Featured Research

from universities, journals, and other organizations

The Skeleton: Size Matters; New Role For Master Patterning Genes In Defining Number Of Vertebrae In Spine

Date:
November 7, 2009
Source:
Instituto Gulbenkian de Ciencia
Summary:
It has long been known that the identity of each vertebra is due to the activation of a class of genes called "Hox." Now, researchers in Portugal show that besides determining the identity of the vertebrae, Hox genes also have a say in how many are going to be formed at all.

Vertebrates have in common a skeleton made of segments, the vertebrae. During development of the embryo, each segment is added in a time dependent manner, from the head-end to the tail-end: the first segments to be added become the vertebrae of the neck, later segments become the vertebrae with ribs and the last ones the vertebra located in the tail (in the case of a mouse, for example). In this process, it is crucial that, on the one hand, each segment, as it matures, becomes the correct type of vertebra and, on the other, that the number of vertebrae in the skeleton, and therefore the size of the spine, are minutely controlled.

It has long been known that the identity of each vertebra is due to the activation of a class of genes called Hox. Now, in the latest issue of Developmental Cell, researchers from the Instituto Gulbenkian de Ciκncia, in Portugal, the Institute KNAW and University Medical Centre (The Netherlands) show that besides determining the identity of the vertebrae, Hox genes also have a say in how many are going to be formed at all.

There is a huge diversity in number of vertebrae in animals: some have many vertebrae, and are thus longer, like a snake, and others have fewer vertebrae and are shorter, like mice. Vertebrae are made from precursors known as somites, formed in the embryos, sequentially from head to tail. This process is directly linked to growth of the embryo at its tail end: the more it grows, the more somites it makes and, as a result the more vertebrae the adult animal has. Of the many genes involved in this growth, a family of genes called Cdx are known to play a central role.

According to Moises Mallo, group leader at the IGC and one of the lead authors on the paper, 'We knew that some Hox genes are not activated when the Cdx genes are turned off, but this was always considered to be part of a mechanism to ensure that each new somite generates the appropriate type of vertebra. We now show that the activation of Hox genes is also part of how Cdx genes promote growth of the embryo at its tail end: when the relevant Hox genes were activated in the Cdx mouse mutants the embryos recovered and were born with a quite normal vertebral column, proving that the Hox genes were able to compensate for the lack of Cdx. This is a novel role for Hox genes'.

The researchers also show that some Hox genes are important to stop the addition of extra segments, at later stages in development. Indeed, if Hox genes that are usually active later on in development, in the last forming segments, are turned on before their time, in mouse embryos, they interrupt addition of new segments and lead to a tail truncation in the vertebral column.

As Mallo puts it, 'This paper provides and important addition to a long-standing view on the role of the Hox genes -- one of the most-studied genes involved in embryonic development: that it controls not only identity, but also number of vertebrae. Although these observations were made in the tail-end region of the embryo, it is very likely that similar mechanisms might be acting to determine the number of segments closer to the head".


Story Source:

The above story is based on materials provided by Instituto Gulbenkian de Ciencia. Note: Materials may be edited for content and length.


Journal Reference:

  1. Young et al. Cdx and Hox Genes Differentially Regulate Posterior Axial Growth in Mammalian Embryos. Developmental Cell, 2009; 17 (4): 516 DOI: 10.1016/j.devcel.2009.08.010

Cite This Page:

Instituto Gulbenkian de Ciencia. "The Skeleton: Size Matters; New Role For Master Patterning Genes In Defining Number Of Vertebrae In Spine." ScienceDaily. ScienceDaily, 7 November 2009. <www.sciencedaily.com/releases/2009/10/091027101413.htm>.
Instituto Gulbenkian de Ciencia. (2009, November 7). The Skeleton: Size Matters; New Role For Master Patterning Genes In Defining Number Of Vertebrae In Spine. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2009/10/091027101413.htm
Instituto Gulbenkian de Ciencia. "The Skeleton: Size Matters; New Role For Master Patterning Genes In Defining Number Of Vertebrae In Spine." ScienceDaily. www.sciencedaily.com/releases/2009/10/091027101413.htm (accessed April 20, 2014).

Share This



More Health & Medicine News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Nine-Month-Old Baby Can't Open His Mouth

Nine-Month-Old Baby Can't Open His Mouth

Newsy (Apr. 19, 2014) — Nine-month-old Wyatt Scott was born with a rare disorder called congenital trismus, which prevents him from opening his mouth. Video provided by Newsy
Powered by NewsLook.com
'Holy Grail' Of Weight Loss? New Find Could Be It

'Holy Grail' Of Weight Loss? New Find Could Be It

Newsy (Apr. 18, 2014) — In a potential breakthrough for future obesity treatments, scientists have used MRI scans to pinpoint brown fat in a living adult for the first time. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) — A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) — The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins