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Proceedings of the National Academy of... Mar 2000Young mated male Caribbean fruit flies [Anastrepha suspensa (Loew)] have greater sexual prowess than their virgin counterparts. After mating for the first time, 6- to...
Young mated male Caribbean fruit flies [Anastrepha suspensa (Loew)] have greater sexual prowess than their virgin counterparts. After mating for the first time, 6- to 7-day-old males released twice as much sex pheromone and acquired another mate in less than half the time required by virgin males of the same age. Mass spectroscopic analysis of extracts of hemolymph from mated and virgin 7-day-old males resulted in identification of juvenile hormone III bisepoxide and juvenile hormone III in a ratio of 2.5:1. Extracts from mated males contained 3-fold more juvenile hormone than did extracts from virgins. Enhancement of sexual signaling, pheromone release, and mating was induced by topical application of juvenile hormone, methoprene, or fenoxycarb. Newly eclosed adult males treated with juvenoids engaged in sexual signaling, released pheromone, and mated at significantly earlier ages than control males. We conclude that juvenile hormone mediated a positive feedback system that imparted a competitive advantage, guaranteeing that males who mated at an early age would out-compete virgins of the same age for mating opportunities. Additionally, the results support the hypothesis that juvenile hormone is a pivotal hormone coordinating the development of sexual signaling and reproductive maturity in these flies.
Topics: Animals; Diptera; Juvenile Hormones; Male; Reproduction; Sex Attractants; Sexual Behavior, Animal; Signal Transduction
PubMed: 10706642
DOI: 10.1073/pnas.97.7.3708 -
Gene Oct 2015In insect, juvenile hormone (JH) titers are tightly regulated in different development stages through synthesis and degradation pathways. During JH degradation, JH...
In insect, juvenile hormone (JH) titers are tightly regulated in different development stages through synthesis and degradation pathways. During JH degradation, JH epoxide hydrolase (JHEH) converts JH to JH diol, and hydrolyses JH acid to JH acid diol. In this study, two full length LdJHEH cDNAs were cloned from Leptinotarsa decemlineata, and were provisionally designated LdJHEH1 and LdJHEH2. Both mRNAs were detectable in the thoracic muscles, brain-corpora cardiaca-corpora allata complex, foregut, midgut, hindgut, ventral ganglia, Malpighian tubules, fat bodies, epidermis, and hemocytes of the day 2 fourth-instar larvae, and in female ovaries as well as male reproductive organs of the adults. Moreover, both LdJHEH1 and LdJHEH2 were expressed throughout all larval life, with the highest peaks occurring 32h after ecdysis of the final (fourth) instar larvae. Four double-stranded RNAs (dsRNAs) (dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2) respectively targeting LdJHEH1 and LdJHEH2 were constructed and bacterially expressed. Ingestion of dsJHEH1-1, dsJHEH1-2, dsJHEH2-1, dsJHEH2-2, and a mixture of dsJHEH1-1+dsJHEH2-1 successfully knocked down corresponding target gene function, and significantly increased JH titer and upregulated Krüppel homolog 1 (LdKr-h1) mRNA level. Knockdown of either LdJHEH1 or LdJHEH2, or both genes slightly reduced larval weight and delayed larval development, and significantly impaired adult emergence. Therefore, it is suggested that knockdown LdJHEH1 and LdJHEH2 affected JH degradation in the Colorado potato beetle.
Topics: Amino Acid Sequence; Animals; Coleoptera; Epoxide Hydrolases; Juvenile Hormones; Molecular Sequence Data; RNA Interference; Sequence Homology, Amino Acid
PubMed: 26079572
DOI: 10.1016/j.gene.2015.06.032 -
General and Comparative Endocrinology May 2016Trade-offs are a central tenet in the life-history evolution and the simplest model to understand it is the "Y" model: the investment of one arm will affect the...
Trade-offs are a central tenet in the life-history evolution and the simplest model to understand it is the "Y" model: the investment of one arm will affect the investment of the other arm. However, this model is by far more complex, and a "branched Y-model" is proposed: trade-offs could exist within each arm of the Y, but the mechanistic link is unknown. Here we used Tenebrio molitor to test if Juvenile Hormone (JH) could be a mechanistic link behind the "branched Y-model". Larvae were assigned to one of the following experimental groups: (1) low, (2) medium and (3) high doses of methoprene (a Juvenile Hormone analogue, JHa), (4) acetone (methoprene diluents; control one) or (5) näive (handled in the same way as other groups; control two). The JHa lengthened the time of development from larvae to pupae and larvae to adults, resulting in adults with a larger size. Males with medium and long JHa treatment doses were favored with female choice, but had smaller testes and fewer viable sperm. There were no differences between groups in regard to the number of spermatozoa of males, or the number of ovarioles or eggs of females. This results suggest that JH: (i) is a mechanistic link of insects "branched Y model", (ii) is a double ended-sword because it may not only provide benefits on reproduction but could also impose costs, and (iii) has a differential effect on each sex, being males more affected than females.
Topics: Animals; Biological Evolution; Female; Juvenile Hormones; Larva; Male; Methoprene; Models, Biological; Pupa; Reproduction; Sexual Behavior, Animal; Spermatozoa; Tenebrio
PubMed: 27013379
DOI: 10.1016/j.ygcen.2016.03.027 -
Insect Biochemistry and Molecular... 2000In the 1950s, Berta Scharrer predicted that neurosecretions from the brain regulated corpus allatum activity based upon the observation of the change in localization of... (Review)
Review
In the 1950s, Berta Scharrer predicted that neurosecretions from the brain regulated corpus allatum activity based upon the observation of the change in localization of neurosecretory material in the brain and change in gland activity after severance of nerves between the brain and corpus allatum. Isolation and characterization of neuropeptide regulators of juvenile hormone production by the corpora allata in the late 1980s has confirmed this prediction. Both a stimulatory allatotropin and an inhibitory allatostatin have been isolated from moth brains. Two families of allatostatins, both quite different from each other and that of moths, have been isolated from cockroaches and crickets. The wide distribution of these peptides in the nervous system, in nerves to visceral muscle, in endocrine cells of the midgut and in blood cells, indicate multifunctions in the insects in which they are allatoregulatory. Some of these other functions have been demonstrated in these insects and in insects in which these neuropeptides occur but do not act as corpus allatum regulators. For the latter group, the neuropeptide regulators of the corpora allata have yet to be isolated. The families of neurosecretory regulators will continue to grow.
Topics: Amino Acid Sequence; Animals; Brain; Corpora Allata; History, 20th Century; Humans; Insect Hormones; Juvenile Hormones; Molecular Sequence Data; Neuropeptides
PubMed: 10876108
DOI: 10.1016/s0965-1748(00)00036-9 -
Journal of Insect Physiology Apr 2005
Topics: Animals; Insecta; Juvenile Hormones
PubMed: 15890176
DOI: 10.3201/eid1105.041272 -
Insect Biochemistry and Molecular... Dec 2003Juvenile hormone (JH) involvement in male reproduction is poorly understood. In Drosophila melanogaster adults, JH deficiency has been shown to result in lowered protein...
Juvenile hormone (JH) involvement in male reproduction is poorly understood. In Drosophila melanogaster adults, JH deficiency has been shown to result in lowered protein synthesis in male accessory glands. To probe additional roles, we have examined males homozygous for a null allele of Methoprene-tolerant (Met). This gene is involved in the action of JH, possibly at the JH receptor level, and Met(27) null mutants reflect a diminution of JH action. Met(27) males were found to have reduced protein accumulation in male accessory glands and to court and mate wild-type females much less avidly than do either Met(+) or Met(27); Met(+) transgenic males. Exposure of Met(27) males to methoprene partially rescued the courtship deficiency. However, sperm transfer as reflected by fertility of Met(27) fathers was found to be similar to that of Met(+). Taken together with previous work examining the JH-deficient mutant apterous, these results corroborate JH involvement in protein synthesis in the male accessory glands and suggest a role for JH in promoting male mating behavior in these flies.
Topics: Alleles; Animals; Courtship; Drosophila melanogaster; Ejaculatory Ducts; Exocrine Glands; Female; Fertility; Genotype; Insect Proteins; Insecticide Resistance; Juvenile Hormones; Male; Methoprene; Mutation; Phenotype; Reproduction; Sexual Behavior, Animal; Sperm Transport
PubMed: 14599489
DOI: 10.1016/j.ibmb.2003.06.007 -
The Journal of Endocrinology Mar 1975
Topics: Animals; Cells, Cultured; Cockroaches; Female; Juvenile Hormones
PubMed: 1133561
DOI: No ID Found -
Molecular and Cellular Endocrinology Oct 1979An in vitro method has been developed for the investigation of the regulation of juvenile hormone biosynthesis by insect corpora allata. Glands were maintained in Marks...
An in vitro method has been developed for the investigation of the regulation of juvenile hormone biosynthesis by insect corpora allata. Glands were maintained in Marks medium 19AB and JH synthesis quantified by a modified radioimmunoassay for juvenile hormone I. The radioimmunoassay is specific for JH I and exhibits approximately 12.6% cross reactivity with JH II and no cross reactivity with JH III. The assay directly measures the JH present in culture medium and has a maximum sensitivity of 50 pg JH I equivalents. Corpora allata from day 5 last instar Manduca sexta larvae were used to define the kinetics parameters of the in vitro system, including a demonstration that small groups of right and left glands synthesize equivalent amounts of juvenile hormone. The juvenile hormones synthesized were identified as juvenile hormones I and II in a ratio of 1:4, respectively. Juvenile hormone III could not be excluded as a product of the corpora allata owing to the low cross reactivity of this homolog (1.7%) in the radioimmunoassay. Corpora allata from different developmental stages exhibited synthesis rates generally consistent with predicted activity based on in vivo hormone titers with the exception of day 5 of the last instar. The variation in gland activity relative to the control of juvenile hormone titer in vivo is discussed.
Topics: Aging; Animals; Corpora Allata; Cross Reactions; Juvenile Hormones; Lepidoptera; Radioimmunoassay
PubMed: 499652
DOI: 10.1016/0303-7207(79)90002-9 -
Zeitschrift Fur Naturforschung. C,... 1995Juvenile hormone analogues were tested for their lytic activity on Trypanosoma cruzi Chagas, 1909 blood tripomastigotes cultivated in vitro. The results indicated that... (Comparative Study)
Comparative Study
Juvenile hormone analogues were tested for their lytic activity on Trypanosoma cruzi Chagas, 1909 blood tripomastigotes cultivated in vitro. The results indicated that the carbamate 4 and the phenoxyphenol derivative 1 are considered good candidates for blood sterilization. The compounds were also assayed for inhibition of development of parasites in infected mice showing a moderated degree of activity.
Topics: Animals; Carbamates; Chagas Disease; Juvenile Hormones; Mice; Phenols; Structure-Activity Relationship; Trypanocidal Agents; Trypanosoma cruzi
PubMed: 7546047
DOI: 10.1515/znc-1995-7-817 -
Hormones and Behavior Feb 2000Behavioral development in the adult worker honey bee (Apis mellifera), from performing tasks inside the hive to foraging, is associated with an increase in the blood...
Behavioral development in the adult worker honey bee (Apis mellifera), from performing tasks inside the hive to foraging, is associated with an increase in the blood titer of juvenile hormone III (JH), and hormone treatment results in precocious foraging. To study behavioral development in the absence of JH we removed its glandular source, the corpora allata, in 1-day-old adult bees. The age at onset of foraging for allatectomized bees in typical colonies was significantly older compared with that of sham-operated bees in 3 out of 4 colonies; this delay was eliminated by hormone replacement in 3 out of 3 colonies. To determine the effects of corpora allata removal on sensitivity to changes in conditions that influence the rate of behavioral development, we used "single-cohort" colonies (composed of only young bees) in which some colony members initiate foraging precociously. The age at onset of foraging for allatectomized bees was significantly older compared with that of sham-operated bees in 2 out of 3 colonies, and this delay was eliminated by hormone replacement. Allatectomized bees initiated foraging at significantly younger ages in single-cohort colonies than in typical colonies. These results demonstrate that JH influences the pace of behavioral development in honey bees, but is not essential for either foraging or altering behavioral development in response to changes in conditions.
Topics: Aging; Animals; Bees; Behavior, Animal; Juvenile Hormones; Methoprene; Pupa; Radioimmunoassay
PubMed: 10712853
DOI: 10.1006/hbeh.1999.1552