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1.
The rate of pheromone emission from wild and laboratory-reared gypsy moth (Lymantria dispar) (Lepidoptera: Lymantriidae) virgin females was determined with an all-glass aeration apparatus. This device incorporated a bed of 1-mm glass beads to extract entrained pheromone from the air flowing over the protruded gland. The temporal pattern of emission was established by monitoring individual females after eclosion for 24 consecutive 2-hr intervals.At a constant 24°C, both wild and laboratory females exhibited a similar diel periodicity of pheromone emission. The mean release rate increased after onset of photophase, generally attained maximal levels between 1600 and 2200 hr and declined during scotophase. Pheromone was released continuously and the mean daily emission increased with age for both wild and laboratory moths. The mean emission rate over the 48-hr monitoring interval was 15.4 ng2 hr for wild females vs 14.7 ng2 hr for laboratory moths. The peak emission from 2-day-old laboratory moths was ca.28 ng2 hr compared with the ca.25 ng2 hr released by their wild counterparts.The calling periodicity of laboratory females was determined at a constant 24°C and under a natural temperature rhythm. At 24°C, the proportion of females calling exceeded 45% throughout the diel period, whereas under the temperature rhythm, calling was virtually eliminated by temperatures below 15°C, indicating that temperature acts as an exogenous cue to modify the expression of the calling rhythm and thus potentially the periodicity of pheromone emission.  相似文献   

2.
Sexual selection has received a great deal of attention from field and laboratory researchers for over a century, but hard evidence of female choice of mates in mixed-sex groups remains scarce. Dominant males typically mate much more often than subordinants but evidence that females “choose” such males is elusive. In Gallus, which includes junglefowl and their domestic fowl descendants, females stay near and mate with dominant, territorial males. We demonstrate here that Gallus females in mixed-sex flocks who have no information about the social dominance status of males orient to, approach and stay near males with larger than average combs whereas females which do not have information about male dominance orient toward and stay near high ranking males. We verify that comb size correlates with male social rank. Hence, Gallus females do actively respond to “high quality” males; they apparently identify such males by male physical characteristics and, if available, information concerning male-male interactions.  相似文献   

3.
G.L. Adessi 《Steroids》1979,34(6):649-661
The metabolism, in vitro, of [3H]-estrone, [3H]-estradiol-17β and [3h]-estrone-3-sulfate by the livers of pregnant, young virgin female and female fetus guinea-pigs has been compared using 900 g supernatants and microsomes. The ability of the guinea-pig livers to synthesize polyhydroxylated estrogens has been found to be small. The major metabolites isolated were unconjugated estrone and estradiol-17β or their glucuronides. The percentage of sulfates was lower after incubations with [3H]-estrone than with [3H]-estradiol-17β. A kinetic study with microsomes has shown a direct conversion of estrone-sulfate to estradiol sulfate. Fetal microsomes have been found to exhibit a more active hydrogenation of estrone to estradiol-17β than microsomes from young female or pregnant animals.  相似文献   

4.
R.D. Randel 《Theriogenology》1984,21(1):170-185
Reproductive function is mediated by season in the Indian breeds of cattle (Bosindicus). The reproductive endocrinology of Bosindicus cattle differs from that of Bostaurus breeds; the estrus is shorter and less intense and occurs late in relation to an estrogen stimulus. Moreover, the Bosindicus female has a smaller preovulatory surge of luteinizing hormone (LH), which occurs earlier relative to the onset of estrus, and she ovulates sooner after the onset of estrus. The corpus luteum is smaller and contains less progesterone, and the serum progesterone concentration is lower in Bosindicus females. Furthermore, they have fewer preovulatory LH surges than Bostaurus females and their luteal cells are less responsive to LH in vitro during the winter. Their fertility is lower during the late fall and winter months. For Bosindicus cattle, recovery of transferable embryos and survival of embryos in the recipient are at their maximum from July through October.  相似文献   

5.
Two experiments were conducted to test for the recovery of brucella organisms from uterine flushings and harvested embryos of sero-positive embryo donor females. In Experiment I, 16 sero-positive cows were superovulated with FSH treatments and artificially inseminated at 12, 24 and 36 hours following the onset of estrus with brucella-free semen. At 48 hours after the onset of estrus, one half the potential donor females were administered an intrauterine inoculation of 3.3 to 4.6 × 104Brucellaabortus (strain 2308) organisms while the remainder received a control inoculation. In Experiment II, the same 16 cows were similarly administered superovulatory treatments and inseminated following estrus. The uterine inoculation was increased to 1.5 to 2.5 × 108 organisms administered 48 hours following estrus. Samples of recovered flushing medium and homogenized embryo residues were placed into a validated invitro culture system to detect the presence of brucella bacteria. Uterine flushings and embryos recovered from 31 females exhibiting estrus following FSH treatments were free from either field strain or the inoculated B.abortus (strain 2308) contamination. The flushings obtained from a single female, which did not respond with estrus following FSH treatment but was inoculated at appointment, did contain B.abortus which was identified as the inoculated strain 2308 and not field strain organisms. These results indicate that brucella contamination of flushing media and harvested embryos will not likely be incurred when collecting embryos from sero-positive donor females. These findings offer further encouragement for the use of embryo transplantation as a method to produce brucella-free offspring from infected cows.  相似文献   

6.
Two experiments were performed to examine aggression and dominance in domestic male and female Rattus norvegicus living in small mixed-sex (3 males and 3 females) groups. Experiment 1 examined the development of aggression in females. A single female (alpha) within each of the six colonies tested showed the preponderance of attacks on male intruders placed into the home-cage when male colony residents were absent. Over 12 weeks of intruder-aggression training female alphas showed only a mild nonsignificant elevation of aggressive behavior. A comparison of aggression of male and female colony alphas tested with opponents of each sex revealed that aggression was mainly directed at like-sex opponents, and that female attack was more defensive in character than male attack regardless of opponent sex. The highest intensity of aggression occurred when male alphas confronted male intruders. Although intruders never showed offense toward male residents, 61% of intruding males showed offense in response to attack by females.Experiment 2 investigated the relationship between aggressive dominance and competitive measures of dominance within each of 10 mixed-sex colonies. Alpha stat s of male and female colony residents did not reliably predict priority of access to food or water in tests of direct resource competition with like-sex colony members. When colony males were simultaneously tested for copulation, the copulatory behavior of alpha males was significantly greater than that of other colony males. Results are discussed in relation to the role of aggression in the reproductive strategy of male and female Rattus norvegicus.  相似文献   

7.
Both d-glucose and its nonmetabolized analog 3-O-methyl-d-glucose are known to protect the pancreatic B-cell against the toxic action of alloxan, as if the protective action of hexoses were to involve a membrane-associated glucoreceptor site. In the present study, the protective actions of the two hexoses were found to differ from one another in several respects. Using the process of glucose-stimulated insulin release by rat pancreatic islets as an index of alloxan cytotoxicity, we observed that the protective action of d-glucose was suppressed by d-mannoheptulose and menadione, impaired by NH4Cl, and little affected by aminooxyacetate. These findings and the fact that d-glucose failed to decrease [2-14C]alloxan uptake by the islets suggest that the protective action of d-glucose depends on an increase in the generation rate of reducing equivalents (NADH and NADPH). The latter view is supported by the observation that the protective action of a noncarbohydrate nutrient, 2-ketoisocaproate, was also abolished by menadione. Incidentally, the protective action of 2-ketoisocaproate was apparently a mitochondrial phenomenon, it not being suppressed by aminooxyacetate. In contrast to that of glucose, the protective action of 3-O-methyl-d-glucose was unaffected by d-mannoheptulose, failed to be totally suppressed by menadione, and coincided with a decreased uptake of [2-14C]-alloxan by the islets. It is concluded that the protective action of d-glucose in linked to the metabolism of the sugar in islet cells, whereas that of 3-O-methyl-d-glucose results from inhibition of alloxan uptake. This conclusion reinforces our opinion that the presence in the B-cell of an alleged stereospecific membrane glucoreceptor represents a mythical concept.  相似文献   

8.
Prostaglandin (PG) synthetase was present in the testes, seminal vesicles, and spermatophores of the male house cricket, Acheta domesticus. The enzyme was not detected in bursa copulatrix, spermatheca, spermathecal canal, and oviducts from virgin females, while substantial activity was measured in the same tissue from mated females. The female appears to receive the enzyme from the spermatophore. A PGE2-like material was detected by radioimmunoassay in A. domesticus testes and to a lesser extent in the remainder of the male reproductive tract. PG went undetected in virgin female reproductive tissues, while the same tissues from mated females contained an average of 589 pg of PGE2-like material per female. In in vivo studies, injected PGE1, PGE2, and to a smaller degree PGF stimulated oviposition by virgin females. Moreover, N-acetyl-p-aminophenol, a PG synthetase inhibitor, suppressed oviposition in mated females. Post-copulatory PG biosynthesis in the female reproductive tract might be partially responsible for triggering oviposition in A. domesticus. Since PG synthetase appears to be acquired from the male, it could be considered a primer pheromone.  相似文献   

9.
The ATPase associated with the membranes of Micrococcus ysodeikticus has been released into the aqueous phase (i.e. solubilized) by extracting the membranes with n-butanol in a two-phase system modified from the procedure of Maddy, A.H. (164) Biochim. Biophys. Acta 88, 448–449. A procedure for the release and purification of the ATPase from the membranes extracted with n-butanol is described as an alternate method to that previously used for the shock-wash ATPase. Upon extracting the membrane suspensions with n-butanol the soluble ATPase released into the buffer phase no longer exhibits stimulation by trypsin in contrast to the shock-wash type of ATPase. As shown by Salton, M. R. J. and Schor, M. T. (1972) Biochem. Biophys. Res. Commun. 49, 350–357, the shock-wash ATPase possesses associated protein(s) as determined by sodium dodecylsulfate polyacrylamide gel electrophoresis whereas these are absent from the purified ATPase released by the n-butanol method. The specific activities of the purified ATPase released by the two methods were generally similar, the n-butanol type being consistently somewhat higher.  相似文献   

10.
11.
N Yasuda  K Takebe  M A Greer 《Life sciences》1976,18(11):1327-1331
Although mean ACTH concentration was significantly higher in cultured adenohypophyseal cells from female than from male rats, there was no significant sex difference in the ACTH secretory response of these cells to hypothalamic extract containing CRF. Hypothalamic CRF content in the “basal” state invivo was slightly higher in female than in male rats.  相似文献   

12.
U E Brady 《Life sciences》1973,13(3):227-235
Cis-9-tetradecen-l-ol acetate was isolated from both extracts of female abdominal tips and of filter paper exposed to female Cadracautella (Walker). It is the second sex stimulant isolated from this species and, in stimulatory bioassays, it is ca. 1/100, 000 as active as the stimulant isolated previously, cis-9, trans-12-tetradecadien-l-ol acetate. According to attractancy tests, the natural sex pheromone system of complex contains other components in addition to these 2 stimulants.  相似文献   

13.
A model of an ant population is presented in which each colony has one queen and one worker. The worker then rears to adulthood one reproductive individual and has complete control of its sex. If a stable polymorphism is allowed to occur between two alleles, one causing the worker to rear a male, the other causing the worker to rear a female, then the sex ratio at equilibrium will be different from the three females to one male predicted by Trivers and Hare. However, if a rare mutant is introduced whose homozygous worker has a 34; probability of producing a female reproductive (and a 14 probability of producing a male reproductive), then the sex ratio will equilibrate at three females to one male as the new mutant goes to fixation. Several details related to this observation are discussed.  相似文献   

14.
G E Pratt  S S Tobe 《Life sciences》1974,14(3):575-586
When corpora allata from adult female Schistocercagregaria are incubated invitro with either 3H-trans, trans farnesenic acid or 3H-trans, trans, cis bishomo-farnesenic acid and [methyl-14C] methionine, they fabricate large quantities of the corresponding double labelled methyl 10, 11-epoxy esters. Radio GLC of these products indicates retention of geometric configuration at the C-2 and C-6 double bonds. Separate analyses of the contents of the glands and medium after incubation show that the epoxy esters are rapidly released from the glands into the medium and that only the glands contain the corresponding unepoxidized esters. We suggest that unepoxidized esters are the intracellular intermediates in the formation of juvenile hormones from the unsaturated acids. Gel filtration shows that the epoxy esters are not released as stable protein complexes but as simple solutes into the medium. Using this method of promoting the synthesis of juvenile-hormone-active compounds, rates of biosynthesis of epoxy esters of up to 33 ng. per pair of glands per hour have been achieved.  相似文献   

15.
Abstract. Virgin mantis females, Hierodula patellifera (Serville) (Dictyoptera: Mantidae), exhibit a characteristic calling posture. When holding the body below a branch or leaf, the female curls the abdomen ventrally, flexing it away from the wings and exposing its dorsal surface. The curling is accompanied by pumping movements. The average age at which females start adopting this calling posture is 14 days after adult moult, and it is related to their nutritional stage. Once initiated, females exhibit the posture everyday until they mate. After mating, the behaviour is completely suppressed. Males are attracted by virgin females adopting the calling posture but are not attracted to mated females. The characteristics of the posture and the responsive behaviour of the males indicate that this female calling involves the release of sex pheromones.  相似文献   

16.
By the combined use of high-pressure liquid chromatography, Galleria bioassay and gas chromatography/ chemical ionization/mass spectrometry we were able to isolate and identify the three known natural juvenile hormones (JHs) from haemolymph extracts of larval and adult females of the cockroach Nauphoetacinerea. This is the first demonstration of the simultaneous occurrence of the three JHs in the same insect and the first time JH I and II have been identified in a hemimetabolous insect. Quantitative investigations show that the composition of the three JHs is different at different developmental stages. The haemolymph of larvae contains a high percentage of JH I and II, whereas the haemolymph of adult females in the oocyte maturation stage contains mostly JH III. This suggests more juvenilizing functions for JH I and II and more gonadotropic functions for JH III.  相似文献   

17.
Fat body cells of vitellogenic females of the cockroach Leucophaea maderae contain a prominent population of large polysomes of approximately 35–40 ribosomes whereas fat bodies of non-vitellogenic females or males of any age do not have these polysomes. Anti-vitellogenin recognizes newly synthesized nascent vitellogenin associated with these large polysomes. Adenosine labelled RNA is likewise precipitated by anti-vitellogenin primarily in the region of this class of polysomes. It is concluded that the class of large polysomes represents the vitellogenin polysomes.  相似文献   

18.
The genetic control of resistance or susceptibility to Trichomonas vaginalis infection has been studied in mice of various strains infected by different routes. BALBc and DBA2 female mice appear to be highly susceptible to intraperitoneal, subcutaneous, or intravaginal infection by T. vaginalis. By contrast, female mice on A background are resistant to T. vaginalis infection via any route. C57BL6 and C3H female mice display intermediate levels of resistance following intraperitoneal or subcutaneous inoculum, whereas they display high levels of resistance to intravaginal infection. On the other hand, susceptibility or resistance to T. vaginalis infection appears to be influenced by the host sex, since males inoculated subcutaneously display much higher levels of resistance than females of the same strain. Lastly, the age of the host seems to play an important role in determining the course of infection. Susceptibility to T. vaginalis decreases with age, being maximal at 3–4 weeks and minimal at 40–42 weeks. All together these results suggest that resistance or susceptibility to T. vaginalis infection is regulated by genes mapping outside the major histocompatibility complex (H-2 in the mouse), whose activity is modulated by the anatomic site first coming into contact with the protozoon, the sex, and the age of the recipient host.  相似文献   

19.
Destruction, by electrocoagulation, of the median neurosecretory cells of the pars intercerebralis of 2-day old adult female Locusta migratoria completely suppressed normal juvenile hormone-biosynthetic activity of the corpora allata in most animals. For example, 6 days after electrocoagulation the rates of spontaneous juvenile hormone biosynthesis, measured by radiochemical assay of freshly isolated glands, showed a median value of less than 1100 that of the corresponding sham operated controls, which were then in mid-vitellogenesis. Injection of graded doses (200–1600 μg) of precocene I at this time, followed by assays five days later, resulted in a similar decline of both corpus allatum volume and precocene epoxidase activity (measured by radiochemical assays of precocene I dihydrodiol formation in vitro) in pars intercerebralis-coagulated and sham-operated animals, when expressed as a percentage of their own zero precocene controls. Electrocoagulation of the pars intercerebralis largely prevented the normal increase in both corpus allatum volume and its epoxidase activity, so that by age 13 days these parameters were about 2.5-fold lower in coagulated vs control (sham operated) animals. In fact, electrocoagulation had no marked effect on the value of epoxidase activity per unit corpus allatum volume. It is concluded that the corpora allata from this species and stage are sensitive to precocene irrespective of whether they are active in biosynthesis of juvenile hormone.  相似文献   

20.
Statistically significant (P < 0.05) thyroid hyperactivity (131I% uptakes) occurs on certain days in Plasmodium berghei infected C3H mice. Male mice thyroid glands are made more hyperactive by the malaria than the female glands. Hyperactive thyroid glands may be at least one cause of hypocholesterolemia in plasmodium-infected rodents. Thyroid hyperplasia was found only in experimental mice (620 males; 820 females). A hyperactive thyroid gland appears to be an unreported aspect of experimental acute P. berghei infections in mice. The hyperthyroidism may be due to possible toxic substances acting either directly on the thyroid gland, or indirectly on the hypothalamus affecting TSH production.  相似文献   

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