This work proves the pathogenicity of four substitution mutations in the androgen-binding domain of the human androgen receptor (hAR) gene of four subjects with varying degrees of androgen insensitivity syndrome (AIS): complete (CAIS), partial (PAIS), or mild (MAIS). Of three unrelated CAIS subjects, two have Arg830Leu, the third has Arg830Gln. Their genital skin fibroblasts (GSF) have negligible androgen binding, but in overexpressing transfectants, the mutant androgen-binding activities have increased dissociation rates and decreased affinity for androgen. Owing to the instability of AR-androgen complexes, both mutants fail to transactivate a reporter gene. Glu771Ala and Arg870Gly caused PAIS and MAIS, respectively. Their normal levels of GSF androgen-binding activity have normal androgen affinity but increased dissociation rates. In transfectants, rates of dissociation resemble those in GSF, but the androgen affinities are questionably abnormal. Instability of Glu771Ala and Arg870Gly AR-androgen complexes caused subnormal transactivation of a reporter gene.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2004. / Härtill 6 uppsatser.

Thesis (Ph. D.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains vi, 125 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 107-122).

Submitted by JONLENO COUTINHO PAIVA PITOMBO null (jomtombo@hotmail.com) on 2016-05-23T15:01:17Z No. of bitstreams: 1 Jonleno Coutinho P Pitombo.pdf: 2907326 bytes, checksum: b153a02592cf15ac920e757f91e472b8 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-05-25T16:58:23Z (GMT) No. of bitstreams: 1 pitombo_jcp_me_arafo.pdf: 2907326 bytes, checksum: b153a02592cf15ac920e757f91e472b8 (MD5) / Made available in DSpace on 2016-05-25T16:58:23Z (GMT). No. of bitstreams: 1 pitombo_jcp_me_arafo.pdf: 2907326 bytes, checksum: b153a02592cf15ac920e757f91e472b8 (MD5) Previous issue date: 2016-03-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Os mecanismos de ação dos andrógenos sobre homeostase e regulação das células que participam do turnover ósseo em fêmeas ainda são pouco compreendidos. Este trabalho teve como principal objetivo avaliar a participação de andrógenos na diferenciação e atividade de osteoclastos in vitro. Células totais de medula óssea de fêmur e tíbia de camundongos fêmeas foram utilizadas como fonte de células precursoras de osteoclastos, sendo cultivadas utilizando-se α-MEM suplementado e em presença de RANK-L (30ng/mL) e M-CSF (50ng/mL). As células foram tratadas com testosterona (T) diidrotestosterona (DHT) e antagonistas de receptores de hormônios sexuais, como flutamida (FLU) e fulvestranto (FUL). O anastrozol (ANA) foi usado para inibição da enzima aromatase e o etanol (0,01%) foi utilizado como controle. Após cinco dias, as células foram fixadas, coradas com TRAP e contadas, considerando-se células TRAP-positivas com 3 ou mais núcleos. Para o ensaio de atividade, foram utilizadas placas revestidas com fosfato de cálcio inorgânico e a área de reabsorção foi calculada com o auxílio de software. O estágio de diferenciação osteoclástica foi avaliado por RT-qPCR e a modulação da expressão de receptores para hormônios sexuais foi avaliada por Western Blot. Os andrógenos (T e DHT) não exerceram efeitos sobre a diferenciação e atividade de osteoclastos (ANOVA; p>0,05). Por outro lado, os tratamentos com ANA, FLU e FUL, associados ou não a T, regularam positivamente a diferenciação e atividade de osteoclastos. A expressão gênica de RANK, Catepsina K, NFATc1 e β3 integrina não foi alterada pelos tratamentos propostos (ANOVA; p>0,05). Além disso, os tratamentos com T, DHT, FLU e FUL modularam a expressão proteica do receptor de andrógeno (AR) e dos receptores de estrógeno (ERα e ERβ) por Western Blot. Tomados em conjunto, nossos resultados indicam que os andrógenos exercem limitada participação na diferenciação e atividade de osteoclastos de camundongos fêmeas e que este processo é mediado, ao menos em parte, por ações indiretas da T e pela modulação de receptores de hormônios sexuais. / The action mechanisms of androgens on homeostasis and the regulation of cells that participate in bone turnover in females are still poorly understood. This study had as main objective to evaluate the participation of androgens in the differentiation and activity of in vitro osteoclasts. Total bone marrow cells from femur and tibia of female mice were used as a source of precursor cells of osteoclasts, they were cultivated using supplemented α-MEM and in the presence of RANK-L (30ng/mL) and M-CSF (50ng/mL). The cells were treated with testosterone (T), dihydrotestosterone (DHT) and antagonists of sexual hormone receptors such as flutamide (FLU) and fulvestrant (FUL). Anastrozole (ANA) was used for inhibiting the aromatase enzyme and ethanol (0.01%) was used as a control. After five days, the cells were fixed, colored with TRAP and counted, considering TRAP-positive cells those ones containing 3 or more nuclei. For the activity assay, were used plaques covered with inorganic calcium phosphate and the area of reabsorption was calculated with the assistance of a software. The osteoclast differentiation stage was evaluated by RT-qPCR and the modulation of the expression of receptors for sexual hormones was assessed by Western Blotting. The androgens (T and DHT) did not exert effects in differentiation and activity of osteoclasts (ANOVA, p> 0.05). On the other hand, the treatments with ANA, FLU and FUL, associated or not to T, positively regulated the differentiation and activity of osteoclasts. The genic expression of RANK, Cathepsin K, NFATc1 and β3 integrin was not altered by the proposed treatments (ANOVA, p> 0.05). Moreover, the treatments with T, DHT, FLU and FUL modulated the protein expression of the androgen receptor (AR) and of the estrogen receptors (ERα and ERβ) by Western Blotting. Taken together, our results indicate that the androgens exert limited participation in differentiation and activity of osteoclasts of female mice and that this process is mediated, at least in part, by indirect actions of T and by the modulation of sexual hormone receptors. / CNPq: 133815/2014-5 / FAPESP: 2013/12014-6

Orientador: Luis Carlos Spolidório / Resumo: Hormônios esteroides sexuais participam de diversos eventos celulares e moleculares, e exercem influência sobre o epitélio e tecido conjuntivo do periodonto. A testosterona (T), principal hormônio androgênico, pode ser convertida em estradiol (E2) pela ação da enzima aromatase, ou em di-hidrotestosterona (DHT) pela ação da enzima 5α-redutase. Para elucidar o impacto de andrógenos sobre as células que compõem os tecidos conjuntivo e epitelial, fibroblastos e queratinócitos foram avaliados em relação aos efeitos de diferentes concentrações de T e DHT, além da exposição ao anastrozol (ANA), flutamida (FLU), fulvestranto (FUL), e às associações farmacológicas T+ANA, T+FLU e T+FUL. Os resultados do presente estudo indicaram que, de modo geral, hormônios esteroides androgênicos exercem efeitos opostos sobre eventos celulares de fibroblastos gengivais humano e células epiteliais HaCaT em cultura celular. Enquanto a T e a DHT agem promovendo o aumento da proliferação e atividade de fibroblastos, a exposição de células HaCaT a estes mesmos andrógenos resulta em inibição ou exiguidade do crescimento celular, atividade metabólica ou a capacidade de repovoamento da área de arranhão in vitro. Além disso, o tratamento farmacológico com ANA, FLU, FUL, e suas respectivas associações à T, parece influenciar eventos celulares de fibroblastos gengivais humano e células epiteliais HaCaT in vitro. / Abstract: Sex steroid hormones take part in different cellular and molecular process and exert their functions on the epithelium and connective tissue of the periodontium. Testosterone (T), the main androgenic hormone can be converted to estradiol (E2) through the aromatase enzyme action, or into dihydrotestosterone (DHT) by 5α-reductase activity. To elucidate the impact of androgens on the cells that constitute the connective and epithelial tissues, fibroblasts and keratinocytes were evaluated under the effects of different concentrations of T and DHT, besides to be both exposed to anastrozole (ANA), flutamide (FLU), fulvestrant (FUL), and the pharmacological associations T+ANA, T+FLU and T+FUL. The results of this study indicated that, in general, androgenic steroid hormones exert opposite effects on cellular events of human gingival fibroblasts and epithelial cells. While androgens act stimulating gingival fibroblasts, in HaCaT cells androgens promotes a shortage or inhibition of cell growth and activity. Furthermore, pharmacological treatment with ANA, FLU, FUL, and their associations to T, appears to influence cellular events of human gingival fibroblasts and HaCaT cells in vitro. / Mestre

Sex steroids influence the storing of fat, and differences in the distribution of fat are a typical secondary sexual characteristic. Androgens act on fatty tissues in males either directly through stimulation of the androgen receptor or indirectly through aromatization of the estrogen receptor. Androgens can be classified as aromatizable or non-aromatizable. Testosterone (T) is the main aromatizable androgen, while its metabolite dihydrotestosterone (DHT) is a non-aromatizable androgen that acts only through the androgen receptor. It is precisely this difference in having activity only through the androgen receptor that has given rise to the hypothesis concerning the differing effects of DHT and T on body composition, with DHT possibly being responsible for male-type fat distribution. As part of my post-graduate studies we analyzed the dependence serum levels of T and DHT on age, as well as changes in their ratio with age. Further, we sought relationships between aromatizable and non-aromatizable androgens and metabolic and anthropometric parameters. We also focused on following any changes in steroidogenesis in obese males. We showed that before puberty the dominant androgen is rather DHT than T, that the fDHT/fT ratio during the life of adult males is constant, and that there is no evidence of a reversal...

Espécies silvestres com grande potencial zootécnico devem ser exploradas de forma racional a fim de se evitar a extinção das mesmas. Assim se dá a importância de pesquisas voltadas à reprodução daquelas criadas em cativeiro, como a cutia (Dasyprocta sp.). Este animal é um mamífero e roedor vivente, em sua maioria, na Caatinga brasileira. A ultraestrutura é a base para determinar os estágios celulares e, assim, facilitar as comparações dos processos entre cutias e roedores silvestres ou outros mamíferos. As enzimas P450 aromatase e P450c17 são responsáveis pela regulagem da produção de estrógenos e andrógenos, respectivamente. Considerando a hipótese de que o comportamento de expressão das enzimas do complexo citocromo P540 permanece o mesmo no testículo e na via espermática de cutias durante as fases de desenvolvimento sexual, objetivou-se observar a atuação das enzimas P450 aromatase e P450c17 (17-α-hidroxilase/17,20-liase) nas diferentes fases do desenvolvimento sexual, detalhar a ultraestrutura dos componentes desta via e constatar o desenvolvimento do processo espermatogênico. Segmentos do ducto deferente, epidídimo e testículo de 28 cutias machos em diferentes idades (um dia, 2-14 meses) foram fixados em paraformoldeído e glutaraldeído. O material foi coletado no Centro de Multiplicação da Universidade Federal Rural do Semiárido, Mossoró, RN (Autorização IBAMA nº 2028236/2008). Foram feitos: histologia, seguindo o protocolo padrão para hematoxilina e eosina; processamento para corte semifino (azul de toluidina); microscopia eletrônica de transmissão e varredura; e imunohistoquímica. Este trabalho foi pioneiro ao observar que o epidídimo de cutias é composto por células basais, células principais, células haloides e, quando impúbere, por células \"limpas\", e por células apicais, quando a partir da puberdade. O ducto deferente de cutias antes da puberdade era caracterizado por duas camadas musculares, possivelmente devido à falta de trânsito espermático. No epitélio germinativo foram encontradas, em sua maioria, células em prófase I, principalmente em paquíteno. A espermiogênese é completa quando na pré-puberdade, entretanto, a espermiação ocorre a partir dos 9 meses de idade. A expressão da enzima P450 aromatase variou ao longo do desenvolvimento sexual, sendo na puberdade seu pico de atividade. A P450c17 não mostrou nenhuma ação em qualquer fase sexual. Pode-se concluir que o epitélio germinativo testicular e intersticial, bem como o epitélio pseudoestratificado estereociliado do epidídimo e do ducto deferente de cutias criadas em cativeiro sofrem mudanças morfológicas e funcionais ao longo do desenvolvimento sexual. As atividades androgênicas preponderantes em cutias criadas em cativeiro ocorrem no período da puberdade. / Wild species with great potential livestock should be explored rationally in order to prevent the extinction of the same. Thus is the importance of research aimed at reproducing those bred in captivity, such as agouti (Dasyprocta sp.). This animal is a mammal and rodent living mostly in the Brazilian Caatinga. The ultrastructure is the basis for determining the stages and thus facilitates comparisons of cases between agouti and wild rodents or other mammals. The enzymes P450 aromatase and P450c17 are responsible for regulating the production of estrogens and androgens, respectively. On the assumption that the behavior of expression of the enzymes of complex cytochrome P540 remains the same in the testis and excurrent canals of the agouti during the stages of sexual development, aimed to observe the activity of the enzymes P450 aromatase and P450c17 (17-α- hidroxilase/17,20-lyase) in different stages of sexual development, detail the ultrastructure of the components of this pathway and observe the development of spermatogenesis. Segments of the vas deferens, epididymis and testis of 28 agouti males at different ages (1 day, 2-14 months) were fixed in glutaraldehyde and paraformoldehyde. The material was collected on Center of Multiplication of Federal Rural University of the Semi-arid, Natal, RN (IBAMA Authorization No. 2028236/2008). Were made: histology following the standard protocol for hematoxylin and eosin; processing to semithin (blue toluidine), electron microscopy of transmission and scanning; and immunohistochemistry. This work was pioneered by observing that the epididymis is composed by basal cells, principal cells, haloids cells; and for clean cells when impubertal and apical cells after puberty in agoutis. The vas deferens before puberty was characterized by two muscle layers, possibly due to the lack of sperm transit. In the germinal epithelium were found mostly cells in prophase I, mainly in pachytene. Spermiogenesis is complete when prepubertal phase; however, spermiation takes place from 9 months of age. The expression of enzymes of the cytochrome complex varied over sexual development and peak activity of P450 aromatase was at puberty. The P450c17 showed no action at any stage of sexual development. It can be concluded that the testicular germinal epithelium and interstitial epithelium as well as the pseudostratified estereociliated epithelium of the epididymis and vas deferens undergo morphological and functional changes during the sexual development. Androgenic activities prevalent in agoutis kept in captivity occur during puberty.

Orientador: Wilma De Grava Kempinas / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T22:18:22Z (GMT). No. of bitstreams: 1 Guerra_MarinaTrevizan_D.pdf: 6009222 bytes, checksum: 1ca90ae1ef82035a0e6930b277dac172 (MD5) Previous issue date: 2013 / Resumo: Os desreguladores endócrinos são substâncias químicas que podem mimetizar ou antagonizar os hormônios endógenos, alterando o equilíbrio hormonal necessário para o desenvolvimento correto. Sabe-se que a exposição de organismos a agentes hormonalmente ativos durante períodos críticos do desenvolvimento pode levar a alterações permanentes detectadas somente na vida adulta. Em várias espécies animais estes compostos podem atingir o feto via placenta ou a prole, pelo leite materno. Embora pesquisas iniciais tenham focado em estrógenos e antiandrógenos ambientais, a presença de compostos com atividade androgênica tem sido descrita como contaminante em rios e animais destinados a alimentação. Vários estudos demonstraram que a exposição de animais a altos níveis de andrógenos durante o período perinatal pode causar alterações morfológicas, bioquímicas e funcionais permanentes em vários órgãos e sistemas. A exposição perinatal a andrógenos exógenos pode causar masculinização fisiológica e comportamental em fêmeas e levar a alterações reprodutivas em machos. O objetivo deste trabalho foi avaliar os possíveis efeitos da exposição a um agente androgênico sobre o sistema genital e a função reprodutiva de animais expostos durante períodos críticos de desenvolvimento. Para tanto, ratas prenhes foram alocadas em quatro grupos experimentais: controle, que recebeu somente óleo de milho (veículo), e tratados com propionato de testosterona nas doses de 0,05mg/kg, 0,1mg/kg, ou 0,2mg/kg. Os tratamentos foram realizados por via subcutânea, do dia gestacional 12 ao final da lactação. A prole feminina foi avaliada quanto ao número de células germinativas fetais, peso corpóreo e distância anogenital no dia pós-natal 1, número de mamilos, idade de instalação da puberdade, histologia uterina e ovariana, dosagens hormonais, comportamento sexual, fertilidade, níveis de receptores esteroides uterinos através de imunohistoquímica, assim como taxa de proliferação/morte celular uterina e testes uterotróficos. Nos filhotes do sexo masculino foram avaliados, na idade adulta e meia idade, a histologia testicular e epididimária, contagens, morfologia e motilidade espermáticas, dosagens hormonais, comportamento sexual e fertilidade. Os resultados demonstraram que em fêmeas, a exposição perinatal ao propionato de testosterona ocasionou alteração na intensidade de marcação dos receptores esteroides uterinos em todas as doses testadas, diminuição nos índices de proliferação e morte celular no tecido uterino nas doses de 0,1 e 0,2mg/kg e aumentou a predisposição uterina a responder a estímulos estrogênicos na dose de 0,1mg/kg e 0,2mg/kg. Entretanto, estas alterações não foram capazes de prejudicar a diferenciação sexual feminina e a fisiologia normal do sistema genital feminino. Em relação aos filhotes do sexo masculino, a exposição perinatal a andrógenos provocou redução na produção e nas reservas espermáticas na idade adulta, sem, contudo, alterar a fertilidade destes animais após acasalamentos naturais. Podemos concluir que a exposição perinatal a andrógenos, nas doses utilizadas neste experimento, provocou o aparecimento de alterações tardias no sistema genital feminino como modificações nos receptores esteroides uterinos e anormalidade na resposta a estímulos estrogênicos e, no sistema genital masculino, alterações na produção espermática. Estas repercussões, entretanto, não foram capazes de alterar o desempenho geral de fertilidade em ambos os sexos / Abstract: Endocrine disruptors are chemicals that may mimic or antagonize endogenous hormones, altering the critical hormonal balance required for proper health and development. It is well known that exposure of organisms to some hormonally active agents during critical periods of development imprints permanent changes that can be detected later in adulthood. In many animal species these substances reach the fetus via placenta and/or the offspring via the mother's milk. Although first researches have focused on environmental estrogens and antiandrogens, androgenic activity has been described as contaminant in rivers and beef cattle. Previous studies demonstrated that exposure of experimental animals to high levels of androgens during perinatal age causes permanent morphological, biochemical, and functional alterations in several organs and systems. Perinatal exposure of female rodents to exogenous androgens results in both physiological and behavioral masculinization and causes reproductive disruption in male rodents. The aim of this study was to assess the possible effects of an androgenic compound on genital system and reproductive function of animals exposed during critical periods of development. Pregnant female rats were allocated into four experimental groups: control, which received corn oil (vehicle), and treated with testosterone propionate at doses of 0.05mg/kg, 0.1mg/kg and 0.2mg/kg. Treatments were performed subcutaneously, from gestational day 12 until the end of lactation. The female offspring was evaluated for fetal germ cell number, body weight and anogenital distance at post-natal day 1, number of nipples, puberty onset, histology of reproductive organs, hormonal levels, sexual behavior, fertility test, immunohistochemistry of steroid receptors, proliferation/apoptotic index, uterotrophic test and uterine stimulation with estrogens. On male offspring, at adult age and middle-age, histology of testis and epididymis, sperm counts, morphology and motility, hormonal levels, sexual behavior and fertility test were evaluated. Results demonstrated that, in females, the perinatal testosterone propionate exposure caused an alteration in the pattern of uterine steroidal receptors imunostaining in all tested doses, a decreased proliferation/apoptotic index in the uterine tissue at 0.1 and 0.2mg/kg and a greater predisposition from uterus in responding to estrogens stimulation at dose of 0.2mg/kg. However, these alterations were not capable of impairing female sexual differentiation and normal physiology of female genital tract. On male offspring, the perinatal androgenization provoked a reduction in sperm production and reserves at adult age, without altering fertility after natural mating. We can conclude that perinatal exposure to androgens, at doses used in this experiment, provoked the appearance of late alterations in the female genital system as modifications in the uterine steroidal receptors and abnormalities in uterine response to estrogenic stimulation, and in male genital system, as spermatic production impairment. These repercussions, however, were not capable to alter the general fertility performance in both sexes / Doutorado / Biologia Celular / Doutora em Biologia Celular e Estrutural

Abstract Prostate cancer is the most frequently diagnosed cancer in men in industrialized countries. Despite the substantial clinical importance of the disease, the mechanisms underlying the development and progression of prostate cancer are poorly understood. In the present study, fragment analysis of chromosome arm 16q was carried out with the aim of searching for sites of consistent chromosomal deletion, possibly uncovering the location of target genes that become inactivated in prostate carcinogenesis. The highest percentage of loss of heterozygosity (LOH) was found at chromosomal region 16q24.1-q24.2, including the gene for 17β-hydroxysteroid dehydrogenase/17-ketosteroid reductase (17HSD/KSR) type 2, HSD17B2. The data further indicated an association between loss of the most commonly deleted region and clinically aggressive features of the disease. A fragment analysis performed using sequential primary and locally recurrent prostate cancer specimens suggested the location of the genes related to prostate cancer progression to be at 16q24.3 and, further, gave rise to a hypothesis of the potential role of locus HSD17B2 as a prognostic marker for prostate cancer progression. Quantitative real-time polymerase chain reaction (PCR) revealed a decreased HSD17B2 gene copy number in prostate cancer specimens compared to their normal counterparts. A diminished HSD17B2 gene copy number was significantly associated with poor differentiation of the tumor. The progression of prostate cancer during androgen deprivation is a serious clinical problem, the molecular mechanisms of which largely remain to be clarified. The present data of enzyme activity measurements performed using high-performance liquid chromatography (HPLC) provided evidence of a substantial decrease in oxidative and an increase in reductive 17HSD/KSR activity during the transition of prostate cancer LNCaP cells into an androgen-independent state. Further, the changes detected in the activities largely coincided with the changes in the relative expression levels of genes for the potential 17HSD/KSR isoenzymes; 17HSD/KSR types 2, 5, and 7, as evidenced by relative quantitative reverse transcription PCR (RT-PCR). The data on the expression analysis of mRNA for 17HSD/KSR types 5 and 7 in prostate tissue specimens performed using in situ hybridization showed a moderately low but constitutive level for 17HSD/KSR7 mRNA in tissues of cancerous as well as hyperplastic origin. The expression of mRNA for 17HSD/KSR type 5, instead, varied considerably between different specimens, the highest expressions being strongly associated with aggressive and metastatic prostate cancer. Interestingly, furthermore, the intense expression of 17HSD/KSR5 was significantly associated with the androgen deprivation achieved either surgically or medically. Since 17HSD/KSRs critically contribute to the control of the bioavailability of active sex steroid hormones locally in the prostate, the variation in intraprostatic 17HSD/KSR activity might be crucially involved in the regulation of the growth and function of the organ.

Whilst individual differences in circulating hormone levels can influence life history traits throughout an animal’s lifetime, this remains a poorly understood area of research, particularly for wild systems where sufficient sets of individual-based data are rare. This thesis aimed to address this dearth of information by identifying key drivers of hormone variation, as well as exploring potential fitness consequences within a single system of wild red deer (Cervus elaphus) on the Isle of Rum National Nature Reserve in Scotland. It focussed on both androgen (e.g. testosterone) and glucocorticoid (e.g. cortisol) levels, and examined among-individual variation in these two hormone groups from samples collected using both traditional (blood: chapters 3 & 4) and non-invasive (faecal: chapters 5 & 6) methods. Results showed both intrinsic and extrinsic factors to influence an individual’s hormone levels. In general, current or recent environment explained the greatest variation, with both hormone groups exhibiting strong temporal trends at multiple scales. Concentrations changed substantially across an individual’s lifetime as they aged (chapters 5 & 6), and calves born in different years differed in their neonatal testosterone levels (chapter 3). Hormone levels also varied across the year, showing clear seasonal cycles which peaked during key reproductive events: the calving season in females (chapter 6) and the rut in males (chapter 5). An individual’s current life history state was also important, particularly a female’s reproductive state (chapter 6). Whilst there was some evidence of maternal effects on neonatal hormone levels (chapter 3) these were not extensive, and maternal hormone concentrations did not appear to influence those in their new-born calves (chapter 6). There was, however, evidence of neonatal circulating testosterone levels being heritable, and despite overall differences between the sexes the underlying genetic architecture of this trait did not differ between male and female calves (chapter 4). Associations were also found between an individual’s hormone levels and their fitness, although these consequences were only apparent in short-term fitness measures or proxies such as reproductive behaviour (e.g. male reproductive effort in chapter 5). Effects were also not ubiquitous within the population. Whilst a calf’s circulating testosterone levels indicated their probability of surviving their first year of life, these effects were only apparent in firstborn males, a group which is particularly vulnerable to mortality (chapter 3). In general, this thesis suggests that the fitness consequences identified by broad-scale hormone manipulation studies can still be found when looking at subtle individual-level differences. The limited evidence of persistent hormone phenotypes (indicated by the lack of among individual variance for most measures, chapter 5 & 6) does, however, emphasise the importance of repeatedly sampling individuals before drawing extensive conclusions about fitness consequences.