Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

’Suicide proteins’ contribute to sperm creation

15.12.2003



You might say that caspases are obsessed with death. The primary agents of programmed cell death, or apoptosis, caspases kill cells by destroying proteins that sustain cellular processes. Apoptosis, a highly controlled sequence of events that eliminates dangerous or unnecessary cells, contributes to a wide variety of developmental and physiological processes--in a developing embryo, apoptosis creates the space between fingers and adjusts nerve cell populations to match the number of cells they target; in an adult, apoptosis counters cell proliferation to maintain tissue size and density. Now it appears that caspases may also play a role in creating life. As Bruce Hay, Jun Huh, and colleagues of the California Institute of Technology, report in this issue, multiple caspases and caspase regulators are required for the proper formation of free-swimming sperm in the fruitfly Drosophila.

Caspases, which typically exist in a quiescent state in nearly all cells, are regulated through a complex network of activators and inhibitors. Once activated, a "caspase cascade" ultimately cleaves and irreversibly alters the function of essential cellular proteins, leading to apoptosis. Not surprisingly, cells keep caspase activation under tight wraps. That’s why it’s intriguing that multiple caspases normally associated with the induction of cell death participate in this non-apoptotic process.

During spermatogenesis, germline precursor cells--the cells that generate sex cells--give rise to 64 haploid spermatids. Spermatids are connected by intracellular "bridges" that, along with most other cytoplasmic components, must be expelled in a process called "individualization" to create terminally differentiated free-swimming sperm. A similar process--elimination of cytoplasm and membrane packaging of individual spermatids--also occurs in mammals, and its disruption is associated with male infertility.



Hay’s group studied the consequences of inhibiting caspase activity in the male germline cells of fruitflies and found that individualization depends on caspase activity. The researchers went on to characterize the pathways that activate caspases during sperm individualization and found that several different apoptosis-related caspases and caspase regulators are recruited through different pathways at distinct points in time and space to create individually packaged, free-swimming sperm, a distinctly non-apoptotic process.

Insights into the molecular basis of caspase activation in sperm individualization could provide clues to male infertility and suggest possible treatments.


All works published in PLoS Biology are open access. Everything is immediately available without cost to anyone, anywhere--to read, download, redistribute, include in databases, and otherwise use--subject only to the condition that the original authorship is properly attributed. Copyright is retained by the author. The Public Library of Science uses the Creative Commons Attribution License.

Dr. Bruce Hay | PLoS
Further information:
http://www.plosbiology.org

More articles from Life Sciences:

nachricht High-Speed Locomotion Neurons Found in the Brainstem
24.10.2017 | Universität Basel

nachricht Antibiotic resistance: a strain of multidrug-resistant Escherichia coli is on the rise
24.10.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Single nanoparticle mapping paves the way for better nanotechnology

24.10.2017 | Physics and Astronomy

A quantum spin liquid

24.10.2017 | Physics and Astronomy

Antibiotic resistance: a strain of multidrug-resistant Escherichia coli is on the rise

24.10.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>