Dose-dependent effects of luteinizing hormone and follicle stimulating hormone on <i>in vitro</i> maturation, apoptosis, secretion function and expression of follicle stimulating hormone receptor and luteinizing hormone receptor of sheep oocytes

Abstract

The present study compared the effects of follicle stimulating hormone (FSH) and luteinizing hormone (LH) on in vitro maturation (IVM), apoptosis, and secretion function in sheep oocytes, as well as gene expressions of the receptors (FSHR, LHR, and GnRHR) in cumulus-oocyte complexes (COCs). The COCs were recovered from sheep ovaries and pooled in groups. The COCs were cultured for 24 hours in IVM medium supplemented with various concentrations of LH (5-30 μg/mL) and FSH (5-30 IU/mL). They were allocated to LH-1 (5 µg/mL), LH-2 (10 µg/mL), LH-3 (20 µg/mL), and LH-4 (30 µg/mL) groups, and FSH-1 (5 IU/mL), FSH-2 (10 IU/mL), FSH-3 (20 IU/mL), and FSH-4 (30IU/mL) groups. The apoptosis of COCs was assessed by terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). The maturation rates of oocytes improved gradually as LH and FSH concentration increased from 0 to 10 μg/mL(IU/mL), reaching a peak value of 44.1% of LH-2 and 48.5% of FSH-2 group. Oocyte apoptosis rates of LH-2 and FSH-2 groups were the lowest among LH-and FSH-treated groups, respectively. The germinal vesicle breakdown (GVBD) rate of the FSH-2 group was higher than that of the control group (CG) and FSH-4 groups. The GVBD rate of LH-2 group also increased in comparison with the CG group. FSH concentration of the FSH-2 group was greater than that of CG. Expression levels of FSHR, LHR, and GnRHR mRNAs of FSH-2, LH-3, and LH-3 group, respectively, were higher than CG. Levels of FSHR proteins in FSH-2 and FSH-3 groups were greater than CG. Levels of GnRHR proteins were increased with a maximum increment of FSH-4. The FSH and LH supplemented into the IVM medium could promote the maturation rate, reduce the apoptosis rate of sheep oocytes, and increase FSH concentrations in IVM medium fluid. Additionally, FSH and LH enhanced expression levels of FSHR, LHR, and GnRHR mRNAs of sheep COCs.

Effect of FSH and eCG on Alpaca (Vicugna pacos) Oocyte Maturation in vitro

“…However, the same concentration of FSH, 0.5μg.mL -1 , has resulted in lower rates of maturation in llamas (Del Campo et al 1994). Similarly, in ewes the rate of oocyte maturation varies amongst different concentrations of FSH (Wei et al 2017;Wei et al 2018).…”

“…Previous studies in alpacas used 0.5µg.mL -1 of FSH as a supplement in maturation medium at a fixed concentration during in vitro maturation of oocytes (Ratto et al 2007;Huanca et al 2014;Ruiz et al 2017), in this process, the use of eCG in alpacas is not typical. However, in other species, different concentrations of gonadotropins in maturation medium have been studied (Choi et al 2001;Farag et al 2012;Wei et al 2017;Wei et al 2018). In dromedary camels, a high in vitro maturation rate of oocytes was reported when supplemented with 10µg.mL -1 of pregnant mare serum gonadotropin (PMSG) plus human chorionic gonadotropin (Farag et al 2012;Farag et al 2013).…”

Influencia De Las Hormonas Folículo Estimulante, Luteinizante Y Gonadotropina Coriónica Equina en La Maduración in Vitro De Ovocitos Y Clivaje De Embriones De Alpaca

“…En el bovino Yak, la adición de FSH al medio de maduración in vitro tuvo mayor efecto sobre aumento de niveles de expresión de mRNA de RFSH y RLH (Xiao et al, 2014). En ovinos, durante la maduración in vitro de ovocitos, los niveles de expresión de los mARN y las proteínas de RFSH en los complejos cúmuloovocito tratados con FSH fueron más elevados que en los grupos tratados con LH (Wei et al, 2018). Las tasas de maduración in vitro de ovocitos son menores, cuando no se usa gonadotropinas en medio de maduración (Galli y Moor, 1991;Salgado et al, 2010;Wang et al, 2013), la administración conjunta de suplementos de rFSH, rLH en medio de maduración in vitro mejora el desarrollo embrionario, tanto en ovocitos bovinos, humanos y murinos, eleva el número de ovocitos maduros hasta los eventos iniciales embrionarios (Anderiesz et al, 2000).…”