scholarly journals Seasonal Changes in Egg Diapause Induction and Effects of Photoperiod and Temperature on Egg Diapause in the Sorghum Plant Bug, Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae)

2008 ◽  
Vol 52 (4) ◽  
pp. 229-232 ◽  
Author(s):  
Shinji Shigehisa
Keyword(s):  
Seasonal Changes ◽  
Diapause Induction ◽  
Egg Diapause ◽  
Sorghum Plant

scholarly journals Transcriptome Sequencing Reveals Potential Mechanisms of the Maternal Effect on Egg Diapause Induction of Locusta migratoria

2019 ◽  
Vol 20 (8) ◽  
pp. 1974 ◽  
Author(s):  
Kun Hao ◽  
Aftab Raza Jarwar ◽  
Hidayat Ullah ◽  
Xiongbing Tu ◽  
Xiangqun Nong ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Locusta Migratoria ◽  
Diapause Induction ◽  
Short Photoperiod ◽  
Egg Diapause ◽  
Forkhead Box ◽  
Regulation Function ◽  
Fat Bodies ◽  
Long Photoperiod ◽  
Foxo Signaling Pathway

Photoperiod is one of the most important maternal factors with an impact on the offspring diapause induction of Locusta migratoria. Previous studies have shown that forkhead box protein O (FOXO) plays an important role in regulating insect diapause, but how photoperiod stimulates maternal migratory locusts to regulate the next generation of egg diapause through the FOXO signaling pathway still needs to be addressed. In this study, the transcriptomes of ovaries and fat bodies of adult locusts under a long and short photoperiod were obtained. Among the total of 137 differentially expressed genes (DEGs) in both ovaries and fat bodies, 71 DEGs involved in FOXO signaling pathways might be closely related to diapause induction. 24 key DEGs were selected and their expression profiles were confirmed to be consistent with the transcriptome results using qRT-PCR. RNA interference was then performed to verify the function of retinoic acid induced protein gene (rai1) and foxo. Egg diapause rates were significantly increased by RNAi maternal locusts rai1 gene under short photoperiods. However, the egg diapause rates were significantly decreased by knock down of the foxo gene in the maternal locusts under a short photoperiod. In addition, reactive oxygen species (ROS) and superoxide dismutase (SOD) activities were promoted by RNAi rai1. We identified the candidate genes related to the FOXO pathway, and verified the diapause regulation function of rai1 and foxo under a short photoperiod only. In the future, the researchers can work in the area to explore other factors and genes that can promote diapause induction under a long photoperiod.

scholarly journals The expression of circadian clock genes in Daphnia magna diapause

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anke Schwarzenberger ◽  
Luxi Chen ◽  
Linda C. Weiss
Keyword(s):  
Gene Expression ◽  
Circadian Clock ◽  
Daphnia Magna ◽  
Seasonal Changes ◽  
Clock Genes ◽  
Diapause Induction ◽  
Day Length ◽  
Circadian Clock Genes ◽  
Short Days ◽  
Gene Expression Levels

AbstractDiapause is a mechanism necessary for survival in arthropods. Often diapause induction and resurrection is light-dependent and therefore dependent on the photoperiod length and on the number of consecutive short-days. In many organisms, including the microcrustacean Daphnia magna, one functional entity with the capacity to measure seasonal changes in day-length is the circadian clock. There is a long-standing discussion that the circadian clock also controls photoperiod-induced diapause. We tested this hypothesis in D. magna, an organism which goes into a state of suspended animation with the shortening of the photoperiod. We measured gene expression of clock genes in diapause-destined embryos of D. magna in the initiation, resting and resurrection phases and checked it against gene expression levels of continuously developing embryos. We demonstrate that some genes of the clock are differentially expressed during diapause induction but not during its maintenance. Furthermore, the photoreceptor gene cry2 and the clock-associated gene brp are highly expressed during induction and early diapause, probably in order to produce excess mRNA to prepare for immediate resurrection. After resurrection, both types of embryos show a similar pattern of gene expression during development. Our study contributes significantly to the understanding of the molecular basis of diapause induction, maintenance and termination.

scholarly journals Comparative Transcriptomic Analysis Reveals Molecular Profiles of Central Nervous System in Maternal Diapause Induction of Locusta migratoria

2019 ◽  
Vol 9 (10) ◽  
pp. 3287-3296 ◽  
Author(s):  
Aftab Raza Jarwar ◽  
Kun Hao ◽  
Ellyn Valery Bitume ◽  
Hidayat Ullah ◽  
Dongnan Cui ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Molecular Mechanisms ◽  
Locusta Migratoria ◽  
Mrna Level ◽  
Tca Cycle ◽  
Diapause Induction ◽  
Short Photoperiod ◽  
Egg Diapause ◽  
The Central Nervous System

Egg diapause in Locusta migratoria L. (Orthoptera: Acridoidea) is believed to be influenced by maternal photoperiod. However, the molecular mechanism regulating the phenomenon of maternal diapause induction is unclear. Here we performed transcriptomic analyses from the central nervous system (CNS) of migratory locusts under long and short photoperiods to identify differentially expressed genes (DEGs) related to diapause induction. There were total of 165750 unigenes from 569491 transcripts, and 610 DEGs were obtained in S_CNS (CNS of short photoperiod treated locusts) vs. L_CNS (CNS of long photoperiod treated locusts). Of these, 360 were up-regulated, 250 were down-regulated, and 84 DEGs were found to be related to FOXO signaling pathways, including citrate cycle/TCA cycle, glycolysis/ gluconeogenesis, oxidative phosphorylation, and PI3K-Akt. The qRT-PCR validation of mRNA expression of 12 randomly selected DEGs showed consistency with transcriptome analysis. Furthermore, the takeout gene thought to be involved in circadian rhythm was cloned and used for RNAi to observe its function in maternal diapause induction. We found that the mRNA level of Lm-takeout was significantly lower in dstakeout treatments as compared to the control under both long and short photoperiods. Similarly, the offspring diapause rate was significantly higher in dstakeout treatment as compared to the control only in short photoperiod. This shows that the Lm-takeout gene might be involved in the inhibition of maternal diapause induction of L. migratoria under short photoperiods. The present study provides extensive data of the CNS transcriptome and particular insights into the molecular mechanisms of maternal effects on egg diapause of L. migratoria. As well for the future, the researchers can explore other factors and genes that may promote diapause in insect species.

Spreading the Word: Seasonal Changes Mean New Opportunities for Media Coverage

ASHA Leader ◽  
2013 ◽  
Vol 18 (7) ◽  
Keyword(s):  
Media Coverage ◽  
Seasonal Changes ◽  
Swimming Pools

Summer kicking into high gear conjures images of swimming pools and barbeques. But before you book your beach house for the weekend, think about what the changing seasons can mean for you professionally.

Seasonal changes in a ultraviolet structural colour signal in blue tits, Parus caeruleus

2002 ◽  
Vol 76 (2) ◽  
pp. 237-245 ◽  
Author(s):  
JONAS ORNBORG ◽  
STAFFAN ANDERSSON ◽  
SIMON C. GRIFFITH ◽  
BEN C. SHELDON
Keyword(s):  
Seasonal Changes ◽  
Parus Caeruleus ◽  
Structural Colour ◽  
Blue Tits ◽  
Colour Signal

Seasonal changes in nitrogen fractions of Pachysandra terminalis, a forest evergreen chamaephyte

1990 ◽  
Vol 79 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Fumio Yoshie ◽  
Hirohito Arai ◽  
Hideaki Nakashima ◽  
Shoichi Kawano
Keyword(s):  
Seasonal Changes ◽  
Nitrogen Fractions

Seasonal changes in phytoplankton community structure in a bioluminescent lagoon, St. Croix, US Virgin Islands

2018 ◽  
Vol 81 (2) ◽  
pp. 109-124 ◽  
Author(s):  
JL Pinckney ◽  
C Tomas ◽  
DI Greenfield ◽  
K Reale-Munroe ◽  
B Castillo ◽  
...  
Keyword(s):  
Community Structure ◽  
Seasonal Changes ◽  
Phytoplankton Community ◽  
Virgin Islands ◽  
Phytoplankton Community Structure ◽  
Us Virgin Islands
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