Circadian clocks and life-history related traits: Is pupation height affected by circadian organization inDrosophila melanogaster?

Dhanashree A. Paranjpe; D. Anitha; Vijay Kumar Sharma; Amitabh Joshi

doi:10.1007/bf02715831

Circadian clocks and life-history related traits: Is pupation height affected by circadian organization inDrosophila melanogaster?

Journal of Genetics ◽

10.1007/bf02715831 ◽

2004 ◽

Vol 83 (1) ◽

pp. 73-77 ◽

Cited By ~ 5

Author(s):

Dhanashree A. Paranjpe ◽

D. Anitha ◽

Vijay Kumar Sharma ◽

Amitabh Joshi

Keyword(s):

Life History ◽

Circadian Clocks ◽

Pupation Height ◽

Circadian Organization

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Time is honey: circadian clocks of bees and flowers and how their interactions may influence ecological communities

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2016.0256 ◽

2017 ◽

Vol 372 (1734) ◽

pp. 20160256 ◽

Cited By ~ 24

Author(s):

Guy Bloch ◽

Noam Bar-Shai ◽

Yotam Cytter ◽

Rachel Green

Keyword(s):

Environmental Pollutants ◽

Circadian Clocks ◽

Alien Invasive Species ◽

Ecological Communities ◽

Compass Orientation ◽

Sun Compass ◽

Circadian Organization ◽

Pollination Network ◽

Key Aspects ◽

Reward Availability

The interactions between flowering plants and insect pollinators shape ecological communities and provide one of the best examples of coevolution. Although these interactions have received much attention in both ecology and evolution, their temporal aspects are little explored. Here we review studies on the circadian organization of pollination-related traits in bees and flowers. Research, mostly with the honeybee, Apis mellifera , has implicated the circadian clock in key aspects of their foraging for flower rewards. These include anticipation, timing of visits to flowers at specified locations and time-compensated sun-compass orientation. Floral rhythms in traits such as petal opening, scent release and reward availability also show robust daily rhythms. However, in only few studies was it possible to adequately determine whether these oscillations are driven by external time givers such as light and temperature cycles, or endogenous circadian clocks. The interplay between the timing of flower and pollinator rhythms may be ecologically significant. Circadian regulation of pollination-related traits in only few species may influence the entire pollination network and thus affect community structure and local biodiversity. We speculate that these intricate chronobiological interactions may be vulnerable to anthropogenic effects such as the introduction of alien invasive species, pesticides or environmental pollutants. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.

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Excess Androgen During Puberty Disrupts Circadian Organization in Female Rats

Endocrinology ◽

10.1210/en.2012-2066 ◽

2013 ◽

Vol 154 (4) ◽

pp. 1636-1647 ◽

Cited By ~ 18

Author(s):

Michael T. Sellix ◽

Zachary C. Murphy ◽

Michael Menaker

Keyword(s):

Phase Distribution ◽

Polycystic Ovary ◽

Critical Factor ◽

Ovarian Follicles ◽

Circadian Clocks ◽

Female Rats ◽

Childbearing Age ◽

End Of Treatment ◽

Circadian Organization ◽

The Impact

Abstract Circadian clocks have been described in each tissue of the hypothalamo-pituitary-ovarian axis. Although a role for the clock in the timing of ovulation is indicated, the impact of diseases that disrupt fertility on clock function or the clocks' role in the etiology of these pathologies has yet to be fully appreciated. Polycystic ovary syndrome (PCOS) is a particularly devastating endocrinopathy, affecting approximately 10% of women at childbearing age. Common features of PCOS are a polycystic ovary, amenorrhea, and excess serum androgen. Approximately 40% of these women have metabolic syndrome, including hyperinsulinemia, dyslipidemia, and hyperleptinemia. It has been suggested that excess androgen is a critical factor in the etiology of PCOS. We have examined the effects of androgen excess during puberty on the phase of circadian clocks in tissues of the metabolic and hypothalamo-pituitary-ovarian axes. Female period1-luciferase (per1-luc) rats were exposed to androgen (5α-dihydrotestosterone [DHT]) or placebo for 4-6 weeks (short term) or 9-15 weeks (long term). As expected, DHT-treated animals gained more weight than controls and had disrupted estrous cycles. At the end of treatment, tissues, including the liver, lung, kidney, white adipose, cornea, pituitary, oviduct, and ovarian follicles, were cultured, and per1-luc expression in each was recorded. Analysis of per1-luc expression revealed that DHT exposure increased phase distribution of multiple oscillators, including ovarian follicles, liver, and adipose, and altered phase synchrony between animals. These data suggest that excess androgen during puberty, a common feature of PCOS, negatively affects internal circadian organization in both the reproductive and metabolic axes.

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Interrelationships of factors of social development are more complex than Life History Theory predicts

Behavioral and Brain Sciences ◽

10.1017/s0140525x19000177 ◽

2019 ◽

Vol 42 ◽

Author(s):

Boris Kotchoubey

Keyword(s):

Life History ◽

Social Development ◽

Life History Theory ◽

Strong Correlations ◽

Behavioral Features

Abstract Life History Theory (LHT) predicts a monotonous relationship between affluence and the rate of innovations and strong correlations within a cluster of behavioral features. Although both predictions can be true in specific cases, they are incorrect in general. Therefore, the author's explanations may be right, but they do not prove LHT and cannot be generalized to other apparently similar processes.

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