Excreted urine,bladder urine,and the delay of sexual maturation in female house mice

A series of experiments tested effects of excreted and bladder urine of group- and singly-caged female house mice (Mus musculus) on sexual maturation of young female mice caged alone or in groups of eight. Puberty was determined by vaginal smears. A maturation-delaying pherompne was present in bladder urine of all female mice and excreted urine of group-caged females, but not in excreted urine from singly-caged females. Test mice treated with bladder urine homogenized with urethras from singly-caged females matured at the same age as controls. Apparently the urethras or associated glands of singly-caged females produce a substance which deactivates the maturation-delaying pheromone contained in bladder urine.     

Partial isolation of a pheromone accelerating puberty in female mice.

The sexual development of female mice is accelerated by exposure to an adult male or to male urine. The component of the urine responsible for this effect is androgen-dependent, heat labile, nondialysable, precipitatable with ammonium sulphate, and is not extractable in ether. These results indicate that the pheromone causing accelerated sexual development is associated with a protein component of male urine. Tests of the active fraction after digestion with proteolytic enzymes suggest that the pheromone may be a portion of a protein or a substance bound to a protein.     

Effects of urine from females in oestrus on puberty in female mice

A series of 9 experiments was conducted to examine various characteristics of the urinary chemosignal found in the urine of oestrous female mice that accelerates the sexual development of conspecific females. This urinary chemosignal was effective in doses as small as 0.001 ml/day, was present in excreted and bladder urine, required 3 days of treatment starting before Day 29 of age to effect an acceleration of puberty, required a minimum daily exposure of 2 h, and was relatively nonvolatile. In addition the chemosignal from oestrous females was effective in summer but not in winter months, was significantly more effective when collected at the middle or end of the dark portion of the daily cycle than at the beginning of the dark phase or middle of the light phase, and was not affected by food deprivation or shortened photoperiod. Simultaneous treatment of test subjects with urine from oestrous females and grouped females resulted in delays in puberty and simultaneous treatment with urine from oestrous females and urine from males or pregnant or lactating females did not result in any enhanced acceleration of puberty.     

Effects of adrenalectomy on the presence of a maturation-delaying pheromone in the urine of female mice

A sequence of three experiments investigated whether adrenalectomy affects a pheromone from grouped female mice which delays puberty in young females. The first two experiments demonstrated that the presence of the adrenal glands is a necessary condition for production and/or excretion of the puberty-delaying pheromone in excreted and bladder urine. The third experiment showed that a blocking effect associated with the urethras of singly caged female mice which inhibits the activity of the maturation-delaying pheromone is not affected by adrenalectomy.     

Effects of ovariectomy on the presence of a maturation-delaying pheromone in the urine of female mice

A sequence of three experiments investigated whether ovariectomy affects the production and/or excretion of a pheromone from grouped female mice which delays puberty in young females. The first two experiments demonstrated that ovariectomy does not influence the presence of the puberty-delaying pheromone in either excreted or bladder urine of group-caged females. The third experiment showed that the blocking effect associated with the urethras of singly caged female mice which inhibits the activity of the maturation-delaying pheromone is not affected by ovariectomy.     

The urinary aversive pheromone of mice: species, strain and grouping effects

The aversive efficacy of the urine of male rats, hamsters, C57Bl mice, 129Re mice and T.T. albino mice was assayed using group-housed subordinate T.T. male mice as subjects. The aversive pheromone was found to be specific only at the strain level, the urine of all other species and strains used having no apparent effect. The aversive properties of: (1) individual isolate urine; (2) pooled isolate urine and (3) the urine of the same donors under grouped conditions, were assessed using conspecific T.T. males as subjects. It was found that the aversive factor was not inividual specific and that grouping of the donors resulted in a complete loss of the urinary aversive factor. The results are discussed in terms of possible control mechanisms and territorial implications.     

Food deprivation affects reproduction in adult female mice (Mus musculus) and the age of puberty for their female progeny

Three experiments were designed to test the effects of food deprivation during various phases of the reproductive cycle on fertility and fecundity of the dams and on the age of sexual maturation and body growth of their female progeny. Food deprivation consisted of removal of all food every other day. Animals were deprived of food either during the period prior to pairing, during the period between pairing and conception or during gestation. Both fertility and fecundity were affected by food deprivation in some, but not all manipulations. The female progeny of food-deprived females reached puberty significantly later than the progeny of non-deprived dams when the food deprivation occurred during the week prior to pairing and up until successful insemination after pairing with a fertile male, but not when food deprivation occurred at other times during the reproductive cycle. Body growth did not differ in the daughters of food-deprived dams across the treatments for any of the experiments.     

Effect of insect density, plant age, and residue duration on acetamiprid efficacy against swede midge

The Swede midge, Contarinia nasturtii Kieffer (Diptera: Cecidomyiidae), a common insect pest in Europe, is a newly invasive pest in North America that constitutes a major threat to crucifer vegetable and field crops. Chemical control of Swede midge with synthetic insecticides under laboratory conditions indicated that insecticides generally could provide very effective control; however, insecticide treatments in the field were rarely able to maintain damage levels within marketable limits. In the current study, factors affecting insecticide efficacy were investigated using a neonicotinoid insecticide, acetamipird, as a foliar spray on cauliflower plants. Our results indicated that Swede midge density did not affect the efficacy of acetamirpid, although it significantly increased the subsequent Swede midge population on the unsprayed cauliflower plants. Additionally, cauliflower plant age did not significantly affect spray coverage and acetamipird efficacy on Swede midge. However, acetamiprid only provided 6-d control of Swede midge and its efficacy was reduced by up to 50% 9 d after spraying. Implications of our results on the development of an overall integrated pest management (IPM) program for Swede midge also are discussed.     

Effect of age and previous mating on the response of Khapra beetle males to female sex pheromone

The pheromone released by the Khapra beetle female is a sex pheromone, specifically attracting males. Maximum response of unmated males to the ether extract of the pheromone was observed with 6–7 day old males. Mated males showed significantly reduced response to the pheromone compared to unmated ones, and physical presence of virgin females considerably reduced attraction of unmated males to the pheromone extract.

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Zusammenfassung Weibliche Khaprakäfer (Trogoderma granarium) scheiden ein in Äther lösliches Sexual-pheromon ab, das nur auf Männchen anziehend wirkt. Die Anzahl der angelockten Männchen nimmt mit dem Alter der Männchen zu. Männchen im Alter von 6–7 Tagen zeigen maximale Reaktionen. Bei noch älteren Männchen nimmt die Reaktion wieder ab. Bereits gepaarte Männchen zeigten signifikant schwächere Reaktionen auf den Pheromonextrakt als noch ungepaarte. Jedoch wurde die Reaktion unverpaarter Männchen auf den Pheromonextrakt durch die Anwesenheit unbegatteter Weibchen stark herabgesenkt.

     

Foraging effort, food intake, fat deposition and puberty in female mice

A novel caging system was used to study the interrelationships between foraging effort, food intake, growth and sexual maturation of peripubertal female mice. Females housed in these cages were forced to work (forage) at various intensities in order to obtain food pellets. It is argued that this is a biologically more meaningful approach to understanding the energetics of sexual development than the traditional approach of simple underfeeding. Female mice exhibited a cascade of developmental adjustments and deficits when challenged to forage harder for less food. The functions most sensitive to increased foraging effort were sexual development and growth in body length; growth in body weight was intermediate and fat deposition was least sensitive of all. The relative insensitivity of fat deposition to higher foraging costs suggests a strategy for survival during the postweaning dispersal movements of the wild ancestors of the laboratory mouse. Finally, regression analyses suggested that heavier females who had less than average body fat and higher than average food intake achieved their pubertal ovulation most rapidly.     

The influence of stimulus duration on the delay tuning of cortical neurons in the FM bat,Myotis lucifugus

1. Echolocating bats use echo delay as the primary cue to determine target distance. During target-directed flight, the emitted pulses increase in repetition rate and shorten in duration as distance decreases. To determine how these parameters affect the delay tuning of neurons in the auditory cortex of the awake bat, Myotis lucifugus, we examined the responses of 104 delay-sensitive neurons as the pulse repetition rate (PRR) and duration were independently varied. Stimulus duration of 4, 2 and 1 ms and PRR of 5-100/s were used for both the pulse and echo to determine delay sensitivity. These parameter ranges span those used during the search, approach, and the initial terminal phases of echolocation. 2. As the stimulus duration was shortened, the range of PRRs for delay sensitivity was extended to higher rates in 41% of the neurons, narrowed or disappeared in 40%, and remained unchanged in 4%. The remaining 15% were not categorized since it was not possible to determine a trend in which the range of delay-sensitive PRRs changed with stimulus duration. 3. Three types of tracking neurons (i.e., neurons that change their best delay during target-directed flight) were found. For the first type, the best delay (BD) shortened with shorter stimulus duration, for the second type, BD shortened with both shorter stimulus durations and higher PRRs, and for the third type, BD shortened with higher PRRs. 4. These results suggest that the stimulus parameters of sonar emission influence delay tuning and hence processing by cortical neurons in FM bats.     

Effect of age and mating on pheromone production in the female olive fruit fly, Dacus oleae (Gmel.)

Virgin female olive fruit flies began producing sex pheromone on the third day after emergence. Production of sex pheromone appears to be cyclical with peaks of production recurring at about 10-day intervals, each peak lasting 2–3 days. As the female ages, the quantity of sex pheromone produced during the period of high pheromone production decreases, but it is always higher than the quantity present in the pheromone gland during the rest of female life.Mated females produced less sex pheromone the first 10 days after mating which then increased to near the same level of that in virgin females.     

Effects of composition and density of the group on the performance,behaviour and age at puberty in swine

Two hundred and eighteen cross-bred pigs (Duroc × Hampshire × Landrace × Yorkshire) were assigned to a 3 × 2 factorial experiment; the factors being composition of the group and density. The composition of the group factor consisted of pigs not reaggregated (NR), re-aggregated below the median body weight (RBMW), and re-aggregated above the median body weight (RAMW) at the time of transfer to the finishing pens. The density factor consisted of groups of 6 or 12 pigs/pen. Two trials with 2 replications of each trial were conducted. Twenty-six gilts from Trial I were used to determine their age and ovulation rate at the pubertal oestrus. During the nursery phase, composition of the group had no effect (P>0.05) on average daily feed intake (ADFI) or feed efficiency (F/G). Pigs in the NR and RAMW groups had a similar (P>0.05) average daily gain (ADG), whereas, those pigs in the RBMW group gained (P<0.05) at a slower rate. Pigs housed in groups of 6 had a higher (P<0.05) ADFI, had similar (P>0.05) ADG and poorer (P<0.05) F/G than those housed in groups of 12. During the finishing phase, composition of the group had no effect (P>0.05) on ADFI, ADG or F/G. Pigs housed in groups of 6 had a greater (P<0.05) ADFI and ADG, but similar (P<0.05) F/G compared to those housed in groups of 12. Correlation coefficients between the various behaviours and the performance variables suggested that the more active pens of pigs gained less per day and were less efficient. Gilts housed in the NR groups of 6 were younger (P<0.05) at puberty than gilts in the other groups of 6 or 12. Also, gilts housed in the RBMW groups of 6 were younger (P<0.05) at puberty than those housed in the RAMW groups of 6, whereas those housed in the RBMW groups of 12 were older (P<0.05) at puberty than those housed in the RAMW groups of 12. Ovulation rate was not affected (P>0.05) by composition of the group, density or their interaction. In summary, composition and density of the group affected the performance of pigs and was correlated to some of the behavioural measurements. The most noticeable effect was that these same factors caused a delay in the onset of puberty in gilts.     

Effects of stock differences in the acceleration of puberty in female mice

Newly born TO strain female mice were exposed daily to the urine from male albino mice of the same and CFLP strains, from feral mice carrying Robertsonian translocation chromosomes and to water as a control condition. At 21 days of age, when exposure was discontinued, there were differences in body weight between treatments which were not present when adult. Exposure to urine from mice with Robertsonian translocations did not accelerate puberty and the interval between vaginal opening and first oestrus was longer (4.2 days) than in mice exposed to the urine from the albino strains (1.8 days). Mice exposed to the urine from the Robertsonian stock were in dioestrus more often than those exposed to the urine from laboratory strains. The Robertsonian mice also differed in their behaviour in an open arena in that they passed fewer faecal pellets than those exposed to the urine from the albino mice. The water control mice defecated the least frequently. The mice exposed to the Robertsonian urine were less active than the laboratory strains but the differences did not reach an acceptable level (P less than 0.06) of significance.     

Relation between body weight, growth rate, chronological age and puberty in male and female rats

Body weight, growth rate, chronological age and puberty in female and male rats from litters of 8 and 12 offsprings/mother have been studied. Age and body weight at the moment of vaginal opening (VO) and balanopreputial separation (BPS) were analyzed. Results show that animals reared in smaller groups grew faster than others. After weaning there was an increase in growth rate. VO and BPS occurred at the same age in groups with different growth rates and different body weights. In conclusion this work evidences that external signs of sexual maturation are not linked to a "critical weight" or to a "growth rate".     

A releaser pheromone that attracts males in the urine of mature female masu salmon

A releaser pheromone of masu salmon Oncorhynchus masou was investigated using Y-maze behavioural experiments. During the reproductive season, urine of mature females contains a releaser pheromone which acts as a sex attractant for spermiating mature male parr. The releaser pheromone in mature female urine is one or more low molecular weight substances (less than 10 000) soluble in ether under basic conditions. The attractant was not present in either the coelomic fluid of ovulated females nor in neutral or acidic extracts of female urine which contain free steroids and F-type prostaglandins, respectively.     

Male priming pheromone is present in bile, as well as urine, of female rainbow trout

The bile of sexually mature female rainbow trout Oncorhynchus mykiss has pheromonal activity which causes a significant increase in concentrations of 17,20β-dihydroxy-4-pregnen-3-one in the plasma of males. Bile from male trout is inactive. The activity in the female bile binds to octadecylsilane and can be eluted with methanol. The synthetic bile acids, taurocholic acid and taurolithocholic acid, are inactive.