Featured Research

from universities, journals, and other organizations

How sperm get into the zona

Date:
June 16, 2014
Source:
The Rockefeller University Press
Summary:
Before it can fertilize an egg, a sperm has to bind to and bore through an outer egg layer known as the zona pellucida. Researchers now identify the protein in the zona pellucida that sperm latch onto. The zona pellucida protects the egg and the early embryo before implantation.

Sperm (blue) latch onto a control egg (left) but can't bind to an egg lacking the glycoprotein ZP2 (right).
Credit: Avella et al., 2014

Before it can fertilize an egg, a sperm has to bind to and bore through an outer egg layer known as the zona pellucida. Despite decades of research, some of the biological mechanisms behind this process remain unclear. A study in The Journal of Cell Biology now identifies the protein in the zona pellucida that sperm latch onto.

The zona pellucida protects the egg and the early embryo before implantation. Its structure seems simple -- in humans it contains four kinds of glycoproteins, and in mice it only contains three. But researchers haven't been able to identify the sperm's binding partner in the layer, although their suspicions have fallen on two of the glycoproteins, ZP2 and ZP3.

To find out more, Jurrien Dean and colleagues from the National Institute of Diabetes and Digestive and Kidney Diseases engineered mice to produce various combinations of human and mouse zona pellucida glycoproteins. Mouse sperm didn't bind to the zona pellucida if it was missing ZP2, and female mice lacking the protein were sterile. The researchers also found that sperm couldn't latch onto eggs if ZP2 was missing a key region at the beginning of the protein. This result jibes with a previous finding that fertilization triggers the release of an enzyme that severs ZP2 in this region, thus preventing additional sperm from attaching to the zona pellucida.

The team also tested the binding of human sperm to mouse eggs surrounded by a zona pellucida harboring human glycoproteins. Human sperm adhered to the mouse zona pellucida if it contained human ZP2 but not if it carried human ZP3, confirming the importance of ZP2.


Story Source:

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


Journal Reference:

  1. Matteo A. Avella, Boris Baibakov, and Jurrien Dean. A single domain of the ZP2 zona pellucida protein mediates gamete recognition in mice and humans. The Journal of Cell Biology, June 2014 DOI: 10.1083/jcb.201404025

Cite This Page:

The Rockefeller University Press. "How sperm get into the zona." ScienceDaily. ScienceDaily, 16 June 2014. <www.sciencedaily.com/releases/2014/06/140616093032.htm>.
The Rockefeller University Press. (2014, June 16). How sperm get into the zona. ScienceDaily. Retrieved August 1, 2014 from www.sciencedaily.com/releases/2014/06/140616093032.htm
The Rockefeller University Press. "How sperm get into the zona." ScienceDaily. www.sciencedaily.com/releases/2014/06/140616093032.htm (accessed August 1, 2014).

Share This




More Plants & Animals News

Friday, August 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Pyrenees Orphan Bear Cub Gets Brand New Home

Pyrenees Orphan Bear Cub Gets Brand New Home

AFP (Aug. 1, 2014) The discovery of a bear cub in the Pyrenees mountains made headlines in April 2014. Despire several attempts to find the animal's mother, the cub remained alone. Now, the Pyrenees Conservation Foundation has constructed an enclosure. Duration: 00:31 Video provided by AFP
Powered by NewsLook.com
Ebola Vaccine Might Be Coming, But Where's It Been?

Ebola Vaccine Might Be Coming, But Where's It Been?

Newsy (Aug. 1, 2014) Health officials are working to fast-track a vaccine — the West-African Ebola outbreak has killed more than 700. But why didn't we already have one? Video provided by Newsy
Powered by NewsLook.com
Study Links Certain Birth Control Pills To Breast Cancer

Study Links Certain Birth Control Pills To Breast Cancer

Newsy (Aug. 1, 2014) Previous studies have made the link between birth control and breast cancer, but the latest makes the link to high-estrogen oral contraceptives. Video provided by Newsy
Powered by NewsLook.com
Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) 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