ABSTRACT
In contrast to the observations of Steele et al. (1994), Robertson et al. (1997) observed that the IPVL from laid chicken eggs, from follicular oocytes and ovulated ova gave similar responses to hydrolysis by sperm in vitro. However, it should be noted that in the above experiment IPVL was used not only in case of follicular oocytes and ovulated ova but also in case of laid eggs, as IPVL was isolated from PVL, whereas Steele et al. (1994) used whole PVL from laid eggs. Robertson et al. (1997) did observe that one of the IPVL glycoproteins, probably ZP3, appeared smaller in laid eggs than from follicular oocytes. Notwithstanding, these authors proposed the use of IPVL from laid eggs instead of IPVL from follicular oocytes or ovulated ova. The former are considerably easier to obtain when performing in vitro assays of sperm-IPVL interaction for predicting the fertilizing ability of semen from different males.
