F-actin involvement in guinea pig sperm motility.
Sperm motility is a must for natural fertilization to occur. During their travel through the epididymis, mammalian spermatozoa gradually acquire the ability to move. This is accomplished through a sliding movement of the outer doublet microtubules of the axoneme which is energized by the dynein ATPase. Within its complex structure, the mammalian sperm flagellum contains F-actin and thus, we decided to test in the guinea pig sperm flagellum the role of F-actin in motility. During maturation, capacitation, and the acrosome reaction, a gradual decrease of the relative concentration of F-actin was observed. Motility increased as spermatozoa became able to fertilize. Gelsolin, phalloidin, and KI inhibited sperm motility. Gelsolin canceled sperm motility within 20 min of treatment while 0.6 M KI had immediate effects. Phalloidin diminished hyperactive sperm motility slightly. All three compounds significantly increased the relative concentration of F-actin. Latrunculins are conventional drugs that destabilize the F-actin cytoskeleton. Latrunculin A (LAT A) did not affect sperm motility; but significantly increased F-actin relative concentration. The results suggested that in guinea pig spermatozoa, randomly severing F-actin filaments inhibits flagellar motility; while end filament alteration does not. Thus, specific filament regions seem to be important for sperm motility.
Azamar
Yenia
Y
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), México DF, México.
Uribe
Salvador
S
Mújica
Adela
A
D000177:Acrosome / Q000378:metabolism / Q000502:physiology; D000199:Actins / Q000378:metabolism* / Q000502:physiology; D000818:Animals; D001426:Bacterial Proteins / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D005407:Flagella / Q000378:metabolism*; D018260:Gelsolin / Q000494:pharmacology; D006168:Guinea Pigs; D008297:Male; D010590:Phalloidine / Q000494:pharmacology; D011193:Potassium Iodide / Q000494:pharmacology; D013075:Sperm Capacitation; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism* / Q000502:physiology; D013301:Streptolysins / Q000494:pharmacology; D053778:Thiazolidines / Q000494:pharmacology
D000199:Actins; D001426:Bacterial Proteins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D018260:Gelsolin; D013301:Streptolysins; D053778:Thiazolidines; C025964:streptolysin O; D010590:Phalloidine; D011193:Potassium Iodide; C037067:latrunculin A