A biologia reprodutiva dos Amphisbaenia é uma das menos estudadas entre os répteis, havendo na literatura informações sobre o ciclo reprodutivo, dimorfismo sexual e fecundidade de poucas espécies do grupo, além de informações pontuais acerca de oviposturas. A histologia das vias genitais, da mesma forma, foi pouco estudada, tornando difícil uma melhor caracterização dos ciclos de machos e fêmeas. No Brasil são encontradas cerca de um terço das espécie do grupo, distribuídas por regiões com diferentes características macroclimáticas. Este trabalho teve por objetivo caracterizar o ciclo reprodutivo de machos e fêmeas de onze espécies brasileiras da família Amphisbaenidae, com base em dados de dissecção e histologia, e analisá-los comparativamente tendo como referência a filogenia molecular já proposta para as Amphisbaenidae do Brasil. Objetivou-se ainda realizar uma análise preliminar da relação entre os ciclos reprodutivos observados e variações sazonais de temperatura e precipitação. Para tanto, foram analisados espécimes depositados em coleções zoológicas, que tiveram suas gônadas e órgãos urogenitais examinados e medidos. Foram ainda realizadas análises histológicas de ovidutos, testículos, ductos deferentes e rins de espécimes coletados em diferentes meses do ano, para análise de sua morfologia e caracterização dos ciclos espermatogênico, de estocagem de esperma e de atividade do segmento sexual renal. Foram ainda analisados espécimes e lâminas histológicas de duas espécies da família Blanidae e uma da família Trogonophidae, permitindo uma melhor discussão das características observadas tendo como referência a filogenia do grupo. Foram analisados também dados de dimorfismo sexual de tamanho do corpo e de fecundidade. Os machos de quatro espécies de Amphisbaenidae amostradas apresentaram ciclos reprodutivos assazonais, com períodos de repouso não sincrônicos entre os indivíduos. Os machos de outras sete espécies de Amphisbaenia, duas de Blanidae e uma de Trogonophidae apresentaram ciclos sazonais. Todas as sete espécies para as quais o ciclo das fêmeas pôde ser caracterizado são sazonais nesse aspecto. Os ciclos de machos foram comparados quanto à época e duração das fases de espermatogênese, estocagem de esperma e atividade secretora do segmento sexual renal, tendo sido obtidas evidências de relação entre essas características e a filogenia do grupo. As fases reprodutivas das espécies de Amphisbaenia brasileiras são mais extensas em comparação com aquelas observadas em Blanidae e Trogonophidae. Também se obtiveram evidências preliminares da relação entre sazonalidade dos ciclos reprodutivos e variações anuais de temperatura e precipitação. Em sete espécies de Amphisbaenidae, foi observado dimorfismo sexual quanto ao comprimento rostro-cloacal ou ao comprimento da cauda. A fecundidade das fêmeas varia entre um e quatro ovos, na maioria das espécies analisadas, mas pode chegar a sete em Amphisbaena mertensi e nove em Amphisbaena trachura. / The reproductive biology of the Amphisbaenia is one of the less known among reptiles. In the literature, there are information on the reproductive cycle, sexual dimorphism, and clutch size for few species, and scarce data on clutches of eggs. Similarly, the histology of the genital tract was studied in few species, which makes difficult to characterize properly the reproductive cycles of males and females. Almost one third of the species of the group occur in Brazil, in regions with different climates. This study aimed to characterize the reproductive cycle of males and females of eleven Brazilian species of the family Amphisbaenidae, based on the dissection and histological analysis of gonads and genital ducts, and to compare the obtained data with regard to the molecular phylogeny already proposed for the Brazilian species of this family. It also aimed to analyze preliminarily the relation between the observed reproductive cycles and seasonal variations of temperature and precipitation. Specimens from zoological collections were analyzed to examination and measuring of the gonads and urogenital organs. Samples of the oviducts, testis, ductus deferens and kidneys from specimens collected in various months were also analyzed using light microscopy to characterize the cycles of spermatogenesis, sperm storage, and activity of the sexual segment of the kidney. Specimens and histology slides of two Blanidae species and one Trogonophidae species were also analyzed, allowing a better discussion of the characteristics of the reproductive cycles referring to the phylogeny of the group. Sexual size dimorphism and clutch size were also analyzed. The males of four Amphisbaenidae species presented aseasonal reproductive cycles, with testicular recrudescence and rest phases not synchronized among individuals. The males of the other seven Amphisbaenidae species, two Blanidae species and one Trogonophidae species presented seasonal reproductive cycles. The seven species for which the reproductive cycles of females could be characterized are seasonal in this regard. The male reproductive cycles were compared considering seasonality and the length of spermatogenesis, sperm storage and secretory activity of the sex segment of the kidney. Evidence of relation between the reproductive cycle characteristics and the phylogeny of the family Amphisbaenidae was obtained. The reproductive seasons of Brazilian Amphisbaenia are longer than those observed in Blanidae e Trogonophidae. Preliminary evidence on the relation between reproductive cycle seasonality and annual variations of temperature were also obtained. Seven Amphisbaenidae species presented sexual dimorphism in snout-vent length or caudal length. Clutch size varies from one to four eggs in most species, but reaches seven eggs in Amphisbaena mertensi and nine in Amphisbaena trachura.

Haloperidol é um antagonista de receptor D2 de dopamina freqüentemente utilizado na clínica para tratamento de pacientes esquizofrênicos. Haloperidol aumenta a liberação de prolactina pela glândula pituitária anterior, e a prolactina é um fator capaz de modular a atividade do sistema imune. Grupos de seis ratos machos e fêmeas receberam tratamento agudo de 2mg/kg de haloperidol (E1), tratamento prolongado com haloperidol (E2) (2mg/kg/dia por 21 dias); retirada abrupta do tratamento prolongado com haloperidol (E3), ou ainda tratamento agudo com 6mg/kg de haloperidol (E4). Os animais controle receberam tratamento similar com veículo de diluição (grupos C1, C2 e C3 respectivamente). Neste trabalho, o tratamento prolongado com haloperidol (E2) aumentou a atividade de macrófagos, aumentando o espraiamento, a fagocitose e a liberação de NO em ratos machos e fêmeas. O tratamento agudo com 2mg/kg de haloperidol (E1) não foi capaz de alterar a atividade de macrófagos, porém a dose de 6mg/kg (E4) aumentou o espraiamento e a fagocitose. Os tratamentos agudo (E1) e prolongado (E2) com haloperidol aumentaram os níveis plasmáticos de corticosterona e de prolactina tanto em machos quanto em fêmeas. Os macrófagos de ratos machos e fêmeas apresentam os mesmos padrões de alterações após os tratamentos com haloperidol, exceto para produção de H2O2 que foi maior apenas para as fêmeas dos grupos C3 e E3. Discutiu-se de que maneira o haloperidol induz ativação de macrófagos, se por uma forma indireta através do aumento nos níveis de prolactina, ou alternativamente, sendo esta ativação uma conseqüência da ação direta do haloperidol sobre os receptores de dopamina dos macrófagos. / Haloperidol is a receptor D2 antagonist frequently used in the treatment of schizophrenic patients. Haloperidol increased prolactin release from anterior pituitary gland, and prolactin modulates immune system activity. Groups of six male and female rats received acute 2mg/kg haloperidol treatment (E1), long-term (E2) haloperidol treatment (2mg/kg/day for 21 days); abrupt withdrawal of long-term (E3) haloperidol treatment, or acute 6mg/kg haloperidol treatment (E4). Control rats were treated similarly, but with vehicle (groups C1, C2 and C3 respectively). In this work long-term haloperidol treatment (E2) increased macrophage spreading, phagocytosis and NO release in male and female rats. Acute 2mg/kg haloperidol treatment (E1) didn?t change macrophage activity, however, the 6mg/kg dose (E4) increased macrophage spreading and phagocytosis. Corticosterone and prolactin serum levels were increased after acute (E1) and long-term (E2) haloperidol treatments in male and female rats. Macrophage of male and female rats presented the same pattern of alterations after acute and long-term haloperidol treatments, except for production of H2O2 that was larger just for the females of the groups C3 and E3. Haloperidol-induced macrophage activation was discussed in the light of a possible indirect effect through prolactin increments in rats, or, alternatively, as a consequence of a direct action of macrophage dopamine receptor.

Historically, metric and morphological standards used in forensic anthropology and bioarcheology were derived from individuals of European and African descent and ancient Native Americans. However, it is unlikely that these standards can be accurately applied to modern Asian populations. Due to different population histories, it is hypothesized that ancient Native American and modern Thai individuals are metrically distinct. This study investigates the metric differences in sexual dimorphism between 102 Native American (American Museum of Natural History) and 100 modern Thai (Khon Kaen University) individuals 17 to 96 years of age. A total of 28 cranial, 9 mandibular and 58 postcranial measurements were compared between Native American and Thai individuals. Subsequently, select measurements were tested in Spradley and Jantz's (2011) American Black and White sex estimation equations to see how equations derived from non-Asian populations perform on Native American and Thai individuals and to ascertain if population differences exist in the expression of sexual dimorphism. Lastly, population-specific logistic regression equations were developed for both sample populations. Using logistic regression equations and discriminant function analyses - quasi-ordinary least squares, the Native American and Thai groups are significantly different in the expression of sexual dimorphism. Further, Spradley and Jantz's (2011) equations often fail to correctly classify Native American and Thai individuals. In particular, the equations derived from American Black and White individuals frequently classified modern Thai and Native American males as females. Conversely, three American White equations and eight American Black equations classified more females as males for both populations. Therefore, the metric sex estimation methods developed on non-Asian populations do not adequately classify Native American and Thai individuals. The application of sex estimation methods developed on non-Asian populations results in reduced discriminatory power because Native Americans and Thais are less sexually dimorphic than African and European American individuals. The equations developed on the modern Thai sample correctly classified 71.1 - 96.0% of the individuals, while those developed on the Native American samples correctly 78.1 - 97.8%.

The advent of sexual reproduction in early evolutionary history had profound effects on the evolution of animals. In most sexually reproducing species, males and females have distinct morphological and behavioral differences that are shaped by the evolutionary imperatives of each sex. Underlying the behavioral differences between males and females are distinct and measurable dimorphisms in the nervous system. These dimorphisms can arise in the form of connectivity, neurotransmitter usage, gene expression or combinations of all three. The androdioecious nematode Caenorhabditis elegans, with its stereotyped development and simple nervous system, offers a remarkably powerful system for studying the conserved mechanisms of sex determination that shape neural development. In this thesis, I present my work on the characterization of several genes that regulate the development of sexual dimorphisms in the nervous system. The first part of the thesis concerns the characterization of the gene ham-3, which codes for a subunit of the C. elegans ortholog of the SWI/SNF chromatin remodeling complex. ham-3 is required for the proper terminal differentiation of the HSN, a serotonergic neuron of the sex-specific nervous system, which it manages by regulating the expression of transcription factors required for crucial steps of migration, axon guidance and serotonergic fate adoption. The second part of the thesis concerns the investigation of sexually dimorphic pruning mechanisms. I show that unc-6/Netrin is subject to direct transcriptional repression in hermaphrodites by tra-1, the master transcriptional regulator of sexual fate determination in C. elegans. This regulation is required for the proper timing of the sexually dimorphic pruning of synapses in the tail region in hermaprhodites. In males, where unc-6 is not repressed by tra-1, unc-6 expression perdures into adulthood and the synapse is maintained. Together, these data provide insight into the ways in which conserved genetic and developmental mechanisms manage the generation differentiation, connectivity, and maintenance of sexually dimorphic nervous systems.

Haloperidol é um antagonista de receptor D2 de dopamina freqüentemente utilizado na clínica para tratamento de pacientes esquizofrênicos. Haloperidol aumenta a liberação de prolactina pela glândula pituitária anterior, e a prolactina é um fator capaz de modular a atividade do sistema imune. Grupos de seis ratos machos e fêmeas receberam tratamento agudo de 2mg/kg de haloperidol (E1), tratamento prolongado com haloperidol (E2) (2mg/kg/dia por 21 dias); retirada abrupta do tratamento prolongado com haloperidol (E3), ou ainda tratamento agudo com 6mg/kg de haloperidol (E4). Os animais controle receberam tratamento similar com veículo de diluição (grupos C1, C2 e C3 respectivamente). Neste trabalho, o tratamento prolongado com haloperidol (E2) aumentou a atividade de macrófagos, aumentando o espraiamento, a fagocitose e a liberação de NO em ratos machos e fêmeas. O tratamento agudo com 2mg/kg de haloperidol (E1) não foi capaz de alterar a atividade de macrófagos, porém a dose de 6mg/kg (E4) aumentou o espraiamento e a fagocitose. Os tratamentos agudo (E1) e prolongado (E2) com haloperidol aumentaram os níveis plasmáticos de corticosterona e de prolactina tanto em machos quanto em fêmeas. Os macrófagos de ratos machos e fêmeas apresentam os mesmos padrões de alterações após os tratamentos com haloperidol, exceto para produção de H2O2 que foi maior apenas para as fêmeas dos grupos C3 e E3. Discutiu-se de que maneira o haloperidol induz ativação de macrófagos, se por uma forma indireta através do aumento nos níveis de prolactina, ou alternativamente, sendo esta ativação uma conseqüência da ação direta do haloperidol sobre os receptores de dopamina dos macrófagos. / Haloperidol is a receptor D2 antagonist frequently used in the treatment of schizophrenic patients. Haloperidol increased prolactin release from anterior pituitary gland, and prolactin modulates immune system activity. Groups of six male and female rats received acute 2mg/kg haloperidol treatment (E1), long-term (E2) haloperidol treatment (2mg/kg/day for 21 days); abrupt withdrawal of long-term (E3) haloperidol treatment, or acute 6mg/kg haloperidol treatment (E4). Control rats were treated similarly, but with vehicle (groups C1, C2 and C3 respectively). In this work long-term haloperidol treatment (E2) increased macrophage spreading, phagocytosis and NO release in male and female rats. Acute 2mg/kg haloperidol treatment (E1) didn?t change macrophage activity, however, the 6mg/kg dose (E4) increased macrophage spreading and phagocytosis. Corticosterone and prolactin serum levels were increased after acute (E1) and long-term (E2) haloperidol treatments in male and female rats. Macrophage of male and female rats presented the same pattern of alterations after acute and long-term haloperidol treatments, except for production of H2O2 that was larger just for the females of the groups C3 and E3. Haloperidol-induced macrophage activation was discussed in the light of a possible indirect effect through prolactin increments in rats, or, alternatively, as a consequence of a direct action of macrophage dopamine receptor.

Thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg in fulfilment of the requirements for the degree of Master of Science. / Breeding was observed in the foam nest frog, Chiromantis xerampelina, over three breeding seasons The mating pattern was characterized by an extended breeding season with a male-biased operational sex ratio and asynchronous and unpredictable female arrival. At more than 90% of nests, from one to seven unpaired males ('peripheral males') gathered around the amplexing pair during nest construction. Those peripheral males closest to the pair competed 'With each other, and with the amplexing male, to position their cloacae against the female's cloaca during oviposition bouts. In a detailed study of a single population, over 80% of males were observed as peripheral males, and 57% of males were observed both in amplexus and as peripheral males. Male mating success and participation at nests was unrelated to size or weight. Chorus participation was the best predictor of male, mating success and participation at nests. The most plausible explanation for the presence of peripheral males was a sperm competition hypothesis; namely that peripheral males compete with the amplexing male for fertilizations by shedding sperm into the nest. I collected data on body mass and testis mass for 13 African anurans. Using additional published data on 19 Japanese anurans, an allometric relationship between body mass and testis mass was calculated. using 16 genera as independent data points. This revealed that C. xerampelina have testes fourteen times heavier than predicted on the basis of body mass. This is consistent with a trend seen in several taxa where testis size is related to the intensity of sperm competition. An additional experiment, in which the arnplexing male was prevented from shedding sperm into the nest, showed that peripheral males are capable of fertilizing eggs. I conclude that peripheral males are engaged in an opportunistic alternative mating tactic involving sperm cosnpetition. More than half the observed females bred polyandrously, some mating with up to three males, This was the result of amplexing males dismounting between nesting sessions, and males displacing one another from amplexus. / Andrew Chakane 2018

Abdominal aortic aneurysms (AAAs), a permanent dilation in the abdominal region of the aorta, is a highly sexually dimorphic disease. AAAs prevalence is ranging from 4-10 fold higher in males than females. Defining the mechanistic basis for reduced (in females) or increased (in males) AAA formation and progression may uncover potential therapeutic targets. The majority of studies examining sexual dimorphism focus on the role of sex hormones. However, genes residing on sex chromosomes, in addition to sex hormones, may contribute to sexual dimorphism of AAAs. For example, the X chromosome contains about 5% of the whole genome, but the role of sex chromosomes genes to sexual dimorphism of cardiovascular diseases such as AAAs is largely unknown. The purpose of this study was to determine the role of sex chromosomes as mediators of sex differences for angiotensin II (AngII)-induced AAAs in hypercholesterolemic mice. We used the four core genotype murine model, which enables the creation of phenotypically normal male and female mice with an XX versus XY sex chromosome complement, to test the hypothesis that an XY sex chromosome complement promotes AngII-induced AAAs. Transgenic male mice expressing the Sry gene on an autosome, but not on the Y-chromosome, were bred to female low-density lipoprotein receptor deficient mice to create male and female mice with an XX or an XY sex chromosome complement. In females, an XY sex chromosome complement doubled the incidence and markedly increased the severity of AngII-induced AAAs. To define mechanisms, we examined gene expression patterns in abdominal aortas and demonstrated elevated expression of inflammatory genes that were linked to increased MMP activity and oxidative stress in aortas from XY females. Moreover, administration of testosterone to XY females, to mimic males, resulted in a striking level of aneurysm rupture. In males, transcriptional profiling of abdominal aortas revealed 450 genes that were influenced by sex chromosomes. Infusion of AngII to XY males resulted in diffuse pathology along the length of the aorta, while XX males developed focal AAAs, with pathology reduced by orchiectomy in both genotypes. Thoracic aortas of XY males exhibited adventitial thickening which was not exist in thoracic aortas from XX males. Following a prolonged period (3 months) of AngII infusions XY males had AAAs with expanded aortic walls, while XX males had thin walled dilated AAAs. In summary, our findings demonstrate a remarkable effect of sex chromosome complement to regulate aortic vasculature and disease development. Aside from demonstrating mechanisms of sexual dimorphism of aortic diseases, these findings indicate that chronic sex hormone therapy in the aging and transgender population may have cardiovascular ramifications. Moreover, identification of targets influenced by sex chromosomes and/or sex hormones in a manner that predicts disease development may identify sex-specific approaches to cardiovascular therapy.

<p>Southern Africa harbours one-third of the world&rsquo / s Testudinid species, many of which inhabit arid or semi-arid areas, but ecological information on these species is scant. I studied the habitat, morphology and ecology of Kalahari tent tortoises over 13 months in semi-arid Savanna at Benfontein farm, Northern Cape Province, South Africa. In order to allow continuous monitoring of individuals, I attached radiotransmitters to males and females, split equally between two habitats, sites E (east) and W (west), with apparent differences in vegetation structure. Results of the study were based on data obtained from 27 telemetered tortoises and 161 individuals encountered opportunistically. Female Kalahari tent tortoises were larger than males and the sex ratio did not differ from 1:1. Based on person-hours to capture tortoises, the population appeared to have a low density, with more time required to capture a juvenile (35 hours) than an adult (10-11 hours). The frequency distribution of body size ranges was indicative of recruitment. Relative age, based on annuli counts, suggested that males were younger than females, perhaps because males as the smaller sex are more predation-prone than females. Linear relationships between annuli counts and shell volume indicated that, after reaching sexual maturity, female body size increased faster in volume than did male body size, possibly because a larger volume may enhance female reproductive success. Body condition differed between sites, sexes and among seasons. The hot and dry summer may account for low summer body condition, whereas vegetation differences and size effects, respectively, may account for the low body condition of tortoises in site W and in males. Site E was sandy with grasses, particularly Schmidtia pappophoroides, being the prevalent growth form. This habitat resembled a Savanna vegetation type Schmidtia pappophoroides &ndash / Acacia erioloba described for a neighbouring reserve. Site W was stonier, dominated by shrubs, and was reminiscent of Northern Upper Karoo vegetation (NKu3). Neither site resembled Kimberley Thornveld (SVk4), the designated vegetation type of the area. Differences in substrate and grazing intensity may have contributed to site vegetation differences. Rainfall had an important influence on seasonal vegetation. Short grass abundance correlated with rainfall and annual plants sprouted after spring rain. Refuge use changed according to season and sex. Males selected denser refuges than females did, perhaps because males were smaller and more vulnerable to predation and solar heat. Tortoises selected sparse, short grass as refuges in cool months, probably to maximise basking whilst remaining in protective cover. During hot periods, mammal burrows were preferred to vegetation as refugia. The smaller males spent more time in cover than females, which may be related to predator avoidance or thermoregulation.&nbsp / Females spent more time basking than males, perhaps due to their larger size and to facilitate reproductive processes. Tortoises did not brumate, but through a combination of basking, and orientation relative to the sun in their refuges, managed to attain body temperatures that allowed small bouts of activity. Body temperature for active tortoises was similar among seasons, and was higher for more specialised active behaviours, such as feeding and socialising, than for walking. Increased activity by males in spring could relate to mating behaviour while females were more active in autumn, when they foraged more than males, perhaps due to the high cost of seasonal reproductive requirements. Males displaced further per day than did females, but home range estimates did not differ between sexes. Annual home range estimates varied substantially among individuals: 0.7&ndash / 306 ha for minimum convex polygons and 0.7&ndash / 181 ha for 95% fixed kernel estimates. The ability to&nbsp / cover large areas would assist tortoises in finding resources, e.g., food, in an area where resource distribution may be patchy. Differences among seasonal home ranges and movements probably reflect seasonal climatic change / activity areas shrinking when temperatures were extreme. In order to assess the effects of a semi-arid environment on the morphology of P. oculifer, I compared its morphology to that of its &lsquo / cool-adapted&rsquo / sister taxon Psammobates geometricus, using live and museum specimens. Both P. oculifer and P. geometricus are sexually dimorphic and differences between the two species could indicate environmental or sexual selection effects, or a combination of the two. The shorter bridge length, which allowed more leg space, and wider front feet in P. oculifer cohorts probably represent traits for manoeuvring in a sandy habitat, while wider heads in P. oculifer possibly relate to interspecific differences in diet. The flatter shell in female P. oculifer, relative to P. geometricus, may represent a trade-off between space for reproductive structures, e.g., eggs, and the need to fit into small refuges, e.g., mammal burrows. Male P. oculifer had wider shells, more space around their hind legs, and wider hind feet than P. geometricus males had, all characteristics which may assist males to fight and mate in a sandy environment.</p>

The dimensions of the lumbar vertebrae are examined in order to determine if these measurements can be used to predict the age of an individual, and if the lumbar vertebrae exhibit sexual dimorphism. Various statistical techniques were utilized to analyze several dimensions of the lumbar vertebrae. Aging patterns in the lumbar elements are distinct between males and females, and females exhibit compression of the L3 element, which may be related to vertebral wedging. Some dimensions of the lumbar vertebrae are sexually dimorphic.

Thesis (Ph. D.)--University of Chicago, Faculty of the Division of the Biological Sciences and the Pritzker School of Medicine, Department of Ecology and Evolution, June 2001. / Includes bibliographical references. Also available on the Internet.