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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.


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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
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December 30, 2011--------News Archive

Success in Making The Spinal Cord Transparent
Stimulating damaged nerve cells to regenerate has been the goal of medicine. Now it is possible to trace nerve paths in a transparent spinal cord section.

Brain Glial Cells Are Much More Than Glue
Glia cells also regulate learning and memory, new research finds.

Stress Can Slow Skin Cancer, At Least Sometimes
Chronic stress is an affliction mostly limited to modern man. However, acute stress is an important response to dangerous situations and can speed recovery.

December 29, 2011--------News Archive

FDA Warning On Change to Infant Acetaminophen
Recent dosing changes to liquid infant acetaminophen, has the FDA urging parents to read the labels. The new form of the popular pain reliever is less concentrated.

Detox Your Diet!
Harvard School of Public Health wants us all to eat food without chemicals as much as possible to avoid changing our own and our kids' body chemistry.

Discovery of Brain Cell Malfunction in Schizophrenia
Schizophrenic brains reveal less flexibility in some histones (the spools that wind DNA) blocking gene function. The problem is more pronounced in young sufferers.

December 28, 2011--------News Archive

When "A Rose by Any Other Name" Is Not
Children and adults do not classify information in the same way.

Childhood Hypersensitivity Linked to OCD
Adult onset of Obsessive Compulsive Disorder could be connected to oral and tactile sensitivities seen in childhood.

Gene Critical for Development Linked to Arrhythmia
Altering the function of a gene called Tbx3 interferes with the development of the cardiac conduction system causing potentially lethal arrhythmias of the heartbeat.

December 27, 2011--------News Archive

Reversing Autoimmune Disease in Mice
A team of scientists has turned the tables on an autoimmune disease.

An Altered Gene Tracks RNA As It Edits Neurons
Biologists use technology to observe individual differences in fruit flies

Mother-Toddler Relationship Linked to Teen Obesity
The quality of the emotional relationship between a mother and her young child could affect the potential for that child to be obese during adolescence.

December 26, 2011--------News Archive

Severe Congenital Disorder Reversed in a Mouse
Adding a sugar to water during pregnancy protects embryos from defects.

lincRNAs Pivotal In Brain Development
Long intervening non-coding RNAs (lincRNAs) play key roles during brain development in zebrafish. Now human versions are substituting for the zebrafish.

Balancing the Womb
New research hopes to explain premature births and failed inductions of labor.

WHO Child Growth Charts

What Is Your BMI?

       



Whitehead Institute scientists have identified conserved, long intervening non-coding RNAs (lincRNAs) that play key roles during embryonic brain development in zebrafish. They also show that the human versions of the lincRNAs can substitute for the zebrafish versions, which implies that the functions of these non-coding RNAs are retained in humans as well as fish.

Until now, lincRNAs have been studied primarily in cell lines rather than at the organismal level, which has precluded research into how lincRNAs affect growth and development.

"These studies show that zebrafish, an animal that is frequently used to study the genetics of animal development, can also serve as a tool to uncover in systematic fashion the functions of lincRNAs," says Whitehead Member David Bartel, who is also a Howard Hughes Medical Institute investigator and a professor of biology at MIT. "This is another case in which a phenomenon in zebrafish provides insight into what's probably happening in humans, as has been established in many studies of protein-coding genes."

Only a minority of RNAs transcribed in a human cell goes on to template protein production, according to a 2007 assessment of the human genome by the Encyclopedia of DNA Elements (ENCODE) Project Consortium, which was funded by the National Human Genome Research Institute. The rest of the RNAs are dubbed non-coding RNAs (ncRNAs), with those located between protein-coding genes and with lengths of 200 base pairs or longer referred to as lincRNAs.

Despite their prevalence in the cell, lincRNAs have been referred to as the "dark matter" of all the transcribed RNAs because little is known of their functions or mechanisms. One limitation to studying this class of RNAs is their low sequence similarity between species. Unlike protein-coding genes, which are frequently well-conserved between species, lincRNA genes typically have a very small bit of conserved DNA between species, if any. This lack of conservation makes identification of related lincRNAs difficult in closely related species and nearly impossible in distantly related species.

For example, Bartel lab scientists Igor Ulitsky and Alena Shkumatava identified more than 500 lincRNAs in zebrafish but found that only 29 of these have homologs in both humans and mice.

Ulitsky and Shkumatava, who report their findings in this week's issue of the journal Cell, tested the function of two of the 29 lincRNAs by knocking them down in zebrafish embryos. Both knockdowns had striking effects on the zebrafish's brain development. Reduction of one of the lincRNAs, which they called cyrano, caused the zebrafish to have enlarged snouts, small heads and eyes, and short, curly tails, while the zebrafish lacking the lincRNA they called megamind had abnormally shaped heads and enlarged brain ventricles.

To test if the human homologs of the cyrano and megamind lincRNAs are functionally equivalent, Shkumatava injected the human versions into the knocked-down zebrafish. Remarkably, the human lincRNAs rescued the zebrafish and restored brain development and head size for both lincRNAs, indicating that the human lincRNAs may have the same role in embryonic development as their zebrafish analogs.

"This work represents a major advance because it provides a framework for studying lincRNAs, a poorly understood, but abundant class of molecules," says Michael Bender, who oversees RNA processing and function grants at the National Institutes of Health's National Institute of General Medical Sciences, which partially funded the work. "The discovery that human lincRNAs appear to function much like their zebrafish counterparts in embryonic development suggests that the framework will prove valuable in bringing new insights on the roles played by lincRNAs in mammalian organisms."

The zebrafish is already a powerful tool for studying genetics. Whitehead Member Hazel Sive, who collaborated with Bartel and his lab members on the Cell paper, uses zebrafish to study brain development and genetic mutations linked to autism.

Says Sive, "The zebrafish is a fantastic, facile system for discovering the mechanisms by which genes work."

"We humans share with zebrafish this subset of ancient, peculiar genes, and the functionality has been retained in them," says Ulitsky. "We can perturb them in zebrafish and then replace them with the human ones and, at least in the lincRNAs we look at, the human ones function to restore proper development."

"Because of this functional conservation of lincRNAs between zebrafish and humans, we're introducing the zebrafish as a new vertebrate tool that could be used basically to uncover the functions of other lincRNAs," says Shkumatava.

This work was supported by the National Institutes of Health's (NIH's) National Institute of General Medical Sciences (NIGMS), European Molecular Biology Organization (EMBO), Human Frontiers Science Program, and the National Science Foundation (NSF).

David Bartel is a Member at Whitehead Institute for Biomedical Research, where his laboratory is located and all his research is conducted. He is also a Howard Hughes Medical Institute Investigator and a professor of biology at Massachusetts Institute of Technology.

Full Citation:
"Conserved function of lincRNAs in vertebrate embryonic development despite rapid sequence evolution" Cell, December 23, 2011

Original article: http://www.wi.mit.edu/news/archives/2011/db_1222.html