Xist and calico cats: How extra genes on X chromosomes get turned off

Oct 29, 2013 by Bill Hathaway
Xist and calico cats: How extra genes on X chromosomes get turned off

Females carry two copies of the X chromosome which—unlike the male's gene-poor Y chromosome—are home to 1000 genes crucial to development. So how does the developing female embryo inactivate duplicate genes along the chromosome, a process that explains the random mix of orange and black color patterns of the calico cat?

Researchers at Yale and collaborators at Massachusetts General Hospital add new details to this complex molecular choreography. Matthew Simon's laboratory at Yale, together with two other labs, studied a large molecule of RNA called Xist—X-inactive specific transcript—that is expressed only in cells where genes along X chromosome are inactivated.

They found that Xist does its job in a two-step process, beginning in a gene-rich environment along the chromosome and then spreading to regions where genes are sparser.

For more details, see the study published online Oct. 27 in the journal Nature.

Explore further: Heaven scent: Finding may help restore fragrance to roses

More information: www.nature.com/nature/journal/vaop/ncurrent/full/nature12719.html

Related Stories

Research finds X doesn't always mark the spot

Sep 25, 2013

Research from the University of Bath has found a greater number of 'escaping genes' on the X chromosome than have been previously detected, with implications for the understanding of mental impairment in humans.

Research sheds light on M.O. of unusual RNA molecules

Jul 05, 2013

(Phys.org) —The genes that code for proteins—more than 20,000 in total—make up only about 1 percent of the complete human genome. That entire thing—not just the genes, but also genetic junk and all ...

Mutations in cancer often affect the X chromosome

Oct 18, 2013

Every case of cancer originates from changes in a person's genetic material (mutations). These usually occur as "somatic mutations" in individual cells during an individual's lifetime, rather than being inherited from a person's ...

Recommended for you

Study on pesticides in lab rat feed causes a stir

Jul 02, 2015

French scientists published evidence Thursday of pesticide contamination of lab rat feed which they said discredited historic toxicity studies, though commentators questioned the analysis.

International consortium to study plant fertility evolution

Jul 02, 2015

Mark Johnson, associate professor of biology, has joined a consortium of seven other researchers in four European countries to develop the fullest understanding yet of how fertilization evolved in flowering plants. The research, ...

Making the biofuels process safer for microbes

Jul 02, 2015

A team of investigators at the University of Wisconsin-Madison and Michigan State University have created a process for making the work environment less toxic—literally—for the organisms that do the heavy ...

Why GM food is so hard to sell to a wary public

Jul 02, 2015

Whether commanding the attention of rock star Neil Young or apparently being supported by the former head of Greenpeace, genetically modified food is almost always in the news – and often in a negative ...

The hidden treasure in RNA-seq

Jul 01, 2015

Michael Stadler and his team at the Friedrich Miescher institute for Biomedical Research (FMI) have developed a novel computational approach to analyze RNA-seq data. By comparing intronic and exonic RNA reads, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.