• UCLA Health
  • myUCLAhealth
  • School of Medicine
U Magazine

U Magazine

U Magazine
  • Home
  • Current Issue
  • Centennial Campaign for UCLA Issue
  • Browse U Magazine
  • Letters to the Editor
  • Subscribe
  • Contact
  • UCLA Health
  • myUCLAhealth
  • School of Medicine

U Magazine

Browse U Magazine

  1. Home
  2. Browse U Magazine
Share this
The Cutting Edge

Germline Cells Shown to be Vulnerable during Pregnancy

  Germline Cells Shown to be Vulnerable during Pregnancy  
 

A human fetal test is showing progenitor germline cells in green with supporting cells shown in red.
Image: Dr. Sofia Gkountela

A new study furthers the understanding of the human germline — the cells that create eggs or sperm in humans during prenatal development. The highly specialized germ cells are the only cell type in the body capable of passing parents’ genes on to their biological children. Abnormalities in the germ cells can cause infertility as well as diseases such as germ-cell tumors in young boys and primary ovarian insufficiency in young girls. The study looks closely at how the genetic information of prenatal germ cells is shielded from harm during development, showing that these important cells lack protection that leaves them vulnerable to damage.

“We know very little about how prenatal germline cells are made in the body,” says Amander Clark, PhD, vice chair of molecular, cell and developmental biology and a member of the UCLA Eli & Edythe Broad Center of Regenerative Medicine & Stem Cell Research. “I am working to understand what they are sensitive to during development and what is protecting them from external environmental factors that could cause them to not work properly.”

A biochemical process that is crucial for protecting human genetic information is called methylation. All healthy human cells are methylated, which acts as a protective coat that safeguards cells from mutations. If cells don’t have methylation, they are vulnerable to damage. Methylation removal, called demethylation, happens infrequently in the human body. One such time is during a short period in prenatal life. This period of germ-cell demethylation was the focus of Dr. Clark’s study, which mapped the amount, duration and location of demethylation in prenatal germ cells from 53 to 137 days of development. The study found that the human germline erases almost all evidence of genome methylation by 113 days of prenatal development. While a large amount of demethylation did occur, some areas of the germ cells retained a small amount of methylation.

“The quality of a person’s germline cells is going to have a huge effect on that person’s ability to have children as an adult,” Dr. Clark says. “Removal of methylation from the germline during prenatal life leaves the germline cells vulnerable to damage. This leads to a critical question: What protects prenatal germline cells from damage or environmental insult during pregnancy?”

Dr. Clark’s model requires her to make human prenatal germline cells from pluripotent stem cells in the lab. In this way, she can study how the germline cells are affected by various factors such as external chemicals or toxins. In the study, Dr. Clark and her team present a detailed ‘reference map’ that contains hundreds of millions of data points. The reference map can be used to ensure that prenatal germ cells created in the lab have the same methylation characteristics as the prenatal germ cells found in a normal human during prenatal life.

“This reference map takes the guess work out of making prenatal germline cells from stem cells,” Dr. Clark says. “Now that we have a high-resolution quantitative analysis of real human germline cells during prenatal life, we can use this information as we make human prenatal germline cells from stem cells for disease-in-a-dish modeling.”

“DNA Demethylation Dynamics in the Human Prenatal Germline,” Cell, June 4, 2015


Previous
REM Sleep Helps Brain Capture Snapshots of Dream Images
Next
New Study Opens Window on Mutations in Genetic Architecture of Schizophrenics


YOU ARE VIEWING

Fall 2015

Fall 2015
E-Brochure
Printable PDF
IN THIS ISSUE
  • We Are the World
  • Camp Leg Power Propels Kids with Cerebral Palsy Forward
  • Portable Finger Probe Measures Liver Function in Potential Donors
  • Stem-cell Therapy Holds Promise for Eliminating HIV Infection
  • REM Sleep Helps Brain Capture Snapshots of Dream Images
  • Germline Cells Shown to be Vulnerable during Pregnancy
  • New Study Opens Window on Mutations in Genetic Architecture of Schizophrenics
  • How Molecular Rules Govern Autoimmune Disorders
  • Predicting Response to Treatment for Obsessive-Compulsive Disorder
  • Why Children’s Recovery Times Vary after Traumatic Brain Injury
  • Potentially Effective Treatment for Meth Addiction
  • Protein that Helps Suppress Cancer Fades as We Age
  • Patient First to Bridge from Experimental Total Artificial Heart to Transplant
  • UCLA Community Based Learning: Bridging the Transition from Youth to Adulthood
  • Get Social
  • The End of Darkness
  • Medicine 2.0
  • White Knight
  • Awards, Honors & Grants
  • In Memoriam
  • Postcard from Malawi
  • In Her Own Words: Lynn L. Huang, MD ’07
  • The Business of Medical Innovation
  • Tribute to a Mentor and Friend
  • Kaleidoscope Ball Highlights Artistic Variety
  • Landmark Gift Paves the Way for Breakthroughs
  • The UCLA Today’s and Tomorrow’s Children’s Fund Names New Awardees
  • Golden Portal Fundraiser Joins Movies, Medicine and Technology
  • Widening the Circle of Giving
  • UCLA Names Landmark New Medical-Education Building Geffen Hall
  • Gifts
  • In Memoriam
  • Good Afternoon, Mrs. Gates
Like Us on Facebook Follow Us on Twitter Subscribe to Our Videos on YouTube Follow us on Instagram Connect with Us on LinkedIn Follow us on Pinterest
UCLA Health hospitals ranked best hospitals by U.S. News & World Report
  • UCLA Health
  • Find a Doctor
  • School of Medicine
  • School of Nursing
  • UCLA Campus
  • Directory
  • Newsroom
  • Subscribe
  • Patient Stories
  • Giving
  • Careers
  • Volunteer
  • International Services
  • Privacy Practices
  • Nondiscrimination
  • Billing
  • Health Plans
  • Emergency
  • Report Broken Links
  • Terms of Use
  • 1-310-825-2631
  • Maps & Directions
  • Contact Us
  • Your Feedback
  • Report Misconduct
  • Get Social
  • Sitemap
Like Us on Facebook Follow Us on Twitter Subscribe to Our Videos on YouTube Follow us on Instagram Connect with Us on LinkedIn Follow us on Pinterest

Sign in to myUCLAhealth