancers that may play a role in birth defects, which in turn may help to develop better diagnostic and therapeutic approaches."

Axel Visel


Visel says he and his collaborators are now in the process of refining their genome-wide maps to gain additional information about the activity patterns of these enhancer sequences. They are also working with human geneticists to perform targeted searches for mutations of these enhancer sequences in human patients who have craniofacial birth defects.

Abstract
The shape of the human face and skull is largely genetically determined. However, the genomic basis of craniofacial morphology is incompletely understood and hypothesized to involve protein-coding genes, as well as gene regulatory sequences. We used a combination of epigenomic profiling, in vivo characterization of candidate enhancer sequences in transgenic mice, and targeted deletion experiments to examine the role of distant-acting enhancers in craniofacial development. We identified complex regulatory landscapes consisting of enhancers that drive spatially complex developmental expression patterns. Analysis of mouse lines in which individual craniofacial enhancers had been deleted revealed significant alterations of craniofacial shape, demonstrating the functional importance of enhancers in defining face and skull morphology. These results demonstrate that enhancers are involved in craniofacial development and suggest that enhancer sequence variation contributes to the diversity of human facial morphology.


In addition to Visel and Attanasio, other authors of the Science paper on this work were Alex Nord, Yiwen Zhu, Matthew Blow, Zirong Li, Denise Liberton, Harris Morrison, Ingrid Plajzer-Frick, Amy Holt, Roya Hosseini, Sengthavy Phouanenavong, Jennifer Akiyama, Malak Shoukry, Veena Afzal, Edward Rubin, David FitzPatrick, Bing Ren, Benedikt Hallgrímsson and Len Pennacchio.

This research was primarily supported by the DOE Office of Science and the National Institutes of Health.

Lawrence Berkeley National Laboratory addresses the world's most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab's scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy's Office of Science. For more, visit http://www.lbl.gov.

Original press release:http://www.eurekalert.org/pub_releases/2013-10/dbnl-wii102313.php