1
|
Majoy SB, Heideman PD. Tau Differences between Short-Day Responsive and Short-Day Nonresponsive White-Footed Mice (Peromyscus leucopus) Do Not Affect Reproductive Photoresponsiveness. J Biol Rhythms 2016. [DOI: 10.1177/074873040001500607] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In laboratory-bred rodent populations, intraspecific variation in circadian system organization is a known cause of individual variation in reproductive photoresponsiveness. The authors sought to determine whether circadian system variation accounted for individual variation in reproductive photoresponsiveness in a single, highly genetically variable population of Peromyscus leucopusrecently derived from the wild. Running-wheel activity patterns of male and female mice, aged 70 to 90 days, from artificially selected lines of reproductively photoresponsive (R) and nonresponsive (NR) lines were monitored under short-day photoperiod (8 h light, 16 h dark), long-day photoperiod (16 h light, 8 h dark), and constant darkness (DD). NR mice displayed a significantly longer mean free-running period (24.08 h) in DD compared with R mice (23.75 h), due in large part to a difference between NR and R females (24.25 h vs. 23.74 h, respectively). All other entrainment characteristics (alpha, phase angle of activity) under short days, long days, and DD were similar between R and NR mice. Variation in free- running period and entrainment characteristics has been shown to affect photoresponsiveness in other rodent species by altering the manner in which the circadian system interprets short days. To determine whether variation in photoresponsiveness in P. leucopus is due to differences in free-running period instead of variation downstream from the central circadian clock in the pathway controlling photoresponsiveness, the authors exposed young R and NR mice to DD and measured the effect on reproductive organ development. If variation in free-running period affected how the circadian system of mice interpreted short days, then both R and NR mice exposed to DD should have exhibited a delay in gonadal development. Only R mice exhibited pubertal delay in DD. NR mice exhibited large paired testes, paired seminal vesicles, paired ovaries, and uterine weight typical of mice nonresponsive to short days, whereas R mice exhibited reproductive organ weight typical of mice responsive to short days. These data suggest that despite significant differences in free-running period between R and NR mice, individual variation in photoresponsiveness is not due to differences in how the circadian systems of R and NR mice interpret the LD cycle.
Collapse
Affiliation(s)
| | - Paul D. Heideman
- Biology Department, College of William and Mary, Williamsburg, VA 23187-8795, USA
| |
Collapse
|
2
|
Bradshaw WE, Holzapfel CM. Light, time, and the physiology of biotic response to rapid climate change in animals. Annu Rev Physiol 2010; 72:147-66. [PMID: 20148671 DOI: 10.1146/annurev-physiol-021909-135837] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Examination of temperate and polar regions of Earth shows that the nonbiological world is exquisitely sensitive to the direct effects of temperature, whereas the biological world is largely organized by light. Herein, we discuss the use of day length by animals at physiological and genetic levels, beginning with a comparative experimental study that shows the preeminent role of light in determining fitness in seasonal environments. Typically, at seasonally appropriate times, light initiates a cascade of physiological events mediating the input and interpretation of day length to the output of specific hormones that ultimately determine whether animals prepare to develop, reproduce, hibernate, enter dormancy, or migrate. The mechanisms that form the basis of seasonal time keeping and their adjustment during climate change are reviewed at the physiological and genetic levels. Future avenues for research are proposed that span basic questions from how animals transition from dependency on tropical cues to temperate cues during range expansions, to more applied questions of species survival and conservation biology during periods of climatic stress.
Collapse
Affiliation(s)
- William E Bradshaw
- Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, OR 97403-5289, USA.
| | | |
Collapse
|
3
|
Yeates-Burghart QS, O’Brien C, Cresko WA, Holzapfel CM, Bradshaw WE. Latitudinal variation in photoperiodic response of the three-spined stickleback Gasterosteus aculeatus in western North America. JOURNAL OF FISH BIOLOGY 2009; 75:2075-2081. [PMID: 20738673 PMCID: PMC4084647 DOI: 10.1111/j.1095-8649.2009.02418.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Reproductive maturation in both male and female three-spined stickleback Gasterosteus aculeatus was strongly photoperiodic in a northern population (Alaska, 61 degrees N) but not in a southern population (Oregon, 43 degrees N) from western North America. Increasing reliance on photoperiod with increasing latitude is a general phenomenon among vertebrates, and is probably due to the anticipation of a narrower window of opportunity for reproduction and development at higher latitudes.
Collapse
Affiliation(s)
| | | | | | | | - W. E. Bradshaw
- Author to whom correspondence should be addressed. Tel.: +1 541 346 4542; fax: +1 346 2364;
| |
Collapse
|
4
|
Seroka CD, Johnson CE, Heideman PD. Variation in nocturnality and circadian activity rhythms between photoresponsive F344 and nonphotoresponsive Sprague Dawley rats. J Circadian Rhythms 2008; 6:8. [PMID: 18782448 PMCID: PMC2542993 DOI: 10.1186/1740-3391-6-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Accepted: 09/09/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Variation in circadian rhythms and nocturnality may, hypothetically, be related to or independent of genetic variation in photoperiodic mediation of seasonal changes in physiology and behavior. We hypothesized that strain variation in photoperiodism between photoperiodic F344 rats and nonphotoperiodic Harlan Sprague Dawley (HSD) rats might be caused by underlying variation in clock function. We predicted that HSD rats would have more activity during the day or subjective day, longer free-running rhythms, poor entrainment to short day length, and shorter duration of activity, traits that have been associated with nonphotoperiodism in other laboratory rodent species, relative to F344 rats. An alternative hypothesis, that differences are due to variation in melatonin secretion or responses to melatonin, predicts either no such differences or inconsistent combinations of differences. METHODS We tested these predictions by examining activity rhythms of young male F344 and HSD rats given access to running wheels in constant dark (DD), short day length (L8:D16; SD), and long day length (L16:D8; LD). We compared nocturnality (the proportion of activity during night or subjective night), duration of activity (alpha), activity onset and offset, phase angle of entrainment, and free running rhythms (tau) of F344 and HSD rats. RESULTS HSD rats had significantly greater activity during the day, were sometimes arrhythmic in DD, and had significantly longer tau than F344 rats, consistent with predictions. However, HSD rats had significantly longer alpha than F344 rats and both strains entrained to SD, inconsistent with predictions. CONCLUSION The ability of HSD rats to entrain to SD, combined with longer alpha than F344 rats, suggests that the circadian system of HSD rats responds correctly to SD. These data offer best support for the alternative hypothesis, that differences in photoresponsiveness between F344 and HSD rats are caused by non-circadian differences in melatonin secretion or the response to melatonin.
Collapse
Affiliation(s)
- Cheryl D Seroka
- Department of Biology, College of William and Mary, Williamsburg, VA 23187, USA.
| | | | | |
Collapse
|
5
|
Bradshaw WE, Holzapfel CM. Evolution of Animal Photoperiodism. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2007. [DOI: 10.1146/annurev.ecolsys.37.091305.110115] [Citation(s) in RCA: 367] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- William E. Bradshaw
- Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, Oregon 97403;
| | - Christina M. Holzapfel
- Center for Ecology and Evolutionary Biology, University of Oregon, Eugene, Oregon 97403;
| |
Collapse
|
6
|
Abstract
The primary nonbiological result of recent rapid climate change is warming winter temperatures, particularly at northern latitudes, leading to longer growing seasons and new seasonal exigencies and opportunities. Biological responses reflect selection due to the earlier arrival of spring, the later arrival of fall, or the increasing length of the growing season. Animals from rotifers to rodents use the high reliability of day length to time the seasonal transitions in their life histories that are crucial to fitness in temperate and polar environments: when to begin developing in the spring, when to reproduce, when to enter dormancy or when to migrate, thereby exploiting favourable temperatures and avoiding unfavourable temperatures. In documented cases of evolutionary (genetic) response to recent, rapid climate change, the role of day length (photoperiodism) ranges from causal to inhibitory; in no case has there been demonstrated a genetic shift in thermal optima or thermal tolerance. More effort should be made to explore the role of photoperiodism in genetic responses to climate change and to rule out the role of photoperiod in the timing of seasonal life histories before thermal adaptation is assumed to be the major evolutionary response to climate change.
Collapse
Affiliation(s)
- W E Bradshaw
- Center for Ecology & Evolutionary Biology, University of Oregon, Eugene, OR 97403-5289, USA.
| | | |
Collapse
|
7
|
Fetsch CR, Heideman PD, Griffin JD. Effects of melatonin on thermally classified anterior hypothalamic neurons in the white-footed mouse (Peromyscus leucopus). J Therm Biol 2006. [DOI: 10.1016/j.jtherbio.2005.12.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
8
|
|
9
|
Hope PJ, Turnbull H, Breed W, Morley JE, Horowitz M, Wittert GA. The effect of ovarian steroids and photoperiod on body fat stores and uncoupling protein 2 in the marsupial Sminthopsis crassicaudata. Physiol Behav 2000; 69:463-70. [PMID: 10913785 DOI: 10.1016/s0031-9384(99)00264-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
To determine the effects of photoperiod and ovarian steroids on fat stores in the marsupial S. crassicaudata, animals were ovariectomised (OVX) or sham operated, and maintained under either short-day (SD) or long-day (LD) photoperiods for 104 days. Photoperiod had no effect on body weight in the sham animals. In the LD OVX animals, body weight fell and remained below baseline for about 45 days, whereafter it returned to baseline. In contrast, body weight of SD OVX animals increased over the first 45 days then returned to baseline. Tail width (a reflection of body fat stores) increased in both sham and OVX animals exposed to SD. When exposed to LD, tail width increased only in the OVX animals. There was no effect of either photoperiod or OVX on total cumulative energy intake. Leptin mRNA expression was increased in the LD OVX animals compared to the shams. Photoperiod had no effect on UCP2 mRNA expression in any tissue; however, OVX decreased UCP2 mRNA expression in muscle. These data indicate that in S. crassicaudata: (a) fat mass increases in response to both SD photoperiod and OVX and they have additive effects; (b) the effects of photoperiod on fat mass are mediated by both gonadal steroid dependent and independent mechanisms; (c) alterations in UCP2 mRNA expression may mediate the effect of OVX, but not photoperiod; and (d) UCP2 mRNA is differentially regulated in muscle and fat.
Collapse
Affiliation(s)
- P J Hope
- Departments of Medicine, University of Adelaide, 5000, South, Adelaide, Australia
| | | | | | | | | | | |
Collapse
|
10
|
Moffatt CA, DeVries AC, Nelson RJ. Winter adaptations of male deer mice (Peromyscus maniculatus) and prairie voles (Microtus ochrogaster) that vary in reproductive responsiveness to photoperiod. J Biol Rhythms 1993; 8:221-32. [PMID: 8280911 DOI: 10.1177/074873049300800305] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Individuals of many nontropical rodent species restrict breeding to the spring and summer. Seasonal reproductive quiescence putatively reflects the energetic incompatibility of breeding and thermoregulatory activities. However, so-called "out-of-season" breeding occurs in virtually all rodent populations examined, suggesting that the incompatibility can be resolved. Both reproductive inhibition and development of energy-saving adaptations are mediated by environmental photoperiod, but some individuals do not inhibit reproduction in short days. In order to assess the costs and benefits of winter breeding, the present study examined the extent to which male prairie voles (Microtus ochrogaster) and deer mice (Peromyscus maniculatus) that maintained summer reproductive function in winter-simulated daylengths also maintained summer thermoregulatory adaptations. Circadian locomotor activity patterns, basal metabolic rate, capacity for nonshivering thermogenesis, nest building, body mass, and daily food consumption were compared among short-day (LD 8:16) regressed males, short-day (LD 8:16) nonregressed males, and long-day (LD 16:8) males. Short-day nonregressed deer mice resembled long-day conspecifics in terms of body mass and nest-building activities; however, the locomotor activity pattern of short-day nonregressed deer mice was similar to that of their short-day regressed conspecifics. Short-day nonregressed prairie voles had body masses similar to those of long-day conspecifics. Regardless of their reproductive response to photoperiod, short-day prairie voles reduced their daily food consumption and wheel-running activity, compared to long-day voles. These results suggest that winter breeding has energetic costs, most likely resulting from maintaining a "summer-like" body mass relative to that of reproductively regressed animals. These costs may be ameliorated to some extent by the reduction in locomotor activity and nest-building behavior emitted by short-day animals, regardless of reproductive response to short days. Thus, the occurrence of winter breeding may be the result of sufficient numbers of reproductively photoperiod-nonresponsive morphs in the population and sufficiently mild ambient conditions to permit survival of these larger animals.
Collapse
Affiliation(s)
- C A Moffatt
- Department of Psychology, Johns Hopkins University, Baltimore, Maryland 21218
| | | | | |
Collapse
|
11
|
McAllan BM, Joss JMP, Firth BT. Phase delay of the natural photoperiod alters reproductive timing in the marsupialAntechinus stuartii. J Zool (1987) 1991. [DOI: 10.1111/j.1469-7998.1991.tb04330.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
12
|
Bosc MJ. Photoperiodic regulation of the time of birth in rats: involvement of circadian endogenous mechanisms. Physiol Behav 1990; 48:441-6. [PMID: 2267252 DOI: 10.1016/0031-9384(90)90341-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A resonance experiment was undertaken to demonstrate that photoperiod regulates birth time by endogenous circadian mechanisms. Pregnant rats were maintained on a standard light-dark (LD) cycle (14L-10D; lights on from 0600 to 2000 hr) or on fixed LD cycles with periods of 12, 24, 36 and 48 hours after day 8 of gestation. In these groups, the light phase (2 hr) started between 0600 and 0800 hr or between 1800 and 2000 hr illuminating exclusively (for periods of 24 and 48 hr) or alternatively (for periods of 12 and 36 hr) the hours corresponding to morning (M) or evening (E) of the standard light regimen. At the end of gestation, the general activity was manifested mainly at moments corresponding to the night of the standard regimen in most groups; it was delayed in the two groups lit up exclusively at E hours. In groups receiving light exclusively at M hours, birth times were delayed compared to the deliveries in groups receiving light at E hours only. An intermediate distribution of birth times was observed when M and E hours were stimulated every 12 hr but not every 36 hr. The apparent stability of the diurnal rhythm of activity and the difference in birth time distributions due to the period of light phase indicate that the regulation of birth time by photoperiod is due to a circadian mechanism in rats. This mechanism implicates at least two endogenous systems which are apparently antagonists with regard to birth.
Collapse
Affiliation(s)
- M J Bosc
- Station de Physiologie de la Reproduction, Institut National de la Recherche Agronomique, Centre de Tours, Monnaie, France
| |
Collapse
|
13
|
Lynch GR, Lynch CB, Kliman RM. Genetic analyses of photoresponsiveness in the Djungarian hamster, Phodopus sungorus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 1989; 164:475-81. [PMID: 2926693 DOI: 10.1007/bf00610441] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Endotherms living at temperate and arctic latitudes must adjust their physiology and behavior in order to survive seasonal change. The Djungarian hamster uses photoperiod to cue annual cycles of reproduction and thermoregulation, and its responses to short photoperiod include loss of body weight and change in pelage color. Some individuals do not exhibit these responses when exposed to short days. In this study individual variation in photoresponsiveness is quantified, and four lines of evidence for a genetic component to that variation are provided. First, two separate breeding stocks differed in both the percent of animals responding to a short-day lighting regimen (SD) and in the degree and timing of their response. Second, analysis of variance within and between families of full sibs for a photoresponsive index, PI (body weight loss +2 (molt index -1] following 12 weeks in SD demonstrated a significant family resemblance (intraclass correlation of 0.36 +/- 0.03). Third, heritability estimates from regression of offspring scores on parent scores for body weight loss, molt index and PI after 12 weeks in SD were 0.34 +/- 0.13, 0.36 +/- 0.10 and 0.37 +/- 0.12, respectively, indicating a strong additive genetic component for the three characters. Finally, a significant response occurred after one generation of artificial selection for and against photoresponsiveness.
Collapse
Affiliation(s)
- G R Lynch
- Department of Biology, Wesleyan University, Middletown, Connecticut 06457
| | | | | |
Collapse
|
14
|
Underwood H, Goldman BD. Vertebrate circadian and photoperiodic systems: role of the pineal gland and melatonin. J Biol Rhythms 1987; 2:279-315. [PMID: 2979667 DOI: 10.1177/074873048700200404] [Citation(s) in RCA: 120] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- H Underwood
- Department of Zoology, North Carolina State University, Raleigh 27695
| | | |
Collapse
|