APR 14, 2016 6:56 PM PDT

Chimeric Organisms During Early Embryonic Development

WRITTEN BY: Kara Marker
Chimeric organisms are ones that are made up of cells or tissues from more than one individual, most commonly thought of as bizarre animal combinations or science experiments. However, errors during human development can also lead to chimeric embryos, which in turn can lead to birth defects.
 
Interesting cases of human chimerism include a 1976 woman with two different blood types, and later a man who appeared phenotypically normal but who also carried feminine XX cells in his skin and other tissues (The-Scientist). While these ostentatious cases are indeed examples of chimerism, the effects of this developmental error are not always so forthcoming. Until genetic technology specific enough to detect chimerism in the DNA was developed, cases of chimerism were only recognized when people showed physical signs.
 
Bovine embryos were examined for abnormal chromosome segregation during development.
A new study from the Cold Spring Harbor Laboratory and KU Leuven, published in Genome Research, looks at the fine details of human genetic chimerism, described by The Scientist as an individual carrying two or more genetically distinct cell lines in different parts of his or her body. While scientists in the past knew that abnormal chromosome combinations, either from two eggs and one sperm or two sperm fertilizing a single egg, research from this new study shows that chimeric embryos can result from normal, error-free fertilization.
 
While not all cases of chimerism result in hermaphroditic embryos or hair and skin discoloration later in life, having different cell lines in the tissues and organs can seriously matter in situations like finding organ donors.
 
The current study involved scientists conducting in vitro fertilization (IVF) in cows to examine the various chromosomal changes that arise in single embryonic cells as a result of errors during early development. Scientists quickly saw a large percentage of embryos with at least one cell with whole or partial gains or losses of chromosomes.
 
The researchers used a method they developed themselves to examine chromosomal origins and other details, called haplarithmisis, from 23 embryos. Nearly 75 percent of these embryos had at least one cell containing partial or whole chromosome abnormalities. Additionally, 39 percent of all embryos experienced some sort of fertilization error that led to mutations in entire sets of embryos.
 
This study was the first to show that normal fertilization can result in chimeric embryos.
 
"Knowing this might occur may improve approaches for embryo selection and ultimately the success of IVF/preimplantation genetic diagnosis,” said senior author Joris Vermeesh, from KU Leuven.
 
 
Source: Cold Spring Harbor Laboratory
 
About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
JAN 14, 2020
Genetics & Genomics
JAN 14, 2020
Genetic Study Reveals Drug Targets for Several Diseases
Some genetic mutations are due to a change in only one base of the genetic code, while others involve large regions of the genome....
FEB 07, 2020
Neuroscience
FEB 07, 2020
People with Autism have Fewer Fatty Sheaths Between Neurons
Myelin, a fatty substance, accelerates the delivery of electrical signals between neurons in the brain. Now, researchers have found that people with autism...
FEB 10, 2020
Genetics & Genomics
FEB 10, 2020
The Broken Genes of the Last Woolly Mammoths
Wooly mammoths are thought to have died out around 4,000 years ago in a remote area off the Siberian coast, called Wrangel Island....
FEB 14, 2020
Cancer
FEB 14, 2020
Cataloging Cancer: DNA fingerprints at work
New research published as part of a global Pan-Cancer Project highlights the world’s most comprehensive catalog to date of DNA fingerprints of cancer...
FEB 27, 2020
Cell & Molecular Biology
FEB 27, 2020
Caloric Restriction Changes Gene Expression, Reduces Inflammation
New research has added to the evidence that suggests that dietary restriction has health benefits....
MAR 07, 2020
Genetics & Genomics
MAR 07, 2020
Learning Why Men Tend to Die Younger
Data has shown conclusively that even though women tend to have poorer health than men during their adult lives, they live longer than men....
Loading Comments...