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Photoperiod

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https://www.readbyqxmd.com/read/29670193/pineal-dependent-increase-of-hypothalamic-neurogenesis-contributes-to-the-timing-of-seasonal-reproduction-in-sheep
#1
Martine Batailler, Didier Chesneau, Laura Derouet, Lucile Butruille, Stéphanie Segura, Juliette Cognié, Joëlle Dupont, Delphine Pillon, Martine Migaud
To survive in temperate latitudes, species rely on the photoperiod to synchronize their physiological functions, including reproduction, with the predictable changes in the environment. In sheep, exposure to decreasing day length reactivates the hypothalamo-pituitary-gonadal axis, while during increasing day length, animals enter a period of sexual rest. Neural stem cells have been detected in the sheep hypothalamus and hypothalamic neurogenesis was found to respond to the photoperiod. However, the physiological relevance of this seasonal adult neurogenesis is still unexplored...
April 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29669062/effects-of-lighting-pattern-and-photoperiod-on-egg-production-and-egg-quality-of-a-native-chicken-under-free-range-condition
#2
A L Geng, Y Zhang, J Zhang, H H Wang, Q Chu, H G Liu
The paper aimed to study the effects of lighting pattern and photoperiod alone and in combination on egg production, egg quality in Beijing You Chicken (BYC). A total of 630 19-wk-old BYC laying hens were randomly allocated to 6 groups with 105 birds each, 3 replicates per group, reared in individually lit floor pens with separate outdoor areas. A 2 × 3 factorial experiment (2 lighting patterns: continuous and intermittent lighting; 3 photoperiods: 16, 14, 12 h) was arranged, including 16L:8D (6:00 to 22:00) for group 1; 12L:2D:4L:6D (6:00 to 18:00, 20:00 to 24:00) for group 2; 14L:10D (6:00 to 20:00) for group 3; 10L:2D:4L:8D (6:00 to 16:00, 18:00 to 22:00) for group 4; 12L:12D (6:00 to 18:00) for group 5, and 8L:4D:4L:8D (6:00 to 14:00, 18:00 to 22:00) for group 6, respectively...
April 14, 2018: Poultry Science
https://www.readbyqxmd.com/read/29667280/grass-greenness-flush-can-influence-breeding-phenology-and-fertility-in-equatorial-thoroughbred-mares-in-the-absence-of-photoperiod-variation
#3
Juan Carranza, Washington A Yoong, Belén Caño Vergara, Abel Briones, Concha Mateos
Reproductive phenology is an important trait subjected to natural selection. Current horses in America belong to the Palearctic original populations after being introduced by European colonizers. Photoperiod variation is the main environmental factor for the adjustment of reproductive timing in horses, but is absent in equatorial areas. Here we hypothesize that seasonality of green-grass availability may influence breeding phenology in equatorial regions. We used data of 929 services to mares from 2006 to 2011 in a thoroughbred equine exploitation in Ecuador that experienced strong grass seasonality...
April 17, 2018: Animal Science Journal, Nihon Chikusan Gakkaihō
https://www.readbyqxmd.com/read/29667247/the-nuclear-factor-constans-complex-antagonizes-polycomb-repression-to-de-repress-flowering-locus-t-expression-in-response-to-inductive-long-days-in-arabidopsis
#4
Xiao Luo, Zheng Gao, Yizhong Wang, Zhijuan Chen, Wenju Zhang, Jirong Huang, Hao Yu, Yuehui He
Many plants sense the seasonal cues, day length or photoperiod changes, to align the timing of the developmental transition to flowering with changing seasons for reproductive success. Inductive day lengths through the photoperiod pathway induces the expression of FLOWERING LOCUS T (FT) or FT relatives that encode a major mobile florigen to promote flowering. In Arabidopsis thaliana, under inductive long days the photoperiod pathway output CONSTANS (CO) accumulates toward the end of the day and associates with the B and C subunits of Nuclear Factor Y (NF-Y) to form the NF-CO complex that acts to promote FT expression near dusk, whereas Polycomb group (PcG) proteins function to silence FT expression...
April 18, 2018: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/29665878/recent-changes-in-reproductive-phenology-of-a-k-selected-aquatic-insect-predator-belostoma-flumineum-say-heteroptera-belostomatidae
#5
S L Kight, G L Coffey, A W Tanner, M P Dmytriw, S L Tedesco, J Hoang, A K Aboagye
The timing of critical events like mating, migration, and development has noticeably and recently shifted in many populations of diverse organisms. Here, we report a change in the breeding phenology of giant waterbugs, Belostoma flumineum Say (Heteroptera, Belostomatidae), in the northeastern United States. Waterbugs collected in 2005 and 2006 exhibited previously typical patterns of mating and reproduction: two annual reproductive peaks in which overwintered adults mated in the spring and young adults from a new generation mated in the fall...
April 18, 2018: Bulletin of Entomological Research
https://www.readbyqxmd.com/read/29664122/effects-of-changes-in-photoperiod-and-temperature-on-the-estrous-cycle-of-a-captive-female-giant-panda-ailuropoda-melanoleuca
#6
Trisha T N Tay, Desheng Li, Yan Huang, Pengyan Wang, Tasha Tahar, Josephine Kawi
The female giant panda's estrus is known to be photoperiod sensitive, triggered by increasing day length. A pair of giant pandas was brought to Singapore in September 2012 and exposed to a constant temperature and photoperiod during the first 2 years. The female did not show any signs of estrus during that period. In November 2014, photoperiod and temperature were manipulated to simulate seasonal changes, to investigate the effects of environmental factors on the sexual behavior of the giant pandas. This paper documents the changes and observations carried out from 2012 to 2016, in the attempt to breed this vulnerable species...
March 2018: Zoo Biology
https://www.readbyqxmd.com/read/29659304/diet-induced-obesity-reduces-core-body-temperature-across-the-estrous-cycle-and-pregnancy-in-the-rat
#7
Rachael C Crew, Brendan J Waddell, Shane K Maloney, Peter J Mark
Obesity during pregnancy causes adverse maternal and fetal health outcomes and programs offspring for adult-onset diseases, including cardiovascular disease. Obesity also disrupts core body temperature (Tc ) regulation in nonpregnant rodents; however, it is unknown whether obesity alters normal maternal Tc adaptations to pregnancy. Since Tc is influenced by the circadian system, and both obesity and pregnancy alter circadian biology, it was hypothesized that obesity disrupts the normal rhythmic patterns of Tc before and during gestation...
April 16, 2018: Chronobiology International
https://www.readbyqxmd.com/read/29657392/effect-of-exogenous-melatonin-and-different-photoperiods-on-oxidative-status-and-antioxidant-enzyme-activity-in-chhotanagpuri-ewe
#8
Pankaj Kumar Choudhary, Ajay Kumar Ishwar, Rajesh Kumar, Debasish Niyogi, Mukesh Kumar
Aim: The present study was conducted to evaluate the effect of exogenous melatonin under different photoperiods on oxidative status in Chhotanagpuri ewe. Materials and Methods: A total of 42 non-pregnant, non-lactating Chhotanagpuri ewe, having body weight ranging between 14.11±0.09 and 15.38±0.06 kg, were selected and were isolated from rams 2 months before melatonin administration. The selected animals were allocated randomly into seven groups, namely, Group I (normal control), Group II (long day [LD] control), Group III (LD+melatonin administration orally, 3 mg/day), Group IV (LD+melatonin administration subcutaneously, 1 mg/day), Group V (short day [SD] control), Group VI (SD+melatonin administration orally, 3 mg/day), and Group VII (SD+melatonin administration subcutaneously, 1 mg/day) comprising six animals in each group...
February 2018: Veterinary World
https://www.readbyqxmd.com/read/29650156/temperature-variation-caused-by-sowing-dates-significantly-affects-floral-initiation-and-floral-bud-differentiation-processes-in-rapeseed-brassica-napus-l
#9
Tao Luo, Jing Zhang, Mohammad Nauman Khan, Jiahuan Liu, Zhenghua Xu, Liyong Hu
To understand the influence of temperature on floral initiation and to reveal the relationship between floral bud development and yield potential of rapeseed (Brassica napus L.), early- ("1358"), intermediate- ("Zhongshuang No.11") and late- ("Zheshuang No.8") maturity genotypes were sown on different sowing dates under field conditions during four crop seasons. A multiplicative model was introduced to distinguish and quantify the effects of photoperiod and temperature on pre-floral initiation phase...
June 2018: Plant Science: An International Journal of Experimental Plant Biology
https://www.readbyqxmd.com/read/29625122/periodic-regulation-of-expression-of-genes-for-kisspeptin-gonadotropin-inhibitory-hormone-and-their-receptors-in-the-grass-puffer-implications-in-seasonal-daily-and-lunar-rhythms-of-reproduction
#10
REVIEW
Hironori Ando, Shahjahan, Takashi Kitahashi
The seasonal, daily and lunar control of reproduction involves photoperiodic, circadian and lunar changes in the activity of kisspeptin, gonadotropin-inhibitory hormone (GnIH) and gonadotropin-releasing hormone (GnRH) neurons. These changes are brought through complex networks of light-, time- and non-photic signal-dependent control mechanisms, which are mostly unknown at present. The grass puffer, Takifugu alboplumbeus, a semilunar spawner, provides a unique and excellent animal model to assess this question because its spawning is synchronized with seasonal, daily and lunar cycles...
April 3, 2018: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/29623078/physical-cues-controlling-seasonal-immune-allocation-in-a-natural-piscine-model
#11
Alexander Stewart, Pascal I Hablützel, Hayley V Watson, Martha Brown, Ida M Friberg, Joanne Cable, Joseph A Jackson
Seasonal patterns in immunity are frequently observed in vertebrates but are poorly understood. Here, we focused on a natural piscine model, the three-spined stickleback ( Gasterosteus aculeatus ), and asked how seasonal immune allocation is driven by physical variables (time, light, and heat). Using functionally-relevant gene expression metrics as a reporter of seasonal immune allocation, we synchronously sampled fish monthly from the wild (two habitats), and from semi-natural outdoors mesocosms (stocked from one of the wild habitats)...
2018: Frontiers in Immunology
https://www.readbyqxmd.com/read/29622517/comparative-survival-of-the-engorged-stages-of-amblyomma-cajennense-sensu-stricto-and-amblyomma-sculptum-under-different-laboratory-conditions
#12
Marcelo B Labruna
Recent studies indicated that the taxon Amblyomma cajennense (Fabricius, 1787) is a complex of 6 valid species, of which only two, Amblyomma cajennense sensu stricto (s.s.) and Amblyomma sculptum Berlese, 1888 are present in Brazil; the former species is found exclusively in areas of the Amazon biome, and A. sculptum mostly in the Cerrado biome. Populations of A. cajennense s.s. and A. sculptum are usually sustained by the same host species, and are found in many areas with similar temperature and photoperiod regimens...
March 21, 2018: Ticks and Tick-borne Diseases
https://www.readbyqxmd.com/read/29618281/melatonin-independent-photoperiodic-entrainment-of-the-circannual-tsh-rhythm-in-the-pars-tuberalis-of-the-european-hamster
#13
Cristina Sáenz de Miera, Dominique Sage-Ciocca, Valérie Simonneaux, Paul Pévet, Stefanie Monecke
Adaptation of biological rhythms to a seasonal environment in circannual mammals is achieved via the synchronization of intrinsic circannual rhythms to the external year by photoperiod. In mammals, the photoperiodic information is integrated to seasonal physiology via the pineal hormone melatonin regulation of pars tuberalis (PT) TSHβ expression and its downstream control of hypothalamic dio2 gene expression. In the circannual European hamster, however, photoperiodic entrainment of the circannual clock is possible in pinealectomized animals...
April 1, 2018: Journal of Biological Rhythms
https://www.readbyqxmd.com/read/29617837/leaf-rolling-in-maize-crops-from-leaf-scoring-to-canopy-level-measurements-for-phenotyping
#14
F Baret, S Madec, K Irfan, J Lopez, A Comar, M Hemmerlé, D Dutartre, S Praud, M H Tixier
Leaf rolling in maize crops is one of the main plant reactions to water stress that can be visually scored in the field. However, leaf-scoring techniques do not meet the high-throughput requirements needed by breeders for efficient phenotyping. Consequently, this study investigated the relationship between leaf-rolling scores and changes in canopy structure that can be determined by high-throughput remote-sensing techniques. Experiments were conducted in 2015 and 2016 on maize genotypes subjected to water stress...
April 2, 2018: Journal of Experimental Botany
https://www.readbyqxmd.com/read/29611072/differential-pheromone-sampling-of-the-gland-of-female-heliothis-virescens-moths-reveals-glandular-differences-in-composition-and-quantity
#15
Stephen P Foster, Karin G Anderson
By differentially sampling the pheromone gland of females of the moth Heliothis virescens, we explored differences in pheromone on the surface, or outer distal layer(s) of the gland, and that located more proximally. For this, we used two sampling approaches, (i) a solid phase microextraction fiber rub followed by solvent extraction of residual pheromone (SPME rub/extract), and (ii) rapid solvent rinsing followed by solvent extraction of residual pheromone (rinse/extract). The SPME rub showed differences in component ratio between the dorsal and ventral gland surfaces...
April 2, 2018: Journal of Chemical Ecology
https://www.readbyqxmd.com/read/29605490/transcriptome-wide-analysis-of-differential-gene-expression-in-response-to-light-dark-cycles-in-a-model-cnidarian
#16
W B Leach, J Macrander, R Peres, A M Reitzel
Animals respond to diurnal shifts in their environment with a combination of behavioral, physiological, and molecular changes to synchronize with regularly-timed external cues. Reproduction, movement, and metabolism in cnidarians have all been shown to be regulated by diurnal lighting, but the molecular mechanisms that may be responsible for these phenotypes remain largely unknown. The starlet sea anemone, Nematostella vectensis, has oscillating patterns of locomotion and respiration, as well as the molecular components of a putative circadian clock that may provide a mechanism for these light-induced responses...
March 22, 2018: Comparative Biochemistry and Physiology. Part D, Genomics & Proteomics
https://www.readbyqxmd.com/read/29605315/low-colostrum-yield-in-jersey-cattle-and-potential-risk-factors
#17
K Gavin, H Neibergs, A Hoffman, J N Kiser, M A Cornmesser, S Amirpour Haredasht, B Martínez-López, J R Wenz, D A Moore
Consumption of an adequate volume of high-quality colostrum is vital to a dairy calf's ability to survive and become a productive herd member. However, some dairy herds have reported a deficiency of colostrum production, which ranges from a low volume to no colostrum produced, by cows during fall and winter. Little information regarding this phenomenon exists. The purpose of this study was to characterize the syndrome and identify potential risk factors for low colostrum yield. A 2,500-cow Jersey dairy farm was enrolled in a prospective cohort study in May 2016, to evaluate possible effects of photoperiod, temperature, and cow factors on colostrum production...
March 28, 2018: Journal of Dairy Science
https://www.readbyqxmd.com/read/29602363/the-distinct-roles-of-insulin-signaling-in-polyphenic-development
#18
REVIEW
H Frederik Nijhout, Kenneth Z McKenna
Many insects have the ability to develop alternative morphologies in response to specific environmental signals such as photoperiod, temperature, nutrition and crowding. These signals are integrated by the brain and result in alternative patterns of secretion of developmental hormones like ecdysone, juvenile hormone and insulin-like growth factors, which, in turn, direct alternative developmental trajectories. Insulin signaling appears to be particularly important when the polyphenism involves differences in the sizes of the body, appendages and other structures, such as wings, mandibles and horns...
February 2018: Current Opinion in Insect Science
https://www.readbyqxmd.com/read/29599268/temporal-specific-interaction-of-nf-yc-and-curly-leaf-during-the-floral-transition-regulates-flowering
#19
Xu Liu, Yuhua Yang, Yilong Hu, Limeng Zhou, Yuge Li, Xingliang Hou
The flowering time of higher plants is controlled by environmental cues and intrinsic signals. In Arabidopsis thaliana, flowering is accelerated by exposure to long-day (LD) conditions via the key photoperiod-induced factor FLOWERING LOCUS T (FT). Nuclear Factor-Y C (NF-YC) proteins function as important mediators of epigenetic marks in different plant developmental stages and play an important role in the regulation of FT transcription, but the mechanistic details of this remain unknown. In this study, we show that Arabidopsis NF-YC homologues temporally interact with the histone methyltransferase CURLY LEAF (CLF) during the flowering transition...
March 29, 2018: Plant Physiology
https://www.readbyqxmd.com/read/29596826/hda9-interacts-with-the-promoters-of-soc1-and-agl24-involved-in-flowering-time-control-in-brassica-juncea
#20
Wei Jiang, Dayong Wei, Wenwen Zhou, Zhimin Wang, Qinglin Tang
HDA9 (a RPD3-like histone deacetylase) belongs to the histone deacetylase family which is involved in flowering time control through repression of AGL19 and FT, but it is still elusive that whether and how HDA9 directly interacts with flowering signal integrators of SOC1 and AGL24 in Brassica juncea. In this study, BjuHDA9 (a homologous HDA9) was cloned from B. juncea and ubiquitously expressed in root, stem, cauline leaf, flower bud and opening flower. BjuHDA9 was highly induced by short-day photoperiod. Yeast two-hybrid and pull-down assays demonstrated that BjuHDA9 could not interact with BjuSOC1 and BjuAGL24 proteins...
May 15, 2018: Biochemical and Biophysical Research Communications
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