Pre-release dietary supplements of methoprene and raspberry ketone increase field abundance of sterile Queensland fruit flies (Diptera: Tephritidae).

The sterile insect technique (SIT) is a sustainable pest management tool based on the release of millions of sterile insects that suppress reproduction in targeted populations. Success of SIT depends on survival, maturation, dispersal, and mating of released sterile insects. Laboratory and field cage studies have demonstrated that dietary supplements of methoprene and raspberry ketone (RK) promote sexual maturation of adult Queensland fruit fly, Bactrocera tryoni (Froggatt), and may hence shorten the delay between release and maturity in the field. We investigated the effects of methoprene and RK dietary supplements on field abundance of sexually mature sterile Q-flies relative to untreated flies fed only sugar and yeast hydrolysate before release at 2 d of age. Compared with untreated flies, more methoprene- and RK-treated flies were recaptured in cuelure traps to which only sexually mature males are attracted. At distances of 100 and 200 m from the release point, recapture rates were higher for methoprene- and RK-treated flies than for untreated flies, but at 300 m recapture rates were low and were similar for treated and untreated flies. Rainfall, relative humidity, wind speed, and wind direction did not affect recapture rates, but temperature was positively correlated with recapture rates for all treatments. There was a strong correlation between the number of sterile and wild flies caught in traps, indicating co-location in the field. Dietary supplements of methoprene and RK can substantially increase abundance of sexually mature sterile male Q-flies in the field following release as 2-d-old immature adults.

Isoflavones alter male and female fertility in different development windows.

Isoflavones are a group of secondary metabolites found in plants belonging to the class of phytoestrogens. These, because they have a chemical structure similar to the endogenous hormone 17ß-estradiol, act as endocrine disruptors over the different development window periods. This study aimed to evaluate male and female reproductive systems' responses when exposed to isoflavones during the development window. It is characterized as a bibliographic review, built after analyzing clinical and preclinical articles indexed in English, Portuguese, and Spanish published in the last ten years. The isoflavones, aglycone or glucosides, have essential therapeutic properties in the relief of postmenopausal symptoms in women, reduce the proliferation of cancers, in addition to being antioxidants. On the other hand, they can still behave in a similar way to 17ß-estradiol, binding to hormone receptors and acting as endocrine disruptors over the gestational period until pre-puberty, negatively affecting the development of the reproductive system. The effects on reproduction are not dose-response but are influenced by the type of isoflavone and period. There are variations in the serum concentration of hormones and action on their negative feedback on the hypothalamic-pituitary-testicular axis in males. Reproductive functions are also affected by spermatogenesis, such as decreased sperm count, lower reproductive performance, reduced litter size, low sperm production, and reduced seminal vesicle size. In females, puberty is reached later, irregular estrous cycle, reduced weight of the ovary, uterus, lower serum levels of estradiol and progesterone, reduced fertility, or interrupted fertility. At the end of the analysis of the selected publications, it can be concluded that despite the beneficial therapeutic effects in the face of pathologies, the unknown consumption of doses and types of isoflavones in food can damage the development and reproduction of individuals. Therefore, further studies must be carried out to elucidate the usual safe doses of the analyzed phytoestrogen. Greater control over insertion in foods targeted at pediatric consumers should be implemented until we have adequate safety.

The reduction in sexual behavior of adult female rats exposed to immune stress in the neonatal period is associated with reduced hypothalamic progesterone receptor expression.

PURPOSE: We examined the mechanism by which neonatal immune stress reduces the sexual behavior of female rats in adulthood. METHODS: Neonatal female rats were randomly divided into 3 groups: control (n = 11), postnatal day 10 lipopolysaccharide (PND10LPS) (n = 23), and PND25LPS (n = 11) groups, which received intraperitoneal injections of LPS (100 µg/kg) or saline on PND10 and 25. Daily inspections of the vaginal opening (VO) were performed from PND27 to PND37. Thereafter, the frequency of estrus was assessed for 15 days. Female rats (at 11-12 weeks of age) were placed in a cage with male rats, and their sexual behavior was monitored for 30 min. The hypothalamic mRNA expression levels of factors related to sexual behavior were examined via real-time PCR. RESULTS: VO occurred later and the frequency of estrus was lower in the PND10LPS group compared to the control group. The number of lordosis behaviors and the total number of mounts performed by male partners were lower in the PND10LPS and PND25LPS groups than in the control group. Acceptability: The lordosis quotient and lordosis rating were lower in the PND10LPS group than in the control group. Proceptive behavior: the number of ear wiggling events was lower in the PND10LPS group than in the other groups, and the number of hops/darts was lower in the PND10LPS group than in the control group. The hypothalamic mRNA expression level of progesterone receptors (PR)A + B was lower in the PND10LPS group than in the control group, and the hypothalamic PRB mRNA expression level was lower in the PND10LPS and PND25LPS groups than in the control group. CONCLUSION: Neonatal immune stress impeded sexual behavior and hypothalamic PR mRNA expression in female rats. Decreased progesterone activity in the hypothalamus might explain the reduction in sexual behavior seen in these rats.

The reduction in sexual behavior induced by neonatal immune stress is not related to androgen levels in male rats.

PURPOSE: It is known that various types of stress in early life increase the incidence of diabetes, myocardial infarctions, and psychiatric disorders in adulthood. We examined the mechanism by which neonatal immune stress reduces sexual behavior in adult male rats. METHODS: Male rats were randomly divided into 3 groups: the control (n = 17), postnatal day 10 lipopolysaccharide (PND10LPS) (n = 31), and PND25LPS (n = 16) groups, which received intraperitoneal injections of LPS (100 µg/kg) or saline (injection volume: ≤0.1 ml/g) on postnatal days 10 and 25. In experiment 1, male rats (age: 11 to 12 weeks) were put together with female rats in a one-to-one setting for mating, and sexual behavior (mounting, intromission, and ejaculation) was monitored for 30 minutes. The serum levels of luteinizing hormone (LH) and testosterone (T) and the hypothalamic mRNA expression levels of factors related to sexual behavior were examined. After experiment 1 finished, the remaining 37 male rats were used for experiment 2: the control group (n = 8), PND10 LPS group (n = 21) and PND25LPS group (n = 8) these rats had been given an i.p. injection of the saline during the expriment1. All of the rats were orchidectomized at 14 weeks of age. After a 3-week recovery period, a silastic tube containing crystalline T was subcutaneously implanted into the back of each rat. The rats' sexual behavior, serum hormone concentrations, and hypothalamic mRNA expression levels were assessed. RESULTS: In experiment 1, preputial separation occurred significantly later in the PND10LPS group than in the control group. The frequency of sexual behavior was significantly lower in the PND10LPS group than in the control group. The serum T concentrations of the PND10LPS and PND25LPS groups were significantly lower than that of the control group, but the serum LH concentrations of the 3 groups did not differ significantly. The hypothalamic mRNA expression levels of progesterone receptor B (PRB) and gonadotropin-releasing hormone (GnRH) were significantly lower in the PND10LPS and PND25LPS groups than in the control group, whereas the hypothalamic PRA + B mRNA expression levels of the 3 groups did not differ significantly. In experiment 2, after T supplementation the frequency of sexual behavior was significantly lower in the PND10LPS and PND25LPS groups than in the control group, although there were no significant differences in the serum T or LH concentrations or the hypothalamic PRB, PRA + B, or GnRH mRNA expression levels of the 3 groups. CONCLUSION: In male rats, immune stress in the early neonatal period delayed sexual maturation, reduced sexual behavior, suppressed the serum T concentration, and downregulated the hypothalamic mRNA expression levels of GnRH and the PR in adulthood. The delayed sexual maturation was presumed to have been caused by the reduction in the serum T concentration. However, the rats that experienced neonatal stress exhibited reduced sexual behavior irrespective of their serum T concentrations.

Impact of zinc on sexual maturation of female sickle cell anemia (SCA) children in Enugu, Southeast Nigeria.

Adolescence is an important developmental period of childhood. Good health and adequate nutrition consisting major food constituents and trace elements like zinc are fundamental for optimal sexual maturation. To determine the relationship between zinc levels and pattern of breast and pubic hair development, as well as menarcheal age of female SCA children aged 6-18 years and their matched controls with hemoglobin genotype AA. Cross sectional, case-control study. Information on biodata, age at menarche, medical and drug history as well as 24-hour dietary recall was documented using interviewer administered questionnaire. Sexual maturation was assessed using Tanner staging and zinc levels determined using Atomic absorption spectrophotometer. Eighty-one subjects were compared with 81 controls. There was significant delay in the mean age of attainment of various Tanner stages of breast and pubic hair in the subjects. Mean age of 14.81 ± 1.07 years at menarche in subjects was significantly higher than 12.62 ± 1.18 years in controls (p = 0.001). Serum zinc of 58.01 ± 10.58 µg/dl in subjects was significantly lower than 68.37 ± 8.67 µg/dl in controls (p = 0.001). Serum zinc levels were found to have a significant positive relationship with stages of sexual maturation and mean age at menarche. Reduced serum zinc in children with SCA was associated with delayed sexual maturation.

Soy protein supplement intake for 12 months has no effect on sexual maturation and may improve nutritional status in pre-pubertal children.

AIM: To evaluate the intake of a soy protein-based supplement (SPS) and its effects on the sexual maturation and nutritional status of prepubertal children who consumed it for a year. METHODS: Healthy children (n = 51) were recruited and randomly assigned to consume the lunch fruit juice with (n = 29) or without (n = 22) addition of 45 g of a commercial soy protein-based supplement (SPS) over 12 months. Nutritional assessment including anthropometry (bodyweight, height, triceps skinfold thickness, mid-upper arm circumference), body mass index (BMI), upper arm muscle area, arm muscle circumference, upper arm area, upper arm fat area data were derived from measures using usual procedures; age and gender-specific percentiles were used as reference. Sexual maturation was measured by Tanner stage. Isoflavones were quantified using liquid chromatography and tandem mass spectrometry. RESULTS: Height, BMI/age, weight/age and height/age were significantly different (P < 0.05) at 12 months between girls in the control and intervention groups. Statistically significant differences between groups by gender (P < 0.05) were found in boys in the control group for the triceps skinfold thickness and fat area. Nutritional status was adequate according to the World Health Organization parameters. On average, 0.130 mg/kg body weight/day of isoflavones were consumed by children, which did not show significant differences in their sexual maturation. CONCLUSION: Consumption of SPS for 12 months did not affect sexual maturation or the onset of puberty in prepubertal boys and girls; however, it may have induced an increase in height, BMI/age, height/age and weight/age of the girls, associated with variations in fat-free mass.

Is the kisspeptin system involved in responses to food restriction in order to preserve reproduction in pubertal male sea bass (Dicentrarchus labrax)?

Previous works on European sea bass have determined that long-term exposure to restrictive feeding diets alters the rhythms of some reproductive/metabolic hormones, delaying maturation and increasing apoptosis during gametogenesis. However, exactly how these diets affect key genes and hormones on the brain-pituitary-gonad (BPG) axis to trigger puberty is still largely unknown. We may hypothesize that all these signals could be integrated, at least in part, by the kisspeptin system. In order to capture a glimpse of these regulatory mechanisms, kiss1 and kiss2 mRNA expression levels and those of their kiss receptors (kiss1r, kiss2r) were analyzed in different areas of the brain and in the pituitary of pubertal male sea bass during gametogenesis. Furthermore, other reproductive hormones and factors as well as the percentage of males showing full spermiation were also analyzed. Treated fish fed maintenance diets provided evidence of overexpression of the kisspeptin system in the main hypophysiotropic regions of the brain throughout the entire sexual cycle. Conversely, Gnrh1 and gonadotropin pituitary content and plasma sexual steroid levels were downregulated, except for Fsh levels, which were shown to increase during spermiation. Treated fish exhibited lower rates of spermiation as compared to control group and a delay in its accomplishment. These results demonstrate how the kisspeptin system and plasma Fsh levels are differentially affected by maintenance diets, causing a retardation, but not a full blockage of the reproductive process in the teleost fish European sea bass. This suggests that a hormonal adaptive strategy may be operating in order to preserve reproductive function in this species.

Effects of exogenous melatonin and photoperiod on sexual maturation in pullets.

Hy-Line Gray commercial pullets were maintained under 8-h photoperiods, 16-h photoperiods and 16-h photoperiods supplemented with a diet containing 20 or 200 mg/kg melatonin (MEL) to investigate the role of MEL in sexual development. A total of 256 Hy-Line Gray commercial pullets were placed, four birds to a cage, in four similar light-proof rooms (8-h photoperiod) at 6 weeks of age. At 70 day, three rooms containing a total of 192 birds were transferred to a 16-h photoperiod, whereas 64 birds were maintained under the 8-h photoperiod. Diets containing MEL at 20 and 200 mg/kg were fed to birds in two of the rooms under 16-h photoperiods. Birds maintained under an 8-h photoperiod matured 11.25 day later than those maintained under a 16-h photoperiod (p < 0.05). The group of birds receiving 20 mg/kg MEL matured 1.19 day later than those maintained under the 16-h photoperiod and 10.06 day earlier than those maintained under the 8-h photoperiod. The group of birds receiving 200 mg/kg MEL matured 3.13 day later than those maintained under a 16-h photoperiod and 8.12 day earlier than those maintained under an 8-h photoperiod. The average body weight of birds maintained under the 8-h photoperiod was greater than that of birds maintained under the 16-h photoperiod (p < 0.05) and was similar between the different MEL groups. The abdominal fat weight was lower in 16L:8D group compared with 8L:16D group (p < 0.05). The concentrations of follicle-stimulating hormone, luteinizing hormone, oestrogen and insulin did not differ significantly among the groups. The melatonin concentration in 200 mg/kg melatonin group was higher than that observed in the other groups; however, this concentration did not differ significantly (p > 0.05). These data suggest that the birds did not perceive the final 8-h photoperiod as being part of the night when they were given the MEL diets; continuously high plasma MEL was not observed in birds that responded as if they were in constant darkness. However, the later maturity of the groups administered MEL diets compared with the groups maintained under a constant 16-h photoperiod clearly indicated that MEL has some influence on the sexual maturity of pullets.

The environmental regulation of maturation in goldfish, Carassius auratus: effects of various LED light spectra.

While there have been a number of studies on the effects of photoperiod and duration of light and dark exposure, much less information is available on the importance of light intensity. This study investigated the effects of exposure of goldfish, Carassius auratus exposed to white fluorescent bulbs, and red (peak at 630nm), and green (530nm) light emitting diodes (LEDs) at approximately 0.9W/m(2) (12-h light:12-h dark) for four months on a number of hormones of the hypothalamus-pituitary-gonad (HPG) axis, in vivo and in vitro. We investigated the effects of native GnRH molecules (gonadotropin-releasing hormones; salmon GnRH, sGnRH; and chicken GnRH-II, cGnRH-II), gonadotropin hormones (GTHα; follicle-stimulating hormone, FSH-ß; luteinizing hormone, LH-ß2), kisspeptin 1 (Kiss1) and G protein-coupled receptor 54 (GPR54) mRNA levels. Furthermore, we measured LH and 17α-hydroxypregnenolone levels in plasma and we performed gonad histological observations. GnRHs, Kiss1, GPR54 and GTH mRNA and plasma LH and 17α-hydroxypregnenolone levels in the in vivo and in vitro groups exposed to green LEDs were significantly higher than the other groups. Histological analysis revealed the presence of oocytes in the yolk stage in fish exposed to green light. These results suggest that green wavelengths regulate the HPG axis and enhance sexual maturation in goldfish.