Characterization of NADPH oxidase 5 in equine testis and spermatozoa.
Reactive oxygen species (ROS) play an important role in normal sperm function, and spermatozoa possess specific mechanisms for ROS generation via an NAD(P)H-dependent oxidase. The aim of this study was to identify the presence of an NADPH oxidase 5 (NOX5) in equine testis and spermatozoa. The mRNA of NOX5 was expressed in equine testis as detected by northern blot probed with human NOX5 cDNA and by RT-PCR. Immunoblotting with affinity purified alpha-NOX5 revealed one major protein in equine testis and other tissues. Immunolocalization of NOX5 showed labeling over the rostral sperm head with some labeling in the equatorial and post-acrosomal regions. In the testis, there was abundant staining in the adluminal region of the seminiferous tubules associated with round and elongating spermatids. The RT-PCR and sequence analysis revealed a high homology with human NOX5. This study demonstrates that NOX5 is present in equine spermatozoa and testes and therefore represents a potential mechanism for ROS generation in equine spermatozoa.
Department of Population Health and Reproduction, University of California, Davis, California 95616, USA.
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D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D016384:Consensus Sequence; D006736:Horses / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D000074664:NADPH Oxidase 5; D019255:NADPH Oxidases / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013077:Sperm Head / Q000201:enzymology; D013087:Spermatids / Q000201:enzymology; D013094:Spermatozoa / Q000201:enzymology*; D013737:Testis / Q000201:enzymology*
D008565:Membrane Proteins; D012333:RNA, Messenger; D000074664:NADPH Oxidase 5; D019255:NADPH Oxidases; C431571:NOX5 protein, human