Izumo meets Juno: preventing
polyspermy in fertilization.
To decrease chances of
polyspermy, males were removed from spawning aquaria once they began to spawn.
The results indicate that (1) males with white spines achieved higher fertilization and were more likely to cause
polyspermy than males with purple spines, and there was no effect of female spine color on fertilization; (2) when comparing the average success of individual matings with pooled-sperm matings, there was a net benefit to polyandry when purple-spine males were pooled, a net cost when white-spine males were pooled, and no difference when mismatched spine color males were pooled; and (3) the success under pooled-sperm trials, with any of the spine color combinations, never exceeded the success of the more successful male in the individual-male trials.
In animal species, this technique has several applications such as avoidance of the
polyspermy problem (e.g.
Fertilization in fishes and the problem of
polyspermy. Acad.
In teleosts, the cortical alveoli content is released into the perivitelline space, at the moment of fertilization, blocking
polyspermy and contributing to chorion hardening (Hart, 1990).
A teleost egg is covered with a thick envelope called a chorion, which has a narrow pore designated as a micropyle that helps to avoid
polyspermy [15].
Parrish [30], states that the number of sperm added to oocytes during IVF affects the percentage of oocytes penetrated and even increase
polyspermy rate.
MYO is an important constituent of follicular microenvironment and it plays a determinant role in both nuclear and cytoplasmatic oocyte development [9], being also a precursor of phospholipids, which are responsible for the generation of important intracellular signals oocytes such as release of cortical granules, inhibition of
polyspermy, and resumption of meiotic process [10].
One of the determining factors for the low efficiency of porcine embryo IVP is the elevated rate of
polyspermy (TOKESHI et al., 2007; FAUSTINI et al., 2010).