Effects of Repeated Exposure to Fox Odor on Locomotor Activity Levels and Spatial Movement Patterns in Breeding Male and Female Meadow Voles (Microtus pennsylvanicus)

Following five days of baseline activity recording, voles were exposed to fox odor for 3 min each day for five days. Immediately following each daily exposure, locomotor activity levels and spatial movement patterns were assessed using an automated activity monitoring system (Digiscan system). Males displayed a significant reduction in levels of various measures of locomotor activity following exposure to fox odor on each exposure day relative to baseline levels. Males preferred the corner of the testing box significantly more on the second day of fox odor exposure relative to baseline. Although females showed only a brief reduction in the number of movements made on the first day of odor exposure, this response lasted significantly longer on each of the subsequent odor exposure days. The reliability of the reductions in activity levels displayed across days by breeding male voles supports the hypothesis that this response is adaptive. Furthermore, the results suggest that, although female voles do not generally display this behavioral response, it can be elicited in females when the predation threat is repeated in consistent context.     

Short-Term Effect of a Low-Protein High-Carbohydrate Diet on Mature Female and Male,and Neomale Rainbow Trout

Rainbow trout are considered as a poor user of dietary carbohydrates, displaying persistent postprandial hyperglycaemia when fed a diet containing high amounts of carbohydrates. While this phenotype is well-described in juveniles, less attention was given to broodstock. Our objective was to assess for the first time the short-term consequences of feeding mature female and male, and neomale trout with a low-protein high-carbohydrate diet on glucose and lipid metabolism. Fish were fed for two days with a diet containing either no or 32% of carbohydrates. We analysed plasma metabolites, mRNA levels and enzymatic activities of glycolysis, gluconeogenesis, de novo lipogenesis and β-oxidation in the liver. Results demonstrated that the glucose and lipid metabolism were regulated by the nutritional status in all sexes, irrespective of the carbohydrate intake. These data point out that carbohydrate intake during a short period (5 meals) at 8 °C did not induce specific metabolic changes in broodstock. Finally, we demonstrated, for the first time, sex differences regarding the consequences of two days of feeding on glucose and lipid metabolism.     

Laboratory Evaluation of Odor Preferences of the Brushtail Possum

The Australian brushtail possum (Trichosurus vulpecula) is the major vertebrate pest in New Zealand. Possums cause significant damage to the country's native and exotic forests and, as a vector of bovine tuberculosis, are a serious threat to the country's meat industry. Strong smelling odors are often used as lures during possum control operations in New Zealand, but little is known about the preferences of possums for these odurs. A test was designed to determine the preferences of captive wild possums for a number of odors commonly used as lures. To assess the effectiveness of the method, the possums were tested for their responses to a familiar food odor (apple) versus no odor. The possums spent significantly more time investigating the apple odor and also sniffed it more often than the no-odor control in the 15-min test period. The same procedure, however, showed that five odors commonly used as lures (almond, cloves, cinnamon, peanut, and orange) were no more preferable than water. Our results suggest that these unfamiliar odors are either equally attractive or unattractive to possums and that odors that are more familiar to these animals may be more appropriate as lures.     

Minor and Intermediate Components Enhance Attraction of Female Mediterranean Fruit Flies to Natural Male Odor Pheromone and Its Synthetic Major Components

The attraction of virgin female medflies to either the natural pheromonal odor of calling males or its synthetic major components was enhanced by both intermediate and minor pheromonal components in multiple choice discrimination tests. The modification of the standard Gow rotating-trap-array, cage olfactometer to allow a single source of natural pheromonal odor to be delivered equally and simultaneously to a number of traps greatly increased trapping efficacy (64% capture rate) and ability to resolve odor preference discrimination by female flies. In olfactometer cage bioassays, responding female medflies expressed preferences in attraction to male odor augmented with either synthetic intermediate or minor components over male odor alone. In dual-choice flight-tunnel bioassays, the minor blend enhanced the attractiveness of both the natural male odor and its synthetic major components. Moreover, the minor blend, when presented together with the synthetic major components, comprised an artificial pheromonal lure competitive for the first time with the natural male odor in attraction of virgin female medflies.     

Reproduction and Urine Marking in Laboratory Groups of Female Common Voles Microtus arvalis

In laboratory groups of common voles, Microtus arvalis, consisting of one mother, two of her daughters and one male, mainly the mother reproduced. The three females spent most of the time in close body contact. By using a modified method of coloring the urine of the three females by nonmetabolizable, nontoxic dyes, we found that mothers display a higher urine marking intensity than their daughters, and urine marks from the mother were distributed more frequently than those from the daughters. The results suggest that both pheromonal and behavioral mechanisms are involved in the regulation of reproduction in matriarchal groups of common voles.     

Both Ovarian Fluid and Female Urine Increase Sex Steroid Hormone Levels in Mature Atlantic Salmon (Salmo salar) Male Parr

We compared the ability of urine and ovarian fluid from female Atlantic salmon (Salmo salar) to stimulate increase in plasma concentrations of sex steroid hormones in mature conspecific male parr (priming effect of the stimuli). We also tested the hypothesis that prostaglandin F₂ (PGF₂) may act as a priming pheromone in the tested stimulants. Individual males of salmon parr were exposed to female urine, ovarian fluid, urine–ovarian fluid mix, or PGF₂. Plasma concentrations of the sex steroids of 17,20-dihydroxy-4-pregnen-3-one (17,20-P) were higher in males exposed to urine, ovarian fluids, and PGF₂ compared to control males. PGF₂ and a mixture of urine and ovarian fluid also gave increased concentrations of 11-ketotestosterone (11-KT). Concentrations of PGF₂ were higher in ovarian fluids than in urine. A behavior test with mature male parr in a fluviarium showed neither attraction to nor avoidance of 0.1 nM PGF₂, but plasma levels of 17,20-P were significantly higher in exposed males compared to controls.     

Attractiveness of Opposite-Sex Odor and Responses to It Vary with Age and Sex in Meadow Voles (Microtus pennsylvanicus)

Current models suggest that among short-lived mammals, such as rodents, older adults are less attractive to the opposite sex and spend less time associated with the opposite sex than do younger adults. The objective of this study was to test two hypotheses in three different age groups of meadow voles. The first hypothesis is that 3- to 5 month old voles produce scents that are more attractive to opposite sex conspecifics than those of 7- to 12 month old and 14- to 18 month old voles. The second hypothesis is that 3- to 5 month old voles spend more time than either 7- to 12 month old or 14- to 18 month old voles investigating the scents of an opposite sex conspecific. The first experiment shows that when choosing between two conspecifics, females prefer the odor of the older male within each pair and that males prefer the odor of the 7- to 12 month old females to those of either 3- to 5 month old or 14- to 18 month old females. Thus, the data did not support the first hypothesis. The second experiment shows that the 14- to 18 month old males spent more time investigating female odors than did either the 3- to 5 month old or 7- to 12 month old males and that 7- to 12 month old females spent more time investigating male odors than did the 3- to 5 month old and 12- to 18 month old females. These data did not support the second hypothesis. Overall, older adult male meadow voles are more interested in and attractive to females than are younger adult males. The present data raise questions as to whether current models predict the age-related effects on the behavior of short-lived mammals.     

Mature Atlantic Salmon (Salmo salar L.) Male Parr Are Attracted to Ovulated Female Urine but Not to Ovarian Fluid

The behavioral responses to urine and ovarian fluids from conspecific and heterospecific ovulated females were studied in mature Atlantic salmon (Salmo salar) male parr in a two-choice fluviarium. The males reacted differently to the stimulants. They spent more time in water scented by urine from salmon or brown trout (Salmo trutta L.) females compared to the time in water with ovarian fluids from salmon females. Furthermore, the males were attracted to salmon female urine (different from an indifferent reaction). Males exposed to urine of either species had higher plasma concentrations of testosterone (T) compared to unexposed controls. Measurement of the concentrations of prostaglandin F₂ (PGF₂) and its major metabolite 15-ketodihydro-prostaglandin F₂ (15-ketodihydro-PGF₂) showed that the concentrations of the substances were higher in ovarian fluids of both species compared to those in urine. PGF₂ showed a greater difference between ovarian fluid and urine than its major metabolite. The results suggest that urine of both species, in contrast to ovarian fluid, contain substances that attract mature Atlantic salmon male parr and that the active substances are neither PGF₂ nor 15-keto-PGF₂.     

Attraction of Mature Ceratitis capitata Females to 2-Heptanone, A Component of Coffee Fruit Odor

In indoor laboratory-cage and outdoor field-cage assays, we evaluated the attraction of released, protein-fed, mature Mediterranean fruit fly females to six volatile compounds emitted by attractive crushed ripe coffee fruit: 3-methyl-1-butanal, decanal, 3-methyl-1-butanol, 2-(Z)-pentenol, 2-(E)-hexenol, and 2-heptanone. Previous tests in a wind tunnel indicated that each of these six compounds was more attractive than clean air to females. In laboratory cage assays, none of the compounds elicited a response significantly greater than that to water. In field-cage assays, 2 or 4 l of 2-heptanone in 5 ml of water (but none of the other compounds at 2 or 4 l in 5 ml of water) consistently attracted protein-fed medflies at significant levels that averaged about five times greater than attraction to water alone, although about 40% less than attraction to odor of coffee fruit extract. All types of mature protein-fed females tested (laboratory-cultured virgin, laboratory-cultured mated, wild mated) in field-cage assays responded similarly to 2-heptanone, whereas same-age (9- to 11-day-old) protein-deprived females did not respond significantly to 2-heptanone. Response of protein-fed females to 2-heptanone increased progressively with increasing dose (1, 2, 4, or 8 l in 5 ml of water). Addition of 2 l of 2-heptanone or 2 l of any of the other compounds tested to 5 ml of water extract of coffee fruit did not enhance attractiveness of the extract. Relative to response to water, protein-fed females consistently exhibited a significant positive response to odor of coffee fruit extract but no significant response to odor of Nulure (a proteinaceous food attractant). Together, our findings suggest that mature protein-fed females were responding to 2-heptanone as though it were an oviposition-site stimulus rather than a feeding-site stimulus.     

Identification of Sex Differentiation-Related microRNAs in Spinach Female and Male Flower

Sex determination and differentiation is an important biological process for unisexual flower development. Spinach is a model plant to study the mechanism of sex determination and differentiation of dioecious plant. Till now, little is known about spinach sex determination and differentiation mechanism. MicroRNAs are key factors in flower development. Herein, small RNA sequencing was performed to explore the roles of microRNAs in spinach sex determination and differentiation. As a result, 92 known and 3402 novel microRNAs were identified in 18 spinach female and male flower samples. 74 differentially expressed microRNAs were identified between female and male flowers, including 20 female-biased and 48 male-biased expression microRNAs. Target prediction identified 22 sex-biased microRNA-target pairs, which may be involved in spinach sex determination or differentiation. Among the differentially expressed microRNAs between FNS and M03, 55 microRNAs were found to reside in sex chromosome; one of them, sol-miR2550n, was functionally studied via genetic transformation. Silencing of sol-miR2550n resulted in abnormal anther while overexpression of sol-miR2550n induced early flowering, indicating sol-miR2550n was a male-promoting factor and validating the reliability of our small RNA sequencing data. Conclusively, this work can supply valuable information for exploring spinach sex determination and differentiation and provide a new insight in studying unisexual flower development.     

Male and Female Noctuid Moths Attracted to Synthetic Lures in Europe

In field tests in Europe, traps baited with a blend of isoamyl alcohol, acetic acid, and isobutanol (compounds previously found attractive to a number of noctuids in North America) caught the following noctuid moths: Agrotis segetum Schiff., Agrotis crassa Hbn., Agrotis exclamationis L., Amathes (Xestia) c-nigrum L., Apatele rumicis L., Amphipyra pyramidea L., Dipterygia scabriuscula L., Discestra trifolii Hfn., Euxoa aquilina Schiff., Euclidia glyphica L., Mamestra brassicae L., Mamestra oleracea L., Mamestra suasa Schiff., Mythimna albipuncta Den. & Schiff., Mythimna l-album L., Noctua pronuba L., and Trachea atriplicis L. A substantial percentage of the catch of each species of moths was females. The presence of isobutanol in the mixture was important for catching A. rumicis, D. trifolii, and E. glyphica. The addition of 3-methyl-1-pentanol to the ternary mixture did not increase trap captures of any of the moths. Traps baited with the floral attractant phenylacetaldehyde alone caught several species of noctuid moths. However, when phenylacetaldehyde was added to the isoamyl-alcohol ternary blend, no increases in catches of any of the species, relative to the ternary blend or phenyacetaldehyde alone, were observed, with catches of most species being depressed. Comparing the noctuid species attracted to the phenylacetaldehyde- and isoamyl alcohol-based lures showed that phenylacetaldehyde attracted predominantly Plusiinae and Melicleptriinae spp., while isoamyl alcohol-based lures attracted species mostly from the Noctuinae or Hadeninae subfamilies.     

Stimulation of Estrus in Female Mice by Male Urinary Proteins

Stimulation of estrus in adult female mice was obtained with major urinary proteins (MUPs) with the natural volatile ligands bound. The MUP threshold concentration for this effect was about 1.8 mg/ml. MUPs without the ligands bound, as purified by organic extraction of hydrophobic compounds, stimulated estrus in mice only when dissolved in carrier urine of juvenile or castrated adult male mouse or ovariectomized female mouse. They did not stimulate estrus when dissolved in water. Mice that had the vomeronasal organ removed were insensitive to MUPs. It is concluded that MUPs are an integral part of the mouse male pheromones that stimulate hormonal activity in females and that the vomeronasal system is involved in the estrus-stimulating effect of the major urinary proteins.     

Chemogenetic Depletion of Hypophysiotropic GnRH Neurons Does Not Affect Fertility in Mature Female Zebrafish

The hypophysiotropic gonadotropin-releasing hormone (GnRH) and its neurons are crucial for vertebrate reproduction, primarily in regulating luteinizing hormone (LH) secretion and ovulation. However, in zebrafish, which lack GnRH1, and instead possess GnRH3 as the hypophysiotropic form, GnRH3 gene knockout did not affect reproduction. However, early-stage ablation of all GnRH3 neurons causes infertility in females, implicating GnRH3 neurons, rather than GnRH3 peptides in female reproduction. To determine the role of GnRH3 neurons in the reproduction of adult females, a Tg(gnrh3:Gal4ff; UAS:nfsb-mCherry) line was generated to facilitate a chemogenetic conditional ablation of GnRH3 neurons. Following ablation, there was a reduction of preoptic area GnRH3 neurons by an average of 85.3%, which was associated with reduced pituitary projections and gnrh3 mRNA levels. However, plasma LH levels were unaffected, and the ablated females displayed normal reproductive capacity. There was no correlation between the number of remaining GnRH3 neurons and reproductive performance. Though it is possible that the few remaining GnRH3 neurons can still induce an LH surge, our findings are consistent with the idea that GnRH and its neurons are likely dispensable for LH surge in zebrafish. Altogether, our results resurrected questions regarding the functional homology of the hypophysiotropic GnRH1 and GnRH3 in controlling ovulation.     

Differences in Sterol Composition between Male and Female Gonads of Dominant Limpet Species

The present study demonstrated here for the first time that there are statistically significant differences in sterol composition between male and female gonads of the dominant limpets Cellana grata and Cellana toreuma, which are intertidal gastropods. Among 11 different sterols identified in this study, unusually high levels (11.2–19.8% of total sterols) of the Δ⁸-sterols 5α-cholest-8-en-3β-ol (zymostenol) and 5α-cholesta-8,24-dien-3β-ol (zymosterol), which have never been reported in aquatic invertebrate gonads, were present in only the male gonads.     

Pheromonal Discrimination of Sex by Male and Female Leopard Geckos (Eublepharis macularius)

The ability of male and female Eublepharis macularius to discriminate among pheromones of males and females and a blank control was investigated. Stimuli were presented on ceramic tiles in the animal's home cages. Males tongue-flicked at significantly lower rates in response to male stimuli than to female and control stimuli. Males also performed aggressive behaviors toward male, but not female or control, stimuli, and tail vibrations toward female, but not male or control, stimuli. Mean tongue-flick rates by females did not differ significantly among conditions. Discrimination of male pheromones by females was demonstrated by greater performance of labial-licking and chin-rubbing in response to male stimuli than to either female or control stimuli.     

Characterization of Male and Female Jojoba Plants Employing Antioxidants,Lipid Peroxidation and Physiological Studies

Jojoba, [Simmondsia chinensis (Link) Schneider] is a commercially important dioecious, desert shrub which is mainly cultivated for liquid wax (oil) present in its seeds (40–60 %). The oil is being utilized by the cosmetic, pharmaceuticals, and other industries for certain formulations. In this study, gender based differences in biochemical and physiological parameters were examined in relation to natural drought conditions. The amount of protein, proline, cysteine, chlorophyll a and b, carotenoids and enzymatic activities were evaluated in leaves of male and female Jojoba genotypes. Significant differences between genders were found which was attributed to higher drought tolerance of males than females. Males showed higher contents of protein (113.05 ± 0.88 mg g^?1 FW), proline (95.13 ± 2.33 µmol g^?1 FW), cysteine (42.47 ± 2.69 µmol g^?1 FW) than females (proteins: 70.77 ± 0.52 mg g^?1 FW, proline: 66.61 ± 1.75 µmol g^?1 FW, cysteine: 17.84 ± 3.00 µmol g^?1 FW). Malondialdehyde (MDA) content was lower in male genotypes (18.29 ± 0.53 µmol g^?1 FW) than female genotypes (23.02 ± 0.70 µmol g^?1 FW). Higher activities of catalase (CAT) [0.088 ± 0.005 nkat mg^?1 protein], guaiacol peroxidase (GPX) [0.006 ± 0.001 nkat mg^?1 protein], glutathione reductase (GR) [9.02 ± 0.04 nkat mg^?1 protein], ascorbate peroxidase (APX) [4.28 ± 0.08 nkat mg^?1 protein] and superoxide dismutase (SOD) [151.75 ± 3.58 nkat mg^?1 protein] were found in males compared to females [CAT: 0.007 ± 00 nkat mg^?1 protein, GPX: 0.003 ± 00 nkat mg^?1 protein, GR: 6.40 ± 0.06 nkat mg^?1 protein, APX: 3.08 ± 0.06 nkat mg^?1 protein, SOD: 52.51 ± 1.73 nkat mg^?1 protein]. Chlorophyll b content was also higher in males than females.     

Attraction of Female and Male Bactrocera papayae to Conspecific Males Fed with Methyl Eugenol and Attraction of Females to Male Sex Pheromone Components

The attraction of female and male Bactrocera papayae to conspecific males fed with methyl eugenol (ME) and female attraction to male synthetic sex pheromone, trans-coniferyl alcohol (CF), were evaluated in a wind tunnel. Earlier and greater attraction were exhibited by both females and males to ME-fed than to non-ME-fed males as dusk approaches. Males increased their precopulatory behavior (i.e., wing fanning and mounting) during the period of higher attractancy. These data confirm that the consumption of ME enhances the mating competitiveness of males and suggest that ME also functions as a precursor to the male sex and aggregation pheromones. Three phenylpropanoid compounds biosynthesized from ME, coniferyl alcohol, 2-allyl-4,5-dimethoxyphenol, and 3,4-dimethoxycinnamyl alcohol, were detected in male rectal gland along with an endogenous rectal compound, N-(3-methylbutyl) acetamide. When offered singly to the females, coniferyl alcohol was found to be most attractive.     

Mice Respond Differently to Urine and Its Major Volatile Constituents from Male and Female Ferrets

Our previous chemical investigation showed that the concentrations of urinary volatiles from males were much higher than those from females in the ferret (Mustela furo). The current study was designed to examine the behavioral significance and ecological relevance of this difference for one of the main prey of the ferret, the house mouse (Mus musculus). Our data showed that male mice displayed no difference in their response to raw male and female ferret urine. However, they showed significantly less response to female mouse urine mixed with ferret urine than to pure female mouse urine, and to female mouse urine mixed with male ferret urine than to female mouse urine mixed with female ferret urine. Furthermore, high levels of the three major volatiles (quinoline, 2,5-dimethylpyrazine, and 4-hepatanone) in male ferret urine were as effective as raw male ferret urine was in inhibiting the response of male mice. We discuss the ecological and behavioral significance of these findings in terms of chemical mimicry and cognitive feature extraction of predator odors in mice.     

Exposure to Predator Odor Reduces Locomotor Activity Levels in Adult Male Rats: Lack of Effect of Hippocampal Lesion

The hippocampus has been implicated in mediating responses to predators. Involvement of the hippocampus was tested in the present study in which a multivariate analysis of the locomotor activity of intact and hippocampectomized (destruction of dentate and CA1 cells) laboratory rats, Rattus norvegicus, was conducted following exposure to a predator odor. Levels of various activity variables were monitored in an automated activity monitoring system following a brief 3-min exposure to 2-propylthietane (weasel odor), caproic acid (goat odor), toluene (organic solvent), and a no-odor condition in hippocampal-lesioned (using colchicine) and sham-operated control male rats. Rats of both groups displayed reduced levels of total distance, movement time, vertical activity, and number of movements following exposure to weasel odor and toluene in comparison to the no-odor condition. Exposure to goal odor resulted only in reduced levels of vertical activity and number of movements. There were no differences in activity levels between hippocampal-lesioned and sham-operated rats during baseline activity recording or following exposure to any of the odors. However, hippocampal-lesioned rats spent less lime in the center of the activity boxes than sham-operated control rats across all conditions. This study demonstrates that laboratory rats show marked changes in locomotion in response to the odor of a predator and suggests that an intact hippocampus is not essential for mediating these responses.     

Electrophysiological Responses of Female and Male Hypsipyla grandella (Zeller) to Swietenia macrophylla Essential Oils

The mahogany shoot borer, Hypsipyla grandella, is one of the most economically important Neotropical forest pest insects because it attacks valuable timber of the Meliaceae. Despite detailed information on the life cycle of H. grandella, factors influencing attack by the shoot borer are not well known. Electroantennogram studies of borer antennae indicate that both female and male moths elicited significant antennal responses to essential oil of the terminal shoots, mature and senescent leaves, in three concentrations. -Himachalene, germacrene D, germacrene A, cadina-1,4-diene, hexadecanoic acid, and ethyl hexadecanoate appeared in all essential oils from Swietenia macrophylla. Germacrene-D and -himachalene were also present in the active essential oil of Cedrela odorata and Toona ciliata. These findings suggest that these compounds play a role in attracting H. grandella to oviposit on the leaves of these plants. The GC-EAD of essential oil from S. macrophylla mature leaves to female H. grandella antennae led to the identification of -caryophyllene as the main constituent responsible for the antennae response.