Accumulation, nature, and possible functions of the malachite green affinity material in ejaculated human spermatozoa.
An electron microscopic study was conducted on human sperm over an incubation period of 5 to 6 hours in Tyrode's solution at room temperature. Examination of aliquots of the cells, fixed at timed intervals, with glutaraldehyde, malachite green, and postosmication revealed that malachite green affinity material (MGA-M) was barely discernible at first but did accumulate considerably upon standing. Biochemical analysis of MGA-M, which is extractable by glutaraldehyde, revealed that MGA-M is a mixture of extractable phospholipids and of their lyso-derivatives. Some of these substances have fusogenic properties; i.e., they are able to fuse together the membranes of two different cells. The appearance and accumulation of these fusogens occurred during the incubation period of 5 to 6 hours, which was previously shown to be required to capacitate human sperm in vitro. It is probable, therefore, that human sperm, during their initial period of incubation either in vivo or in vitro, not only become capacitated and undergo the acrosome reaction but also develop the fusogenic substance(s) which are necessary for the imminent fusion of their plasma membrane to the vitelline membrane of the mature oocyte.
D003593:Cytoplasm / Q000032:analysis; D006801:Humans; D008297:Male; D010743:Phospholipids / Q000302:isolation & purification; D013075:Sperm Capacitation; D013094:Spermatozoa / Q000032:analysis* / Q000648:ultrastructure
D010743:Phospholipids