Effect of kisspeptin on in vitro maturation of sheep oocytes

Abstract

Aim:The aim of this study was to investigate the effect of kisspeptin (KP) on in vitro maturation (IVM) of sheep oocytes aspirated from the ovaries collected from slaughterhouse.Materials and Methods:Two different experiments were conducted to investigate the effect of KP (5, 10 and 15 µg/ml) alone (experiment 1) or in combination with follicle-stimulating hormone (FSH), luteinizing hormone (LH), and Estradiol (E2) (experiment 2) on IVM of sheep oocytes. Tissue culture medium 199 supplemented with Gentamicin was used as control medium. Good quality oocytes were randomly allocated into different IVM media and cultured at 38.5°C in 5% CO2 under humidified atmosphere for 24 h. The oocytes were evaluated for their cumulus cell expansion (CCE) and extrusion of the 1st polar body (PB) at the end of maturation.Results:The proportion of oocytes showing CCE and extrusion of PB was highest when the oocytes were matured in the medium supplemented with 10 µg/ml of KP. In experiment 2, oocytes were matured in 12 different maturation media (G1-G12: G1: Control, G2: KP alone, G3: FSH, G4: FSH+KP, G5: LH, G6: LH+KP, G7: E2, G8: E2+KP, G9: FSH+LH+E2, G10: FSH+LH+E2+KP, G11: FSH+LH+E2+fetal bovine serum (FBS), G12: FSH+LH+E2+FBS+KP). The proportion of oocytes showing cumulus expansion and PB extrusion was highest (98.33±1.05 and 89.17±2.38) when they were matured in FSH+LH+E2+FBS+KP (G12) and was significantly higher than other groups. The proportion of CCE and extrusion of PB was significantly increased when KP was supplemented to FSH and E2, but no effect was observed with LH. The maturation rates were significantly increased when FSH, LH, and E2 (G9) containing media were additionally supplemented with KP (G10).Conclusion:This study demonstrated that the addition of KP (10 µg/ml) to the FSH, LH, and E2 supplemented media would enhance the sheep oocyte maturation in vitro.

Effect of Kisspeptin on in vitro Maturation of Buffalo Oocytes

“…The results of the present study indicate that Kp has some local interactions with FSH, LH and E2 during In Vitro maturation of buffalo oocytes as also hypothesized in the earlier studies by Saadeldin et al, (2012) in pigs and Byri et al, (2017) in sheep. Further, the development competence of the oocytes matured in the presence of Kp needs to be tested by in vitro fertilization.…”

“…Addition of Kp either with FSH or LH, to the maturation medium, resulted in significantly (P0.05) higher CCE% (86.05% and 81.34% respectively) and PB extrusion (63.99% and 59.94% respectively) when compared to that shown by Kp alone (Table 2). This shows that addition of Kp to the maturation media fortified with FSH or LH enhances oocyte maturation, reflecting the synergistic action of Kp with FSH and LH during IVM of buffalo oocytes as also reported by Byri et al, (2017). Kp might have modulated the expression of receptor of GnRH and LH on cumulus cells and oocyte, thus enhanced cumulus cell expansion and PB expression during the maturation process.…”

“…The ability of Kp to induce ovulation following intravenous administration has been demonstrated in bovine (Naniwa et al, 2013), prepubertal ewe lambs (Redmond et al, 2011), anestrous ewes (Caraty et al, 2007) and mare (McGrath et al, 2016). Moreover, supplementation of Kp to maturation media has been reported to improve the efficiency of pig (Saadeldin et al, 2012), bovine (Ming et al, 2015 andOliveira et al, 2016) and sheep (Byri et al, 2017) oocyte maturation in vitro. Yet, until today, its effect on IVM of buffalo oocytes has not been elucidated.…”

ERβ regulated ovarian kisspeptin plays an important role in oocyte maturation

“…We observed that treatment of oocytes with a low dose (1nM) of KP-10 improved in vitro maturation of rat oocytes. Previous studies on pig (Saadeldin et al, 2012) and sheep (Byri et al, 2017) oocytes also support our findings. Although Erβ null oocytes showed a reduced rate of in vitro maturation, both of wildtype and Erβ null oocytes responded to rat KP-10 treatment showing a similar improvement.…”

Clinical Translational Studies of Kisspeptin and Neurokinin B

“…Ovarian kisspeptin expression is undetectable in immature oocytes, but is increased at ovulation. 34 Kisspeptin has been shown to increase in vitro maturation of ovine 35 and porcine immature oocytes, 36 and smaller follicles contributed more to the oocyte yield than following other triggers in humans. 37 Furthermore, intrafollicular kisspeptin levels correlate with the number of mature oocytes retrieved.…”