scholarly journals SEX DETERMINATION IN BEES. IV. GENETIC CONTROL OF JUVENILE HORMONE PRODUCTION IN MELIPONA QUADRIFASCIATA (APIDAE)

Genetics ◽  
1975 ◽  
Vol 81 (4) ◽  
pp. 749-756
Author(s):  
Warwick Estevam Kerr ◽  
Yukio Akahira ◽  
Conceição A Camargo
Keyword(s):  
Juvenile Hormone ◽  
High Volume ◽  
Cell Number ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Caste Determination ◽  
Prepupal Stage ◽  
Hormone Production ◽  
Melipona Quadrifasciata ◽  
Phases Of Development

ABSTRACT Cell number and volume of corpora allata was determined for 8 phases of development, the first prepupal stage to adults 30 days old, in the social Apidae Melipona quadrifasciata. In the second prepupal stage a strong correlation was found between cell number and body weight (r=0.651**), and cell number and corpora allata volume in prepupal stage (r=0.535*), which indicates that juvenile hormone has a definite role in caste determination in Melipona. The distribution of the volume of corpus allatum suggest a 3:1 segregation between bees with high volume of corpora allata against low and medium volume. This implies that genes xa and xb code for an enzyme that directly participates in juvenile hormone production. It was also concluded that the number of cells in the second prepupal stage is more important than the weight of the prepupa for caste determination. A scheme summarizing the genic control of sex and caste determination in Melipona bees in the prepupal phase is given.

Hormone Balance and the Control of Metamorphosis in Rhodnius Prolixus (Hemiptera)

1952 ◽  
Vol 29 (4) ◽  
pp. 620-631
Author(s):  
V. B. WIGGLESWORTH
Keyword(s):  
Juvenile Hormone ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Stage Larva ◽  
Mature Adults ◽  
Hormone Balance ◽  
Low Concentrations ◽  
Moulting Cycle ◽  
Increased Activity ◽  
Reduced Activity

A technique is described by which the intact larva of Rhodnius can be transfused with blood from another larva without interfering with ecdysis. If the 4th-stage larva receives blood from a 3rd-stage larva it develops characters little different from those of the 4th instar. This is attributed to the 3rd-stage larva producing juvenile hormone at a higher concentration. If the 4th-stage larva at 24 hr. after feeding receives blood from another 4th-stage larva at 8 days after feeding it develops characters intermediate between those of the 4th and 5th instars. This is attributed to the juvenile hormone being introduced too early in the moulting cycle. The hormone balance is upset by abnormal temperatures. The 4th-stage larva will not moult at a temperature of 36° C. although the larvae can survive up to about 40° C. At temperatures a little below 36° C. moulting is somewhat delayed and the characters developed are slightly ‘adultoid’ (prothetely). This is attributed to slightly reduced activity of the corpus allatum. At temperatures below 20° C. moulting is greatly delayed and the characters developed are slightly ‘juvenile’ (metathetely). This is attributed to relatively increased activity of the corpus allatum. Low concentrations of oxygen (less than 5 %) have an effect similar to that of high temperature. If 5th-stage larvae of Rhodnius receive implants of corpora allata from mature adults of Periplaneta they develop into 6th-stage larvae and many of these subsequently into 7th-stage larvae. The ‘juvenile hormone’ appears to be the same in the two insects. No evidence could be obtained for the persistence of juvenile hormone in the blood from one instar of Rhodnius to the next. The hypothesis of an active elimination of juvenile hormone by the corpus allatum at the time of metamorphosis remains therefore unproven.

Changes in cell number and activity of the corpora allata of the cockroach Diploptera punctata: a role for mating and the ovary

1984 ◽  
Vol 62 (11) ◽  
pp. 2178-2182 ◽  
Author(s):  
S. S. Tobe ◽  
N. Clarke ◽  
B. Stay ◽  
R. P. Ruegg
Keyword(s):  
Juvenile Hormone ◽  
Cell Number ◽  
Neurosecretory Cells ◽  
Corpora Allata ◽  
Surgical Removal ◽  
Gonotrophic Cycle ◽  
Biosynthetic Activity ◽  
Diploptera Punctata ◽  
Number Of Cells ◽  
Mated Female

The corpora allata (CA) of mated female Diploptera punctata showed an increase in cell number from 6000 cells/CA on the day of emergence to a maximum of about 9000 cells/CA by day 5. The number of cells per CA then declined and, by day 8, the CA was composed of about 6000 cells. In the normal mated animal, the previously established increase in biosynthetic activity of the CA correlated with the increase in number of cells in the CA. In virgin females no significant change in cell number was observed during this period and this correlates with the demonstrated low and constant rates of juvenile hormone (JH) biosynthesis. Following ovariectomy, however, an increase in cell number occurred (to 10 000 cells/CA) by day 5 and cell number remained elevated until at least day 8. Low rates of JH biosynthesis have been observed previously in ovariectomized females and thus the increase in cell number observed in these females is not accompanied by a corresponding increase in biosynthetic activity. The cell number of the CA in ovariectomized females was reduced by injection of 20-hydroxyecdysone. We propose that either mating or surgical removal of inhibitory signals from cerebral neurosecretory cells permits the proliferation of the cells of the CA. We also propose that factors from the ovary are responsible for both the initiation of the cycle of JH biosynthesis and the reduction of CA cell number at the end of the gonotrophic cycle.

scholarly journals The effect of ovary implants on juvenile hormone production by corpora allata of male Diploptera punctata

2003 ◽  
Vol 3 (30) ◽  
pp. 1-6 ◽  
Author(s):  
J. K. Hass ◽  
K. A. Cassias ◽  
A. P. Woodhead ◽  
B. Stay
Keyword(s):  
Juvenile Hormone ◽  
Corpora Allata ◽  
Hormone Production ◽  
Diploptera Punctata

scholarly journals Neuroendocrine Regulation of Reproductive Dormancy in the Fruit Fly Drosophila melanogaster: A Review of Juvenile Hormone-Dependent Regulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Yoshitomo Kurogi ◽  
Yosuke Mizuno ◽  
Eisuke Imura ◽  
Ryusuke Niwa
Keyword(s):  
Drosophila Melanogaster ◽  
Juvenile Hormone ◽  
Environmental Conditions ◽  
Fruit Fly ◽  
Reproductive Organs ◽  
Corpus Allatum ◽  
Corpora Allata ◽  
Day Length ◽  
Control Mechanisms ◽  
Wide Range

Animals can adjust their physiology, helping them survive and reproduce under a wide range of environmental conditions. One of the strategies to endure unfavorable environmental conditions such as low temperature and limited food supplies is dormancy. In some insect species, this may manifest as reproductive dormancy, which causes their reproductive organs to be severely depleted under conditions unsuitable for reproduction. Reproductive dormancy in insects is induced by a reduction in juvenile hormones synthesized in the corpus allatum (pl. corpora allata; CA) in response to winter-specific environmental cues, such as low temperatures and short-day length. In recent years, significant progress has been made in the study of dormancy-inducing conditions dependent on CA control mechanisms in Drosophila melanogaster. This review summarizes dormancy control mechanisms in D. melanogaster and discusses the implications for future studies of insect dormancy, particularly focusing on juvenile hormone-dependent regulation.

Evidence against the hypothesis that metacestodes of Hymenolepis diminuta inhibit corpora allata functioning in the intermediate host, Tenebrio molitor

Parasitology ◽  
1987 ◽  
Vol 95 (1) ◽  
pp. 93-96 ◽  
Author(s):  
Hilary Hurd ◽  
R. J. Weaver
Keyword(s):  
Juvenile Hormone ◽  
Intermediate Host ◽  
Endocrine System ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Corpora Allata ◽  
Hormone Production ◽  
Control Female ◽  
And Control

SUMMARYSeveral of the pathophysiological responses made by the beetle Tenebrio molitor, when infected with metacestodes of Hymenolepis diminuta, may be attributed to a parasite-induced reduction in host juvenile hormone titre. It has been suggested that production of this hormone by the corpora allata may be inhibited in parasitized insects. This hypothesis was tested using an in vitro radiochemical assay to compare the biosynthesis of juvenile hormone by single pairs of corpora allata taken from mated 12- and 15-day-old infected and control female insects. The results demonstrate, however, that there was no difference in hormone production associated with metacestode infection. Other possible mechanisms for parasite interference in this host endocrine system are discussed.

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