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Endogenous programs in avian reproductive seasonal life history transitions have been known for over 30 years. Attempts to identify the neural and molecular substrates of photoperiodic time measurement have, to date, focussed on blunt changes in light exposure during a restricted period of photoinducibility. Here we report mediobasal hypothalamus (MBH) and pituitary gland specific transcript expression cascades associated with photoperiod-induced seasonal life history transitions. We identified multiple waves of transcript expression that were not synchronized across brain regions. Follicle-stimulating hormone-β (FSHβ) expression increased during the simulated vernal equinox, prior to photoinduced increases in prolactin, thyrotropin-stimulating hormone-β and testicular growth. Analyses showed sustained elevated levels of daily FSHβ expression in the pituitary under conditions of the vernal, compared to autumnal equinox, short (12L) photoperiods. FSHβ expression increased in Quail held in non-stimulatory photoperiod, indicative of an endogenous programmed change in transcription. These data identify that FSHβ provides an endogenous program for the photoperiod-dependent external coincidence timing for seasonal transitions in reproduction. FSHβ may prime the pituitary for subsequent stimulation by triiodothyronine-mediated changes in tanycytes during the photoinducible phase. Overall, the data indicate a multi-cellular, multi-neural interval timing mechanism resides in the brain to control seasonal life-history transitions in birds.

Quantitative PCR (qPCR) is a common molecular tool to analyse the expression of transcripts in non-traditional animal models. Most animals experience tissue-specific seasonal changes in cell structure, growth, and cellular function. As a consequence, the choice of reference or ‘house-keeping’ genes is essential to standardize expression levels of target transcripts of interest for qPCR analyses. This study aimed to determine the abundance, efficiency and stability of several reference genes commonly used for normalisation of qPCR analyses in a model of seasonal biology: the Siberian hamster (Phodopus sungorus). Liver, brown-adipose tissue (BAT), white adipose tissue (WAT), testes, spleen, kidney, the hypothalamic arcuate nucleus, and the pituitary gland from either long or short photoperiod Siberian hamsters were dissected to test tissue-specific and photoperiod effects on reference transcripts. qPCR was conducted for common reference genes including 18s ribosomal RNA (18s), glyceraldehyde 3-phosphate dehydrogenase (Gapdh), hypoxanthine-guanine phosphoribosyltransferase (Hprt), and actin-β (Act). Cycling time (Ct), efficiency (E) and replicate variation of Ct and E measured by percent coefficient of variance (CV%) was determined using PCR miner. Measures of stability were assessed using a combined approach of NormFinder and BestKeeper. 18s and Act did not vary in Ct across photoperiod conditions. Splenic, WAT and BAT Gapdh Ct was higher in long compared to short photoperiod. Splenic Hprt Ct was higher in long photoperiods. There was no significant effect of photoperiod, tissue or interaction on measures of efficiency, Ct CV%, or efficiency CV%. NormFinder and BestKeeper confirmed that 18s, Gapdh and Hprt were highly stable, while Act showed low stability. These findings suggest that 18s and Hprt show the most reliable stability, efficiency, and abundance across the tissues. Overall, the study provides a comprehensive and standardised approach to assess multiple reference genes in the Siberian hamster and help to inform molecular assays used in studies of photoperiodism.

In most animals, annual rhythms in environmental cues and internal programs regulate seasonal physiology and behavior. Prolactin, an evolutionarily ancient hormone, serves as a molecular correlate of seasonal timing in most species. Prolactin is highly pleiotropic with a wide variety of well-documented physiological effects; in a seasonal context prolactin is known to regulate annual changes in pelage and molt. While short-term homeostatic variation of prolactin secretion is under the control of the hypothalamus, long-term seasonal rhythms of prolactin are programmed by endogenous timers that reside in the pituitary gland. The molecular basis of these rhythms is generally understood to be melatonin dependent in mammals. Prolactin rhythmicity persists for several years in many species, in the absence of hypothalamic signaling. Such evidence in mammals has supported the hypothesis that seasonal rhythms in prolactin derive from an endogenous timer within the pituitary gland that is entrained by external photoperiod. In this review, we describe the conserved nature of prolactin signaling in birds and mammals and highlight its role in regulating multiple diverse physiological systems. The review will cover the current understanding of the molecular control of prolactin seasonality and propose a mechanism by which long-term rhythms may be generated in amniotes.

Political scientists have under-studied those who actually “do” formal politics – politicians, particularly those operating below the level of heads of state. This neglect has been acute in African politics, resulting from, and contributing to, a generalised disdain for African politicians and a set of unflattering assumptions about their allegedly self-interested and materialistic motivations and methods. This blind-spot has impoverished debates around democratisation, party-voter linkage, and economic development, amongst others. Approaching politics through the eyes of politicians, and taking Malawi as a case, this thesis focuses on an especially neglected yet important area: MPs’ attitudes towards, and behaviour within, their constituencies. Utilising an adjusted version of Fenno’s concept of “home styles” – and based upon close observation of MPs “at home” as well as extended interviews with them – the thesis addresses MPs’ motivations for entering politics; their experiences of primary contests; the logistics and sociology of campaigning for election; their constituency service, before and after taking office, in terms of both development projects and “handouts”; and finally, how their experiences of being a constituency MP inform their reflections about how democracy is (and is not) working in contemporary Malawi. I argue that MPs’ motivations transcend self-interest. Broadly (and in common with many aid donors) they have a deeply ambivalent attitude to democracy, grounded in an image of a country and of constituents lacking in necessary (self-) discipline. They seek office by making a presentation of themselves as an embodied exemplar of certain virtues and once in office usually try to hold a line on handouts, communicating a “presentation of (their) role” as elected representatives designed in part to limit the pressure that holding office places on their personal resources. Typically, MPs perceive themselves as failing on all fronts and adopt a distinctly pessimistic orientation towards democracy as a whole.