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 15, 2013

 

Structure of the RNA-tagging machinery shows that only one pair
of proteins (blue) can add tags to the RNA (red) at a time.

Credit: EMBL/Carlomagno









WHO Child Growth Charts

 

 

 

RNA folding is like choreographed origami

Folding RNA means pairing-up tags on specific molecules to fold and build a working proteins—much like folding orgami shapes.

An important step in building ribosomes – the cell's protein factories – is like a strictly choreographed dance, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have discovered. To build these factories, other 'machines' inside the cell have to produce specific RNA molecules and fold them into the right shape, then combine the folded RNA with proteins to form a working ribosome.


Like a budding origami artist pencilling in the folds, the cell uses tags called methyl groups to help mark where and how an RNA molecule should be folded.

In work published online today in Nature, the scientists have discovered that pairs of these tags are added in a specific order. The study combined nuclear magnetic resonance at EMBL and neutron scattering at the Institut Laue-Langevin (ILL) in Grenoble, France.

Led by Teresa Carlomagno at EMBL, the scientists were able to determine the 3D structure of the complex that adds methyl tags to the RNA, with the RNA molecules attached. They discovered that the different components of this tagging machine pair up and move in sequence, like dancers following a set choreography.


"We found that the complex has four copies of each protein, and four methylation sites on the RNA, but those methylation sites aren't all the same," Carlomagno says. "They come in pairs, and one pair has to be methylated before the other."

The fact that the pairs of tags have to be added in a particular order could be a way for the cell to control how the RNA is folded, and ultimately when and where ribosomes are formed, the scientists believe.

Abstract
Post-transcriptional modifications are essential to the cell life cycle, as they affect both pre-ribosomal RNA processing and ribosome assembly. The box C/D ribonucleoprotein enzyme that methylates ribosomal RNA at the 2′-O-ribose uses a multitude of guide RNAs as templates for the recognition of rRNA target sites. Two methylation guide sequences are combined on each guide RNA, the significance of which has remained unclear. Here we use a powerful combination of NMR spectroscopy and small-angle neutron scattering to solve the structure of the 390 kDa archaeal RNP enzyme bound to substrate RNA. We show that the two methylation guide sequences are located in different environments in the complex and that the methylation of physiological substrates targeted by the same guide RNA occurs sequentially. This structure provides a means for differential control of methylation levels at the two sites and at the same time offers an unexpected regulatory mechanism for rRNA folding.

The study provides a detailed view of the complex in a form that's very close to what's found inside our cells. To obtain it, the EMBL scientists teamed up with Frank Gabel at the Institut Laue-Langevin (ILL) and the Institut de Biologie Structurale (IBS), both in Grenoble, France, to combine their expertise in nuclear magnetic resonance (NMR) with the Gabel lab's skills in small angle neutron scattering (SANS).

Original press releas:http://www.eurekalert.org/pub_releases/2013-10/embl-co101113.php