| First Author | Bray C | Year | 2005 |
| Journal | Biol Reprod | Volume | 73 |
| Issue | 4 | Pages | 807-14 |
| PubMed ID | 15944242 | Mgi Jnum | J:115434 |
| Mgi Id | MGI:3691713 | Doi | 10.1095/biolreprod.105.042184 |
| Citation | Bray C, et al. (2005) Mice deficient in CHRNA7, a subunit of the nicotinic acetylcholine receptor, produce sperm with impaired motility. Biol Reprod 73(4):807-14 |
| abstractText | In this study we investigate the role of the CHRNA7 subunit (also known as the alpha7 subunit) of the nicotinic acetylcholine receptor in mouse sperm function. We confirm by reverse-transcription-polymerase chain reaction the expression in adult mouse testis of Chrna7 mRNA and demonstrate the subunit's presence in mouse sperm by immunoblot. Alpha-bungarotoxin binds a range of nicotinic acetylcholine receptor subunits, including the CHRNA7 subunit. Localization studies using a fluorescent alpha-bungarotoxin-tetramethyl-rhodamine conjugate revealed specific binding sites on the midpiece of mouse sperm with fainter alpha-bungarotoxin binding on the remainder of the flagellum. Mice engineered with a double-null disruption of the Chrna7 gene displayed only faint fluorescence on the midpiece, suggesting that the CHRNA7 contributed the majority of the observed alpha-bungarotoxin binding sites. The location of alpha-bungarotoxin binding suggested that nicotinic acetylcholine receptors may play an ionotropic role in sperm motility. Sperm from Chrna7(-/-) mice display no difference in number, morphology, viability or spontaneous acrosome reaction rate compared with Chrna7(+/+) sperm. Studies using computer-assisted sperm analysis indicate the motility of Chrna7(-/-) sperm is significantly impaired. This impairment is characterized by significantly reduced swimming velocities, failure to maintain vigorous swimming, and lower levels of hyperactivated swimming patterns in Chrna7(-/-) sperm compared with Chrna7(+/+) sperm. This is the first genetic evidence that sperm nicotinic acetylcholine receptors are important for maintenance of normal sperm motility. |
