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https://www.readbyqxmd.com/read/28215679/causes-of-declining-fertility-in-dairy-cows-during-the-warm-season
#1
REVIEW
F De Rensis, F Lopez-Gatius, I García-Ispierto, G Morini, R J Scaramuzzi
In the Northern Hemisphere, from June to September and in the Southern Hemisphere from December to March, there are periods of reduced fertility (sub-fertility) in dairy cows that are described as summer infertility. Several factors contribute to sub-fertility during this time, such as ambient temperature, humidity and photoperiod. During the warm season there is a reduction in feed intake that may compromise the energy balance of the cow and/or induce an imbalance in the activity of the hypothalamo-hypophyseal-ovarian axis...
March 15, 2017: Theriogenology
https://www.readbyqxmd.com/read/28210981/assessing-common-bean-cultivars-for-resistance-to-the-soybean-looper-chrysodeixis-includens-lepidoptera-noctuidae
#2
R Morando, E L L Baldin, P L Cruz, A L Lourenção
The soybean looper Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae) is known as an important pest of leguminous plants worldwide. In Brazil, this pest species is gaining importance to producers of the common bean Phaseolus vulgaris L. (Fabaceae) because it limits field production of the crop. Chemical control is still the primary method of insect control. However, due to the possible harmful effects of pesticides to humans and the environment, alternative and less aggressive practices are being investigated...
February 16, 2017: Neotropical Entomology
https://www.readbyqxmd.com/read/28206856/effect-of-photoperiod-on-permethrin-resistance-in-aedes-aegypti
#3
O Karina Villanueva, Gustavo Ponce, Beatriz Lopez, Selene M Gutierrez, Iram P Rodriguez, Guadalupe Reyes, Karla J Saavedra, William C Black, Julian Garcia, Barry Beaty, Lars Eisen, Adriana E Flores
Living organisms have been exposed to light-dark cycles that allowed them to adapt to different ecological niches. Circadian cycles affect hormone release, metabolism, and response to xenobiotic compounds. Current studies have shown that insect susceptibility to toxic agents depends on circadian cycles, mainly because the biochemical processes involved in detoxification and responses to oxidative stress are modulated by this process. The goal of this study was to determine the effect of photoperiod on resistance to permethrin in Aedes aegypti ...
December 2016: Journal of the American Mosquito Control Association
https://www.readbyqxmd.com/read/28202598/early-flowering-3-redundancy-fine-tunes-photoperiod-sensitivity
#4
Andrew J S Rubenach, Valerie Fg Hecht, Jacqueline K Vander Schoor, Lim Chee Liew, Gregoire Aubert, Judith Burstin, James L Weller
Three pea loci controlling photoperiod sensitivity, HIGH RESPONSE (HR), DIE NEUTRALIS (DNE) and STERILE NODES (SN) have recently been shown to correspond to orthologs of Arabidopsis circadian clock genes EARLY FLOWERING3 (ELF3), ELF4, and LUX ARRHYTHMO, respectively. A fourth pea locus, PHOTOPERIOD (PPD), also contributes to the photoperiod response in a similar manner to SN and DNE, and recessive ppd mutants on a spring-flowering hr mutant background show early, photoperiod-insensitive flowering. However, the molecular identity of PPD has so far remained elusive...
February 15, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28199332/photoperiod-regulate-gonad-development-via-kisspeptin-kissr-in-hypothalamus-and-saccus-vasculosus-of-atlantic-salmon-salmo-salar
#5
Liang Chi, Xian Li, Qinghua Liu, Ying Liu
Atlantic salmon exhibit seasonal reproduction. However, the mechanisms governing this are still unclear. Generally speaking, kisspeptin has been recognized as a regulator of reproduction. Here, we report a relationship between kisspeptin, GnRH and photoperiod in Atlantic salmon. The results demonstrated that the expression of the Atlantic salmon kisspeptin-receptor (skissr) was not always consistent with the expression pattern of Atlantic salmon GnRH3 (sGnRH3) during all developmental processes. Kisspeptin may exert its influence primarily in the early and later stages of gonad development by promoting the secretion of sGnRH3...
2017: PloS One
https://www.readbyqxmd.com/read/28198917/environmental-drivers-on-leaf-phenology-of-ironstone-outcrops-species-under-seasonal-climate
#6
Letícia C Garcia, Fernanda V Barros, José P Lemos-Filho
Banded iron formations (BIF) have a particular vegetation type and provide a good model system for testing theories related to leaf phenology, due to unique stressful environmental conditions. As a consequence of the stressful conditions of BIF environment, we hypothesize that most species would retain at least some significant canopy cover, even at the end of the dry season, independently of growth form - trees, shrubs, and sub-shrubs. Considering the strong seasonality, we also hypothesize that photoperiod and rainfall act as triggers for leaf fall and leaf flushing in these environments...
February 9, 2017: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/28188883/effects-of-pinealectomy-on-the-neuroendocrine-reproductive-system-and-locomotor-activity-in-male-european-sea-bass-dicentrarchus-labrax
#7
Mairi Cowan, José A Paullada-Salmerón, José Fernando López-Olmeda, Francisco Javier Sánchez-Vázquez, José A Muñoz-Cueto
The seasonally changing photoperiod controls the timing of reproduction in most fish species, however, the transduction of this photoperiodic information to the reproductive axis is still unclear. This study explored the potential role of two candidate neuropeptide systems, gonadotropin-inhibitory hormone (Gnih) and kisspeptin, as mediators between the pineal organ (a principle transducer of photoperiodic information) and reproductive axis in male European sea bass, Dicentrarchus labrax. Two seven-day experiments of pinealectomy (Px) were performed, in March (end of reproductive season) and August (resting season)...
February 8, 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
https://www.readbyqxmd.com/read/28185374/estimating-the-ability-of-plants-to-plastically-track-temperature-mediated-shifts-in-the-spring-phenological-optimum
#8
Christine J Tansey, Jarrod D Hadfield, Albert B Phillimore
One consequence of rising spring temperatures is that the optimum timing of key life-history events may advance. Where this is the case, a population's fate may depend on the degree to which it is able to track a change in the optimum timing either via plasticity or via adaptation. Estimating the effect that temperature change will have on optimum timing using standard approaches is logistically challenging, with the result that very few estimates of this important parameter exist. Here we adopt an alternative statistical method that substitutes space for time to estimate the temperature sensitivity of the optimum timing of 22 plant species based on >200 000 spatiotemporal phenological observations from across the United Kingdom...
February 10, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28185293/assessing-frost-damages-using-dynamic-models-in-walnut-trees-exposure-rather-than-vulnerability-controls-frost-risks
#9
Guillaume Charrier, Isabelle Chuine, Marc Bonhomme, Thierry Améglio
Frost damages develop when exposure overtakes frost vulnerability. Frost risk assessment therefore needs dynamic simulation of frost hardiness using temperature and photoperiod in interaction with developmental stage. Two models, including or not the effect of photoperiod were calibrated using five years of frost hardiness monitoring (2007-2012), in two locations (low and high elevation) for three walnut genotypes with contrasted phenology and maximum hardiness (Juglans regia cv Franquette, Juglans regia x nigra 'Early' and 'Late')...
February 9, 2017: Plant, Cell & Environment
https://www.readbyqxmd.com/read/28183869/behavioral-and-physiological-traits-of-migrant-and-resident-white-crowned-sparrows-a-common-garden-approach
#10
Marilyn Ramenofsky, Andrew W Campion, Jonathan H Pérez, Jesse S Krause, Zoltán Németh
: To accommodate a migratory life history, migrants express a greater number of physiological and behavioral stages per annum than residents and are thus considered to have higher finite state diversity (FSD). To investigate the physiological mechanisms and constraints associated with migration, direct comparison of two subspecies of White-crowned Sparrow - migrant, Zonotrichia leucophrys gambelii and resident, Z.l.nuttalli - were made under common garden conditions of photoperiod and housing, as birds progressed from winter through the vernal life history stages...
February 9, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28178375/melatonin-restores-hippocampal-neural-precursor-proliferation-and-prevents-cognitive-deficits-induced-by-jet-lag-simulation-in-adult-mice
#11
Deetje Iggena, York Winter, Barbara Steiner
Frequent flyers and shift workers undergo circadian dysrhythmia with adverse impact on body and mind. The circadian rhythm disorder "jet lag" disturbs hippocampal neurogenesis and spatial cognition, which represent morphological and functional adult brain plasticity. This raises the question if pro-neurogenic stimuli might prevent those consequences. However, suitable measures to mitigate jet lag induced adverse effects on brain plasticity have been neglected so far. Here, we used adult C57Bl6 mice to investigate the pro-neurogenic stimuli melatonin (8mg/kg i...
February 8, 2017: Journal of Pineal Research
https://www.readbyqxmd.com/read/28177078/genetic-basis-underlying-rapid-evolution-of-an-introduced-insect-ophraella-communa-coleoptera-chrysomelidae-heritability-of-photoperiodic-response
#12
Koichi Tanaka, Kouhei Murata
No abstract text is available yet for this article.
February 1, 2017: Environmental Entomology
https://www.readbyqxmd.com/read/28168840/mother-s-age-and-hatching-phenology-strategy-of-heterocypris-incongruens-crustacea-ostracoda-in-unpredictable-environment
#13
Valeria Rossi, Andrea Gandolfi, Paolo Menozzi
We report experimental evidence of egg polyphenism in clonal lineages of Heterocypris incongruens from an ephemeral pond on a Mediterranean Island (Lampedusa, Italy). In controlled laboratory conditions, clonal females produced three different kinds of eggs: (i) resting and desiccation-resistant eggs, (ii) nonresting eggs that hatched gradually within 2 month hydroperiod, and (iii) nonresting delayed development eggs that hatched synchronously. Clonal females showed a diversified bet-hedging strategy to spread risk of reproduction in ponds with unpredictable hydroperiod...
February 7, 2017: Journal of Experimental Zoology. Part A, Ecological Genetics and Physiology
https://www.readbyqxmd.com/read/28161445/is-diapause-an-ancient-adaptation-in-drosophila
#14
Valeria Zonato, Lewis Collins, Mirko Pegoraro, Eran Tauber, Charalambos P Kyriacou
D. melanogaster enters a state of reproductive arrest when exposed to low temperatures (12°C) and shorter photoperiods. A number of studies have suggested that diapause has recently evolved in European D. melanogaster populations, that it is not present in the sibling species D. simulans, that it is non-photoperiodic in American D. melanogaster populations, and that it spontaneously terminates after 6-8weeks. We have studied the overwintering phenotype under different conditions and observe that American, European and, surprisingly, African D...
February 2, 2017: Journal of Insect Physiology
https://www.readbyqxmd.com/read/28161439/lipid-signaling-and-fat-storage-in-the-dark-eyed-junco
#15
Jacqueline M Ho, Christine M Bergeon Burns, Nikki M Rendon, Kimberly A Rosvall, Heather B Bradshaw, Ellen D Ketterson, Gregory E Demas
Seasonal hyperphagia and fattening promote survivorship in migratory and wintering birds, but reduced adiposity may be more advantageous during the breeding season. Factors such as photoperiod, temperature, and food predictability are known environmental determinants of fat storage, but the underlying neuroendocrine mechanisms are less clear. Endocannabinoids and other lipid signaling molecules regulate multiple aspects of energy balance including appetite and lipid metabolism. However, these functions have been established primarily in mammals; thus the role of lipid signals in avian fat storage remains largely undefined...
February 1, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28153924/correlations-between-circadian-rhythms-and-growth-in-challenging-environments
#16
Yuri Dakhiya, Duaa Hussien, Eyal Fridman, Moshe Kiflawi, Rachel M Green
In plants, the circadian system controls a plethora of processes, many with agronomic importance such as photosynthesis, photoprotection, stomatal opening, and photoperiodic development, as well as molecular processes such as gene expression. It has been suggested that modifying circadian rhythms may be a means to manipulate crops to develop "improved" plants for agriculture. However, there is very little information on how the clock influences the performance of crop plants. We have used a non-invasive, high-throughput technique, based on prompt chlorophyll fluorescence (F), for measuring circadian rhythms and demonstrated that the technique works in a range of plants...
January 30, 2017: Plant Physiology
https://www.readbyqxmd.com/read/28149319/effects-of-the-social-environment-during-adolescence-on-the-development-of-social-behaviour-hormones-and-morphology-in-male-zebra-finches-taeniopygia-guttata
#17
Stefanie Bölting, Nikolaus von Engelhardt
BACKGROUND: Individual differences in behaviour are widespread in the animal kingdom and often influenced by the size or composition of the social group during early development. In many vertebrates the effects of social interactions early in life on adult behaviour are mediated by changes in maturation and physiology. Specifically, increases in androgens and glucocorticoids in response to social stimulation seem to play a prominent role in shaping behaviour during development. In addition to the prenatal and early postnatal phase, adolescence has more recently been identified as an important period during which adult behaviour and physiology are shaped by the social environment, which so far has been studied mostly in mammals...
2017: Frontiers in Zoology
https://www.readbyqxmd.com/read/28145515/role-of-thermal-physiology-and-bioenergetics-on-adaptation-in-tree-shrew-tupaia-belangeri-the-experiment-test
#18
Lin Zhang, Fang Yang, Zheng-Kun Wang, Wan-Long Zhu
Ambient conditions, as temperature and photoperiod, play a key role in animals' physiology and behaviors. To test the hypothesis that the maximum thermal physiological and bioenergetics tolerances are induced by extreme environments in Tupaia belangeri. We integrated the acclimatized and acclimated data in several physiological, hormonal, and biochemical markers of thermogenic capacity and bioenergetics in T. belangeri. Results showed that T. belangeri increased body mass, thermogenesis capacity, protein contents and cytochrome c oxidase (COX) activity of liver and brown adipose tissue in winter-like environments, which indicated that temperature was the primary signal for T...
February 1, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28144785/afferent-neural-pathways-from-the-photoperiodic-receptor-in-the-bean-bug-riptortus-pedestris
#19
Jili Xi, Ikuyo Toyoda, Sakiko Shiga
Adult diapause in the bean bug, Riptortus pedestris, is controlled by the photoperiod, which is received by retinal cells in the central region of the compound eyes. To resolve the afferent neural pathways involved in the photoperiodic response, we examine fibre projections from the photoperiodic receptors to the brain and investigate the roles of the posterior optic tract (POT) in the photoperiodic response. Reduced-silver impregnation and synapsin immunolabelling revealed that the medulla was divided into nine strata: the outer layer comprises 4 strata, the inner layer comprises 4 strata and a serpentine layer separates the inner and outer layers...
February 1, 2017: Cell and Tissue Research
https://www.readbyqxmd.com/read/28138075/transposable-element-mediated-balancing-selection-at-hsp90-underlies-embryo-developmental-variation
#20
Bing Chen, Bo Zhang, Lingling Xu, Qing Li, Feng Jiang, Pengcheng Yang, Yanan Xu, Le Kang
Understanding the roles of transposable elements (TEs) in the evolution of genome and adaptation is a long-sought goal. Here, we present a new model of TE co-option, in which a TE is harnessed by an essential gene and confers local adaptation through heterozygote advantage. We characterized a human Alu-like TE family, the Lm1 elements, in the genome of the migratory locust Locusta migratoria that harbors 0.7 million copies of the elements. Scanning Lm1 insertions in the natural locust populations revealed the widespread high polymorphism of Lm1 An Lm1 was recruited into the coding region of Heat-shock protein 90 (Hsp90), an important molecular chaperone for diverse signal transduction and developmental pathways...
January 30, 2017: Molecular Biology and Evolution
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