Nutritional influences on folliculogenesis

Early milk-feeding regimes in calves exert long-term effects on the development of ovarian granulosa cells

BACKGROUND

Nutrition has not only an impact on the general wellbeing of an animal but can also affect reproductive processes. In cattle, feeding regimes can influence the age of puberty onset and alter gonadal development. We analyzed effects of different milk replacer (MR) feeding regimes during rearing on ovarian physiology with specific emphasis on the numbers as well as gene expression characteristics of granulosa cells (GCs) at the age of puberty onset. Two groups of calves received either 10% or 20% of bodyweight MR per day during their first 8 weeks. After weaning, both groups were fed the same mixed ration ad libitum until slaughter at 8 months.

RESULTS

Animals of the 20% feeding group had a significantly higher body weight, but the proportion of animals having a corpus luteum at the time of slaughter was not different between groups, suggesting a similar onset of puberty. Calves of the 10% group showed a constant GC count regardless of the number of follicles (r = 0.23) whereas in the 20% group increasing numbers of GCs were detected with a higher follicle count (r = 0.71). As a first effort to find a possible molecular explanation for this unexpected limitation of GC numbers in the 10% group, we comparatively analyzed GC transcriptomes in both diet groups. The mRNA microarray analysis revealed a total of 557 differentially expressed genes comparing both groups (fold change > |1.5| and p < 0.05). OAS1X, MX2 and OAS1Z were among the top downregulated genes in the 20% vs. the 10% group, whereas top upregulated genes comprised BOLA and XCL1. All of these genes are known to be regulated by interferon. Subsequent signaling pathway analysis revealed the involvement of several immune response mechanisms in accordance with a number of interferons as upstream regulators.

CONCLUSIONS

The results indicate that the plane of MR feeding in early life has an impact on the number and physiology of GCs later in life. This might influence the overall reproductive life initiated by the onset of puberty in cattle. In addition, the observed alterations in GCs of calves fed less MR might be a consequence of interferon regulated immunological pathways.

The effects of low-level laser therapy on polycystic ovarian syndrome in rats: three different dosages

The main objective of this in vivo study was to investigate the effect of different low-level laser therapy (LLLT) doses on polycystic ovary syndrome (PCOS). In the present experimental study, a single dosage of estradiol valerate (EV) was administered to induce PCOS in female rats. After administration of the EV for induction of PCOS, rats were divided into 5 groups (n = 8/group): C group (animals that were not exposed to any form of procedure), PC group (no treatment following EV induction), L1 group (1 J/cm2 LLLT treatment following EV induction), L2 group (2 J/cm2 LLLT treatment following EV induction), L3 group (6 J/cm2 LLLT treatment following EV induction). The results indicated that no significant difference was found in the serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and progesterone (P4) between the C and L2 groups (p < 0.05). Although the serum levels of testosterone (T) were significantly higher in the C group compared with other groups (p < 0.05), the L2 group was determined to be the closest to the C group. Additionally, the LH, FSH, and T receptor level of the L2 group was closest to the C group. In conclusion, a 2 J/cm2 dosage of LLLT (L2 group) can be considered the most potentially effective treatment of PCOS in the rat. However, more studies are needed to determine the optimal dose of LLLT for the treatment of PCOS.

High body energy reserve influences extracellular vesicles miRNA contents within the ovarian follicle

Aiming to evaluate the effects of increased body energy reserve (BER) in Nellore cows' reproductive efficiency, cows were fed with different nutritional plans to obtain animals with high BER (HBER; Ad libitum diet) and moderate BER (MBER: cows fed 70% of HBER group ingestion). To evaluate the BER, cows were weekly weighted and evaluated for subcutaneous fat thickness and insulin serum concentration along the experimental period. At the end of the experimental period, animals were submitted to estrous synchronization and artificial insemination. Animals were slaughtered approximately 120 h after ovulation induction and the reproductive tracts were collected for embryo recovery and samples collection. Cumulus-oocyte-complexes (COC) and follicular fluid were collected from 3-6 mm in diameter ovarian follicles to perform miRNA analysis of cumulus cells (CC) and extracellular vesicles from follicular fluid (EV FF). As expected, differences were observed among MBER and HBER groups for body weight, fat thickness, and insulin serum concentration. HBER animals showed lower ovulation and embryo recovery rates compared to MBER animals. Different miRNAs were found among CC and EV FF within groups, suggesting that the BER may influence follicular communication. This suggests that small follicles (3-6 mm diameter) are already under BER effects, which may be greater on later stages of follicular development.

Dynamics of the Reproductive Changes and Acquisition of Oocyte Competence in Nelore (Bos taurus indicus) Calves during the Early and Intermediate Prepubertal Periods

The purpose of this study was to characterize the reproductive physiology, oocyte competence, and chromatin compaction in Nelore calves in the early-prepubertal period (EPP) and the intermediate-prepubertal period (IPP). Calves aged 2-5 (EPP) and 8-11 months old (IPP) were assigned to Trial 1 (morpho-physiological-endocrine evaluations, n = 8) or Trial 2 (oocyte donors, n = 8) vs. the respective control groups of cows (n = 8, each). All morphological endpoints, except the antral follicle count, increased from the EPP to the IPP. The EPP LH-FSH plasma concentrations were similar to cows, whereas LH was lower and FSH was higher in the IPP than in cows. . Cows produced more Grade I (12.9% vs. 4.1% and 1.7%) and fewer Grade III COC (30.1% vs. 44.5% and 49.0%) than the EPP and IPP calves, respectively. The IPP calves' oocyte diameter was similar to those from cows but greater than those from EPP females (124.8 ± 8.5 and 126.0 ± 7.5 μm vs. 121.3 ± 7.5 μm, respectively). The expression of the chromatin compaction-related gene HDAC3 was downregulated in calves. The proportion of the blastocyst rate to the controls was lower in EPP than in IPP calves (43.7% vs. 78.7%, respectively). Progressive oocyte competence was found during the prepubertal period, which can help to decide whether to recover oocytes from calves.

Anti-Müllerian hormone stimulates expression of the collagen-specific chaperone 47-kDa heat shock protein in bovine uterine epithelial cells

Uterine collagen is the most abundant component of the uterine extracellular matrix and plays a critical role in pregnancy. The 47-kDa heat shock protein (HSP47) is the sole collagen-specific molecular chaperone. We investigated the mechanisms regulating the expression of HSP47 in the uterus by assessing the effect of anti-Müllerian hormone (AMH) stimulation on HSP47 expression in cultured bovine uterine epithelial cells. AMH receptor type 2 (AMHR2), AMH, and HSP47 expression was assessed by fluorescence immunocytochemistry in uterine epithelial layers of the uteri of Japanese Black cows. The effect of AMH on HSP47 expression was assessed in cultured epithelial cells. The effect of MEK/ERK inhibitor on AMH-induced HSP47 expression was also assessed. We confirmed the expression of AMHR2, AMH, and HSP47 in the uterine epithelial layers. We confirmed the expression of AMHR2, AMH, HSP47, and type IV collagen in cultured uterine epithelial cells. AMH treatment at 10 or 100 ng/ml promoted significant HSP47 expression (p < 0.05). MEK/ERK inhibitor U0126 pretreatment suppressed such AMH stimulation on HSP47. These findings indicate that AMH induced HSP47 protein expression through the ERK pathway in bovine uterine epithelial cells.

The ovarian follicle of ruminants: the path from conceptus to adult

This review resulted from an international workshop and presents a consensus view of critical advances over the past decade in our understanding of follicle function in ruminants. The major concepts covered include: (1) the value of major genes; (2) the dynamics of fetal ovarian development and its sensitivity to nutritional and environmental influences; (3) the concept of an ovarian follicle reserve, aligned with the rise of anti-Müllerian hormone as a controller of ovarian processes; (4) renewed recognition of the diverse and important roles of theca cells; (5) the importance of follicular fluid as a microenvironment that determines oocyte quality; (6) the 'adipokinome' as a key concept linking metabolic inputs with follicle development; and (7) the contribution of follicle development to the success of conception. These concepts are important because, in sheep and cattle, ovulation rate is tightly regulated and, as the primary determinant of litter size, it is a major component of reproductive efficiency and therefore productivity. Nowadays, reproductive efficiency is also a target for improving the 'methane efficiency' of livestock enterprises, increasing the need to understand the processes of ovarian development and folliculogenesis, while avoiding detrimental trade-offs as greater performance is sought.

Anti-Müllerian hormone receptor type 2 (AMHR2) expression in bovine oviducts and endometria: comparison of AMHR2 mRNA and protein abundance between old Holstein and young and old Wagyu females

Anti-Müllerian hormone (AMH) is a glycoprotein produced by granulosa cells of preantral and small antral follicles that has multiple important roles in the ovaries. Recent studies have revealed extragonadal AMH regulation of gonadotrophin secretion from bovine gonadotrophs. In this study we investigated whether the primary receptor for AMH, AMH receptor type 2 (AMHR2), is expressed in bovine oviducts and endometria. Reverse transcription-polymerase chain reaction detected expression of AMHR2 mRNA in oviductal and endometrial specimens. Western blotting and immunohistochemistry were performed to analyse AMHR2 protein expression using anti-bovine AMHR2 antibody. Immunohistochemistry revealed robust AMHR2 expression in the tunica mucosa of the ampulla and isthmus, as well as in the glandular and luminal epithelium of the endometrium. AMHR2 mRNA (measured by real-time polymerase chain reaction) and AMHR2 protein expression in these layers did not significantly differ among oestrous phases in adult Wagyu cows (P>0.1). In addition, AMHR2 mRNA and protein expression in these layers did not differ among old Holsteins (mean (±s.e.m.) age 91.9±6.4 months) and young (26.6±0.8 months) and old (98.8±10.2 months) Wagyu cows. Therefore, AMHR2 is expressed in bovine oviducts and endometria.

Anti-Müllerian hormone is expressed and secreted by bovine oviductal and endometrial epithelial cells

In this study, we investigated whether bovine oviducts and endometria produce anti-Müllerian hormone (AMH) (for paracrine and autocrine signaling). Reverse transcription-polymerase chain reaction and western blotting detected AMH expression in oviductal and endometrial specimens. Immunohistochemistry revealed robust AMH expression in the ampulla and isthmus epithelia, and the glandular and luminal endometrial epithelia (caruncular endometria). AMH mRNA (measured by real-time PCR) and protein expression in these layers did not significantly differ among estrous phases in adult Japanese Black (JB) heifers (p > .1). Furthermore, the expression in these layers also did not differ among Holstein cows (93.8 ± 5.8 months old), JB heifers (25.5 ± 0.4 months old), and JB cows (97.9 ± 7.9 months old). We also compared AMH concentrations in the oviduct and uterine horn fluids among the three groups (measured by immunoassays). Interestingly, the AMH concentration in the oviduct fluid, but not in the uterine horn fluid, of Holstein cows was lower than those in JB heifers and cows (p < .05). Therefore, bovine oviducts and endometria express AMH and likely secrete it into the oviduct and uterine fluids.

Anti-Müllerian hormone and its receptor are detected in most gonadotropin-releasing-hormone cell bodies and fibers in heifer brains

Circulating concentrations of Anti-Müllerian hormone (AMH) can indicate fertility in various animals, but the physiological mechanisms underlying the effect of AMH on fertility remain unknown. We recently discovered that AMH has extragonadal functions via its main receptor, AMH receptor type 2 (AMHR2). Specifically, AMH stimulates the secretion of luteinizing hormone and follicle-stimulating hormone from bovine gonadotrophs. Moreover, gonadotrophs themselves express AMH to exert paracrine/autocrine functions, and AMH can activate gonadotropin-releasing-hormone (GnRH) neurons in mice. This study aimed to evaluate whether AMH and AMHR2 are detected in areas of the brain relevant to neuroendocrine control of reproduction: the preoptic area (POA), arcuate nucleus (ARC), and median eminence (ME), and in particular within GnRH neurons. Reverse transcription-polymerase chain reaction detected both AMH and AMHR2 mRNA in tissues containing POA, as well as in those containing both ARC and ME, collected from postpubertal heifers. Western blotting detected AMH and AMHR2 protein in the collected tissues. Triple fluorescence immunohistochemistry revealed that most cell bodies or fibers of GnRH neurons were AMHR2-positive and AMH-positive, although some were negative. Immunohistochemistry revealed that 75% to 85% of cell bodies and fibers of GnRH neurons were positive for both AMH and AMHR2 in the POA, ARC, and both the internal and external zones of the ME. The cell bodies of GnRH neurons were situated around other AMH-positive cell bodies or fibers of GnRH and non-GNRH neurons. Our findings thus indicate that AMH and AMHR2 are detected in most cell bodies or fibers of GnRH neurons in the POA, ARC, and ME of heifer brains. These data support the need for further study as to how AMH and AMHR2 act within the hypothalamus to influence GnRH and gonadotropin secretion.

Relationship between body conditions and environmental contaminants in bovine ovarian cells

The effect of body condition and environmental contaminants on reproductive processes is known; however, it is not known whether basic ovarian cell functions and their response to these contaminants depend on body condition. This study aimed to understand the interrelationships between body conditions and environmental contaminants on ovarian cells. For this purpose, we compared ovarian granulosa cells isolated from cows with an emaciation tendency (body condition score, BCS2 on a scale from 1 to 5) and cows with average body condition (BCS3); proliferation, apoptosis, secretory activity and the response to environmental contaminants were all assessed in the cells. In the 1st series of experiments, ovarian granulosa cells isolated from BCS2 and BCS3 cows were cultured with and without benzene, xylene, and toluene (0.1%). The accumulation of nuclear and cytoplasmic markers of apoptosis (p53 and bax, respectively), a proliferation marker (PCNA), progesterone (P4), and insulin-like growth factor I (IGF-I) was evaluated by Western blot and radioimmunoassay (RIA) experiments. In the 2nd series of experiments, the groups of granulosa cells were cultured with and without mycotoxine deoxynivalenol (DON, 0, 10, 100, or 1000 ng/ml). The secretion of P4 and testosterone (T) was measured by RIA. In comparison to cells from BCS2 animals, ovarian cells isolated from BCS3 cows accumulated higher levels of bax and PCNA but not p53, and they secreted higher amounts of IGF-I but not P4 or T. In cells from BCS2 animals, benzene and xylene promoted p53 accumulation, and toluene reduced the accumulation. In the BCS2 group, all treatments promoted bax and PCNA expression. However, in cells from BCS3 animals, all environmental pollutants inhibited p53, toluene inhibited PCNA but not bax, and xylene did not affect the expression of proliferation or apoptosis markers. In the BCS2 group, P4 was inhibited by xylene, and IGF-I was stimulated by xylene but not by benzene or toluene. Low-dose exposure to DON (10 ng/ml) promoted P4 release from cells from both BCS2 and BCS3 animals, but high-dose exposure to DON (1000 ng/ml) reduced P4 secretion from the cells from BCS2 animals but not from the cells from BCS3 animals. The release of T was inhibited by high-dose exposure to DON (1000 ng/ml), irrespective of the BCS. An emaciation tendency reduces proliferation, apoptosis, and IGF-I release, and it induces or reverses the action of environmental contaminants on ovarian functions. Taken together, these observations demonstrate the effect of body condition and the direct influence of environmental contaminants on basic bovine ovarian functions. Furthermore, they demonstrate for the first time that the response of ovarian cells to environmental contaminants can be regulated by cow body condition.

Discovery of new receptors regulating luteinizing hormone and follicle-stimulating hormone secretion by bovine gonadotrophs to explore a new paradigm for mechanisms regulating reproduction

Previous studies in the 1960s and 1970s have reported that both gonadotropin-releasing hormone (GnRH) and estradiol-activated nuclear estrogen receptors regulate gonadotropin secretion in women. However, I had previously reported that gonadotroph function is regulated by complex crosstalk between several membrane receptors. RNA-seq had previously revealed 259 different receptor genes expressed in the anterior pituitary of heifers. However, the biological roles of most of these receptors remain unknown. I identified four new receptors of interest: G protein-coupled receptor 30 (GPR30), anti-Mullerian hormone (AMH) receptor type 2 (AMHR2), and G protein-coupled receptors 61 and 153 (GPR61 and GPR153). GPR30 rapidly (within a few minutes) mediates picomolar, but not nanomolar, levels of estradiol to suppress GnRH-induced luteinizing hormone (LH) secretion from bovine gonadotrophs, without decreasing mRNA expressions of the LHα, LHβ, or follicle-stimulating hormone (FSH) β subunits. GPR30 is activated by other endogenous estrogens, estrone and estriol. Moreover, GPR30 activation by zearalenone, a nonsteroidal mycoestrogen, suppresses LH secretion. AMHR2, activated by AMH, stimulates LH and FSH secretion, thus regulating gonadotrophs, where other TGF-β family members, including inhibin and activin, potentially affect FSH secretion. I also show that GPR61, activated by its ligand (recently discovered) significantly alters LH and FSH secretion. GPR61, GPR153, and AMHR2 co-localize with the GnRH receptor in unevenly dispersed areas of the bovine gonadotroph cell surface, probably lipid rafts. The findings summarized in this review reveal a new paradigm regarding the mechanisms regulating reproduction via novel receptors expressed on bovine gonadotrophs.

Expression profiling of primary cultured buffalo granulosa cells from different follicular size in comparison with their in vivo counterpart

This study aimed to: (i) characterize cultured granulosa cells (GCs) from different follicle sizes morphologically and molecularly; and (ii) select a suitable model according to follicular size that maintained GC function during culture. Buffalo ovaries were collected from a slaughterhouse and follicles were classified morphologically into: first group ≤ 4 mm, second group 5-8 mm, third group 9-15 mm and fourth group 16-20 mm diameter. GC pellets were divided into two portions. The first portion served as the control fresh pellet, and the secondwas used for 1 week for GC culture. Total RNA was isolated, and qRT-PCR was performed to test for follicle-stimulating hormone receptor (FSHR), cytochrome P450 19 (CYP19), luteinizing hormone/choriogonadotropin receptor (LHCGR), proliferating cell nuclear antigen (PCNA), apoptosis-related cysteine peptidase (CASP3), anti-Müllerian hormone (AMH), and phospholipase A2 group III (PLA2G3) mRNAs. Estradiol (E2) and progesterone (P4) levels in the culture supernatant and in follicular fluids were measured using enzyme-linked immunosorbent assay (ELISA). Basic DMEM-F12 medium maintained the morphological appearance of cultured GCs. The relative abundance of FSHR, CYP19, and LHCGR mRNAs was 0.001 ≤ P ≤ 0.01 and decreased at the end of culture compared with the fresh pellet. There was a fine balance between expression patterns of the proliferation marker gene (PCNA) and the proapoptotic marker gene (CASP3). AMH mRNA was significantly increased (P < 0.001) in cultured GCs from small follicles, while cultured GCs from other three categories (5-8 mm, 9-15 mm and 16-20 mm) showed a clear reduction (P < 0.001). Interestingly, the relative abundance of PLA2G3 mRNA was significantly (P < 0.001) increased in all cultured GCs. E2 and P4 concentrations were significantly (P < 0.001) decreased in all cultured groups. Primary cultured GCs from small follicles could be a good model for better understanding follicular development in Egyptian buffaloes.

The Effects of Cholesterol Metabolism on Follicular Development and Ovarian Function

Cholesterol is an important substrate for the synthesis of ovarian sex hormones and has an important influence on follicular development. The cholesterol in follicular fluid is mainly derived from plasma. High-density lipoprotein (HDL) and lowdensity lipoprotein (LDL) play important roles in ovarian cholesterol transport. The knockout of related receptors in the mammalian HDL and LDL pathways results in the reduction or absence of fertility, leading us to support the importance of cholesterol homeostasis in the ovary. However, little is known about ovarian cholesterol metabolism and the complex regulation of its homeostasis. Here, we reviewed the cholesterol metabolism in the ovary and speculated that regardless of the functioning of cholesterol metabolism in the system or the ovarian microenvironment, an imbalance in cholesterol homeostasis is likely to have an adverse effect on ovarian structure and function.

Anti-Müllerian hormone receptor type 2 is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion

Preantral and small antral follicles may secret anti-Müllerian hormone (AMH) to control gonadotrophin secretion from ruminant gonadotrophs. The present study investigated whether the main receptor for AMH, AMH receptor type 2 (AMHR2), is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion. Expression of AMHR2 mRNA was detected in anterior pituitaries (APs) of postpubertal heifers using reverse transcription-polymerase chain reaction. An anti-AMHR2 chicken antibody was developed against the extracellular region near the N-terminus of bovine AMHR2. Western blotting using this antibody detected the expression of AMHR2 protein in APs. Immunofluorescence microscopy using the same antibody visualised colocalisation of AMHR2 with gonadotrophin-releasing hormone (GnRH) receptor on the plasma membrane of gonadotrophs. AP cells were cultured for 3.5 days and then treated with increasing concentrations (0, 1, 10, 100, or 1000pgmL-1) of AMH. AMH (10-1000pgmL-1) stimulated (P<0.05) basal FSH secretion. In addition, AMH (100-1000pgmL-1) weakly stimulated (P<0.05) basal LH secretion. AMH (100-1000pgmL-1) inhibited GnRH-induced FSH secretion, but not GnRH-induced LH secretion, in AP cells. In conclusion, AMHR2 is expressed in gonadotrophs of postpubertal heifers to control gonadotrophin secretion.

Photobiomodulation can improve ovarian activity in polycystic ovary syndrome-induced rats

Follicular cystic ovary disease is a common reproductive disorder in women and females of domestic animals, characterized by anovulation and the persistence of follicle is a common cause of reproductive failure in mammalian. Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism (HA), chronic anovulation and polycystic ovaries, and it is a common reproductive endocrine disease with clinical manifestations including hirsutism, acne, infertility and obesity that can affect 5-20% of women in their reproductive age. Photobiomodulation (PBM) has been investigated and used in clinical practice, related to biomodulatory influences on cellular functions in animals and humans, both in vivo and in vitro. In this study, we include endocrine and reproductive features in a rat model for PCOS and the effects of PBM on ovarian activities. Forty-five adult female Wistar rats PCOS-induced by a single dose of the estradiol valerate (EV) were used in the study. After the EV injection for PCO induction, rats were divided into 9 groups (n = 5/group) named C30, C45 and C60 (Control group), S30, S45 and S60 (PCO group) and L30, L45 and L60 (PCO/Laser group). The rats were irradiated with laser 3 times/week. The results shown that EV PCO-induced rats had increased body mass, reduced ovary mass, and reduced GSI. The plasma levels of P4 and T were increased, and the LH plasma level was decreased by PBM stimulation. The number of ovarian follicles and corpus luteum were increased, and the number of ovarian cysts was decreased by PBM stimulation. Thus, reproductive and endocrine characteristics were modulated by PBM.

Bovine gonadotrophs express anti-Müllerian hormone (AMH): comparison of AMH mRNA and protein expression levels between old Holsteins and young and old Japanese Black females

Anti-Müllerian hormone (AMH) is secreted from ovaries and stimulates gonadotrophin secretion from bovine gonadotroph cells. Other important hormones for endocrinological gonadotroph regulation (e.g. gonadotrophin-releasing hormone, inhibin and activin) have paracrine and autocrine roles. Therefore, in this study, AMH expression in bovine gonadotroph cells and the relationships between AMH expression in the bovine anterior pituitary (AP) and oestrous stage, age and breed were evaluated. AMH mRNA expression was detected in APs of postpubertal heifers (26 months old) by reverse transcription-polymerase chain reaction. Based on western blotting using an antibody to mature C-terminal AMH, AMH protein expression was detected in APs. Immunofluorescence microscopy utilising the same antibody indicated that AMH is expressed in gonadotrophs. The expression of AMH mRNA and protein in APs did not differ between oestrous phases (P&gt;0.1). We compared expression levels between old Holsteins (79.2±10.3 months old) and young (25.9±0.6 months old) and old Japanese Black females (89.7±20.3 months old). The APs of old Holsteins exhibited lower AMH mRNA levels (P&lt;0.05) but higher AMH protein levels than those of young Japanese Black females (P&lt;0.05). In conclusion, bovine gonadotrophs express AMH and this AMH expression may be breed-dependent.

Mojave Yucca (Yucca Schidigera Roezl) Effects on Female Reproduction a Review

Yucca is an important source of biologically active substances such as steroidal saponins and stilbenes providing many beneficial effects when administered to humans and other animals. These substances offer a great potential in the prevention and treatment of current civilized diseases as well as to their: antioxidant, hypocholesterolaemic, anti-inflammatory, phytoestrogenic, pro-apoptotic, anti-proliferative, and anti-carcinogenic properties. This review focuses on the roles of two main yucca constituent groups and their ability to modulate ovarian functions and female reproductive performance. Both the biological activity of yucca substances and the mechanisms of their actions on ovaries are still incompletely understood. Thus, the direct effects of yucca extract on ovarian cells in animal models under in vitro conditions, as well as actions after yucca consumption will be discussed.

Cow body condition affects the hormonal release of ovarian cells and their responses to gonadotropic and metabolic hormones

The body condition score (BCS) of cows affects their reproductive efficiency, but the underlying mechanism is unclear. We examined the effect of BCS on the basic ovarian cell functions and their responses to gonadotropic and metabolic hormones. We isolated ovarian cells from cows with a tendency toward emaciation (BCS2) and those with an average body condition (BCS3), and we compared their hormonal release and responses to FSH, leptin, ghrelin, and neuropeptide Y (NPY) added at doses of 0, 1, 10, or 100 ng/mL. Progesterone, testosterone, estradiol, and insulin-like growth factor I (IGF-I) release were evaluated by RIA. No differences were found in progesterone or testosterone release between BCS2 and BCS3 cells; however, ovarian cells from BCS2 cows released more estradiol and IGF-I than cells from BCS3 cows. FSH, ghrelin, and NPY promoted progesterone release in BCS2 cells but had no stimulatory or inhibitory effect on BCS3 cells. In contrast, leptin promoted progesterone release in BCS3 cells and inhibited progesterone release in BCS2 cells. FSH also promoted testosterone release in both BCS2 and BCS3 cells but inhibited progesterone at a low dose in BCS3 cells. Leptin inhibited testosterone release in BCS3 cells but not in BCS2 cells. Estradiol release was promoted by leptin and ghrelin in BCS3 cells; however, it was unaffected by leptin and inhibited by ghrelin in BCS2 cells. IGF-I production was promoted by FSH and inhibited by leptin in both groups. Ghrelin suppressed IGF-I release in BCS2 cells and increased IGF-I release in BCS3 cells. NPY promoted IGF-I release in BCS2 cells but not in BCS3 cells. Our results demonstrate the effects of BCS on ovarian cell estradiol and IGF-I (but not progesterone or testosterone) release, as well as on the responses of ovarian cells to FSH, leptin, ghrelin, and NPY.

Metabolic state can define the ovarian response to environmental contaminants and medicinal plants

Environmental contaminants and medicinal plants can affect reproductive processes. The aim of this study was to investigate the effect of maternal metabolic status on the response of mouse ovaries to the environmental contaminants benzene and xylene, as well as to extracts of the medicinal plant yucca. Ovaries isolated from normal-lean and slightly obese mice were cultured with or without 0.1% benzene or xylene for 24 h. Similarly, ovaries isolated from normal-lean, slightly obese, and significantly obese mice were cultured for 24 h with or without an extract of Yucca shidigera (YS, 10 μ g/mL). We found that the metabolic status did not influence the release of basal progesterone (P4), testosterone (T), or insulin-like growth factor I (IGF-I), but obesity influenced the effects of the environmental contaminants and YS. Benzene reduced P4 output in ovaries from obese but not normal-lean mice; it also reduced IGF-I (but not T) release from ovaries irrespective of the metabolic status. Xylene dramatically increased P4 and T (but not IGF-I) release by ovaries from normal-lean mice, but there were no changes in P4 and only small increases in T output in obese mice. YS increased P4 (but not T or IGF-I) release in normal-lean and slightly obese animal ovaries, whilst significant obesity was associated with a lack of P4 response to YS. Obesity might affect the basal ovarian release of T or IGF-I and increases the sensitivity of ovaries to the action of benzene but decreases their responsiveness to xylene and YS.

Positive correlations of age and parity with plasma anti-Müllerian hormone concentrations in Japanese Black cows

Anti-Müllerian hormone (AMH) is secreted from the preantral and small antral follicles. It regulates follicle development and inhibits follicular atresia. This study examined how age, parity, and time after parturition affect plasma AMH concentrations in Japanese Black cows. We measured plasma AMH concentrations in primiparous, secundiparous, and multiparous (third parity or higher) cows at four time points: day 2 (day 0 = parturition), day 8, 2 days before first postpartum ovulation (pre-1stOv), and 12 days after first ovulation (post-1stOV). We observed a positive correlation between plasma AMH concentration and age (in months) and parity on day 2, day 8, and post-1stOV, but not on pre-1stOv. The multiparous cows had higher AMH concentrations than primiparous cows throughout the postpartum period (P < 0.05). Our results indicate that age and parity significantly influence plasma AMH concentrations in Japanese Black cows during the voluntary waiting period.

Postnatal pituitary and follicular activation: a revisited hypothesis in a sheep model

The importance of postnatal pituitary activation as regards female reproductive development is not yet understood. By taking advantage of the experimental model developed in a previous study, i.e. ewe lambs expressing markedly different ovarian phenotypes at 50 days of age, we designed this study to determine whether differences found in ovarian status during the early prepubertal period are due to different patterns of postnatal pituitary activation, and to assess whether these differences have long lasting effects on subsequent reproductive performance. Results showed that ewe lambs with high antral follicle count (AFC) at 50 days of age had significantly lower plasma FSH concentrations and higher anti-Mullerian hormone (AMH) concentrations during the first 9 weeks of age compared with low AFC ewe lambs (P<0.0001). With a longitudinal experiment we showed that a high AFC in the early prepubertal period is associated with consistently higher AMH concentrations and numbers of antral follicles up to the postpubertal period, and with higher pregnancy rates in the first breeding season. In addition, the effect of age in decreasing AMH concentrations was more marked in the low AFC group. Results of the present study demonstrate that ewe lambs undergo different patterns of postnatal pituitary activation. A high AFC at 50 days of age indicates an advanced phase of ovarian maturation, which was accompanied by constantly higher AMH concentrations up to the postpubertal period, a greater ovarian response to FSH stimulation and by higher pregnancy rates at first mating, as compared with the low AFC group.

Identificação imuno-histoquímica de VEGF e IGF-1 em ovários de cadelas no anestro e estro

Com o objetivo de verificar a presença de VEGF e IGF-1 nos ovários de cadelas, foram realizadas análises imuno-histoquímicas do estroma cortical; teca e granulosa de folículos secundários, terciários e terciários pré-ovulatórios luteinizados; e ovócitos de folículos primários, secundários e terciários de ovários de cinco cadelas em anestro (Anest) e cinco em estro (Est). A identificação das fases do ciclo estral foi realizada por citologia vaginal associada a dosagem plasmática de progesterona. Os ovários foram submetidos a tratamento imuno-histoquímico para identificação de VEGF (anticorpo primário PU 360-UP, Biogenex, USA; diluição 1:30) e IGF-1 (anticorpo primário PabCa, Gro-Pep, Austrália; diluição 1:100). Determinou-se um índice de imunomarcação (IM), para cada tecido avaliado, pela razão entre a área positivamente marcada dividida pela área total analisada. Para os ovócitos, verificou-se imunomarcação positiva ou negativa. As comparações de IM entre tecidos foram realizadas pelo teste de Wilcoxon (diferentes tecidos em mesmo grupo) ou Mann-Whitney (mesmo tecido entre diferentes grupos), todas no nível de 5% de significância. VEGF e IGF-1 foram identificados, de forma semelhante (P>0,05), em todas as estruturas avaliadas em ambos os grupos experimentais. Conclui-se que esses fatores de crescimento estão presentes em cadelas no anestro e estro, no estroma cortical ovariano, folículos em diferentes estádios de desenvolvimento e ovócitos.

Transgenerational effects of binge drinking in a primate model: implications for human health

OBJECTIVE

To determine if binge ethanol consumption before ovulation affects oocyte quality, gene expression, and subsequent embryo development.

DESIGN

Binge levels of ethanol were given twice weekly for 6 months, followed by a standard in vitro fertilization cycle and subsequent natural mating.

SETTING

National primate research center.

ANIMAL(S)

Adult female rhesus monkeys.

INTERVENTION(S)

Binge levels of ethanol, given twice weekly for 6 months before a standard in vitro fertilization cycle with or without embryo culture. With in vivo development, ethanol treatment continued until pregnancy was identified.

MAIN OUTCOME MEASURE(S)

Oocyte and cumulus/granulosa cell gene expression, embryo development to blastocyst, and pregnancy rate.

RESULT(S)

Embryo development in vitro was reduced; changes were found in oocyte and cumulus cell gene expression; and spontaneous abortion during very early gestation increased.

CONCLUSION(S)

This study provides evidence that binge drinking can affect the developmental potential of oocytes even after alcohol consumption has ceased.

Metabolic control of oocyte development: linking maternal nutrition and reproductive outcomes

Obesity, diabetes, and related metabolic disorders are major health issues worldwide. As the epidemic of metabolic disorders continues, the associated medical co-morbidities, including the detrimental impact on reproduction, increase as well. Emerging evidence suggests that the effects of maternal nutrition on reproductive outcomes are likely to be mediated, at least in part, by oocyte metabolism. Well-balanced and timed energy metabolism is critical for optimal development of oocytes. To date, much of our understanding of oocyte metabolism comes from the effects of extrinsic nutrients on oocyte maturation. In contrast, intrinsic regulation of oocyte development by metabolic enzymes, intracellular mediators, and transport systems is less characterized. Specifically, decreased acid transport proteins levels, increased glucose/lipid content and elevated reactive oxygen species in oocytes have been implicated in meiotic defects, organelle dysfunction and epigenetic alteration. Therefore, metabolic disturbances in oocytes may contribute to the diminished reproductive potential experienced by women with metabolic disorders. In-depth research is needed to further explore the underlying mechanisms. This review also discusses several approaches for metabolic analysis. Metabolomic profiling of oocytes, the surrounding granulosa cells, and follicular fluid will uncover the metabolic networks regulating oocyte development, potentially leading to the identification of oocyte quality markers and prevention of reproductive disease and poor outcomes in offspring.

Comprehensive analysis of Sichuan white geese (Anser cygnoides) transcriptome

High-throughput RNA sequencing was performed for comprehensively analyzing the transcriptome of geese. A total of 28,803,759 bp of raw sequence data was generated by 454 GS Flx+. After removal of adaptor sequences, 28,730,361 bp remained and 117,279 reads were obtained, with an average length of 244 bases. Simultaneously, complementary DNA samples from two different reproductive stages of goose ovarian, hypothalamus and pituitary tissue were sequenced separately using Illumina MiSeq platform. A total of 12 688 673 148 bp of raw sequence data were generated by Illumina MiSeq. After removal of adaptor sequences, 8 198 126 562 bp remained and 60 382 786 clean reads were obtained, with an average length of 135 bases. Assembly of all the reads from both 454 Flx+ and Illumina platforms formed 56,839 contigs. The sequence size ranges from 38 to 28,206 bp in size, with an average size of 2584 bp and an N50 of 4624. The assembly produced a substantial number of large contigs: 35,545 (62.5%) were longer than 1 kb, of which 8850 (15.6%) were longer than 5 kb. The sequencing depth was 85 X on average. We performed comprehensive function annotations on unigenes including protein sequence similarity, gene ontology (GO) term classification, and Kyoto Encylcopedia of Genes and Genomes (KEGG) pathway enrichment. GO analysis showed that approximately 63% of the contigs had annotation information, among the 35,953 annotated isotigs in Nr database, 24,783 (68.9%) sequences were assigned with one or more GO terms. There were 14,634 (40.7%) isotigs for biological processes, 10,557(29.3%) isotigs for cellular component, 22,607 (62.9%) isotigs for molecular function. The result of KEGG pathway mapping 8926 sequences had the pathway annotation, and took part in 477 pathways. Additionally, 10,685 simple sequence repeat (SSR) markers were identified from the assembled sequences. The most frequent repeat motifs were trinucleotides, which accounted for 53.03% of all SSRs, followed by dinucleotides (39.9%), tetranucleotides (5.08%), pentanucleotides (1.68%) and hexanucleotides (0.32%). Transcriptome sequencing on mixture issue of the geese yielded substantial transcriptional sequences and potentially useful SSR markers which provide an important data source for geese research.