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Product Reference
15-Lipoxygenase is a component of the mammalian sperm cytoplasmic droplet.
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| Author |
K A Fischer, K Van Leyen, K W Lovercamp, G Manandhar, M Sutovsky, D Feng, T Safranski, P Sutovsky |
| Citation Information |
Reproduction (Cambridge, England), 130:213-22 (2005) |
| Keywords |
Animals, Arachidonate 15-Lipoxygenase, Blotting, Western, Cytoplasm, Epididymis, Immunohistochemistry, Male, Mammals, RNA, Messenger, Reverse Transcriptase Polymerase Chain Reaction, Semen, Spermatozoa, Swine, Testis |
| Related Products |
AB1761 |
| Pub Med ID |
16049159 |
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Abstract
Lipoxygenases (LOXs) are a family of enzymes capable of peroxidizing phospholipids. A member of the LOX family of enzymes, 15-LOX, participates in the degradation of mitochondria and other organelles within differentiating red blood cells, the reticulocytes. The present study provides biochemical and immunocytochemical evidence for the presence of 15-LOX in the sperm cytoplasmic droplet (CD). Testicular, epididymal and ejaculated spermatozoa were evaluated for the presence of 15-LOX using an affinity-purified immune serum raised against a synthetic peptide corresponding to the C-terminal sequence of rabbit reticulocyte 15-LOX. Western blotting revealed an appropriate single band of approximately 81 kDa in boar spermatozoa but not in boar seminal plasma. When ejaculated boar spermatozoa were subjected to separation on a 45/90% Percoll gradient, 15-LOX co-migrated with the immotile sperm and cellular debris/CD fractions, but not with the motile sperm fraction containing morphologically normal spermatozoa without CDs. Varied levels of 15-LOX were expressed in ejaculated sperm samples from boars with varied semen quality. By immunofluorescence, prominent 15-LOX immunoreactivity was found within the residual body in the testis and within the CDs from caput, corpus and cauda epididymal and ejaculated spermatozoa. Components of the ubiquitin-dependent proteolytic pathway, which is thought to facilitate both spermiogenesis and reticulocyte organelle degradation, were also detected in the sperm CD. These included ubiquitin, the ubiquitin-conjugating enzyme E2, the ubiquitin C-terminal hydrolase PGP 9.5, and various 20S proteasomal core subunits of the alpha- and beta-type. The 15-LOX and various components of the ubiquitin-proteasome pathway were also detected in sperm CDs of other mammalian species, including the human, mouse, stallion and wild babirusa boar. We conclude that 15-LOX is prominently present in the mammalian sperm CD and thus may contribute to spermiogenesis, CD function or CD removal.
