X Marks the Sex-Skewed Spot

Alterations in epigenetic markers on the X chromosome may be why males outnumber females among murine offspring bred through in vitro fertilization.

| 3 min read

Register for free to listen to this article
Listen with Speechify
0:00
3:00
Share

Intracytoplasmic sperm injection of a human oocyteWIKIMEDIA, EUGENE ERMOLOVICHOffspring conceived by in vitro fertilization (IVF) are more likely to be male than female. Now, a team led by Jianhui Tian of China Agricultural University in Beijing has found that problems with X chromosome inactivation, the process of silencing one of the female embryo’s X chromosomes, is responsible for much of this sex-ratio skew in mice. The team also demonstrated a method of reversing the male-dominant ratio by modifying the culture that murine preimplantation IVF embryos are grown in. The team’s results were published in PNAS today (March 7).

Paulo Rinaudo, a reproductive endocrinologist with the University of California, San Francisco, who was not involved in the study, noted that researchers previously suspected X chromosome inactivation played some role in this phenomenon. “The authors did a great job in going after a mechanism,” Rinaoudo wrote in an email.

In the U.S., around 1.5 percent of newborns are conceived via IVF. Elsewhere, the rate of IVF-conceived babies is as high as 4 percent. The assisted reproductive technology is also extensively used in cow, pig, and other livestock breeding programs, where researchers began documenting the skew toward male offspring in the early 1990s. In the past decade, a similar sex ratio has been found among human IVF embryos, but supporting evidence for the imbalance was inconsistent.

...

Interested in reading more?

Become a Member of

The Scientist Logo
Receive full access to more than 35 years of archives, as well as TS Digest, digital editions of The Scientist, feature stories, and much more!
Already a member? Login Here

Keywords

Meet the Author

  • Rina Shaikh-Lesko

    This person does not yet have a bio.
Share
3D illustration of a gold lipid nanoparticle with pink nucleic acid inside of it. Purple and teal spikes stick out from the lipid bilayer representing polyethylene glycol.
February 2025, Issue 1

A Nanoparticle Delivery System for Gene Therapy

A reimagined lipid vehicle for nucleic acids could overcome the limitations of current vectors.

View this Issue
Considerations for Cell-Based Assays in Immuno-Oncology Research

Considerations for Cell-Based Assays in Immuno-Oncology Research

Lonza
An illustration of animal and tree silhouettes.

From Water Bears to Grizzly Bears: Unusual Animal Models

Taconic Biosciences
Sex Differences in Neurological Research

Sex Differences in Neurological Research

bit.bio logo
New Frontiers in Vaccine Development

New Frontiers in Vaccine Development

Sino

Products

Tecan Logo

Tecan introduces Veya: bringing digital, scalable automation to labs worldwide

Inventia Life Science

Inventia Life Science Launches RASTRUM™ Allegro to Revolutionize High-Throughput 3D Cell Culture for Drug Discovery and Disease Research

An illustration of differently shaped viruses.

Detecting Novel Viruses Using a Comprehensive Enrichment Panel

Twist Bio 
Zymo Research

Zymo Research Launches Microbiome Grant to Support Innovation in Microbial Sciences