Mating systems are classifications of the outcome of individual strategies aimed at maximising reproductive success. These systems have two components; one describes how individuals socially relate and bond to mating partners and the other describes the genetic outcome of actual mating activities. Reproductive activity is under strong endocrine and behavioural regulation where inter-sexual discrepancies in the regulation of reproductive success have resulted in the majority of mammal species exhibiting polygynous mating systems, with only 5% of mammals being socially monogamous. However, in monogamous species there can be a discrepancy between social pair bonds and sexual mating activities. Aardwolves are extreme diet specialists ii on a temporally fluctuating resource, Trinervertermes spp. A number of studies have described them as socially monogamous but at the same time observed a high frequency of extra pair copulations (EPCs). A recent study also linked sex variation in den use to polygamous mating. However, it is unclear to what extent these EPC's contribute to individual fitness, and how these contrasting mating strategies influence space use and reproductive physiology. The aim of this project was to determine if there was seasonality in reproductive activity and to test if endocrine physiology, home range size and space use were similar between males and females as predicted for a socially monogamous species. We assessed reproductive endocrinology in zoo-housed aardwolves and quantified if physiological and behavioural data in wild aardwolves relate more to predictions based on social monogamy or polygamy. We found physiological support for previous behavioural observations of reproductive seasonality in both zoo-housed and wild aardwolves. We suggest that the seasonal breeding strategy in aardwolves is as a direct consequence of their strong dietary preference on a temporally fluctuating resource, where it is important for aardwolves to time periods of high physiological investment in reproduction with high seasonal abundance of these termites. Our data on zoo-housed aardwolves also showed that the social environment appeared to modify physiological responses to variation in environmental conditions. We suggest that due to strict seasonal breeding in wild aardwolves females are time constrained in receptivity which, combined with their largely solitary behaviour, implies that males have to be dynamic in the onset of their reproductive activity to closely match that of locally receptive females. Therefore, it may be adaptive for aardwolves to retain social receptivity even if resource distributions cause these animals to forage alone. We also found that physiological and behavioural traits correspond better to predictions based on social monogamy than polygamous mating in a population of wild aardwolves. However, earlier studies in the same population found that behavioural traits were more related to predictions based on polygamous mating. Therefore, our data and other studies show how a difference between traits can relate to either social monogamy or polygamous mating in wild aardwolves in the same study area. We suggest that social mating system components regulate the observed endocrine and behavioural parameters more than actual mating patterns, which implies that social components pose a stronger selective pressure on physiology and behaviour than sexual mating patterns. Overall, we conclude that due to the discrepancy in traits that correspond to predictions based on different mating systems, aardwolves do not fit discreetly into any current mating system classification. We suggest that the evolutionary causes for the potentially conflicting mating strategies as well as the fitness benefits of these strategies need to be further investigated. / Dissertation (MSc)--University of Pretoria, 2013. / gm2013 / Zoology and Entomology / unrestricted

Mating system, mating behavior and the evolution thereof is the foundation of this study. More specifically the effect of inbreeding on the evolution of mating behavior is investigated. To this end the pollinating fig wasp, Platyscapa awekei, lends itself to inquiry about inbreeding and the effect on its behavior. A pollinating fig wasp female will lay her eggs inside a syconium, and all offspring will mate with each other. Interestingly the abovementioned pollinating wasp exhibits male dispersal, not commonly expected to occur in a haplodiploid species observed to inbreed frequently. Several theories attempt to explain the evolution of male dispersal in this case, but very little work has been done on the effect of inbreeding on the choice to disperse. In order to study the effects of inbreeding it was necessary to be able to measure the inbredness of individuals. For this reason I developed micro satellite markers both to determine the inbredness of individuals but also to derive parentage from offspring genotypes. With the inbreeding status in hand I had to correlate this with fitness measures in order to derive the effect of inbreeding on this species. Interestingly I found both inbreeding and outbreeding depression, with optimal fitness at some point between fully inbred and fully outbred status. I give some explanations for the occurrence of dispersal in this species but come to the conclusion that dispersal is merely part of a mixed mating system and that more detailed work need to be done to derive what the specific effect of dispersal is on fitness. / Dissertation (MSc(Agric))--University of Pretoria, 2009. / Genetics / unrestricted

No description available.

No description available.

No description available.

This thesis is an evaluation of the hypothesis that the spennathecae of spiders affects the sperm precedence patterns in a predictable way (Austad 1984). Spermathecae come in two varieties: cul-de-sac and conduit. Cul-de-sac spennathecae, according to the hypothesis, are supposed to lead to second male sperm priority and conduit to first male sperm priority . The hypothesis was evaluated both directly and indirectly. Direct measurements were made of paternity in two species, Pholcus phalangioides and Tetragnatha montana, both of which are cul-de-sac species. It was found that P. phalangioides complies with the predicted precedence pattern and thus does not disprove the hypothesis. This second male priority pattern was despite a much shorter mating time by second mating males. In T. montana no precedence pattern was found, with equal likelihood of first or second mating males of gaining paternity. There was in T. montana a possible influence of the duration of mating affecting the precedence pattern, with longer mating males gaining a higher paternity no matter what order they mated in. It is discussed whether or not this is due to sperm loading or genitalic stimulation (Eberhard 1985). Indirect evaluation of the hypothesis included an analysis of mating behaviour in Zygiella x-notata which is a conduit species and was chosen as a comparison to the two cul-de-sac species. In Z. x-notata it was found that there was no difference between mating duration in first and second mating males. Mating persistence is thus the same in first and second mating males, suggesting that the males cannot detect that the female is a denuded resource to second mating males. Hence first male priority may not be a factor in this species. Other indirect methods of evaluating the hypothesis involved charting the incidence of mate-guarding and mating-plugs. The expected pattern of mate-guarding was for conduit species to pre-mate guard and for cul-de-sac species to post-mate guard, because of the predicted sperm precedence patterns associated with the spermathecae. The predicted pattern was not found. In the case of mating-plugs it was predicted that these should be deployed by cul-de-sac species because it is in these species that second males are able to usurp paternity to a large extent. The opposite pattern was found with mating-plugs of various design being utilized by conduit species. It is postulated that mating-plugs are the mechanism by which first male priorities are established in conduit species, where this pattern is found. The absence of plugs in cul-de-sac species is possibly the reason that second males can cuckold. The additional data collected since 1984 reveal that patterns of paternity found in spiders seem to be more complex than was originally assumed by Austad (1984). Spermathecae are species-specific in character and this may reflect a species specificity in sperm precedence patterns. Thus the conduit I cul-de-sac dichotomy may not reflect a useful prediction of paternity patterns.

The bounded Fatou components for certain quadratic polynomials are attached to each other at the boundary and form chain-like structures called ``bubble rays". In the context of mating quadratic polynomials, these bubble rays can serve as a replacement for external rays. The main objective of this thesis is to apply this idea to the mating of starlike quadratics.

The bounded Fatou components for certain quadratic polynomials are attached to each other at the boundary and form chain-like structures called ``bubble rays". In the context of mating quadratic polynomials, these bubble rays can serve as a replacement for external rays. The main objective of this thesis is to apply this idea to the mating of starlike quadratics.

No description available.

Anthracnose of lentil caused by the fungal pathogen Colletotrichum lentis is an economically important disease in Western Canada. The pathogen population is divided into two races (0 and 1) and two sexual incompatibility groups (IG-1 and IG-2). Resistance to anthracnose race 1 is found in cultivated Lens cultivars whereas for the more aggressive race 0, higher levels of resistance have been reported only from wild Lens species. Furthermore, C. lentis seems to only possess one (MAT1-2) of the two mating type idiomorphs commonly present in heterothallic ascomycete fungi with the typical bipolar mating system. The purpose of this study was to verify the phylogenetic relationship between race 0 and 1 isolates of C. lentis and to sequence and characterize the MAT1-2 of C. lentis. A morphological, multi-locus phylogenetic and host-range study was conducted with isolates of C. lentis, C. truncatum (from various host species and the epitype), C. destructivum, C. dematium, C. higginsianum, C. linicola and C. lindemuthianum. Sequence data from six conserved loci displayed 100% identity for C. lentis isolates of both races that formed a single cluster separate from other Colletotrichum species including C. destructivum, the epitype of C. truncatum and isolates from other hosts identified as C. truncatum. Conidia of C. lentis were slightly falcate with obtuse apices compared to cylindrical conidia with rounded ends of C. destructivum, and longer lunate to falcate conidia of the epitype C. truncatum. Host range tests undertaken on Lens culinaris, Pisum sativum, Cicer arietinum, Vicia faba, Glycine max, Phaseolus vulgaris, Phaseolus lunatus, Trifolium pratense, Medicago sativa, Medicago truncatula, Brassica chinensis and Arabidopsis thaliana under controlled environmental conditions revealed that the host ranges of C. linicola and C. higginsianum overlapped with that of lentil isolates. In contrast, the epitype specimen of C. truncatum was pathogenic on Pisum sativum, Phaseolus vulgaris, T. pratense and Medicago sativa, but not on L. culinaris. All Colletotrichum spp. infected Medicago truncatula and all but the lentil isolates caused disease on G. max. The mating type gene MAT1-2 of C. lentis contained two introns and three exons and an open reading frame of 726 bp coding for a putative protein of 241 amino acids including the high mobility group (HMG) domain characteristic of the MAT1-2 in fungi. The MAT1-2 nucleotide sequences of C. lentis isolates were identical irrespective of IG. An isolate from each of the two IGs, CT-21 (IG-2), CT-30 (IG-1) and a co-culture of CT-21 and CT-30 was used to study the expression levels of MAT1-2 at seven different in vitro time points (0h, 6h, 12h, 18h, 24h, 36, 48h after inoculation in glucose yeast media) and investigate for possible alternative splicing events. MAT1-2 expression for CT-21, CT-30 and the co-culture was observed at all seven time points indicating that it is constitutively expressed, and no differences in the transcript size were seen, ruling out the possibility of a splicing event.