Latitude affects photoperiod-induced changes in immune response in meadow voles (Microtus pennsylvanicus)

2005 ◽  
Vol 83 (10) ◽  
pp. 1271-1278 ◽  
Author(s):  
L M Pyter ◽  
Z M Weil ◽  
R J Nelson
Keyword(s):  
Immune Responses ◽  
Microtus Pennsylvanicus ◽  
Day Length ◽  
Delayed Type Hypersensitivity ◽  
Deer Mice ◽  
Meadow Voles ◽  
Short Day ◽  
Long Day ◽  
Induced Changes ◽  
Short Days

Animals use day length (photoperiod) to time seasonal adaptations to annual changes in their environment. Reproductive adjustments in deer mice (Peromyscus maniculatus (Wagner, 1845)) from high latitudes are more extensive in response to short days than in deer mice from low latitudes. These adjustments may permit individuals to survive the severe seasonal changes (e.g., temperature and food abundance) in high-latitude environments. Immune function is also affected by photoperiod. Short days were predicted to result in elevated immune and reproductive responses in meadow voles (Microtus pennsylvanicus (Ord, 1815)) from the Northwest Territories (NWT), Canada (~62°N), compared with voles from Ohio (OH), USA (~39°N). Male voles from both latitudes were maintained in long or short days for 10 weeks prior to a delayed-type hypersensitivity (DTH) immune challenge. Both populations displayed similar testicular regression and reduction of testosterone concentrations in short days. DTH immune responses, however, diverged between the two populations. DTH immune responses were enhanced in long-day NWT voles and short-day OH voles, but decreased in short-day NWT voles and long-day OH voles. Total and free corticosterone concentrations did not explain the latitudinal differences in immune responses. These results suggest that photoperiod affects reproductive and immune systems differently and that immune responses may reflect other environmental factors.

scholarly journals Managing flowering time in Miscanthus and sugarcane to facilitate intra- and intergeneric crosses

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0240390
Author(s):  
Hongxu Dong ◽  
Lindsay V. Clark ◽  
Xiaoli Jin ◽  
Kossonou Anzoua ◽  
Larisa Bagmet ◽  
...  
Keyword(s):  
Flowering Time ◽  
High Latitude ◽  
Floral Induction ◽  
Day Treatment ◽  
Day Length ◽  
Close Relative ◽  
Short Day ◽  
Culm Length ◽  
Low Latitudes ◽  
Short Days

Miscanthus is a close relative of Saccharum and a potentially valuable genetic resource for improving sugarcane. Differences in flowering time within and between Miscanthus and Saccharum hinders intra- and interspecific hybridizations. A series of greenhouse experiments were conducted over three years to determine how to synchronize flowering time of Saccharum and Miscanthus genotypes. We found that day length was an important factor influencing when Miscanthus and Saccharum flowered. Sugarcane could be induced to flower in a central Illinois greenhouse using supplemental lighting to reduce the rate at which days shortened during the autumn and winter to 1 min d-1, which allowed us to synchronize the flowering of some sugarcane genotypes with Miscanthus genotypes primarily from low latitudes. In a complementary growth chamber experiment, we evaluated 33 Miscanthus genotypes, including 28 M. sinensis, 2 M. floridulus, and 3 M. ×giganteus collected from 20.9° S to 44.9° N for response to three day lengths (10 h, 12.5 h, and 15 h). High latitude-adapted M. sinensis flowered mainly under 15 h days, but unexpectedly, short days resulted in short, stocky plants that did not flower; in some cases, flag leaves developed under short days but heading did not occur. In contrast, for M. sinensis and M. floridulus from low latitudes, shorter day lengths typically resulted in earlier flowering, and for some low latitude genotypes, 15 h days resulted in no flowering. However, the highest ratio of reproductive shoots to total number of culms was typically observed for 12.5 h or 15 h days. Latitude of origin was significantly associated with culm length, and the shorter the days, the stronger the relationship. Nearly all entries achieved maximal culm length under the 15 h treatment, but the nearer to the equator an accession originated, the less of a difference in culm length between the short-day treatments and the 15 h day treatment. Under short days, short culms for high-latitude accessions was achieved by different physiological mechanisms for M. sinensis genetic groups from the mainland in comparison to those from Japan; for mainland accessions, the mechanism was reduced internode length, whereas for Japanese accessions the phyllochron under short days was greater than under long days. Thus, for M. sinensis, short days typically hastened floral induction, consistent with the expectations for a facultative short-day plant. However, for high latitude accessions of M. sinensis, days less than 12.5 h also signaled that plants should prepare for winter by producing many short culms with limited elongation and development; moreover, this response was also epistatic to flowering. Thus, to flower M. sinensis that originates from high latitudes synchronously with sugarcane, the former needs day lengths >12.5 h (perhaps as high as 15 h), whereas that the latter needs day lengths <12.5 h.

Flowering of Stylosanthes guianensis in controlled temperatures under natural photoperiod

1984 ◽  
Vol 35 (2) ◽  
pp. 219 ◽  
Author(s):  
RL Ison ◽  
LR Humphreys
Keyword(s):  
Floral Initiation ◽  
Minimum Duration ◽  
Stylosanthes Guianensis ◽  
Short Day ◽  
Long Day ◽  
Natural Photoperiod ◽  
Low Levels ◽  
Short Days

Seedlings of Stylosanthes guianensis var. guianensis cv. Cook and cv. Endeavour were grown in naturally lit glasshouses at Brisbane (lat. 27� 30' S.) at 35/30, 30/25 and 25/20�C (day/night), and were sown so as to emerge at 18-day intervals from 18 January to 11 June. Cook behaved as a long day-short day plant, with seedlings emerging after 5 February flowering incompletely or remaining vegetative until the experiment was terminated in mid-October. In the 25/20�C regimen flowering was incomplete in Cook; in Endeavour flowering was delayed but a conventional short-day response was observed. At 35/30�C Endeavour flowering was inhibited in the shortest days of mid-winter, suggesting a stenophotoperiodic response, but short days were confounded with low levels of irradiance. Minimum duration of the phase from emergence to floral initiation was c. 66-70 days in Cook and c. 40-45 days in Endeavour; the duration of the phase floral initiation to flower appearance was linearly and negatively related to temperature.

scholarly journals Prior exposure to long-day photoperiods alters immune responses and increases susceptibility to parasitic infection in stickleback

2020 ◽  
Vol 287 (1930) ◽  
pp. 20201017
Author(s):  
James R. Whiting ◽  
Muayad A. Mahmud ◽  
Janette E. Bradley ◽  
Andrew D. C. MacColl
Keyword(s):  
Immune Responses ◽  
Parasitic Infection ◽  
Population Variation ◽  
Host Susceptibility ◽  
Day Length ◽  
Previous Exposure ◽  
Parasite Abundance ◽  
Susceptibility To Infection ◽  
Long Day ◽  
Host Parasite

Seasonal disease and parasitic infection are common across organisms, including humans, and there is increasing evidence for intrinsic seasonal variation in immune systems. Changes are orchestrated through organisms' physiological clocks using cues such as day length. Ample research in diverse taxa has demonstrated multiple immune responses are modulated by photoperiod, but to date, there have been few experimental demonstrations that photoperiod cues alter susceptibility to infection. We investigated the interactions among photoperiod history, immunity and susceptibility in laboratory-bred three-spined stickleback (a long-day breeding fish) and its external, directly reproducing monogenean parasite Gyrodactylus gasterostei . We demonstrate that previous exposure to long-day photoperiods (PLD) increases susceptibility to infection relative to previous exposure to short days (PSD), and modifies the response to infection for the mucin gene muc2 and Treg cytokine foxp3a in skin tissues in an intermediate 12 L : 12 D photoperiod experimental trial. Expression of skin muc2 is reduced in PLD fish, and negatively associated with parasite abundance. We also observe inflammatory gene expression variation associated with natural inter-population variation in resistance, but find that photoperiod modulation of susceptibility is consistent across host populations. Thus, photoperiod modulation of the response to infection is important for host susceptibility, highlighting new mechanisms affecting seasonality of host–parasite interactions.

Photoperiod modulates the effects of norepinephrine on lymphocyte proliferation in Siberian hamsters

2003 ◽  
Vol 285 (4) ◽  
pp. R873-R879 ◽  
Author(s):  
Gregory E. Demas ◽  
Timothy J. Bartness ◽  
Randy J. Nelson ◽  
Deborah L. Drazen
Keyword(s):  
Lymphocyte Proliferation ◽  
Splenic Tissue ◽  
Splenocyte Proliferation ◽  
Short Day ◽  
Siberian Hamsters ◽  
Long Day ◽  
Β Adrenergic Receptors ◽  
Short Days

Siberian hamsters ( Phodopus sungorus) rely on photoperiod to coordinate seasonally appropriate changes in physiology, including immune function. Immunity is regulated, in part, by the sympathetic nervous system (SNS), although the precise role of the SNS in regulating photoperiodic changes in immunity remains unspecified. The goal of the present study was to examine the contributions of norepinephrine (NE), the predominant neurotransmitter of the SNS, to photoperiodic changes in lymphocyte proliferation. In experiment 1, animals were maintained in long [16:8-h light-dark cycle (16:8 LD)] or short days (8:16 LD) for 10 wk, and splenic NE content was determined. In experiment 2, in vitro splenocyte proliferation in response to mitogenic stimulation (concanavalin A) was assessed in spleen cell suspensions taken from long- or short-day hamsters in which varying concentrations of NE were added to the cultures. In experiment 3, splenocyte proliferation was examined in the presence of NE and selective α- and β-noradrenergic receptor antagonists (phenoxybenzamine and propranolol, respectively) in vitro. Short-day animals had increased splenic NE content compared with long-day animals. Long-day animals had higher proliferation compared with short-day animals independent of NE. NE (1 μM) further suppressed splenocyte proliferation in short but not long days. Last, NE-induced suppression of proliferation in short-day hamsters was blocked by propranolol but not phenoxybenzamine. The present results suggest that NE plays a role in photoperiodic changes in lymphocyte proliferation. Additionally, the data suggest that the effects of NE on proliferation are specific to activation of β-adrenergic receptors located on splenic tissue. Collectively, these results provide further support that photoperiodic changes in immunity are influenced by changes in SNS activity.

Regional differences in fat pad responses to short days in Siberian hamsters

1989 ◽  
Vol 257 (6) ◽  
pp. R1533-R1540 ◽  
Author(s):  
T. J. Bartness ◽  
J. M. Hamilton ◽  
G. N. Wade ◽  
B. D. Goldman
Keyword(s):  
Body Weight ◽  
Body Fat ◽  
Subcutaneous Fat ◽  
Short Photoperiod ◽  
Fat Pad ◽  
Initial Exposure ◽  
Short Day ◽  
Siberian Hamsters ◽  
Long Day ◽  
Induced Changes

Siberian hamsters exhibit decreased body weight and fat after initial exposure to short photoperiods and increased body weight and fat after extended short photoperiod exposure. The purpose of the present experiments was to determine if uniform changes in white adipose tissue (WAT) pad weights and lipid metabolism correspond to these short photoperiod-induced changes in body fat. Carcass lipid content and testes and fat pad weights [retroperitoneal WAT (RWAT), epididymal WAT (EWAT), and inguinal and dorsal subcutaneous WAT, respectively] were decreased in male hamsters relative to their long day counterparts after 6 and 12 wk of short-day exposure. Moreover, EWAT and RWAT weight, EWAT specific lipoprotein lipase activity, and specific and total lipogenesis were disproportionately decreased relative to the subcutaneous fat pads. The changes in fat pad weight and metabolism were generally reversed coincident with the return to a long-day-like reproductive status after prolonged short-day exposure (24 and 30 wk). In a less detailed experiment, female Siberian hamsters had decreased body, fat pad, and uterine weights after 6 wk of short-day exposure; however, no fat pad-specific changes in weight were observed. The results of these experiments demonstrate that short-day-exposed male Siberian hamsters may be a useful model for examining mechanisms underlying fat pad-specific responses. In addition, gender appears to influence the pattern of short-day-induced lipid depletion in this species.

scholarly journals Photoperiodic Response of Peanut Species1

1983 ◽  
Vol 10 (2) ◽  
pp. 59-62 ◽  
Author(s):  
H. T. Stalker ◽  
J. C. Wynne
Keyword(s):  
North Carolina ◽  
Day Treatment ◽  
Photoperiodic Response ◽  
Reproductive Capacity ◽  
Arachis Species ◽  
Short Day ◽  
The North ◽  
Long Day ◽  
Wild Peanut ◽  
Short Days

Abstract Many Arachis species collections do not produce pegs in North Carolina even though they flower profusely. To investigate reasons for the failure of fruiting, nine wild peanut species of section Arachis and three A. hypogaea cultivars representing spanish, valencia and virginia types were evaluated for response to short and long-day treatments in the North Carolina State Phytotron Unit of the Southeastern Environmental Laboratories. The objective of this investigation was to determine the flowering and fruiting responses of Arachis species to short and long-day photoperiods. Plant collections grown under a 9-hour short-day treatment were generally less vigorous, but produced more pegs than corresponding plants grown in long-day treatments which were produced by 9 hours of light plus a 3-hour interruption of the dark period. Annual species produced significantly more flowers and pegs than perennial species during both long and short days. The total number of flowers produced ranged from 0 during short days for A. correntina to more than 300 for A. cardenasii in long-day treatments. Only one plant of each species A. chacoense and A. villosa, and no plants of A. correntina, flowered in short days. Total numbers of pegs produced in short-day treatments were generally greater than in long-day treatments and the ratio of total number of pegs/total number of flowers was consistently greater during short-day treatments. A general trend was observed for more flowers produced in long-day treatments, but more pegs produced in short days. This study indicated that photoperiod can be manipulated to increase the seed set of some species and the success rate of obtaining certain interspecific hybrids. Furthermore, introgression from wild to cultivated species may possibly alter the reproductive capacity of A. hypogaea to photoperiod.

Short Day Induction of Inflorescence Initiation in Some Winter Wheat Varieties

1987 ◽  
Vol 14 (3) ◽  
pp. 277 ◽  
Author(s):  
LT Evans
Keyword(s):  
Winter Wheat ◽  
High Irradiance ◽  
Inflorescence Development ◽  
Wheat Varieties ◽  
Short Day ◽  
Long Day ◽  
European Winter Wheat ◽  
Lower Irradiance ◽  
Short Days ◽  
Winter Wheat Varieties

Experiments in the Canberra phytotron with several European winter wheat varieties, especially cv. Templar, have shown that their need for vernalisation at low temperature can be replaced entirely by growth in short days at 21/16°C for the same period. In fact, although wheat is usually classified as a long day plant, inflorescence initiation at 21/16°C in unvernalised plants was twice as rapid in 8 h photoperiods as in 16 h ones. Short day induction was fastest in photoperiods of less than 12 h and was relatively insensitive to irradiance. Inflorescence development following initiation was faster the longer the photoperiod. At high irradiance, anthesis eventually occurred in 8 h days, but not at lower irradiance. These wheats are therefore short-long day plants, and may appear to be indifferent to daylength if only their time to anthesis is observed. Although short days can replace low temperatures, there are several important differences in their modes of action, and short day induction is better not referred to as short day vernalisation. Vernalisation of developing grains in the ear was more effective in long days.

scholarly journals Inflorescence Initiation in Lolium Temulentum l. II. Evidence for Inhibitory and Promotive Photoperiodic Processes Involving Transmissible Products

1960 ◽  
Vol 13 (4) ◽  
pp. 429 ◽  
Author(s):  
LT Evans
Keyword(s):  
Leaf Blade ◽  
Light Period ◽  
Continuous Illumination ◽  
Rate Of Development ◽  
Lolium Temulentum ◽  
Short Day ◽  
Long Day ◽  
Inductive Treatment ◽  
Short Days

Plants of Lolium temulentum, raised in short days, were given an inductive treatment by exposure of one leaf blade to a 32-hr period of continuous illumination. Then either the leaf exposed to this one long light period or varying areas of lower leaves which were simultaneously in short-day conditions were removed at intervals after the long-day exposure. The longer the long-day leaves remained on the plants, the greater was the proportion of plants which initiated inflorescences and the greater the rate of development of their inflorescences. This was so even when short-day leaves were present above the long-day ones. The longer the short-day leaves remained, and the greater their area, the lower was the proportion of plants which initiated inflorescences.

scholarly journals Day-Length Control of Inflorescence Initiation in the Grass Rottboellia Exaltata L.F.

1962 ◽  
Vol 15 (2) ◽  
pp. 291 ◽  
Author(s):  
LT Evans
Keyword(s):  
Day Length ◽  
Inflorescence Development ◽  
Short Day ◽  
Critical Photoperiod ◽  
The One ◽  
Short Days

R. exaltata is a strict short�day plant with a critical photoperiod of about 13 hr. The number of short days required for inflorescence initiation varies with age, being 6 with plants 5 weeks old. Exposure to additional short days increases the rate of inflorescence development. The expanding leaf is the one most sensitive to short.day induction and removal of the leaves below it accelerates inflorescence development.

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