The mammalian Y chromosome contains genes important for male sexual maturity and reproduction. The mouse Y chromosome long arm harbours a number of multi-copy genes whose absence or reduced representation has been linked to sperm defects and offspring sex ratio distortion in favour of females. Understanding the biological mechanisms of sex ratio distortion and related sperm aberrations could not only result in benefits for fertility research, but also in the development of methods for large scale animal breeding pre-implantation sex selection. The distortion has been linked to an intragenomic conflict between the X and Y chromosomes that impacts spermiogenesis. Since the proportion of X- and Y-bearing sperm does not differ in affected animals, and there is no selective destruction of male embryos post-fertilisation, a functional difference must exist between the X- and Y-bearing sperm. This thesis describes the investigation into the physiological and molecular mechanisms of a large Y-chromosome long arm deletion in the mouse model MF1XYRIIIqdel. The examination of physiological characteristics revealed a distinct sperm morphology within the deletion model. Detailed characterisation of sperm shape demonstrated that aberrations consistently occur within specific regions of the sperm head, linking the distorted morphology to particular maturation stages in the sperm cycle. Using sperm fluorescence in situ hybridisation, a novel and detailed comparison of X- and Y- bearing sperm has shown that a subtle distinction in shape also exists between the X- and Y- bearing sperm in the deletion model. Breeding data were examined and showed a skew towards female offspring and a slightly reduced litter size. Sperm enzyme activity assays did not reveal altered hyaluronidase activity in MF1XYRIIIqdel sperm. Physiological differences between X- and Y- bearing sperm must result from differential gene expression, complicated by the syncitial nature of sperm development. To explore this, a detailed molecular characterisation of the MF1XYRIIIqdel phenotype in developing haploid spermatids was performed. Cellular elutriation and fractionation techniques were employed to separate spermatids at different stages of maturation and isolate different subcellular compartments. Differences in the transcriptional profile between these populations were analysed by microarray and RNA sequencing analysis of total and micro RNA. This work yielded a collection of coding and non-coding transcripts which show distinctive expression and compartmentalisation differences between the deletion model and its wild-type counterpart across several sperm maturation stages. Combining these strategies has led to the identification of several gene products potentially implicated in observed physiological differences and the offspring sex ratio skew, providing candidate genes for further research.

Reproductive behaviour and aspects of group dynamics in the genus Acomys were studied in the respect to the individuals? physical condition, life history traits and social environment. Three of the presented studies reveal the important effect of social environment on the behaviour of group members to the new-coming male and reproductive behaviour of females (sex ratio of the pups and litter size). The other two studies investigate the costs associated with group living and cooperative breeding in Sinai spiny mice and the factors influencing alloparental behaviour. Results of this Ph.D. thesis reveal several aspects of social and reproductive behaviour of group-living mammals and contribute to the understanding of the formation and maintenance of the societies in general.

Selfish genetic elements can distort the sex ratios of their hosts by increasing their own transmission to the next generation in a non-mendelian fashion. These elements can be either nuclear genes on a sex chromosome or cytoplasmically inherited microbes, and achieve an increased transmission by manipulating gametogenesis or host reproduction. Often these selfish elements benefit from a female biased population (for example heritable microbes are passed on maternally in the egg cytoplasm), while non-selfish, autosomal genes are selected to produce a balanced sex ratio. These differing reproductive strategies cause a genetic conflict that results in an “evolutionary arms race” that can promote the evolutionary change of sex determination systems. In this thesis, I investigate an extreme sex ratio distortion in a species of booklouse, Liposcelis sp. This species contains two distinct female types, one of which carries a maternally transmitted selfish genetic element that results in exclusively female offspring being produced. Recently, a candidate for the sex ratio distortion was identified as a horizontally transferred bacterial gene, that we have called Odile, and that is present in the genome of the (distorter) female carrying the distorting element. The gene originates from the endosymbiotic bacterium Wolbachia that is well known for its ability to distort the sex ratio of its hosts. I investigated this horizontal gene transfer event and attempt to characterize Odile. I provide evidence that this Wolbachia gene has been integrated into the genome of the distorter females and is not a bacterial contaminant. I found that the Odile gene has been duplicated and may have been horizontally transferred from Wolbachia independently to at least three other insect genomes. Additionally, I found that Odile is transcribed at low levels in a life-stage specific manner that is suggestive of a role in development. Additionally, I looked into male mate choice in this species as one aspect of the persistence of the distorting element. I found that male Liposcelis sp. do not discriminate between the two female types and do not spend more time mating with one female type over the other. These results contribute to ongoing research into the extreme sex ratio distortion found in this species and the candidate gene that may be the cause. Selfish genetic elements are an important driver of sex determination evolution, and Liposcelis sp. provides a unique and exciting system to investigate the implications of selfish elements in a genome further. / Graduate / 2019-12-17

Orientador: Giovana Bertini / Resumo: O objetivo deste estudo foi verificar a dinâmica populacional do camarão M. olfersii ao longo do Rio Ribeira de Iguape, enfocando a distribuição espaço temporal, período reprodutivo, recrutamento, razão sexual, maturidade sexual, crescimento e longevidade. Os camarões foram coletados mensalmente de janeiro a dezembro de 2007, em quatro regiões ao longo do Rio Ribeira de Iguape (Eldorado, Sete Barros, Registro e Iguape) por meio de armadilhas e peneira. Todos animais coletados foram identificados e quantificados, e após a subamostragem, mensurados na região do comprimento da carapaça (CC) e sexados. Obteve-se 23.818 indivíduos, sendo 9.691 analisados (6.655 jovens, 1.746 machos, 892 fêmeas e 398 fêmeas ovígeras) com tamanho variando de 2,2 a 25,4 mm CC. A região de Iguape foi representada por 4.913 inds, seguida de Registro (1.714), Sete Barras (1.666) e Eldorado (1.398). As comparações entre as técnicas de coleta evidenciaram que mais de 95% da abundância total foi obtida pela peneira junto a vegetação marginal, sendo a maior parte dessa abundância constituída pelos jovens, resultando na menor média de tamanho dos indivíduos obtidos nesta técnica de coleta. A população foi estatisticamente menor em Iguape tendo alta frequência de jovens, indicando que os indivíduos estão realizando o comportamento de migração a montante do rio, após completar o desenvolvimento larval no estuário. O período reprodutivo foi descontínuo em Eldorado, Sete Barras e Registro e contínuo em Iguape, t... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to verify the population dynamics of prawn M. olfersii along the Ribeira de Iguape river, focusing on the distribution, reproductive period, recruitment, sex ratio, sexual maturity, growth and longevity. The prawns were collected monthly from January to December 2007, in four regions along the Ribeira de Iguape river (Eldorado, Sete Barros, Registro and Iguape) by traps and sieve. All animals were identified and quantified, and after the subsampling, measured in the region of carapace length (CC) and sexed. A total of 23,818 individuals were obtained, of which 9,691 were analyzed (6,655 juveniles, 1,746 males, 892 females and 398 ovigerous females), ranging from 2.2 to 25.4 mm CC. The Iguape region was represented by 4,913 individuals, followed by Registro (1,714), Sete Barras (1,666) and Eldorado (1,398). The comparisons between the collection methods showed that more than 95% of the total abundance was obtained by the sieve in the marginal vegetation. Most of this abundance was represented by the juveniles, resulting in the smaller average size of the individuals obtained in this collection method. The size of the population was statistically lower in Iguape with a high frequency of juveniles, indicating that the individuals are performing the migratory behavior upstream of the river after the larval period in the estuary. The reproductive period was discontinuous in Eldorado, Sete Barras and Registro and continuous in Iguape, but all with peak in ... (Complete abstract click electronic access below) / Mestre

Submitted by LIZANDRA FERNANDES MIAZAKI null (lizandrafmiazaki@hotmail.com) on 2017-04-18T13:59:15Z No. of bitstreams: 1 Dissertação - Lizandra Fernandes Miazaki FINAL.pdf: 1415555 bytes, checksum: 30ab873a5ee74e11ad9187af979a4bac (MD5) / Rejected by Luiz Galeffi (luizgaleffi@gmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido não contém o certificado de aprovação. Corrija esta informação e realize uma nova submissão com o arquivo correto. Agradecemos a compreensão. on 2017-04-18T19:12:55Z (GMT) / Submitted by LIZANDRA FERNANDES MIAZAKI null (lizandrafmiazaki@hotmail.com) on 2017-05-03T14:30:40Z No. of bitstreams: 1 Dissertação - Lizandra Miazaki com atestado.pdf: 1485604 bytes, checksum: a3af97a6b774bafe24203fda675024c2 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-03T14:42:37Z (GMT) No. of bitstreams: 1 miazaki_lf_me_bot.pdf: 1485604 bytes, checksum: a3af97a6b774bafe24203fda675024c2 (MD5) / Made available in DSpace on 2017-05-03T14:42:37Z (GMT). No. of bitstreams: 1 miazaki_lf_me_bot.pdf: 1485604 bytes, checksum: a3af97a6b774bafe24203fda675024c2 (MD5) Previous issue date: 2017-02-20 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O caranguejo Hepatus pudibundus possui ampla distribuição no litoral brasileiro, é intensamente capturado como fauna acompanhante (bycatch) na pesca dos camarões peneídeos, mas não apresenta valor comercial. No entanto, está sujeito aos mesmos impactos causados à espécie alvo. Em vista disso, a dinâmica populacional foi investigada no presente estudo, com enfoque nos seguintes aspectos: proporção sexual, maturidade sexual morfológica e gonadal, período reprodutivo, recrutamento juvenil, crescimento e longevidade dos indivíduos. Foram realizadas coletas mensais na região de Cananéia/SP entre julho/2012 e junho/2014 em sete estações de coleta, por meio de um barco camaroeiro equipado com duas redes de arrasto do tipo “otter trawl”. Temperatura e salinidade da água de fundo, o teor de matéria orgânica, granulometria do sedimento e a pluviosidade foram averiguados. Foram amostrados 1.650 espécimes. Os machos apresentaram-se maiores que as fêmeas. A proporção sexual foi desviada em favor das fêmeas. O tamanho estimado para a maturidade sexual morfológica e gonadal, respectivamente (LC50) foram 42,26 mm e 48,97 mm para machos e 43,09 mm e 47,15 mm para as fêmeas. As fêmeas reprodutivas ocorreram em todo o período e os juvenis foram amostrados na maioria dos meses. Ambas as categorias demográficas correlacionaram-se positivamente com a temperatura. Os parâmetros de crescimento apresentaram diferenças entre os sexos sendo: LC∞ = 78,91 mm, k = 0,0066/dia, t0 = 0,0965 para os machos e LC∞ = 67,68 mm, k = 0,0064/dia, t0 = 0,0032 para as fêmeas. A longevidade foi estimada em 1,91 anos e 1,98 anos para machos e fêmeas, respectivamente. O dimorfismo sexual possivelmente está relacionado às diferenças comportamentais entre machos e fêmeas. A proporção sexual desviada a favor das fêmeas provavelmente está relacionada à diferentes taxas de crescimento e mortalidade, restrição de alimento e uso distinto do habitat por cada sexo. Os valores estimados para maturidade morfológica foram maiores para as fêmeas, o qual favorece o sucesso reprodutivo da espécie pois, fêmeas com uma maior cavidade cefalotorácica podem produzir e exteriorizar um número superior de ovos em relação às menores. Em contrapartida, para maturidade gonadal estimou-se um maior tamanho para os machos, o que também pode ser favorável à reprodução da espécie, uma vez que, machos maiores se beneficiariam quanto a proteção e manipulação das fêmeas durante a cópula. Os resultados sugerem uma reprodução e recrutamento contínuos, os quais são típicos de regiões tropicais e subtropicais quentes, corroborando com o paradigma do efeito latitudinal, bem como os parâmetros de crescimento e longevidade. Os dados apresentados fornecem um maior entendimento a respeito do ciclo de vida da espécie. Adicionalmente, visto que as redes não são seletivas, o presente estudo também disponibiliza subsídios para um possível plano de manejo e gerenciamento mais abrangente da pesca de arrasto, abordando não só os camarões, mas também as espécies acessórias. / The crab Hepatus pudibundus is wide distributed in the Brazilian coast. The species has no commercial value but is intensely captured as bycatch of penaeid shrimp fishery, so it suffers the same impacts of the target species. In this view, the present study investigates the population dynamics, focusing on the following aspects: sex ratio, morphological sexual maturity and gonads, reproductive period, juvenile recruitment, growth and longevity of individuals. Sampling was performed monthly in the region of Cananéia/SP, from July/2012 to June/2014 in seven stations, with a shrimping boat equipped with otter trawl nets. Temperature and salinity of the bottom water, the organic matter content, sediment granulometry and rainfall were investigated. A total of 1,650 specimens were captured. Males were larger than females. The sex ratio skewed towards females. The estimated sizes for morphological and gonadal sexual maturity (CW50) were 42.26 mm and 48.97 mm for males, and 43.09 mm and 47.15 mm for females, respectively. Reproductive females occurred throughout the studied period and juveniles were captured in most months. Such demographic categories were positively correlated with temperature. Growth parameters showed differences between sexes: CW∞ = 78.91 mm, k = 0.0066/day, t0 = 0.0965 for males and CW∞ = 67.68 mm, k = 0.0064/day, t0 = 0.0032 for females. Longevity was estimated at 1.91 years and 1.98 years for males and females, respectively. The sexual dimorphism found in this study is possibly related to behavioral differences between males and females. The sex ratio skewed towards females may be related to different growth and mortality rates, food restriction and different use of habitat for each sex. The estimated values for morphological maturity were higher for females, which favor the reproductive success of the species; females with a larger cephalothorax cavity can produce and externalize a higher number of eggs in relation to minors. In contrast, the size of gonadal maturity estimated was higher in males, which may also be favorable to the reproduction of the species; larger males are in advantage when protecting and manipulating the female during copulation. The results suggest a continuous reproduction and recruitment, which are typical of warm tropical and subtropical regions, corroborating the paradigm of latitudinal effect as well as the parameters of growth and longevity. The data presented provide a greater understanding of the life cycle of the species. Additionally, since trawl nets are not selective, this study also provides information for a better trawl fishery management, addressing not only the target shrimp but also the bycatch species. / FAPESP: 2015/20382-0

Submitted by ANA ELISA BIELERT LOPES null (anaelisa_lopes@hotmail.com) on 2017-09-29T18:51:09Z No. of bitstreams: 1 Dissertação Ana Elisa B. Lopes - com artigo anexado.pdf: 3755415 bytes, checksum: 2f9f1960e6fda6593835653e5f78966a (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-09-29T19:28:01Z (GMT) No. of bitstreams: 1 lopes_aeb_me_bot.pdf: 3755415 bytes, checksum: 2f9f1960e6fda6593835653e5f78966a (MD5) / Made available in DSpace on 2017-09-29T19:28:01Z (GMT). No. of bitstreams: 1 lopes_aeb_me_bot.pdf: 3755415 bytes, checksum: 2f9f1960e6fda6593835653e5f78966a (MD5) Previous issue date: 2017-08-02 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / This is the first study to evaluate in broad spatiotemporal scales the growth parameters and population structure of Rimapenaeus constrictus, a barely damaged species composing the bycatch from shrimp fishing in the Western Atlantic. The abundance and size-class frequency distribution, growth, longevity and sex ratio were evaluated from monthly samples obtained in the northern littoral of São Paulo state from Jan/1998 to Jun/2003. We measured 5,812 individuals in which the sex ratio was skewed toward females; this was more evident in size classes greater than 10 mm in CL (carapace length) (binomial test, p<0.05). We selected 16 growth cohorts of females, and 8 of males, the majority consisting of younger individual cohorts excluded from the fisheries closure period. Growth estimates resulted in a CL∞ of 17.42 mm, a growth coefficient of 0.008 and a longevity of 579 days (1.60 year) for females, as well as a CL∞ of 16.3 mm, a growth coefficient of 0.01 and a longevity of 425 days (1.17 year) for males. Our results provide information of incontestable relevance to our knowledge of fishing management. We therefore strongly recommend that the fisheries closure period be changed to protect this species’ recruitment period and consequently its adult individuals. The reproduction and recruitment were analyzed in order to determine the size at the onset of sexual maturity, the reproductive and recruitment patterns and the copulation period. In our study, 6,456 shrimps were captured among which 5,774 were measured, which 4,322 were females and 1,452 were males. The estimated maturity was 8.3 mm and 11.2 mm, for males and females, respectively. Reproductive females were found over the 5-year study. These results suggests a continuous reproduction pattern, with peaks in summer and in spring. We verified a positive significant relation between reproductive females and temperature (lag +1 and +3), although the decrease in bottom water temperature in some peaks of reproductive activity (spawning), which was probably induced due to SACW intrusion. The recruitment was considered episodic and even though no significant relation was found between immatures and reproductive females, we suggested that the main recruitment peaks observed were a consequence of the major reproductive activities a few months prior to it. The copulation period was continuous in the sampled period, and ISP females (recently copulated) were significant correlated with reproductive males (lag 0). Thus, we propose that during this period the sexual proportion is 1:1, probably due to the migration of reproductive males, attracted to copulate. Our results provide information of incontestable relevance to our wide knowledge of the species’ reproductive biology, in order to support an accurate fishing management. / FAPESP: 2015/13639-5

Resumo: Lagartas das traças-da-cera Galleria mellonella e Achroia grisella foram oferecidas a fêmeas do endoparasitóide solitário Apanteles galleriae de uma população mantida em condições de laboratório (população de laboratório), e a fêmeas de uma população selvagem, formada a partir de casulos coletados em apiários de Rio Claro e Araras, SP, Brasil (população de campo). Os parasitóides de cada população foram criados por 4 gerações consecutivas. Dois parasitóides machos e uma fêmea, emergidos no mesmo dia e da mesma espécie de hospedeiro foram transferidos para frascos de 30 mL, para propiciar o acasalamento. A cada fêmea fecundada de A. galleriae foram oferecidas 5, 10, 15 ou 20 lagartas de Galleria mellonella ou Achroia grisella de 5º e 6º instar, respectivamente, por uma hora. Após este período, a fêmea foi devolvida ao frasco de origem e as lagartas receberam dieta "ad libidum". Tal procedimento foi realizado a cada 2 dias, desde o 3º dia de vida da fêmea, até a sua morte. O objetivo da pesquisa foi comparar as proles obtidas de ambas as populações, em relação ao número de descendentes e à razão sexual, bem como avaliar a capacidade de parasitismo do parasitóide, em função da idade da fêmea e da densidade de hospedeiros submetidos ao parasitismo. Utilizou-se um teste de proporções para comparar as freqüências de lagartas de G. mellonella e A. grisella parasitadas por fêmeas de A. galleriae de cada população (F4 ou Lab) e uma análise de variâncias para testar o efeito da idade das fêmeas das duas populações sobre o número de descendentes emergidos, para as quatro densidades de hospedeiros. Uma análise de correlação de Pearson foi usada para avaliar o efeito da idade materna sobre a razão sexual registrada para os parasitóides obtidos em cada grupo experimental. As maiores eficiências de parasitismo registradas foram 42,59% para... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Caterpillars of Galleria mellonella and Achroia grisella were offered to females of the solitary endoparasitoid Apanteles galleriae from a population maintained under laboratory conditions (laboratory population), and females from a wild population, formed from cocoons collected in apiaries of Rio Claro and Araras, SP, Brazil (field population). The parasitoids of each population were reared by four consecutive generations. Two males and a female, emerged on the same day and reared in the same host species, were transferred to a 30 mL vial in order to allow mating. Caterpillars of A. grisella (sixth instar) or G. mellonella (fifth instar) were offered for sixty minutes to each mated and expert female, with 2 to 5 days of age, in one of the four host densities used in this research (5, 10, 15 and 20 hosts/female). After this period, the female was given back to the original vial, and the caterpillars received diet "ad libidum". Such procedure was accomplished every 2 days, since the 3rd day of the female life until her death. The objective of this research was to compare the offsprings from both populations, in relation to the number of descendants and sex ratio, and also the capacity of parasitism of A. galleriae in relation to the age of the female and the density of hosts submitted to the parasitism. A test for difference of proportions was applied to compare the frequencies of caterpillars of G. mellonella and A. grisella parasitized by A. galleriae females of each population (F4 or Lab), and an analysis of variances was used to evaluate the effect of the age of females from both populations on the number of descendants emerged, as a function of the host densities. A Pearson's correlation analysis was utilized to test the effect of maternal age on sexual proportion recorded for parasitoids of each experimental group. The highest efficiencies of parasitism recorded were 42.59% to ... (Complete abstract click electronic access below) / Orientador: José Chaud Netto / Coorientador: Nivar Gobbi / Banca: Ana Eugenia de Carvalho Campos Farinha / Banca: Julio Marcos Melges Walder / Banca: Sonia Silveira Ruiz / Banca: Giuliano Grici Zacarin / Doutor

abstract: Life History Theory suggests that, in order to maximize reproductive fitness, individuals make trade-offs between allocating resources to mating and parenting. These trade-offs are influenced by an individual's sex, life history strategy, and environment. Here, I explored the usefulness of a Life History Theory framework for understanding endorsement of child support laws. This study experimentally manipulated sex ratio, and gathered information about participants' endorsement of child support, sexual restrictedness, and mate value. As predicted, women endorsed child support more than men, whereas men favored greater restriction of child support in the form of required paternity testing. However, in general, results do not support an effect of sex ratio, sexual restrictedness, or mate value on endorsement of child support. Results suggest sensitivity to exploitation in a male-biased sex ratio, reflected by an increase in men's endorsement of paternity testing requirements under a male-biased sex ratio prime. Women, on the other hand, report especially unfavorable beliefs toward paternity testing in a male-biased sex ratio. Although results of the current study are mixed, there remains much to be gained from applying an evolutionary perspective to understanding variability in endorsement of child support. / Dissertation/Thesis / M.A. Psychology 2013

Orientador: Fosca Pedini Pereira Leite / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T22:39:00Z (GMT). No. of bitstreams: 1 Siqueira_SilvanaGomesLeite_M.pdf: 3457727 bytes, checksum: 6c473d589145fe72fa976a3a068adb64 (MD5) Previous issue date: 2007 / Resumo: Este estudo teve como objetivo caracterizar a biologia populacional e a fecundidade do gamarídeo Leucothoe sp. associado à ascídia Phallusia nigra no Canal de São Sebastião, Litoral Norte do Estado de São Paulo. A estrutura populacional, crescimento, razão sexual, fecundidade, dimorfismo sexual e mortalidade deste anfípode foram observadas bimestralmente em oito costões do infralitoral e relacionados com a temperatura da água e a biomassa das ascídias. Em cada período e local foram coletadas três ascídias. Indivíduos de todos os estágios de desenvolvimento de Leucothoe sp. foram encontrados associados a P. nigra, caracterizando o ambiente como estável e propício para a sua reprodução e alimentação. A associação não variou no período de estudo, não foi influenciada pela biomassa da ascídia e nem pela temperatura da água. A maior parte da população de Leucothoe sp. foi composta de jovens. O menor número de indivíduos adultos pode estar relacionado a fatores como mortalidade e à busca dos jovens por novos hospedeiros. Os dados referentes à estrutura de tamanho e crescimento indicam que Leucothoe sp. pode viver entre 7,2 e 11 meses caracterizando um ciclo de vida semi-anual. A razão sexual de Leucothoe sp. foi desviada a favor das fêmeas, fato provavelmente relacionado com migração e mortalidade diferencial dos machos. A reprodução de Leucothoe sp. é contínua e a fecundidade está positivamente relacionada com o tamanho do corpo, como é freqüente entre os gamarídeos. Machos e fêmeas de Leucothoe sp. apresentam diferenças morfológicas nos segundos gnatópodo indicando a presença de dimorfismo sexual / Abstract: The aim of this study was to characterize the population biology and the fecundity of the gammaridean amphipod Leucothoe sp. associated to the ascidia Phallusia nigra on the Channel of São Sebastião, situated in the north coast of Estado de São Paulo, analyzing aspects such as population structure, growth, sex-ratio, fecundity, sexual dimorphism and mortality of this amphipod. Every two months, three ascidians had been collected in the sub littoral of eight rocky coasts of the Channel. The results were related with the temperature of the water and the biomass of the ascidian. Individuals of all development stages of Leucothoe sp. had been found associated with the P. nigra, characterizing this host as a steady and propitious environment for its reproduction and feeding. The association did not vary with the study period and wasn¿t influenced by the biomass of the ascidians or by the water temperature. Most of the population of Leucothoe sp. inside P. nigra was composed by juveniles. The reduced number of adults can be related to the increase of mortality and to the exit of the juveniles for searching new hosts. The data related to the population, size structure and growth indicate that Leucothoe sp. can live from 7.2 to 11 months characterizing an semi-annual life cycle. The sex-ratio of Leucothoe sp. was deviated in favor of the females, fact probably related with migration and differential mortality of the males. The reproduction of Leucothoe sp. is continuous and the fecundity is positively related with body size, an usual pattern for gammarideans. Males and females of Leucothoe sp. present sexual dimorphism with morphologic differences in the second gnathopods / Mestrado / Mestre em Ecologia

Orientador: Louis Bernard Klaczko / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-04T11:23:51Z (GMT). No. of bitstreams: 1 Montenegro_Horacio_D.pdf: 10351368 bytes, checksum: 5516ef31afbe4c57e6bf15156c33fdb7 (MD5) Previous issue date: 2005 / Resumo: Elementos genéticos egoístas são partículas herdáveis de etiologia e mecanismos de ação variados, mas com a caracterítica em comum de modificar a segregação mendeliana dos alelos em favor próprio, aumentando a própria freqüência. Elementos citoplásmaticos egoístas são um caso especial de elementos genéticos egoístas, como são herdados apenas pelo citoplasma materno, eles sofrem seleção para causar desvios na proporção sexual, em favor de um excesso de fêmeas. A proporção sexual nas progênies de organismos que se reproduzem sexualmente é, em geral, 1.___.__)LVKHU________SURS{V_D_SULPHLUD_H[SOLFDoão baseada em seleção natural para esta proporção. O princípio de Fisher prediz que o sexo mais raro tem maior valor adaptativo, pois sua contribuição média por indivíduo é maior. Assim, a seleção favorecerá alelos que aumentem a freqüência do sexo raro nas progênies. Quando a proporção chegar a 1.___.__indivíduos dos dois sexos terão o mesmo valor adaptativo. Parasitas reprodutivos, endosimbiontes herdados maternalmete, representam a maior parte dos elementos citoplasmáticos egoístas, e uma das causas mais comuns de desvios à proporção de 1.___.__ Agentes androcidas, endossimbiontes que matam os embriões machos, são um destes parasitas reprodutivos. Como conseqüência, a proporção sexual da prole das fêmeas infectadas afasta-se de 1.___.__apresentando excesso ou totalidade de fêmeas. Agentes androcidas foram encontrados em mais de 40 espécies de 6 ordens de insetos. Várions táxons de bactérias já foram associados com o fenótipo, e a filogenia dos parasitas e hospedeiros não é congruente, indicando transmissão horizontal freqüente. Neste trabalho, estudamos o agente androcida de Drosophila melanogaster, descrito recentemente. Sistemática molecular mostrou que trata-se de uma bactéria do gêneroSpiroplasma, muito próxima ao agente androcida encontrado em D. nebulosa. As seqüências comparadas (3000 pares de base, representando seqüências parciais de 3 genes) são idênticas, portanto, as duas bactérias têm um ancestral comum muito recente. De fato, possivelmente as duas espécies de Drosophila só entraram em contato há 4 ou 5 séculos, com a expansão mundial de D. melanogaster, e a transmissão do Spiroplasma de D. nebulosa para D. melanogaster deve ter ocorrido depois disso. Em uma coleta em Recife, foi encontrado que 2,3% das fêmeas estavam infectadas com Spiroplasma; outro parasita reprodutivo, a bactéria Wolbachia (que causa incompatibilidade citoplasmática) infectava 96% das fêmeas. Além disso, as duas bactérias co-infectavam os mesmos indivíduos, uma observação até agora incomum para parasitas reprodutivos com fenótipos diferentes. Como parasitas reprodutivos tem transmissão exclusivamente materna, seu valor adaptativo é altamente correlacionado com o das fêmeas hospedeiras. Desta forma, espera-se que parasitas reprodutivos não tenham efeitos deletérios no valor adaptativo das fêmeas hospedeiras, ou até que sejam benéficos. Por outro lado, a eficiência de transmissão ou a intensidade do fenótipo de manipulação reprodutiva podem estar positivamente correlacionados com a densidade de bactérias no hospedeiro, de forma que parasitas mais eficientes causem efeitos deletérios no valor adaptativo da fêmea. Para verificar se existem efeitos de Spiroplasma e Wolbachia no valor adaptativo de fêmeas, medimos a viabilidade larval e a fecundidade de fêmeas adultas, comparando com a de fêmeas não-infectadas. Nenhuma das duas características parece ser afetada por Spiroplasma ou Wolbachia, nem por infecção com as duas bactérias simultaneamente. Finalmente, foi verificado que temperaturas baixas (em torno de 16,5°C) interrompem a transmissão do agente androcida para a progênie das moscas infectadas / Abstract: Selfish genetic elements are inheritable particles with diverse ethiology and mechanisms, but sharing the fact that they modify the Mendelian segregation for their own benefit, thus increasing their own frequency. Selfish cytoplasmic elements are a special instance of selfish genetic elements, as they are inherited only by maternal cytoplasm, they suffer strong selection to alter the sexual proportion, in direction to an excess of females. The usual sexual proportion in sexually reproducing organisms is 1.___.__)LVKHU________ was the first to propose an explanation based on the natural selection for this proportion. Fisher¿s principle predicts that, if one of the sexes is rarer, it will have higher fitness, because its individual average contribution will be larger. Thereafter, selection will favour alleles that increase the frequencies of the rarer sex in broods. When the proportion reaches 1.___.__both sexes will have the same fitness. Reproductive parasites, maternally inherited endosymbionts, are the majority of selfish cytoplasmic elements, and one of the most common causes of departures from the 1.___._sexual proportion. Male killers, endosymbionts that kill male embryos, are one of these reproductive parasites. Consequently, the sexual proportion of infected females deviates from 1.___.__towards an excess or totality of females. Male killers have been found in more than 40 species of 6 insect orders. Several bacterial taxa have been associated with male-killing phenotype, and the phylogeny of parasites ad hosts is not congruent, indicating frequent horizontal transmission. In this work, we studied the recently described male killer agent found in Drosophila melanogaster. Molecular systematics showed that this agent is a Spiroplasma bacterium, closely related to the D. nebulosa male-killer. The compared sequences (3000 base pairs, partial sequence from 3 genes) are identical, thus both bacteria share a very recent common ancestral. Indeed, only since D. melanogaster worldwide expansion, 4 or 5 centuries ago, both Drosophila species overlap in their distribution, and the Spiroplasma transmission from D. nebulosa to D. melanogaster probably occurred after this. In one collection in Recife, Spiroplasma has been found infecting 2.3% of all females, another reproductive parasite, the bacterium Wolbachia (which causes cytoplasmic incompatibility) infected 96% of all females. Wolbachia was also found co-infecting flies alongside with Spiroplasma, a rather uncommon observation for reproductive parasites with different phenotypes. As reproductive parasites have exclusively maternal transmission, their fitness is highly correlated with its female host fitness. Consequently, it is expected that reproductive parasites do not pose deleterious fitness effects to their female hosts, or even be beneficial. However, transmission efficiency or the intensity of the reproductive manipulation phenotype could be positively correlated to the bacterial load on the host, in a way that more efficient parasites will have a deleterious fitness effect on females. In order to verify if Spiroplasma and Wolbachia have any kind of fitness effects on female hosts, we assessed larval viability and fecundity of adult females, in relation to uninfected females. Both characteristics showed signs of being affected by Spiroplasma or Wolbachia, nor by double-infection with both bacteria. Finally, low temperature (approximately 16.5°C) interrupts transmission of the male killing agent to the progeny of infected females / Doutorado / Genetica Animal e Evolução / Doutor em Genetica e Biologia Molecular