Human sperm fertilizing potential in vitro is correlated with differential expression of a head-specific mannose-ligand receptor.
OBJECTIVE
To determine whether different patterns of surface expression of mannose-ligand binding sites are correlated with capacitation and predictive of the ability of human sperm to recognize and fertilize eggs in vitro.


METHODS
Analysis of motile sperm populations (from fertile donors, males presenting for routine semen analysis, and men undergoing IVF) before and after incubation in capacitating media.


METHODS
Patients from an infertility practice at a major university hospital.


METHODS
None.


METHODS
The mannose ligand-binding capacity of sperm populations were initially assayed by solid-phase mannosylated polyacrylamide bead binding studies. Sperm surface D-mannose binding sites thus detected were localized and visualized by fluorescence microscopy after reaction with a mannosylated fluorescein isothiocyanate-labeled neoglycoprotein probe. Results were correlated with acrosomal status, reproductive histories, and IVF outcomes.


RESULTS
The percent of sperm with head-directed surface expression of a mannose-specific receptor was increased in fertile donors and males exhibiting normal fertilization in IVF after incubation in albumin-supplemented Ham's F-10 medium (GIBCO Laboratories, Grand Island, NY). In normospermic males exhibiting zona binding failure in IVF, mannose-specific receptor was observed over the head surface of few incubated sperm.


CONCLUSIONS
The appearance of D-mannose-ligand binding sites on the surface of heads of human spermatozoa is associated with zona binding ability in IVF and is a putative determinant in human gamete recognition and fertilization.
Benoff
S
S
North Shore University Hospital-Cornell University Medical College, Manhasset, New York 11030.
Cooper
G W
GW
Hurley
I
I
Napolitano
B
B
Rosenfeld
D L
DL
Scholl
G M
GM
Hershlag
A
A
D000180:Acrylic Resins / Q000378:metabolism; D001665:Binding Sites; D005307:Fertilization in Vitro; D006801:Humans; D007248:Infertility, Male / Q000378:metabolism; D037181:Lectins, C-Type; D008297:Male; D008358:Mannose / Q000378:metabolism*; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic / Q000032:analysis*; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000737:chemistry / Q000502:physiology*; D000099166:Polyacrylamides
D000180:Acrylic Resins; D037181:Lectins, C-Type; D008358:Mannose; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D000099166:Polyacrylamides