Characterizing mouse male germ cell-specific actin capping protein alpha3 (CPalpha3): dynamic patterns of expression in testicular and epididymal sperm.
OBJECTIVE
To characterize mouse capping protein alpha3 (CPalpha3) during spermatogenesis and sperm maturation.


METHODS
We produced rat anti-CPalpha3 antiserum and examined the expression of CPalpha3 in various mouse tissues using Western blot analysis and the localization of CPalpha3 in testicular and epididymal sperm using immunohistochemical analyses. We also examined how the localization of CPalpha3 and beta-actin (ACTB) in sperm changed after the acrosomal reaction by performing immunohistochemical analyses using anti-CPalpha3 antiserum and anti-actin antibody.


RESULTS
Western blot analysis using specific antiserum revealed that CPalpha3 was expressed specifically in testes. Interestingly, the molecular weight of CPalpha3 changed during sperm maturation in the epididymis. Furthermore, the subcellular localization of CPalpha3 in sperm changed dynamically from the flagellum to the post-acrosomal region of the head during epididymal maturation. The distribution of ACTB was in the post-acrosomal region of the head and the flagellum. After inducing the acrosomal reaction, the CPalpha3 and ACTB localization was virtually identical to the localization before the acrosomal reaction.


CONCLUSIONS
CPalpha3 might play an important role in sperm morphogenesis and/or sperm function.
Tokuhiro
Keizo
K
TANAKA Project, Center for Advanced Science and Innovation, Osaka University, 3-1 Yamadaoka, Osaka 565-0871, Japan.
Miyagawa
Yasushi
Y
Tanaka
Hiromitsu
H
D020101:Acrosome Reaction / Q000502:physiology; D000199:Actins / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D051347:CapZ Actin Capping Protein / Q000378:metabolism*; D002478:Cells, Cultured; D004822:Epididymis / Q000166:cytology* / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D013077:Sperm Head / Q000378:metabolism; D013082:Sperm Tail / Q000378:metabolism; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*; D013737:Testis / Q000166:cytology* / Q000378:metabolism
D000199:Actins; C090518:CAPZA3 protein, mouse; D051347:CapZ Actin Capping Protein