Protein delivers selenium for normal sperm development
A paper to be published in the journal Biology of Reproduction offers evidence that a protein circulating in the blood of mammals delivers the dietary micronutrient selenium to germ cells, enabling these cells to develop into normal sperm.
Previously, the function of this protein, selenoprotein P, was unknown, although it was believed to play a role as an antioxidant and to transport selenium throughout the body.
Dietary selenium is essential for normal sperm development and male fertility. Selenoprotein P, or SEPP1, carries about 60 percent of the selenium in blood plasma.
To understand the physiological function of SEPP1 in the testes and epididymis of mammals, a team of scientists at Vanderbilt University in Nashville studied male mice that lack the gene to produce SEPP1. These genetically altered males have levels of selenium in the testis that are less than 10 percent of those in control mice, and they are generally infertile.
The research team, headed by Dr. Gary E. Olson, found that the mutant male mice lacking SEPP1 develop sperm with defective tails, similar to the sperm produced by unaltered male mice fed a low-selenium diet.
Furthermore, the mutant mice do not recover normal sperm production after prolonged feeding on a diet supplemented with high levels of selenium, and they remain infertile. Thus, even selenium supplements could not overcome the need for SEPP1 to facilitate normal sperm development.
These findings, according to Olson and colleagues, strongly indicate that SEPP1 is the source of the selenium needed for development of normal sperm and for male mice to maintain their fertility.
Dr. Gary E. Olson | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
Nano-hologram paves way for integration of 3-D holography into everyday electronics
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...