Immunisation against inhibin enhances follicular development, oocyte maturation and superovulatory response in water buffaloes

Abstract

This study was carried out to test the feasibility of enhancing embryo production in vivo and in vitro by immunoneutralisation against inhibin or follistatin. In Experiment 1, multi-parity buffaloes were assigned into three groups: High group (n=8), which received one primary (2mg) and two booster (1mg) vaccinations (28-day intervals) with a recombinant inhibin α subunit in 1 mL of white oil adjuvant; Low group (n=8), which received half that dose; and Control group (n=7), which received only adjuvant. Immunisation against inhibin stimulated development of ovarian follicles. Following superovulation and artificial insemination, inhibin-immunised buffaloes had more developing follicles than the Control buffaloes. The average number of embryos and unfertilised ova (4.5±0.6, n=6) in the High group was higher (P<0.05) than in the Control group (2.8±0.6, n=5) and was intermediate (4.1±0.7, n=7) in the Low group. The pooled number of transferable embryos of the High and Low groups (3.2±0.5, n=13) was also higher (P<0.05) than that (1.6±0.7, n=5) of the controls. The immunised groups also had higher plasma concentrations of activin, oestradiol and progesterone. In Experiment 2, the addition of anti-inhibin or anti-follistatin antibodies into buffalo oocyte IVM maturation medium significantly improved oocyte maturation and cleavage rates following parthenogenic activation. Treatment with anti-follistatin antibody also doubled the blastocyst yield from activated embryos. These results demonstrated that immunisation against inhibin stimulated follicular development, enhanced oocyte quality and maturation competence, yielded more and better embryos both in vivo and in vitro.

The Highly Prolific Phenotype of Lacaune Sheep Is Associated with an Ectopic Expression of the B4GALNT2 Gene within the Ovary

“…However, inhibin A has also been shown to exert a blocking action on the activin A and other TGFß member dependent regulation of steroidogenesis and proliferation within the ovary [16]. Immunization against inhibin can promote an increase in ovulation rate and prolificacy [40] through enhanced follicular development in sheep [41], goat [42] and water buffalo [43]. It has been suggested that inhibin antibodies may act primarily by an intraovarian paracrine action rather than by reducing the suppressive action of inhibin on pituitary FSH release [43], [44].…”

Polymorphism of the inhibin βA gene and its relationship with superovulation traits in Chinese Holstein cows

“…Passive and active (Ishigame et al, 2004) immunization against inhibin results in increased pituitary secretion and plasma concentrations of FSH, which could stimulate follicle development and improve the ovarian response to superovulation, resulting in increased ovulation rates and higher yields of transferable embryos in sheep (D'Alessandro et al, 1999), heifers or cows Mei et al, 2009), and water buffalo (Li et al, 2011). Due to the important role of inhibin in FSH secretion and as a growth factor in the ovary, INHβA was confirmed to be an important candidate gene for improving reproductive performance (Xue et al, 2004;Phillips, 2005;Chu et al, 2007).…”

“…In addition, because of its inhibitory action on FSH secretion, inhibin has been widely used in the treatment of superovulation. Previous studies have demonstrated that immunization against inhibin could improve the ovarian response to superovulation, resulting in increased ovulation rates and higher yields of transferable embryos in sheep (D'Alessandro et al, 1999), heifers or cows Mei et al, 2009), and water buffalo (Li et al, 2011). Therefore, inhibin is a potential candidate gene for superovulation performance.…”

Trends in recombinant protein use in animal production

“…However, in many other cases inhibin has been produced in mammalian cells [16, 92]. Importantly, recombinant inhibin has been used as an antigen for the immunization against endogenous inhibin in hens [93, 94], cockerels [95], heifers [87, 89, 96], water buffaloes [88], guinea pigs [97], goats [98], and sheep [99–102]. Only in a minority of cases, the recombinant inhibin α subunit used is obtained synthetically [103–106] or purified from follicular fluid [107].…”