Effects of Day Length, Temperature, and Green Food on Testicular Development in a Desert Pocket Mouse Perognathus formosus

1981 ◽  
Vol 54 (1) ◽  
pp. 62-73 ◽  
Author(s):  
G. J. Kenagy ◽  
George A. Bartholomew
Keyword(s):  
Day Length ◽  
Testicular Development ◽  
Green Food ◽  
Pocket Mouse

Simulated natural day lengths synchronize seasonal rhythms of asynchronously born male Siberian hamsters

2007 ◽  
Vol 293 (1) ◽  
pp. R402-R412 ◽  
Author(s):  
Matthew P. Butler ◽  
Kevin W. Turner ◽  
Jin Ho Park ◽  
James P. Butler ◽  
Justin J. Trumbull ◽  
...  
Keyword(s):  
Somatic Growth ◽  
Day Length ◽  
Delayed Puberty ◽  
Testicular Development ◽  
Early Puberty ◽  
Seasonal Rhythms ◽  
Siberian Hamsters ◽  
Natural Photoperiod ◽  
Timing Of Puberty ◽  
Short Days

Photoperiodism research has relied on static day lengths and abrupt transitions between long and short days to characterize the signals that drive seasonal rhythms. To identify ecologically relevant critical day lengths and to test the extent to which naturally changing day lengths synchronize important developmental events, we monitored nine cohorts of male Siberian hamsters ( Phodopus sungorus) born every 2 wk from 4 wk before to 12 wk after the summer solstice in a simulated natural photoperiod (SNP). SNP hamsters born from 4 wk before to 2 wk after the solstice underwent rapid somatic and gonadal growth; among those born 4–6 wk after the solstice, some delayed puberty by many weeks, whereas others manifested early puberty. Hamsters born eight or more weeks after the solstice failed to undergo early testicular development. The transition to delayed development occurred at long day lengths, which induce early puberty when presented as static photoperiods. The first animals to delay puberty may do so predominantly on the basis of postnatal decreases in day length, whereas in later cohorts, a comparison of postnatal day length to gestational day length may contribute to arrested development. Despite differences in timing of birth and timing of puberty, autumn gonadal regression and spring gonadal and somatic growth occurred at similar calendar dates in all cohorts. Incrementally changing photoperiods exert a strong organizing effect on seasonal rhythms by providing hamsters with a richer source of environmental timing cues than are available in simple static day lengths.

Cue hierarchies and testicular development: Is food a more potent stimulus than day length in an opportunistic breeder (Taeniopygia g. guttata)?

2008 ◽  
Vol 53 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Nicole Perfito ◽  
Jenitta M.Y. Kwong ◽  
George E. Bentley ◽  
Michaela Hau
Keyword(s):  
Day Length ◽  
Testicular Development

Definition of a prenatal sensitive period for maternal-fetal communication of day length

1987 ◽  
Vol 253 (6) ◽  
pp. E701-E704 ◽  
Author(s):  
D. R. Weaver ◽  
J. T. Keohan ◽  
S. M. Reppert
Keyword(s):  
Gestational Age ◽  
Present Report ◽  
Reproductive Development ◽  
Prenatal Development ◽  
Postnatal Period ◽  
Day Length ◽  
Sensitive Period ◽  
Testicular Development ◽  
Djungarian Hamster ◽  
Definition Of

The duration of the nocturnal elevation of melatonin in the dam is a key feature in providing the Djungarian hamster fetus with a prenatal photoperiodic history. The developing animal compares the prenatal photoperiod with the photoperiod experienced during the postnatal period to properly time puberty. In the present report, we define the period during gestation when melatonin administered to the dam is effective in providing the fetus with a prenatal photoperiodic history. The administration of melatonin (50 ng delivered over 10 h at night) by timed infusions to pregnant, pinealectomized Djungarian hamsters for the last 4-7 days of gestation stimulated testicular weights of male pups reared in 14 h of light/day. Single 10-h melatonin infusions were ineffective in stimulating reproductive development (testes weights on day 34) of the male pups, irrespective of the gestational age of the fetus at the time of treatment. In contrast, two consecutive nightly 10-h infusions during gestation clearly stimulated testicular development. The gestational age of the fetus at the time of infusion strongly influenced the response, however. Treatments beginning between 6 and 3 days before birth were effective in stimulating postnatal reproductive development of the offspring. These results indicate that there is a well-delineated, sensitive period during prenatal development when melatonin can provide the fetus with a prenatal photoperiodic history.

Reduction of spermatogonia and testosterone in rat testes flown on space lab-3

1986 ◽  
Vol 44 ◽  
pp. 248-249
Author(s):  
Delbert E. Philpott ◽  
W. Sapp ◽  
C. Williams ◽  
T. Fast ◽  
J. Stevenson ◽  
...  
Keyword(s):  
Social Interaction ◽  
Social Status ◽  
Population Size ◽  
Physiological Response ◽  
Social Rank ◽  
Reproductive Function ◽  
Testicular Development ◽  
Organ Weights ◽  
Reproductive Maturation ◽  
Metabolic Activities

Space Lab 3 (SL-3) was flown on Shuttle Challenger providing an opportunity to measure the effect of spaceflight on rat testes. Cannon developed the idea that organisms react to unfavorable conditions with highly integrated metabolic activities. Selye summarized the manifestations of physiological response to nonspecific stress and he pointed out that atrophy of the gonads always occurred. Many papers have been published showing the effects of social interaction, crowding, peck order and confinement. Flickinger showed delayed testicular development in subordinate roosters influenced by group numbers, social rank and social status. Christian reported increasing population size in mice resulted in adrenal hypertrophy, inhibition of reproductive maturation and loss of reproductive function in adults. Sex organ weights also declined. Two male dogs were flown on Cosmos 110 for 22 days. Fedorova reported an increase of 30 to 70% atypical spermatozoa consisting of tail curling and/or the absence of a tail.

Postnatal growth rate and gonadal development in circadian tau mutant hamsters reared in constant dim red light

Reproduction ◽  
2000 ◽  
pp. 327-330 ◽  
Author(s):  
RJ Lucas ◽  
JA Stirland ◽  
YN Mohammad ◽  
AS Loudon
Keyword(s):  
Time Course ◽  
Red Light ◽  
Somatic Growth ◽  
Postnatal Growth ◽  
Gonadal Development ◽  
Testicular Development ◽  
Wild Type ◽  
Similar Time ◽  
Syrian Hamsters ◽  
Body Weights

The role of the circadian clock in the reproductive development of Syrian hamsters (Mesocricetus auratus was examined in wild type and circadian tau mutant hamsters reared from birth to 26 weeks of age under constant dim red light. Testis diameter and body weights were determined at weekly intervals in male hamsters from 4 weeks of age. In both genotypes, testicular development, subsequent regression and recrudescence exhibited a similar time course. The age at which animals displayed reproductive photosensitivity, as exhibited by testicular regression, was unrelated to circadian genotype (mean +/- SEM: 54 +/- 3 days for wild type and 59 +/- 5 days for tau mutants). In contrast, our studies revealed a significant impact of the mutation on somatic growth, such that tau mutants weighed 18% less than wild types at the end of the experiment. Our study reveals that the juvenile onset of reproductive photoperiodism in Syrian hamsters is not timed by the circadian system.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

scholarly journals Cytochrome c Deficiency Differentially Affects the In Vivo Mitochondrial Electron Partitioning and Primary Metabolism Depending on the Photoperiod

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 444
Author(s):  
Igor Florez-Sarasa ◽  
Elina Welchen ◽  
Sofia Racca ◽  
Daniel H. Gonzalez ◽  
José G. Vallarino ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Tca Cycle ◽  
Day Length ◽  
Primary Metabolism ◽  
Stress Signaling ◽  
Alternative Pathways ◽  
Tca Cycle Intermediates ◽  
Growth Adaptation ◽  
Plant Respiration

Plant respiration provides metabolic flexibility under changing environmental conditions by modulating the activity of the nonphosphorylating alternative pathways from the mitochondrial electron transport chain, which bypass the main energy-producing components of the cytochrome oxidase pathway (COP). While adjustments in leaf primary metabolism induced by changes in day length are well studied, possible differences in the in vivo contribution of the COP and the alternative oxidase pathway (AOP) between different photoperiods remain unknown. In our study, in vivo electron partitioning between AOP and COP and expression analysis of respiratory components, photosynthesis, and the levels of primary metabolites were studied in leaves of wild-type (WT) plants and cytochrome c (CYTc) mutants, with reduced levels of COP components, under short- and long-day photoperiods. Our results clearly show that differences in AOP and COP in vivo activities between WT and cytc mutants depend on the photoperiod likely due to energy and stress signaling constraints. Parallel responses observed between in vivo respiratory activities, TCA cycle intermediates, amino acids, and stress signaling metabolites indicate the coordination of different pathways of primary metabolism to support growth adaptation under different photoperiods.

scholarly journals FLOWERING HTH1 is involved in CONSTANS-mediated flowering regulation in Arabidopsis

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Soon Ae Sim ◽  
Su Gyeong Woo ◽  
Dae Yeon Hwang ◽  
Jin-Hong Kim ◽  
Seung Sik Lee ◽  
...  
Keyword(s):  
Subcellular Location ◽  
Day Length ◽  
Interacting Protein ◽  
Photoperiodic Flowering ◽  
Family Protein ◽  
Flowering Regulation ◽  
Delayed Flowering ◽  
The Right ◽  
Two Hybrid ◽  
Repression Domain

Abstract Flowering at the right time is essential for maximum reproductive fitness. In Arabidopsis thaliana, the CONSTANS (CO) protein facilitates the transition from the vegetative phase to the reproductive phase under long-day conditions. The formation of heterodimeric complexes between CO and DNA binding domain-containing transcription factors is important for the induction of day length-dependent flowering. Here, we report a myb-like helix turn helix (HTH) transcriptional regulator family protein as a new modulator of floral transition, which we have named FLOWERING HTH1 (FHTH1). We isolated FHTH1 as a CO-interacting protein by a yeast two-hybrid screen using an Arabidopsis transcription factor library. Our analysis showed that FHTH1 presented in the nucleus and the FHTH1-CO complex was formed in the same subcellular location. We also observed the expression of a FHTH1:GUS construct in the leaf vasculature, where CO exists. Transgenic plants overexpressing FHTH1 fused with the plant-specific repression domain SRDX showed a delayed flowering phenotype in long days, resembling the phenotype of the co mutant. Our results suggest that FHTH1 may contribute to CO-mediated photoperiodic flowering regulation.

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