Featured Research

from universities, journals, and other organizations

MicroRNA controls mammary gland development in mice: Novel mechanism for vertebrate organ development

Date:
November 10, 2010
Source:
Max-Planck-Gesellschaft
Summary:
Hormones, growth factors and several proteins ensure that development occurs in the right way, at the right time. The components that cause breast development in mammals, for example, were thought to be largely known. However, as scientists in Germany have now discovered, in the case of breast development, hormones and proteins do not account for the full story. The scientists have shown that tiny ribonucleic acid molecules play a key role in this process. The mammary glands of mice lacking the gene for the microRNAs 212 and 132 failed to grow at puberty.

Mammary gland tissue of milk-producing mice with (top) and without (bottom) miR-212/132: the consequences of the lack of the ribonucleic acid molecules are clear to see. The milk ducts (dark red) did not grow in the tissue without the microRNAs.
Credit: Max Planck Institute for Biophysical Chemistry

Hormones, growth factors and several proteins ensure that development occurs in the right way, at the right time. The components that cause breast development in mammals, for example, were thought to be largely known. However, as a team of scientists from Gφttingen, Frankfurt and Hanover have now discovered, in the case of breast development, hormones and proteins do not account for the full story. The scientists have shown that tiny ribonucleic acid molecules play a key role in this process. The mammary glands of mice lacking the gene for the microRNAs 212 and 132 failed to grow at puberty.

The research is published in the journal Nature Genetics.

The scientists have demonstrated for the first time in an animal model that small ribonucleic acid molecules, so-called microRNAs, also fulfil an important function in organ development. "This came as a surprise to us," says project leader Kamal Chowdhury from the Max Planck Institute for Biophysical Chemistry in Gφttingen. "The mice used in our experiments had all of the hormones, growth factors and proteins that ensure normal breast development. But the absence of the microRNAs miR-212 and miR-132 resulted in the complete failure of duct development in the mammary glands of mice."

It is well known that microRNAs perform very important regulatory functions inside living cells. Although they do not code for proteins, they are responsible for the fine-tuning of the production of certain proteins and intervene extensively in metabolic processes. The question is however: how does this activity shape the morphology of the whole organism? "Using various experiments, we were able to demonstrate that this RNA family plays a key role in mammary gland development and we could locate where these molecules presumably intervene on a regulatory basis," explains Chowdhury.

The mammary gland, which is also known as the milk gland, consists of the milk ducts and the surrounding connective tissue, which has a supportive and regulatory function. The connective tissue also appears to be the location where miR-212 and miR-132 are produced and intervene in the developmental process. Chowdhury and his colleague Ahmet Ucar were able to demonstrate with their experiments that this is the only place where the genes for these ribonucleic acid molecules are "switched on" in the breast tissue.

Molecular dimmer

According to the researcher's model, the microRNA molecules appear to control the production of a protein called MMP-9. "The microRNAs can down-regulate the production of MMP-9, like a dimmer switch," explains Ucar. If the microRNAs are missing, more MMP-9 proteins are produced and they accumulate near the milk ducts. They appear to activate a signalling pathway there, which prevents the normal growth of the milk ducts in the glandular tissue. "These tiny RNA molecules carry out their regulatory function by influencing the communication between the two tissues of the mammary gland," says Ucar.

Other experiments now need to be carried out to examine whether these microRNAs also regulate breast development in humans. At the moment, the scientists can only speculate about what happens when the microRNAs do not function correctly. "Whether such malfunctions can lead to the formation of tumours, for example, is something that needs to be examined in further studies," says Chowdhury.


Story Source:

The above story is based on materials provided by Max-Planck-Gesellschaft. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ahmet Ucar, Vida Vafaizadeh, Hubertus Jarry, Jan Fiedler, Petra A B Klemmt, Thomas Thum, Bernd Groner, Kamal Chowdhury. miR-212 and miR-132 are required for epithelial stromal interactions necessary for mouse mammary gland development. Nature Genetics, 2010; DOI: 10.1038/ng.709

Cite This Page:

Max-Planck-Gesellschaft. "MicroRNA controls mammary gland development in mice: Novel mechanism for vertebrate organ development." ScienceDaily. ScienceDaily, 10 November 2010. <www.sciencedaily.com/releases/2010/11/101109095433.htm>.
Max-Planck-Gesellschaft. (2010, November 10). MicroRNA controls mammary gland development in mice: Novel mechanism for vertebrate organ development. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2010/11/101109095433.htm
Max-Planck-Gesellschaft. "MicroRNA controls mammary gland development in mice: Novel mechanism for vertebrate organ development." ScienceDaily. www.sciencedaily.com/releases/2010/11/101109095433.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) — The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) — The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) — Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
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