<i>Leptophyes punctatissima</i> is unusual in that both sexes call. The male calls, the female replies and the male performs phonotaxis to the stationary female. Consequently mate choice could occur at either of two stages: first, during the interchange of calls and second, on the basis of proximate criteria once the male has approached. There is no evidence that females choose their mates on the basis of calling behaviour or call characteristics, though males that call more may achieve more matings. There is no evidence that body asymmetry has any effect on mating success for either sex. Males on a protein-supplemented diet do not produce larger spermatophores than males whose diet is not supplemented, but they do mate more often, possibly as a result of female choice but more likely because diet affects the rate at which males can produce spermatophores. Unsupplemented females mate more often than supplemented females, possibly as a result of male male choice or because they are seeking matings so that they can supplement their diet with spermatophores. Males give larger spermatophores to unsupplemented females. Larger males produce larger spermatophores. They also mate more often than smaller males, possibly as a consequence of female choice, success in male-male contests, or because larger males have larger energy reserves and can produce spermatophores more quickly. Larger females mate more often than smaller females but only when their diet was supplemented. Females lay more eggs the more times they mate. Females lay heavier eggs after their first mating than they do in later batches, and unsupplemented females lay more eggs after their first mating than supplemented females do, but otherwise female size, diet or level of asymmetry has no effect on the size or weight of eggs, or the number of eggs laid. The total weight of spermatophores females receive does not affect any measure of female reproductive success: neither fecundity, egg size or egg weight is affected by the weight of spermatophores females consume, irrespective of the diet the females were maintained on. Diet, size or number of matings does not affect female longevity.

Submitted by Hiolanda Rêgo (hiolandarego@gmail.com) on 2014-10-21T17:15:11Z No. of bitstreams: 1 Dissertação_ICS_ Talita de Jesus Caldas Nunes.pdf: 1705477 bytes, checksum: db29ce9e44a8eae162753f3c1c22e8d9 (MD5) / Made available in DSpace on 2014-10-21T17:15:11Z (GMT). No. of bitstreams: 1 Dissertação_ICS_ Talita de Jesus Caldas Nunes.pdf: 1705477 bytes, checksum: db29ce9e44a8eae162753f3c1c22e8d9 (MD5) / A criptococose é uma micose sistêmica causada por leveduras pertencentes ao gênero Cryptococcus, cujas principais espécies de importância clínica são C. neoformans e C. gattii. Essas duas espécies são divididas em cinco sorotipos (A, B, C, D e AD) e mais raramente têm sido relatados os sorotipos BD e AB. O gênero possui dois mating types (α e a) determinados em um único locus MAT, com dois alelos. Diferenças genéticas têm sido detectadas através de métodos moleculares e tem sido essenciais para se entender a biologia do fungo. Nesse sentido, o objetivo dessa dissertação foi avaliar a variabilidade genética, através de extração de DNA por fervura, de amostras de Cryptococcus isolados de casos de meningite, diagnosticados no Hospital Especializado Couto Maia, Salvador-BA, no período de 2006 a 2011. A extração de DNA foi realizada através da fervura de suspensão fúngica e a determinação do mating type, das variedades e do sorotipo através da técnica da Reação em Cadeia da Polimerase associada ao Polimorfismo do Tamanho do Fragmento de Restrição (PCR-RFLP). A técnica de extração do DNA genômico por fervura foi bem reproduzida e, após ter sido empregada diretamente na reação da PCR, foi possível observar que nenhuma diferença houve com relação aos produtos da PCR com DNA extraído pela técnica tradicional. Dos 94 isolados analisados, a determinação de mating types e da ploidia mostrou que todos apresentaram padrão compatível com mating type α, assim como haploidia. A técnica molecular de sorotipagem permitiu observar que 88% dos isolados eram da variedade grubii (sorotipo A) e 12% da variedade gattii (sorotipo B). Nossos resultados mostram como se pode facilitar a PCR de leveduras com uma técnica que envolve um menor tempo de execução e menor custo, além de contribuir para a epidemiologia da criptococose, no que se refere à importância de se ter um diagnóstico diferencial entre as variedades envolvidas no processo infeccioso.

The sexual functions of the mating type gene (mt) of Neurospora crassa include specification of mating identity (Shear and Dodge, 1927) and perithecial maturation (Griffiths and DeLange, 1978; Staben and Yanofsky, 1990). The gene also acts as a vegetative incompatibility locus, so that A + a heterokaryons (Beadle and Coonradt, 1944) or A/a duplication strains (Newmeyer and Taylor, 1967) grow poorly or not at all. An intriguing question regarding the mating type gene is this: How does it control both the switch between somatic and meiotic events and heterokaryon incompatibility? Several research groups (Glass, et al., 1990; Staben and Yanofsky, 1990) are presently studying the sexual functions of the mating type genes. I present a study of the incompatibility function. Two experiments were performed. The first was a search for new suppressors of mating type-associated incompatibility, which resulted in the identification of seven new suppressors, none of which was allelic with the one known suppressor, tol. The second was the comparison of growth rates of a mating type mutant (fertile, heterokaryon compatible) in a mixed mating type heterokaryon and in a mixed mating type duplication to determine whether or not cytoplasmic incompatibility is separable from nuclear incompatibility. The results obtained suggest that the mating type mutant, am33, eliminates heterokaryon incompatibility without eliminating nuclear incompatibility. The search for suppressors was attempted in order to define more of the genes involved in A/a incompatibility. The analysis of heterokaryon versus nuclear incompatibility was done to investigate the cellular interactions involved in A/a incompatibility. / Science, Faculty of / Botany, Department of / Graduate

Sexual reproduction is an important process amongst eukaryotic organisms, with one function being to maintain genetic variation. The idea that complex eukaryotic species can persist for millions of years in the absence of sex defies fundamental evolutionary dogma, yet a group of organisms known as ancient asexuals were thought to have evolved clonally under deep evolutionary time. Prominent among these are the arbuscular mycorrhizal fungi (AMF), which are obligate plant symbionts that colonize the root cells of plants and extend their hyphae into the soil assisting the plant in acquiring key nutrients. Unlike most eukaryotes, AMF cells are multinucleate with thousands of nuclei moving through a continuous cytoplasm. Genomic analyses have identified a putative mating-type (MAT) locus within the nuclear genomes of model AMF Rhizophagus irregularis, a region that in other fungi dictates the process of sexual reproduction. Additional findings demonstrated that AMF strains carry one of two nuclear organizations. They can be either homokaryotic (AMF homokaryons), where all nuclei within the cytoplasm are virtually identical, or heterokaryotic (AMF dikaryons), where two MAT-locus variants co-exist within the cytoplasm. Despite a lack of observable traits indicative of sex, this homo/heterokaryotic dichotomy is reminiscent of the nuclear organization of sexual fungi. My research aims to build on these findings to investigate the actual role of the MAT-locus in driving AMF reproduction. To address this, I build my thesis into three main chapters. The first chapter reviews our current understanding of AMF genetics and what drives genome evolution in these organisms. The second chapter establishes a relatively easy, inexpensive, and reproducible approach to genotype known MAT variants of R. irregularis in natural and experimental conditions. The last chapter uses experimental crossings between strains to assess cytoplasmic compatibility and nuclear exchange. I demonstrate that dikaryotic spore progenies can be formed after co-culturing two distinct AMF homokaryotic strains. Further analyses of various genomic regions also reveal possible recombination in homokaryotic spore progenies from co-cultures. Overall, this research provides new experimental insights into the origin of genetic diversity in AMF. These findings open avenues to produce genetically new AMF strains in the lab using conventional crossing procedures and provide a glimpse of the mechanisms that generate AMF genetic diversity in the field.

No description available.

rhe non-copulatory estrous behaviour of semi-free ranging female Japanese monkeys was observed for 3 months, in order to investigate the role of the female in the establishment of mating pairs. It was concluded that the females play a very active role in the formation of mating pairs, showing three times more solicitation behaviour than males. They also reject more than 30% of the advances they do receive. This is interpretated as an indication of selectivity in the choice of sexual partners. The behaviour of the female in this courtship context is described, with emphasis on preceptive or solicitation behaviour. The data were tested for behavioural differences based on the female's age, rank, parity, number of offspring and the presence of an infant, and for differences based on the age, rank and spatial status of the interacting male. Age of the female had the greatest effect on behaviour, with older females behaving in a more calm, sophisticated manner when soliciting a male. Age was also the most significant male variable, with females showing more rejection to younger males. Other than age related findings it must be concluded that these sociological characteristics of the animals are not predictive of the females' courtship behaviour. A number of alternate lines of inquiry for future research are suggested. They include an investigation of the hormonal basis of estrous behaviour, a multivariate analysis, and a sequential analysis of behaviour. / Thesis / Master of Arts (MA)

Menopause, the complete cessation of menstrual cycles, apparently is a detrimental trait, yet all women experience it. Numerous theories have been proposed to explain the origin of menopause, but none has been satisfactory. In 2013, Morton et al. proposed a mate choice hypothesis to explain menopause and, using a computational model, showed how a bias in mating (i.e., older men preferring younger women) could have allowed such an otherwise detrimental trait to evolve neutrally through accumulation of female fertility-reducing mutations. To investigate whether biased mating could affect fecundity and fertility in a real system, two experimental populations were established using Drosophila melanogaster. Older males were mated with younger females and vice versa. Information was obtained, including data on fecundity, fertility, ovariole and matured egg chambers, and lifespan, for experimental, age-restricted-mating and control populations. A negative effect on the fecundity and fertility of the younger-mating sex was observed in restricted-mating compared to control populations. Age-restricted mating had no effect on longevity. Menopause could evolve according to the mate choice hypothesis. / Thesis / Master of Science (MSc) / All animals are expected to remain fertile until they die. Menopause is an enigma and an unsolved problem in evolutionary biology. Numerous theories have been proposed to explain menopause, but there is no clear understanding of how this fertility reducing trait evolved in the human population. It has been proposed that biased mate choice i.e., preference for younger females can lead to accumulation of fertility-reducing mutations and the evolution of menopause. In this study, mate choice theory was tested using altered (biased) mating schemes with Drosophila melanogaster and the results support the mate choice theory of menopause.

Field studies were conducted to evaluate the effect of mating disruption on the mating success of the gypsy moth, Lymantria dispar (L), in low-density populations. The gypsy moth is an insect pest of hardwood forests in many regions of the world. The discovery of the sex pheromone disparlure (cis-7,8-epoxy-2-methyloctadecane) produced by females marked the start of a new era in the control and management of gypsy moth populations. Sex pheromones, like disparlure, have been used for detecting new populations, monitoring the spread of populations and for population control based on the disruption of mating communication. Although mating disruption has been used against populations of insect pests in agricultural and forest systems, considerable information about the use of this method for managing gypsy moths is still lacking. Studies, therefore, were designed and carried out specifically to improve current understanding of the mechanism of mating success, to evaluate existing techniques for mating disruption, and to develop methods that would improve the application of pheromone used for mating disruption so as to reduce the costs associated with the use of this management tactic. The first study was conducted to compare the mating success and mortality of gypsy moth females in low-density populations in Virginia and Wisconsin because of differences, which have been observed in the population dynamics and the impact of management strategies between these two states. The results suggested that the higher rate of population spread in Wisconsin might be due to the increased mating success of females compared with Virginia, which may be due in part to increased long-distance dispersal of males and increased longevity of females. The effect of artificial pheromone applied at various doses and formulations on mating success in low-density gypsy moth populations also was studied. Dose-response relationships were obtained for pheromone doses ranging from 0.15 to 75 g a.i./ha. The doses of 37.5 and 15 g a.i./ha of pheromone were shown to effectively disrupt mating and, therefore, have been recommended for operational use. The results also showed that the disruption of mating and attraction of males to pheromone-baited traps as a result of application of pheromone formulated in plastic flakes (Disrupt® II, Hercon Environmental, Emigsville, PA) was stronger and lasted longer than for the pheromone formulated as microcapsule (3M Canada Co., London, Ontario, Canada) and in liquid (Shin-Etsu Chemical Co. Ltd, Tokyo, Japan). Another study was carried out to improve the use and efficacy of the pheromone for mating disruption by reducing the amount of pheromone that was sprayed and the flight distance during aerial application. This study showed that in mountainous landscapes the effect of disparlure along the valley between mountains could be observed at a larger distance (633 ± 63 m) from the treated area than across the valley (104 ± 22m). In a relatively flat area, the effective distance for mating disruption was similar to the effective distance across the valley in a mountainous area (67 ± 17m). These dispersal characteristics of the pheromone provided further evidence that it could be used effectively in mating disruption treatments. Finally, a portable Electroantennogram (EAG) device was evaluated for its ability to detect disparlure sprayed for mating disruption in gypsy moth populations. The study found no relationship between the dose of artificial airborne pheromone and response of gypsy moth antenna as measured by the voltage ratio. The inability to detect differences between airborne pheromone concentrations in the plots treated for mating disruption might have been due to high variability among antennae and also by the inability of the EAG device to detect the low concentration of airborne pheromone used operationally for mating disruption. Further studies are required to improve the sensitivity of the portable EAG device before it can be recommended for use in the field. / Ph. D.

The populations of aphidophagous insects in low-spray and conventional programs were surveyed in Virginia apple orchards. Two sampling methods were utilized;aphid colony collection and beating tray collection. The low-spray blocks employed the use of mating disruption for control of the key direct pests, codling moth, Cydia pomonella (Linnaeus), and leafrollers. The abundance and diversity of aphid predators in low-spray mating disruption programs and conventionally controlled apple orchards was compared. Both sampling methods suggested that aphid predators were more plentiful in the mating disruption blocks. Several mating disruption blocks were found to accumulate significantly more predator-days and diversity than the matched control blocks. The reduction of insecticide input into the low-spray blocks may have allowed higher populations of aphidophagous insects to occur. Aphid populations in mating disruption blocks sometimes declined faster and had less resurgence than those in the conventionally controlled blocks. The tufted apple bud moth (TABM), Platynota idaeusalis (Walker), populations in four apple orchards in Winchester, Virginia, were compared for resistance to azinphosmethyl. These orchards were suspected by the growers to have resistant populations of TABM. Pheromone traps with insecticide incorporated into the adhesive were used to collect and test the moths. The results were not analyzed due to the low number of moths collected and high variability in mortality. / Master of Science

The mating behaviour and reproductive ecology of the big-handed crab Heterozius rotundifrons was studied at Kaikoura between November 1997 and December 1998. H. rotundifrons was found at mean densities of 7.6 per m² (± 1.4) within the middle and low shore levels and varied little between seasons. The variance! mean ratio indicated that males and females aggregated within these shore levels. The sex ratio was significantly female biased during the majority of the year. Allometric growth rates indicated that males and females reached sexual maturity at 11 mm carapace width (CW). In males, spermatozoa production occurred between 9-9.99 mm CW. Ovigerous females were present every month except February. The first broods of the year were produced in March which coincides with a decrease in the female gonado-somatic index (GSI). These broods were incubated for approximately nine months whereas broods produced in August were incubated for only five months. Female brood production appeared to be cyclical, alternating between a winter incubation period and a summer incubation period. The completed cycle takes approximately three years with two broods produced during the cycle. Fecundity increased with female size but egg mortality was quite high (19%). Instantaneous mortality rate increased with increasing brood development. Females mate when recently moulted (soft-shelled). Although females moulted through out the year, in small numbers, there was a peak in female moulting during October and November. The operational sex ratio (OSR) was male biased during all months of the year. Females released an attractant prior to moulting which initiated pre-copulatory mate guarding by the male. Once the female moulted, copulation occurred approximately 6 h later. Copulation lasted for approximately 3 h and was followed by a period of post-copulatory mate guarding. Males increased the duration of post-copulatory mate guarding if another male was present. Large males out competed small males for receptive females. Males used their large cheliped to subdue competitors and to provide protection for the soft female. Mate guarding was shown to reduce cannibalism from other females. Spermatozoa are packaged in spermatophores within the vas deferens of males but are quickly dehisced within the spermathecae (ventral-type) of newly mated females. Last male to copulate probably achieves the highest level of paternity. Postcopulatory mate guarding by the male was found and ejaculates were found in discrete packets within the spermatheca. Sperm competition appeared to be important because large males displaced small males during copulation, males left when a female was still receptive and the females could retain sperm between moults. It is concluded that H. rotundifrons probably has a polygynous mating system in which males compete for soft females (female centered competition)