scholarly journals Skew in ovarian activation depends on domicile size in phyllode-glueing thrips

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
J. D. J. Gilbert ◽  
A. Wells ◽  
S. J. Simpson
Keyword(s):  
Ovarian Activation

scholarly journals Chemical Variation among Castes, Female Life Stages and Populations of the Facultative Eusocial Sweat Bee Halictus rubicundus (Hymenoptera: Halictidae)

2021 ◽  
Author(s):  
Iris Steitz ◽  
Robert J Paxton ◽  
Stefan Schulz ◽  
Manfred Ayasse
Keyword(s):  
Chemical Communication ◽  
North American ◽  
Specific Chemical ◽  
Eusocial Insects ◽  
Queen Signal ◽  
Ovarian Activation ◽  
Chemical Profiles ◽  
Reproductive Division Of Labor ◽  
Reproductive Division ◽  
Eusocial Species

AbstractIn eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to control worker reproduction through physical aggression by the queen rather than via pheromones, suggesting the evolutionary establishment of chemical signals with more derived sociality. However, studies supporting this hypothesis are largely missing. Socially polymorphic halictid bees, such as Halictus rubicundus, with social and solitary populations in both Europe and North America, offer excellent opportunities to illuminate the evolution of caste-specific signals. Here we compared the chemical profiles of social and solitary populations from both continents and tested whether (i) population or social level affect chemical dissimilarity and whether (ii) caste-specific patterns reflect a conserved queen signal. Our results demonstrate unique odor profiles of European and North American populations, mainly due to different isomers of n-alkenes and macrocyclic lactones; chemical differences may be indicative of phylogeographic drift in odor profiles. We also found common compounds overproduced in queens compared to workers in both populations, indicating a potential conserved queen signal. However, North American populations have a lower caste-specific chemical dissimilarity than European populations which raises the question if both use different mechanisms of regulating reproductive division of labor. Therefore, our study gives new insights into the evolution of eusocial behavior and the role of chemical communication in the inhibition of reproduction.

scholarly journals Ovarian activation in Melipona quadrifasciata queens triggered by mating plug stimulation (Hymenoptera, Apidae)

Apidologie ◽  
2001 ◽  
Vol 32 (4) ◽  
pp. 355-361 ◽  
Author(s):  
Gabriel A.R. Melo ◽  
Maria Luisa T. Buschini ◽  
Lucio A.O. Campos
Keyword(s):  
Mating Plug ◽  
Melipona Quadrifasciata ◽  
Ovarian Activation

Role of light and temperature in the regulation of reproduction in the red-sided garter snake, Thamnophis sirtalis parietalis

1987 ◽  
Vol 65 (8) ◽  
pp. 2090-2096 ◽  
Author(s):  
Joan M. Whittier ◽  
Robert T. Mason ◽  
David Crews ◽  
Paul Licht
Keyword(s):  
Sexual Behavior ◽  
Courtship Behavior ◽  
Cold Temperature ◽  
Thamnophis Sirtalis ◽  
Garter Snakes ◽  
Thamnophis Sirtalis Parietalis ◽  
Long Day ◽  
Exposure To Cold ◽  
Ovarian Activation

The influence of photoperiodic manipulation on sexual behavior and ovarian recrudescence of male and female red-sided garter snakes (Thamnophis sirtalis parietalis) was examined over a 4-year period. Snakes were exposed to photoperiodic manipulations before, during, and after a 17-week cold temperature dormancy; sexual behavior of males and females and ovarian recrudescence were observed after emergence from cold temperature dormancy. In the 1st year (1982), males were exposed to two conditions representing minimum and maximum exposure to daylight: (i) 6 weeks of a short-day prehibernation period (10L:14D, 28:18 °C), followed by 17 weeks of hibernation in complete darkness (0L:24D, 4 °C) and emergence into warm dark conditions (0L:24D, 28:18 °C); and (ii) 6 weeks of a long-day prehibernation period (14L:10D, 28:18 °C), followed by 17 weeks of hibernation with exposure to light (12L:12D, 4 °C) and emergence into warm, long days (14L:10D, 28:18 °C). Males in both conditions exhibited intense courtship behavior on emergence from hibernation. Females in 1982 were significantly influenced only by long-day prehibernation conditions (14L:10D, 28:18 °C); under these conditions, ovarian recrudescence on emergence was inhibited. Long prehibernation photoperiod did not significantly influence female receptive behavior on emergence, indicating that neuroendocrine control of ovarian activation and sexual behavior may be separate in this species. In three subsequent years (1983, 1984, 1985) none of the photoperiodic conditions significantly influenced male or female sexual behavior or ovarian recrudescence. Slight differences in experimental protocol in these subsequent years that may account for differences in results from 1982 are discussed. Finally, ovarian development was found to be clearly tied to the duration of cold temperature dormancy in this species. Females receiving 7 or 17 weeks of exposure to cold (4 °C) underwent vitellogenesis at similar frequencies. Most females receiving 0 or only 4 weeks of exposure to cold (4 °C) did not become vitellogenic. Mating on emergence was not a requirement for the initiation of vitellogenesis in this study.

scholarly journals Postnatal Ovarian Activation Has Effects in Estrogen Target Tissues in Infant Girls

2013 ◽  
Vol 98 (12) ◽  
pp. 4709-4716 ◽  
Author(s):  
Tanja Kuiri-Hänninen ◽  
Mikko Haanpää ◽  
Ursula Turpeinen ◽  
Esa Hämäläinen ◽  
Raija Seuri ◽  
...  
Keyword(s):  
Ovarian Activation

scholarly journals Ovarian activation delays in peripubertal ewe lambs infected with Haemonchus contortus can be avoided by supplementing protein in their diets

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Paula Suarez-Henriques ◽  
Camila de Miranda e Silva Chaves ◽  
Ricardo Cardoso-Leite ◽  
Danielle G. Gomes-Caldas ◽  
Luciana Morita-Katiki ◽  
...  
Keyword(s):  
Immune Response ◽  
Haemonchus Contortus ◽  
Ovarian Follicle ◽  
Physiological State ◽  
Protein Supplementation ◽  
Ovis Aries ◽  
P Value ◽  
Ewe Lambs ◽  
Ovarian Activation ◽  
Follicle Activation

Abstract Background The ewe lamb nutritional and physiological state interfere with the ovarian environment and fertility. The lack or excess of circulating nutrients reaching the ovary can change its gene expression. A protein deficiency in the blood caused by an Haemonchus contortus abomasal infection is detrimental to the organism’s development during puberty. The peripubertal period is a time of intensive growth that requires a high level of nutrients. An essential feature controlling pubertal arousal and female reproductive potential is ovarian follicle growth activation. Protein supplementation improves the sheep’s immune response to helminthic infections. We aimed to determine if supplementing protein in infected ewe lambs’ diet would impact the ovarian environment leading to earlier ovarian follicle activation than in infected not supplemented animals. Methods We fed 18 Santa Ines ewe lambs (Ovis aries) - bred by the same ram - with either 12% protein (Control groups) or 19% protein (Supplemented groups) in their diets. After 35 days of the diet, they were each artificially infected or not with 10,000 Haemonchus contortus L3 larvae. Following 77 days of the diet and 42 days of infection, we surgically collected their left ovaries and examined their genes expression through RNA sequencing. Results We found that protein supplementation in infected animals led to an up-regulation of genes (FDR p-values < 0.05) and biological processes (p-value cut-off = 0.01) linked to meiotic activation in pre-ovulatory follicles and primordial follicle activation, among others. The supplemented not infected animals also up-regulated genes and processes linked to meiosis and others, such as circadian behaviour. The not supplemented animals had these same processes down-regulated while up-regulated processes related to tissue morphogenesis, inflammation and immune response. Conclusion Diet’s protein supplementation of peripubertal infected animals allowed them to express genes related to a more mature ovarian follicle stage than their half-sisters that were not supplemented. These results could be modelling potential effects of the interaction between environmental factors, nutrition and infection on reproductive health. When ovarian activation is achieved in a timely fashion, the ewe may generate more lambs during its reproductive life, increasing sheep breeders’ productivity.

scholarly journals Juvenile hormone affects age polyethism, ovarian status, and cuticular hydrocarbon profile in workers of a Polybia occidentalis wasp

2021 ◽  
Author(s):  
Amanda Prato ◽  
Rafael C. da Silva ◽  
Diego S. Assis ◽  
Sidnei Mateus ◽  
Klaus Hartfelder ◽  
...  
Keyword(s):  
Juvenile Hormone ◽  
Division Of Labor ◽  
Cuticular Hydrocarbon ◽  
Age Polyethism ◽  
Social Hymenoptera ◽  
Polybia Occidentalis ◽  
Ovary Activation ◽  
Social Species ◽  
Ovarian Activation ◽  
Chemical Profiles

Division of labor is one of the most striking features in the evolution of eusociality. Juvenile hormone (JH) mediates reproductive status and aggression among nestmates in primitively eusocial Hymenoptera (species without morphologically distinct castes). In highly social species it has apparently lost its gonadotropic role and primarily regulates the division of labor in the worker caste. Polybia occidentalis, a Neotropical swarm-founding wasp, is an ideal model to understand how JH levels mirror social context and reproductive opportunities because of the absence of a clear morphological caste dimorphism. In this study, we tested the hypothesis that JH influences division of labor, ovary activation and cuticular hydrocarbon profiles of workers. Our observations confirmed that JH analog (methoprene) and precocene affected the cuticular chemical profile associated with the age polyethism. Also, methoprene and precocene-I influenced differently ovarian activation of treated females (individuals treated with methoprene expressed more activated ovaries while precocene treatment did not have significant effect). These results suggest that different hormonal levels induce a differential expression in the cuticular chemical profiles associated with the workers’ age polyethism, which may be essential for keeping the social cohesion among workers throughout their lives in the colony. Furthermore, JH is likely to play a gonadotropic role in P. occidentalis. JH has apparently undergone certain modifications in social Hymenoptera, presenting multifaceted functions in different species.

scholarly journals Evolution of ageing, costs of reproduction and the fecundity–longevity trade-off in eusocial insects

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170380 ◽  
Author(s):  
Pierre Blacher ◽  
Timothy J. Huggins ◽  
Andrew F. G. Bourke
Keyword(s):  
Bombus Terrestris ◽  
Causal Role ◽  
Costs Of Reproduction ◽  
High Quality ◽  
Trade Off ◽  
Negatively Associated ◽  
Eusocial Insect ◽  
Eusocial Insects ◽  
Ovarian Activation

Eusocial insects provide special opportunities to elucidate the evolution of ageing as queens have apparently evaded costs of reproduction and reversed the fecundity–longevity trade-off generally observed in non-social organisms. But how reproduction affects longevity in eusocial insects has rarely been tested experimentally. In this study, we took advantage of the reproductive plasticity of workers to test the causal role of reproduction in determining longevity in eusocial insects. Using the eusocial bumblebee Bombus terrestris , we found that, in whole colonies, in which workers could freely ‘choose’ whether to become reproductive, workers' level of ovarian activation was significantly positively associated with longevity and ovary-active workers significantly outlived ovary-inactive workers. By contrast, when reproductivity was experimentally induced in randomly selected workers, thereby decoupling it from other traits, workers' level of ovarian activation was significantly negatively associated with longevity and ovary-active workers were significantly less long-lived than ovary-inactive workers. These findings show that workers experience costs of reproduction and suggest that intrinsically high-quality individuals can overcome these costs. They also raise the possibility that eusocial insect queens exhibit condition-dependent longevity and hence call into question whether eusociality entails a truly reversed fecundity–longevity trade-off involving a fundamental remodelling of conserved genetic and endocrine networks underpinning ageing.

IMPLANTATION OF OESTROGEN IN THE BRAIN AND THE INDUCTION OF OVULATION IN THE GUINEA-PIG

1974 ◽  
Vol 62 (1) ◽  
pp. 153-160 ◽  
Author(s):  
JANET E. BOOTH ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Anterior Hypothalamus ◽  
Oestrous Cycle ◽  
Pars Distalis ◽  
Initial Exposure ◽  
Medial Basal Hypothalamus ◽  
Induction Of Ovulation ◽  
Gonadotrophin Secretion ◽  
Ovarian Activation ◽  
The Brain

SUMMARY In the guinea-pig, when bilateral oestrogen implants were placed in the medial basal hypothalamus, anterior hypothalamus or suprachiasmatic area on day 10 of the oestrous cycle, ovarian changes indicative of gonadotrophin secretion were observed on day 15. Similarly located cholesterol implants and oestrogen implants outside this region were without effect. The gonadotrophin release was likely to have been induced by an action of the steroid at the hypothalamic, rather than the pituitary level, since bilateral implants of oestrogen in the pars distalis caused ovarian activation in only one out of eight animals. Signs of normal ovulation were evident in only three out of 19 animals in which oestrogen was implanted in the medial basal hypothalamus on day 10 and left in place for 10 days. The ovaries of some other animals bore the traces of luteal bodies formed in response to the initial exposure to oestrogen; other ovaries contained only large healthy or atretic follicles and spontaneous ovulation was apparently blocked. It is concluded that exposure of the hypothalamo-hypophysial system of the guinea-pig to an increased amount of oestrogen initially stimulates and then inhibits ovulatory gonadotrophin secretion. Tonic gonadotrophin secretion is unaffected.

scholarly journals Nutritional benefit of fungal spores for honey bee workers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jorgiane B. Parish ◽  
Eileen S. Scott ◽  
Katja Hogendoorn
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
Nutritional Value ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Poor Quality ◽  
Colletotrichum Acutatum ◽  
Hypopharyngeal Glands ◽  
Ovarian Activation ◽  
Honey Bee Workers

Abstract The collection of fungal spores by honey bees, Apis mellifera, can be classified as active or passive, the latter when spores are associated with pollen, nectar or honey dew. While low quality and shortage of pollen have been raised as hypotheses for fungal spore collection, the nutritional value of fungal spores for honey bees is poorly understood. Here we investigated the effect of consumption of fungal spores on survival, ovarian activation and the development of the hypopharyngeal glands (HPGs) in honey bee workers. Two pollen diets (Eucalyptus sp. pollen and a multifloral pollen) supplemented or not with spores of Botrytis cinerea, Cladosporium sp. or Colletotrichum acutatum were used. Consumption of diets that contained fungal spores increased the longevity of honey bee workers but had no significant effect on the development of their HPGs and ovaries. This demonstrates that fungal spores may have nutritional value for honey bees and that the consumption of fungal spores may compensate for nutritional imbalances of poor-quality pollen diets.

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