Featured Research

from universities, journals, and other organizations

Young sperm, poised for greatness, but are they under-achievers?

Date:
May 19, 2014
Source:
University of Utah
Summary:
It was long assumed that the joining of egg and sperm launched a dramatic change in how and which genes were expressed. Instead, new research shows that totipotency is a step-wise process, manifesting as early as in precursors to sperm, called adult germline stem cells (AGSCs), which reside in the testes.

Sperm illustration (stock image). Typically, sperm precursors live a mundane life. They divide, making more cells like themselves, until they receive the signal instructing them to mature into sperm. There is evidence, however, that these cells have the potential to do more.
Credit: © Luk Cox / Fotolia

In the body, a skin cell will always be skin, and a heart cell will always be heart. But in the first hours of life, cells in the nascent embryo become totipotent: they have the incredible flexibility to mature into skin, heart, gut, or any type of cell.

It was long assumed that the joining of egg and sperm launched a dramatic change in how and which genes were expressed. Instead, new research shows that totipotency is a step-wise process, manifesting as early as in precursors to sperm, called adult germline stem cells (AGSCs), which reside in the testes.

The study was co-led by Bradley Cairns, Ph.D., University of Utah professor of oncological sciences, and Huntsman Cancer Institute investigator, and Ernesto Guccione, Ph.D., of the Agency for Science Technology and Research in Singapore. They worked closely with first author and Huntsman Cancer Institute postdoctoral fellow, Saher Sue Hammond, Ph.D. The research was published online in the journal Cell Stem Cell.

Typically, sperm precursors live a mundane life. They divide, making more cells like themselves, until they receive the signal instructing them to mature into sperm.

There is evidence, however, that these cells have the potential to do more. Under the unusual conditions that promote the cells to form dense cancerous masses called testicular teratomas, the young sperm transform into precursors of skin, muscle, and gut.

This realization prompted the investigators to examine the gene program within sperm precursors. They wondered, would it be like that of a cell that is destined to become a single cell type, or like that of a cell with the potential to become anything?

The answer, they found, is that the sperm precursors are somewhere in between. The most telling evidence is the status of a quartet of genes: Lefty, Sox2, Nanog, and Prdm14. When activated, the genes can trigger a cascade of events that give cells stem cell properties. In cells limited to becoming one cell type, the genes are silent.

Yet in sperm precursors, the genes bear a code of chemical tags, called methylation groups, indicating that the four genes are silenced, but poised to become active. In other words, embedded within these cells, is the potential to become totipotent.

Cairns compares the tags on the poised genes to bookmarks. "Sperm cells and their precursors put 'bookmarks' at all the important genes they need to access quickly." Once fertilization occurs, he explains, cells have to become fully totipotent in a short amount of time. "Then, when the sperm and egg come together, all you have to do is complete the job that you had already started."

The engineering principal, as he calls it, ensures the transition occurs rapidly and accurately.

The result is just one of many that together comprise a detailed playbook documenting genetic and epigenetic changes that take place along the journey to becoming totipotent. The rich resource will guide future studies toward a deeper understanding of totipotency, cancer, and fertilization.


Story Source:

The above story is based on materials provided by University of Utah. Note: Materials may be edited for content and length.


Journal Reference:

  1. Saher Sue Hammoud, Diana H.P. Low, Chongil Yi, Douglas T. Carrell, Ernesto Guccione, Bradley R. Cairns. Chromatin and Transcription Transitions of Mammalian Adult Germline Stem Cells and Spermatogenesis. Cell Stem Cell, 2014; DOI: 10.1016/j.stem.2014.04.006

Cite This Page:

University of Utah. "Young sperm, poised for greatness, but are they under-achievers?." ScienceDaily. ScienceDaily, 19 May 2014. <www.sciencedaily.com/releases/2014/05/140519104743.htm>.
University of Utah. (2014, May 19). Young sperm, poised for greatness, but are they under-achievers?. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2014/05/140519104743.htm
University of Utah. "Young sperm, poised for greatness, but are they under-achievers?." ScienceDaily. www.sciencedaily.com/releases/2014/05/140519104743.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Idaho Boy Helps Brother With Disabilities Complete Triathlon

Newsy (July 23, 2014) — An 8-year-old boy helped his younger brother, who has a rare genetic condition that's confined him to a wheelchair, finish a triathlon. Video provided by Newsy
Powered by NewsLook.com
Thousands Who Can't Afford Medical Care Flock to Free US Clinic

Thousands Who Can't Afford Medical Care Flock to Free US Clinic

AFP (July 23, 2014) — America may be the world’s richest country, but in terms of healthcare, the World Health Organisation ranks it 37th. Thousands turned out for a free clinic run by "Remote Area Medical" with a visit from the Governor of Virginia. Duration: 2:40 Video provided by AFP
Powered by NewsLook.com
Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) — The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) — The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. 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