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

May 4, 2012--------News Archive Return to: News Alerts


mtDNA is always inherited from your mother - and mutations in mtDNA can lead
to maternally inherited diseases.
Unlike Nuclear DNA which undergoes
recombination, mtDNA does not change from parent to offspring
which makes it easier to trace between generations.

WHO Child Growth Charts

What Is Your BMI?

       

Improved Identification of Mitochondrial Genes as Passed from Mother to Child

A study which also highlights shortcomings of current genetic testing methods to prevent certain genetic disorders

Research conducted at the Oregon National Primate Research Center at Oregon Health & Science University helps answer some long-standing questions about how certain disease-causing gene mutations are inherited.

The research specifically focused on gene mutations in cell mitochondria that can cause several diseases, including forms of cancer, diabetes, infertility and neurodegenerative diseases.

With this new information, it is now better understood how and when mitochondrial mutations are passed to children. The research was published online in the journal Cell Reports, Thursday May 3.

Shoukhrat Mitalipov, Ph.D., who previously developed a method for preventing the passing of mitochondrial genetic mutations from mother to infant in 2009, directed the research.

This latest breakthrough, which was conducted in rhesus macaque monkeys because of their similarity to humans, demonstrates the specific stage of early embryonic development when genetic mutations are passed from mother to fetus. This stage, referred to by scientists as "the bottleneck," occurs when an early embryo - a blastocyst - transitions into a fetus.

To conduct the research, Mitalipov needed to design a way to mark and track specific mitochondrial genes as they transitioned from egg, through fertilization, to embryo and then to fetus. This was accomplished by combining two separate mitochondrial genomes into one egg cell.

More specifically, one-half of an egg cell from a species of Indian-continent rhesus macaque monkey was merged with one-half of an egg cell from a Chinese-continent monkey. Because these animal species have distinct mitochondrial gene sequences (like breeding two distinct species of dogs), their genetics could be tracked closely.

The microscopic manipulation of splitting and uniting two halved egg cells takes specialized skills and expertise, which the Mitalipov lab has developed over a period of several years. A link to a video explaining this process can be found in the multimedia section of this press release.

By studying the development of these joined and then fertilized eggs, scientists were surprised to see that eggs transitioned from containing a 50/50 split of genetics to a fetus that contained a nearly 100 percent either Indian or Chinese-based genome.

"We discovered that during early development, each individual cell in the eight-cell embryo would contain varying percentages of the Indian and Chinese rhesus genes. Some would be a 50/50 split. But others would be 90/10 and so on," explained Mitalipov.

"When these percentages were combined as a whole embryo, the average genetic split between the two species was about equal as initially created. However, later during the transition from a blastocyst to fetus, the genetics would swing one way or another. The resulting offspring would always have a genome that is predominantly Chinese or Indian. Our study tells us precisely when this mitochondrial gene switch occurs and how this can lead to disease."

This finding raises significant questions about the validity of current methods for genetic diagnosis in early embryos. When a woman is known to carry a mitochondrial gene mutation, she may pass that disease to her children.

"The current pre-implantation genetic diagnosis method is to examine genetic disease risk is by taking one cell from an early eight-cell embryo, and then looking for mutations in that one particular cell. This is done to predict if the remaining embryo is mutation-free," explained Mitalipov.

"The problem with this approach is that you may choose a cell that may not have mutations. But that does not mean the remaining cells in an embryo are mutation-free. Our research suggests that such an approach could be flawed because diagnosis takes place prior to the stage when an offspring's mitochondrial genetics is truly established."

With this new information, Mitalipov believes that new methods for genetic diagnosis for mitochondrial disease should be used. The research demonstrates that their lab's previously developed method for preventing the passing of mitochondrial mutations from mother to child is highly successful.

The ONPRC is a registered research institution, inspected regularly by the United States Department of Agriculture. It operates in compliance with the Animal Welfare Act and has an assurance of regulatory compliance on file with the National Institutes of Health. The ONPRC also participates in the voluntary accreditation program overseen by the Association for Assessment and Accreditation of Laboratory Animal Care International (AAALAC).

Oregon Health & Science University is the state's only academic health and research university. As Portland's largest employer with nearly 14,000 employees, OHSU's size contributes to its ability to provide many services and community support not found anywhere else in the state. OHSU serves patients from every corner of Oregon and is a conduit for learning for more than 4,300 students and trainees. OHSU is the source of more than 200 community outreach programs that bring health and education services to each county in the state.

Original article: http://www.eurekalert.org/pub_releases/2012-05/ohs-oss050212.php