A paper in print 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.
While selenoprotein P was believed to play a role as an antioxidant and
to transport selenium throughout the body, its physiological
function was unknown.
Over 20 selenoproteins have been identified, including key enzymes for
oxidant defense such as the glutathione peroxidases and the thioredoxin
reductases. Selenoproteins are usually enzymes that contain a single
selenocysteine as a constituent of the active site. Dietary selenium is essential for normal sperm development
and male fertility. Selenoprotein P (SEPP1) is a unique family member
that is an extracellular glycoprotein and depending on the species,
contains 10-17 selenocysteine residues in its primary structure, thereby carrying about 60 percent of the selenium in blood
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 the normal concentration.
The research team, headed by Dr. Gary E. Olson, found that the mutant
male mice lacking SEPP1 were generally infertile because of sperm
development with defective tails, similar to the sperm produced by
unaltered male mice fed a low-selenium diet. Even further, the
infertility of the mutant mice could not be cured by prolonged feeding
on a diet supplemented with high levels of selenium.
According to Olson and his colleagues, these findings strongly indicate
that SEPP1 is the source of the selenium needed for development of
normal sperm and for male mice to maintain their fertility.
The original paper:
Gary E. Olson, Virginia P. Winfrey, Subir K. NagDas, Kristina E. Hill, Raymond F. Burk, Selenoprotein P Is Required for Mouse Sperm Development
, Biol. Reprod., 73 (2005) 201-2011. doi: 10.1095/biolreprod.105.040360 Related publications:
Carlo Foresta, Leopold Flohé, Andrea Garolla, Antonella Roveri, Fulvio Ursini, Matilde Maiorino, Male Fertility Is Linked to the Selenoprotein Phospholipid Hydroperoxide Glutathione Peroxidase
, Biol. Reprod., 67/3 (2002) 967-971. doi: 10.1095/biolreprod.102.003822
L. Flohé, Selenium in mammalian spermiogenesis
, Biol. Chem., 388/10 (2007) 987-995. DOI: 10.1515/BC.2007.112
Sonia Shalini, M.P. Bansal, Alterations in selenium status influences reproductive potential of male mice by modulation of transcription factor NFKB
, BioMetals, 20 (2007) 49–59. DOI: 10.1007/s10534-006-9014-2
M. Sánchez-Gutiérrez, E. A. García-Montalvo, J. A. Izquierdo-Vega, L. M. Del Razo, Effect of dietary selenium deficiency on the in vitro fertilizing ability of mice spermatozoa
, Cell. Biol. Toxicol., 24 (2008) 321–329. DOI 10.1007/s10565-007-9044-8
A.A. Turanov, M. Malinouski, V.N. Gladyshev, Selenium in Male Reproduction
, in: D.L: Hatfield, M.J. Berry, V.N. Gladyshev, Selenium: Its Molecular Biology and Role in Human Health, Springer, 2012, 409-417. Doi: 10.1007/978-1-4614-1025-6_32
last time modified: July 14, 2013