No abstract

Asprosin is a novel fasting-induced protein encoded by fibrillin-1 (FBN1) gene, produced when FBN1 is cleaved by the enzyme furin, and is associated with insulin resistance and polycystic ovarian syndrome in humans. To characterize mRNA abundance of FBN1, furin, and the presumed asprosin receptor, olfactory receptor family 4 subfamily M member 1 (OR4M1) in granulosa (GC) and theca cells (TC), and identify hormones regulating FBN1 mRNA expression, GC and TC from small (1-5 mm; SM) and large (>8 mm; LG) follicles were collected from ovaries of heifers obtained at an abattoir and used for real-time PCR gene expression analysis or in vitro evaluation of hormone regulation and asprosin effects. SMTC had 151-fold greater (P < 0.05) FBN1 mRNA abundance than SMGC, and LGTC had 50-fold greater FBN1 mRNA than LGGC. In contrast, OR4M1 mRNA was 81-fold greater in SMGC than LGGC and did not differ from SMTC, but LGTC had 9-fold greater OR4M1 mRNA than LGGC. Furin mRNA was 2.6-fold greater in SMTC than SMGC, but did not differ among follicular sizes. In cultured TC, leptin, insulin, LH, IGF1 and steroids did not affect FBN1 mRNA, but TGFβ1 increased (P < 0.05) FBN1 mRNA by 2.2-fold; EGF and FGFs increased FBN1 mRNA by 1.3- to 1.5-fold. Asprosin enhanced LH-induced TC androstenedione production, reduced IGF1-induced TC proliferation, and had no effect on progesterone production. Developmental regulation of FBN1, furin and OR4M1 along with direct effects of asprosin on TC suggests that asprosin may be a novel regulator of ovarian follicular function.

In this study, we examined the effects of superstimulation using follicle‐stimulating hormone ( FSH ) followed by gonadotropin‐releasing hormone (Gn RH ) on buffalo embryo production by ultrasound‐guided ovum pick‐up ( OPU ) and in vitro fertilization ( IVF ). Nine Murrah buffaloes were subjected to OPU ‐ IVF without superstimulation (control). The morphologies of the oocytes collected were evaluated, and oocytes were then submitted to in vitro maturation ( IVM ). Two days after OPU , same nine buffaloes were treated with twice‐daily injections of FSH for 3 days for superstimulation followed by a Gn RH injection. Oocytes were collected by OPU 23–24 hr after the Gn RH injection and submitted to IVM (the superstimulated group). The total number of follicles, number of follicles with a diameter > 8 mm, and number of oocytes surrounded by multi‐layered cumulus cells were higher in the superstimulated group than in the control group ( p ≤ 0.05). After IVF , the percentages of cleavage and development to blastocysts were higher in the superstimulated group than in the control group ( p < 0.05). In conclusion, superstimulation improved the quality of oocytes and the embryo productivity of OPU ‐ IVF in river buffaloes.

No abstract

Emerging Fusarium mycotoxins beauvericin (BEA), enniatins (ENNs), and moniliformin (MON) are gaining increasing interest due to their wide presence especially in cereals and grain‐based products. In vitro and in vivo studies indicate that Fusarium mycotoxins can be implicated in reproductive disorders in animals. Of these mycotoxins, BEA may affect reproductive functions, impairing the development of oocytes in pigs and sheep. Studies show dramatic inhibitory effects of BEA and ENNA on bovine granulosa cell steroidogenesis. ENNs also inhibit boar sperm motility and cause detrimental effects on embryos in mice and pigs. Although little data are reported on reproductive effects of MON, in vitro studies show inhibitory effects of MON on Chinese hamster ovary cells. The present review aims to summarize the reproductive toxicological effects of emerging Fusarium mycotoxins BEA, ENNs, and MON on embryo development, ovarian function, and testicular function of animals. In vitro and in vivo toxicological data are reported although additional studies are needed for proper risk assessment.

No abstract

The emerging Fusarium mycotoxins enniatins (ENNs) have been the focus of new research because of their well-documented existence in various cereal and grain products. Research findings indicate that reproductive disorders may be caused by exposure to Fusarium mycotoxins, but little work has evaluated ENNs on reproductive function. Therefore, to determine the effects of ENNA on the proliferation and steroidogenesis of granulosa cells (GC), experiments were conducted using bovine GC cultures. In vitro, ENNA (1–5 μM) inhibited (p < 0.05) hormone-induced GC progesterone and estradiol production. The inhibitory effect of ENNA on estradiol production was more pronounced in small- than large-follicle GC. In large-follicle GC, 0.3 μM ENNA had no effect (p > 0.10) whereas 1 and 3 μM ENNA inhibited GC proliferation. In small-follicle GC, ENNA (1–5 μM) dramatically decreased (p < 0.05) GC proliferation. Using cell number data, the IC50 of ENNA was estimated at 2 μM for both follicle sizes. We conclude that ENNA can directly inhibit ovarian function in cattle, decreasing the proliferation and steroid production of GC.

The E2F family of transcription factors plays an important role in the control of the cell cycle, cell proliferation, and differentiation, and their role in ovarian function is just emerging. Although some evidence suggests a possible role of E2F1 in ovarian follicular development, what regulates its production in ovarian cells is unknown. Objectives of this study were to determine whether: (i) E2F1 gene expression in granulosa cells (GCs) and theca cells (TCs) change with follicular development and (ii) E2F1 mRNA abundance in TC and GC is hormonally regulated. Using real-time PCR, E2F1 mRNA abundance in GC was 5.5-fold greater (P &lt; 0.05) in small (SM; 1 to 5 mm) than large (LG; &gt;8 mm) follicles, but in TC, E2F1 expression did not differ among follicle sizes. SM-follicle GC had 2.1-fold greater (P &lt; 0.05) E2F1 mRNA than TC. In SM-follicle GC, FGF9 induced a 7.6-fold increase in E2F1 mRNA abundance; however, FGF9 did not affect (P &gt; 0.10) abundance of E2F1 mRNA in LG-follicle TC or GC. Follicle-stimulating hormone (FSH) had no effect (P &gt; 0.10) on E2F1 gene expression in SM- or LG-follicle GC. SM-follicle GC were concomitantly treated with insulin-like growth factor 1 (30 ng/mL), FSH (30 ng/mL), and either 0 or 30 ng/mL of FGF9 with or without 50 µM of an E2F inhibitor (E2Fi; HLM0064741); FGF9 alone increased (P &lt; 0.05) GC numbers, whereas E2Fi alone decreased (P &lt; 0.05) GC numbers, and concomitant treatment of E2Fi with FGF9 blocked (P &lt; 0.05) this stimulatory effect of FGF9. Estradiol production was inhibited (P &lt; 0.05) by FGF9 alone and concomitant treatment of E2Fi with FGF9 attenuated (P &lt; 0.05) this inhibitory effect of FGF9. SM-follicle GC treated with E2Fi decreased (P &lt; 0.05) E2F1 mRNA abundance by 70%. Collectively, our studies show that GC E2F1 mRNA is developmentally and hormonally regulated in cattle. Inhibition of E2F1 reduced FGF9-induced GC proliferation and attenuated FGF9-inhibited estradiol production, indicating that E2F1 may be involved in follicular development in cattle.