Me. Schalkoff et al., AN ULTRASTRUCTURAL ANALYSIS OF AN OOCYTE FROM AN IN-VITRO FERTILIZATION PATIENT WITH REPEATED POLYSPERMIC FERTILIZATION, Journal of assisted reproduction and genetics, 13(6), 1996, pp. 477-484
Objective: Our goal was to determine any ultrastructural anomalies in
an oocyte from a patient with a history of polyspermy. Results: Ultras
tructural observations of the cortical ooplasm of several oocytes from
each of three control patients showed a large population of intact co
rtical granules. Conversely, one oocyte from a patient with repeated p
olyspermic fertilization contained a relative paucity of granules in t
he cortex. Quantitative analysis of the cortices of control oocytes in
dicated that there were 17.02 +/- 0.52 cortical granules present per m
easured field of view, compared with 4.40 +/- 2.92 granules per field
in the other oocyte. Conclusions: The presence of sufficient cortical
granules is necessary for normal (monospermic) fertilization to occur:
When contrasted to the cortical granule population of oocytes from se
veral control patients, the cortex of one oocyte from the other patien
t showed few of these organelles. Therefore, the absence of a sufficie
nt number of granules may have precluded normal fertilization from occ
urring in the eggs of this patient.