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 in 1993 as a first generation internet teaching tool consolidating human embryology teaching for first year medical students.

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.

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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!

A map of 'shortcuts' between all human genes

Some diseases are caused by single gene mutations. However, current techniques for identifying disease-causing genes in a patient produces hundreds of potential gene candidates, making it difficult to pinpoint the single causative gene.

Now, a team of researchers led by Rockefeller University scientists have created a map of gene "shortcuts" to simplify the hunt for disease-causing genes. The investigation, spearheaded by Yuval Itan, a postdoctoral fellow in the St. Giles Laboratory of Human Genetics of Infectious Diseases, has led to the creation of what he calls the human gene connectome, the full set of distances, routes (the genes on the way), and degrees of separation, between any two human genes.

Itan, a computational biologist, says the computer
program he developed to generate the connectome uses
the same principles that GPS navigation devices use
to plan a trip between two locations.

The research is reported in the online early edition of the journal Proceedings of the National Academy of Sciences.

"High throughput genome sequencing technologies generate a plethora of data, which can take months to search through," says Itan. "We believe the human gene connectome will provide a shortcut in the search for disease-causing mutations in monogenic diseases."

Itan and his colleagues, including researchers from the Necker Hospital for Sick Children, the Pasteur Institute in Paris, and Ben-Gurion University in Israel, designed applications for the use of the human gene connectome. They began with a gene called TLR3, which is important for resistance to herpes simplex encephalitis, a life-threatening infection from the herpes virus that can cause significant brain damage in genetically susceptible children.

Researchers in the St. Giles lab, headed by Jean-Laurent Casanova, previously showed that children with HSE have mutations in TLR3 or in genes that are closely functionally related to TLR3. In other words, these genes are located at a short biological distance from TLR3. As a result, novel herpes simplex encephalitis-causing genes are also expected to have a short biological distance from TLR3.

To test how well the human gene connectome could predict
a disease-causing gene, the researchers sequenced exomes –
all DNA of the genome that is coding for proteins – of two
patients recently shown to carry mutations
of a separate gene, TBK1.

"Each patient's exome contained hundreds of genes with potentially morbid mutations," says Itan. "The challenge was to detect the single disease-causing gene." After sorting the genes by their predicted biological proximity to TLR3, Itan and his colleagues found TBK1 at the top of the list of genes in both patients. The researchers also used the TLR3 connectome – the set of all human genes sorted by their predicted distance from TLR3 – to successfully predict two other genes, EFGR and SRC, as part of the TLR3 pathway before they were experimentally validated, and applied other gene connectomes to detect Ehlers-Danlos syndrome and sensorineural hearing loss disease causing genes.

"The human gene connectome is, to the best of our
knowledge, the only currently available prediction of the
specific route and distance between any two human genes
of interest, making it ideal to solve the needle in the
haystack problem of detecting the single disease causing
gene in a large set of potentially fatal genes.

This can now be performed by prioritizing any number
of genes by their biological distance from genes that
are already known to cause the disease.

Yuval Itan
Postdoctoral fellow
St. Giles Laboratory of Human Genetics
and Infectious Diseases

"Approaches based on the human gene connectome have the potential to significantly increase the discovery of disease-causing genes for diseases that are genetically understood in some patients as well as for those that are not well studied." says Itan. The human gene connectome should also progress the general field of human genetics by predicting the nature of unknown genetic mechanisms."

Original article: http://www.eurekalert.org/pub_releases/2013-03/ru-rcm031813.php