The biology of Euphranta connexa was investigated to assess its potential as a biological control agent for introduction in North America against the invasive weeds Vincetoxicum rossicum (Kleopow) and V. nigrum (L.) (Apocynaceae). A range of temperatures suitable for development was determined for the pupal and egg stages of E. connexa. The pupa is the overwintering stage of E. connexa and does not exhibit a diapause, but undergoes a cold induced quiescence. The relationship of temperature to pupal developmental was investigated and did not differ among insects from sites over a range of altitude of 1300 m, indicating E. connexa may not be locally adapted. When adult female E. connexa emerged from pupae they had not developed eggs but 10 to 15 days later they had a full complement of developed eggs. Mating of E. connexa did not affect the egg load of females but egg load was reduced in females that had spent longer as pupae in cold conditions. There was evidence that females could reabsorb previously developed eggs. In surveys for larval and larval-pupal parasitoids of E. connexa infested seedpods of V. hirundinaria from three countries, there were a total of 1599 parasitoids from eight Hymenoptera families,and most parasitoids were Braconidae. Prior to the survey, the fruit midge, Contarinia asclepiadis (Diptera: Cecidomyiidae) was considered rare, but it was found in seedpods from all collection sites in Switzerland and infested about 9.2% of seedpods at two localities in 2013. Of 13 parasitoid morphospecies found in the survey, two braconid and one ichneumonid morphospecies were frequent and were parasitoids of E. connexa, three platygastrid morphospecies were probably parasitoids of C. asclepiadis, and three morphospecies were probably hyperparasitoids. The thesis research will allow development of effective methods for studying impact and host range of E. connexa, studies that are required to assess the potential as a biological control agent against V. rossicum and V. nigrum.

Co-variation in the genetic architecture, and co-localization of quantitative trait loci (QTL), for embryonic developmental rate and age at maturation in male rainbow trout (Oncorhynchus mykiss) was examined. Two lots (September and December spawning) of 2 x 5 (male x female) diallel crosses were performed and the resulting progeny were raised to maturity. Higher incidences of precocious maturation were observed in the September lot fish compared to December lot fish, which was uncoupled to developmental rate. However, precocious maturation and body size was higher in early hatching December lot fish. A genome scan was also completed across 4 linkage groups previously reported to possess embryonic developmental rate QTL and/or age at maturation QTL. No evidence of co-localization of QTL for the two traits was detected. However, the presence of QTL for embryonic developmental rate on RT-8 and RT-24 and one for age at maturation on RT-17 supports previous results.

Freshwater cyclopoid copepods exhibit at least a fivefold range in somatic genome size and a mechanism, chromatin diminution, which could account for much of this interspecific variation. These attributes suggest that copepods are well suited to studies of genome size evolution. We tested the nucleotypic hypothesis of genome size evolution, which poses that variation in genome size is adaptive due to the 'bulk' effects of both coding and noncoding DNA on cell size and division rates, and their correlates. We found a significant inverse correlation between genome size and developmental (growth) rate in five freshwater cyclopoid species at three temperatures. That is, species with smaller genomes developed faster. Species with smaller genomes had significantly smaller bodies at 22°C, but not at cooler and warmer temperatures. Species with smaller genomes developed faster at all three temperatures, but had smaller bodies only at 22°C. We propose a model of life history evolution that adds genome size and cell cycle dynamics to the suite of characters on which selection may act to mold life histories and to influence the distribution of traits among different habitats.

Environmental factors, such as diet, can have a significant impact on the health of animals, influencing lifespan, development, and disease progression. The model organism Caenorhabditis elegans is a bacterivore whose development is characterized by an invariant pattern of cell division. This study investigated how C. elegans developmental rate is altered in response to 48 different bacterial diets. The bacterial species studied had a wide range of effects on developmental progression, with some bacteria dramatically decreasing developmental rate, while others caused developmental arrest in early larval stages. From these analyses, Staphylococcus species that caused very slow development of animals in the L1 stage were selected for further characterization. The slow developmental rate observed in these animals was rescued by supplementation with essential amino acids. Genetic analysis revealed that these effects were mediated through TOR signaling and were independent of insulin signaling. Loss of daf-15(raptor), a central component of TOR complex 1, inhibited the rescuing effects of the amino acid supplementation on developmental rate, suggesting that the slow development induced by Staphylococcus could be rescued by activating the TORC1 pathway. Autophagy, negatively regulated by TOR, is increased in worms fed Staphylococcus species, suggesting TOR activity is reduced, and supplementation through amino acids reduced autophagy. These data suggest that TOR signaling is reduced in C. elegans in response to certain bacterial diets, resulting in decreased developmental rate, and that this effect may be due to amino acid deficiency. / Thesis / Master of Science (MSc)

Previous studies of the relationship between egg size and the embryonic development time showed a positive correlation between the two variables at interspecies level, thus offering the idea that the evolution of the latter could be a limiting factor for enlarging the size of eggs during evolution. Some research into interspecies and intraspecific level of reptiles doesn't confirm this correlation. At the same time, the relationship between the development time and egg size is influenced by many factors, such as shifts in ontogenetic stages of the embryo at the time of ablation of eggs, due to temperature and humidity, the presence of embryonic diapause during embryogenesis or synchronization of hatching time, of which the authors of previous studies took no account or filtered out inaccurately. I think that most of these factors can be well controlled in intraspecific studies, but, variation in egg size within species also tends to be small, which prevents a reliable test for correlation. The solution can be to compareclosely related species with high variability in the size of the eggs, in our case the geckos of the genus Paroedura and family Eublepharidae. I eliminated temperature effects by comparing the time of incubation in two equal constant temperatures. The results show that, in this narrower...

I investigated the effect of environmental factors (temperature and food availability) on the development and growth of semiaquatic bug Microvelia reticulata Burmeister, 1835. I focused on the developmental rate isomorphy. In a cross-designed experiment, M. reticulata was individually kept over whole juvenile period (eggs to reaching maturity) and subjected to treatments of three temperature (17, 21, 25 °C) and two food availability (full - daily feeding and reduced - 2 days interval) and their interaction. Development and growth was strongly influenced by temperature. Longest postembryonic development measured in individuals kept in the lowest temperature (54 days) contrasted to those kept in the highest temperature (16 days). Mortality was also significantly influenced by temperature; highest mortality rate was found in the 17 °C treatment. Effect of food availability was significant only in low temperature, resulting in the better survival of individuals on the high food level. In other temperature treatments, I found no effect of food on survival rate of M. reticulata. However, the food level influenced development significantly. In the 21 °C and 25 °C treatment, individuals on a full food developed faster than individuals on a reduced food. In 17 °C the food availability had no effect on time required to reach maturity. The best fitness (expressed as combination of low mortality rate and short development) was observed in 21 °C, both other temperature treatment were found stressing. Food availability had stronger effect on female individuals compared to males. In conclusion, I found no evidence of developmental rate isomorphy in M. reticulata. The research was supported by project of the Grant Agency of the Czech Republic GAČR P505/10/0096.

<p>The main aim of this work was to identify local adaptation processes in amphibian populations, thereby improving the general understanding of genetics and mechanisms behind the evolution and maintenance of biological diversity. Phenotypic and genetic variation in life-history traits was studied within and between populations common frog (<i>Rana temporaria</i>) populations along a 1600 km transect from southern Sweden to northern Finland.</p><p>Embryonic and larval development and growth was investigated both under field and laboratory conditions. The results suggest ample genetic diversity in larval life-history traits among Fennoscandian common frog populations. Larval developmental rate along the gradient has evolved a countergradient variation pattern of genotypes and phenotypes as indicated by the positive relationship between developmental rate and latitude under laboratory conditions and the lack of such a relationship in the field. The data suggest that this pattern has evolved because of time constraints due to decreasing length of growth season with latitude. Neither field-caught adults nor laboratory raised larvae displayed a linear latitudinal size cline as expected from the so called Bergmanns rule. Rather, size increased towards the mid-latitude populations and decreased thereafter, indicating that body size is a product of direct environmental induction or a trade-off with other life-history characters. Age and size at hatching showed no consistent latitudinal pattern, indicating that the embryonic stage is not as time constrained as the larval stage.</p><p>A large part of the variation in age and size at metamorphosis among populations was due to additive genetic effects. However, small, but significant maternal effects, mostly due to variation in egg size and non-additive genetic effects also contributed to among population variation. A comparison of divergence in presumably neutral molecular genetic markers (F_ST) and quantitative characters (Q_ST) revealed that although both estimates of divergence were relatively high, estimates of Q_ST was generally higher than those of F_ST, indicating that the genetic variation observed in larval traits is primarily a result of natural selection rather than genetic drift. Hence, our results reinforce the conclusion that intraspecific genetic heterogeneity in the young northern European ecosystems may be more widespread than previously anticipated</p>

The main aim of this work was to identify local adaptation processes in amphibian populations, thereby improving the general understanding of genetics and mechanisms behind the evolution and maintenance of biological diversity. Phenotypic and genetic variation in life-history traits was studied within and between populations common frog (Rana temporaria) populations along a 1600 km transect from southern Sweden to northern Finland. Embryonic and larval development and growth was investigated both under field and laboratory conditions. The results suggest ample genetic diversity in larval life-history traits among Fennoscandian common frog populations. Larval developmental rate along the gradient has evolved a countergradient variation pattern of genotypes and phenotypes as indicated by the positive relationship between developmental rate and latitude under laboratory conditions and the lack of such a relationship in the field. The data suggest that this pattern has evolved because of time constraints due to decreasing length of growth season with latitude. Neither field-caught adults nor laboratory raised larvae displayed a linear latitudinal size cline as expected from the so called Bergmanns rule. Rather, size increased towards the mid-latitude populations and decreased thereafter, indicating that body size is a product of direct environmental induction or a trade-off with other life-history characters. Age and size at hatching showed no consistent latitudinal pattern, indicating that the embryonic stage is not as time constrained as the larval stage. A large part of the variation in age and size at metamorphosis among populations was due to additive genetic effects. However, small, but significant maternal effects, mostly due to variation in egg size and non-additive genetic effects also contributed to among population variation. A comparison of divergence in presumably neutral molecular genetic markers (FST) and quantitative characters (QST) revealed that although both estimates of divergence were relatively high, estimates of QST was generally higher than those of FST, indicating that the genetic variation observed in larval traits is primarily a result of natural selection rather than genetic drift. Hence, our results reinforce the conclusion that intraspecific genetic heterogeneity in the young northern European ecosystems may be more widespread than previously anticipated