Neither retinal nor pineal photoreceptors mediate photoperiodic control of seasonal reproduction in American tree sparrows (<i>Spizella arborea</i>)

Wilson, Fred E.

doi:10.1002/jez.1402590114

Cited by 104 publications

(52 citation statements)

References 37 publications

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“…McMillan et al 1975). Thorough studies by Wilson (1989Wilson ( , 1991 have led to the conclusive demonstration that at least in the Arctic breeding tree sparrow, neither the eyes nor the pineal gland are needed for the stimulation of gonadal growth by long days, the onset of photorefractoriness in response to long days or the breaking of refractoriness in response to short days. The eyes are not needed in either males or females in this species ( Wilson 1991).…”

Section: Basics Of the Environmental Regulation Of Annual Cycles In Bmentioning

confidence: 99%

“…Thorough studies by Wilson (1989Wilson ( , 1991 have led to the conclusive demonstration that at least in the Arctic breeding tree sparrow, neither the eyes nor the pineal gland are needed for the stimulation of gonadal growth by long days, the onset of photorefractoriness in response to long days or the breaking of refractoriness in response to short days. The eyes are not needed in either males or females in this species ( Wilson 1991). It is thus clear that, at least in the photoperiodic species that have been studied, the sensory receptor mediating the response of initial predictive information seems quite independent of those mediating the response to supplementary cues.…”

Section: Basics Of the Environmental Regulation Of Annual Cycles In Bmentioning

confidence: 99%

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Sex differences in the response to environmental cues regulating seasonal reproduction in birds

Ball

Ketterson

2007

Phil. Trans. R. Soc. B

194

161

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Although it is axiomatic that males and females differ in relation to many aspects of reproduction related to physiology, morphology and behaviour, relatively little is known about possible sex differences in the response to cues from the environment that control the timing of seasonal breeding. This review concerns the environmental regulation of seasonal reproduction in birds and how this process might differ between males and females. From an evolutionary perspective, the sexes can be expected to differ in the cues they use to time reproduction. Female reproductive fitness typically varies more as a function of fecundity selection, while male reproductive fitness varies more as a function sexual selection. Consequently, variation in the precision of the timing of egg laying is likely to have more serious fitness consequences for females than for males, while variation in the timing of recrudescence of the male testes and accompanying territory establishment and courtship are likely to have more serious fitness consequences for males. From the proximate perspective, sex differences in the control of reproduction could be regulated via the response to photoperiod or in the relative importance and action of supplementary factors (such as temperature, food supply, nesting sites and behavioural interactions) that adjust the timing of reproduction so that it is in step with local conditions. For example, there is clear evidence in several temperate zone avian species that females require both supplementary factors and long photoperiods in order for follicles to develop, while males can attain full gonadal size based on photoperiodic stimulation alone. The neuroendocrine basis of these sex differences is not well understood, though there are many candidate mechanisms in the brain as well as throughout the entire hypothalamo-pituitary-gonadal axis that might be important.

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Section: Basics Of the Environmental Regulation Of Annual Cycles In Bmentioning

confidence: 99%

Section: Basics Of the Environmental Regulation Of Annual Cycles In Bmentioning

confidence: 99%

Sex differences in the response to environmental cues regulating seasonal reproduction in birds

Ball

Ketterson

2007

Phil. Trans. R. Soc. B

194

161

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“…At this time, reproductive activities are curtailed although photoperiod remains well in excess of the vernal threshold for stimulation. The insensitivity to previously stimulating photoperiod that defines photorefractoriness is independent of ocular and pineal inputs (Wilson, 1990(Wilson, , 1991 and is believed to originate centrally (for review, see Nicholls et al, 1988;Juss, 1993). Photorefractoriness is associated with decreased GnRH production and circulating LH levels, rapid gonadal involution, and molt (Wingfield et al, 1980;Foster et al, 1987;Kubokawa et al, 1994;Hahn and Ball, 1995;Parry et al, 1997;Cho et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Changes in Brain Gonadotropin-Releasing Hormone- and Vasoactive Intestinal Polypeptide-like Immunoreactivity Accompanying Reestablishment of Photosensitivity in Male Dark-Eyed Juncos (Junco hyemalis)

Deviche

Saldanha

Silver

2000

General and Comparative Endocrinology

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In seasonally breeding, photoperiodic birds, the development of photorefractoriness is associated with decreased brain expression of gonadotropin-releasing hormone-like immunoreactivity (GnRH-li ir) and increased expression of vasoactive intestinal polypeptide-like immunoreactivity (VIP-li ir). Dissipation of photorefractoriness and reestablishment of photosensitivity are associated with increased GnRH-li ir brain production, but concurrent changes in VIP-li ir expression have not been investigated. To address this question, we compared the expression of VIP-li ir in the infundibulum (INF) of adult male dark-eyed juncos (Junco hyemalis) that were made photorefractory (PR) by prolonged exposure to long days with that of birds that were not photostimulated (PS), but had regained photosensitivity by exposure to short days for 5 (shortterm-PS, ST-PS) or 13 (long-term-PS, LT-PS) consecutive months. Photosensitive males had smaller INF VIP-li ir cell bodies than PR males, but the numbers of INF VIP-li ir cells were independent of photoperiodic condition. Changes in infundibular VIP-li ir were correlated with changes in preoptic area (POA) GnRH-li expression. Specifically, photosensitive males had more and larger POA GnRH-li ir cells and more GnRH-li ir fibers in this region than PR males. Further, LT-PS males had more GnRH-li ir POA fibers and larger testes than ST-PS juncos. Thus, induction of photorefractoriness is associated with increased VIP and decreased GnRH brain expression whereas dissipation of photorefractoriness concurs with decreased VIP and increased GnRH brain expression. These results suggest a physiological role for VIP in the control of changes in GnRH expression as a function of the photosensitive condition. KeywordsGnRH; VIP; reproduction; prolactin; seasonality; photoperiodism; photosensitivity; photorefractoriness; immunocytochemistry; preoptic area; infundibulum Most birds breeding at middle and high latitudes reproduce only during spring and early summer, when environmental conditions are the most favorable to successful raising of (Lack, 1968;Perrins, 1970). In these species and as originally demonstrated experimentally in dark-eyed juncos (Junco hyemalis;Rowan, 1925), photoperiod plays an essential role in the control of seasonal changes of reproductive system activity. Exposing photosensitive birds to daylength longer than approximately 12 h (defined as long days, LD), as is naturally the case during the spring, stimulates the release of hypothalamic gonadotropin-releasing hormone (GnRH) and pituitary-luteinizing hormone (LH) and follicle-stimulating hormone (FSH; Lewis and Farner, 1973;Wingfield et al., 1980;Dawson and Goldsmith, 1983;Fehrer et al., 1985;Wilson, 1985;Foster et al., 1987;McNaughton et al., 1995;Meddle and Follett, 1997). These hormones in turn induce gonadal development and the secretion of gonadal hormones that control many behavioral changes associated with the breeding period as well as the development of secondary sexual characteristics (Balthazart et al., 1979;...

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“…Photoperiodic mammals rely on the annual cycle of changes in nocturnal secretion of melatonin to drive their reproductive responses (6). In contrast, a dogma has existed that birds do not use seasonal changes in melatonin secretion to time their reproductive effort, and a role for melatonin in birds has remained enigmatic (7,8). Despite the accepted dogma, there is strong evidence that melatonin is involved in regulation of several seasonal processes, including gonadal activity and gonadotropin secretion (9)(10)(11)(12)(13)(14)(15).…”

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confidence: 99%

Melatonin induces the expression of gonadotropin-inhibitory hormone in the avian brain

Ubuka

Bentley

Ukena

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

296

251

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We recently identified a novel hypothalamic neuropeptide inhibiting gonadotropin release in quail and termed it gonadotropininhibitory hormone (GnIH). Cell bodies and terminals containing the dodecapeptide GnIH are localized in the paraventricular nucleus (PVN) and median eminence, respectively. To understand the physiological role of GnIH, we investigated the mechanisms that regulate GnIH expression. In this study, we show that melatonin originating from the pineal gland and eyes induces GnIH expression in the quail brain. Pinealectomy (Px) combined with orbital enucleation (Ex) (Px plus Ex) decreased the expression of GnIH precursor mRNA and content of mature GnIH peptide in the diencephalon, which includes the PVN and median eminence. Melatonin administration to Px plus Ex birds caused a dosedependent increase in expression of GnIH precursor mRNA and production of mature peptide. The expression of GnIH was photoperiodically controlled and increased under short-day photoperiods, when the duration of melatonin secretion increases. To identify the mode of melatonin action on GnIH induction, we investigated the expression of Mel 1c, a melatonin receptor subtype, in GnIH neurons. In situ hybridization of Mel1c mRNA combined with immunocytochemistry for GnIH revealed that Mel 1c mRNA was expressed in GnIH-immunoreactive neurons in the PVN. Melatonin receptor autoradiography further revealed specific binding of melatonin in the PVN. These results indicate that melatonin is a key factor for GnIH induction. Melatonin appears to act directly on GnIH neurons through its receptor to induce GnIH expression. This is the first demonstration, to our knowledge, of a direct action of melatonin on neuropeptide induction in any vertebrate class. melatonin receptor ͉ photoperiod ͉ reproduction

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Neither retinal nor pineal photoreceptors mediate photoperiodic control of seasonal reproduction in American tree sparrows (Spizella arborea)

Cited by 104 publications

References 37 publications

Sex differences in the response to environmental cues regulating seasonal reproduction in birds

Sex differences in the response to environmental cues regulating seasonal reproduction in birds

Changes in Brain Gonadotropin-Releasing Hormone- and Vasoactive Intestinal Polypeptide-like Immunoreactivity Accompanying Reestablishment of Photosensitivity in Male Dark-Eyed Juncos (Junco hyemalis)

Melatonin induces the expression of gonadotropin-inhibitory hormone in the avian brain

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