Sericin is a water-soluble member of the family of serine
(Ser)-rich silk proteins of mulberry as well as non-mulberry
silkworms that glues fibroin fibers together to form a robust
cocoon [4]. It accounts for 20–30% of weight of the Bombyx mori
cocoon fiber and is usually removed by the degumming
process during silk processing. Currently, in some laboratoriessericin is used as a replacement for fetal bovine serum (FBS) in
cell culture media [5]. It was reported that sericin stimulated
the proliferation of insect and mammalian cells and improved
the viability of many cell lines following cryopreservation [5].
Also, Hosoe et al. [6] reported that the addition of sericin
instead of FBS to maturation medium enlarged the perivitelline space, increased hyaluronic acid (HA) production and
decreased polyspermic fertilization in bovine oocytes. These
findings suggest that sericin may be used not only as a FBS
replacement, but also as a supplementation of culture medium
containing FBS. However, information concerning the effect of
various concentrations of sericin on in vitro embryo development in ovine is scarce. Therefore, the objective of the current
study was to determine whether potassium simplex optimized
medium (KSOM-aa) supplemented with different concentrations of sericin improves the cleavage rate and subsequent
embryonic development in vitro. Further studies are necessary
to evaluate the exact role and mechanism of sericin action on
ovine oocyte maturation and embryonic development.