Migration and ultrastructural localization of the c-kit receptor protein in spermatogenic cells and spermatozoa of the mouse.
OBJECTIVE
The c-kit receptor is a proto-oncogene important in germ cell migration and maturation and has also been demonstrated on the acrosomal region of mature sperm. The purpose of the present study was to examine the ultrastructural location of the c-kit receptor in mouse testis and sperm.


METHODS
Testis and sperm from mature male mice were examined for the c-kit receptor utilizing electron microscopy and Western blot analysis techniques. Thin sections of mouse testis and sperm were stained with immunogold-labeled anti-c-kit antibodies. The protein from these testes and sperm was also utilized for Western blot analysis.


RESULTS
The c-kit protein was localized within the mouse testes to the type A spermatogonia, the round spermatids, and the mature testicular spermatozoa. The c-kit receptor was noted to migrate from the lumen of the acrosomal vesicles in the early spermatids to the plasma membrane of the late spermatids. It was also noted in the acrosomal region of the testicular spermatozoa, as well as the sperm from the epididymis. Sperm undergoing the acrosome reaction demonstrated association of the c-kit receptor with the plasma membrane of the acrosome, but not on the acrosomal membrane itself. Western blot analysis demonstrated protein bands of 150 kDa in testis and intact sperm.


CONCLUSIONS
The present study confirms the presence of the c-kit receptor in mouse testis and sperm. It also demonstrates that this receptor is localized to the region of the developing acrosome.
Sandlow
J I
JI
Department of Urology, University of Iowa, Iowa City 52242-1089, USA.
Feng
H L
HL
Zheng
L J
LJ
Sandra
A
A
D020101:Acrosome Reaction; D000818:Animals; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D013091:Spermatogenesis; D013094:Spermatozoa / Q000737:chemistry*; D013737:Testis / Q000737:chemistry*
D019009:Proto-Oncogene Proteins c-kit