This thesis deals with plants from the flowering plant order Lamiales, and especially the two families Scrophulariaceae and Stilbaceae. Both families have their main geographical distribution in southern Africa. The thesis presents phylogenies of Scrophulariaceae s. lat. that can be used as a framework both for a future formal classification of the Scrophulariaceae and of allied taxa. A new circumscription of the tribe Manuleeae of Scrophulariaceae is presented including also genera earlier placed in the tribe Selagineae (sometimes recognised as a family of its own, Selaginaceae). Manuleeae now consists of the genera: Barthlottia, Chaenostoma, Chenopodiopsis, Dischisma, Glekia, Globulariopsis, Glumicalyx, Gosela, Hebenstretia, Jamesbrittenia, Limosella, Lyperia, Manulea, Manuleopsis, Melanospermum, Phyllopodium, Polycarena, Pseudoselago, Reyemeia, Selago, Strobilopsis, Sutera, Tetraselago, Trieenea and Zaluzianskya. The genera Sutera and Selago are given new circumscriptions; Sutera is divided into two genera, Sutera and Chaenostoma. Selago is circumscribed to contain also taxa that formerly have been placed in Microdon and Cromidon. A new circumscription and infrafamiliar classification of the family Stilbaceae is also presented. Stilbaceae will consist of the three tribes: Bowkerieae, consisting of the genera Anastrabe, Bowkeria and Ixianthes; Hallerieae, consisting of Charadrophila and Halleria; and Stilbeae, consisting of Nuxia and Stilbe. Furthermore, the genera Campylostachys, Euthystachys, Kogelbergia and Retzia are all included in the genus Stilbe. The results in the thesis are based on parsimony and Bayesian phylogenetic inferences of DNA sequence data. Further, morphological characters are analysed and compared to the molecular phylogenies.

At the centre of the vertebrate immune system is a group of proteins called MHC (major histocompatibility complex) molecules. These function in self – non self recognition and activation of the immune defence against intruding parasites and pathogens. In this thesis I have investigated individual variation in MHC class II genes and antibody producing ability in relation to ecology and behaviour in the great snipe (Gallinago media), a lekking bird, breeding in northern Europe. There was much variation in the MHC genes of the great snipe and the sequence data show that balancing selection has been acting on these genes. I found genetic differentiation in the MHC between two separate geographic regions of the great snipe distribution. Furthermore, this structure was more pronounced than that previously found in neutral genetic markers, suggesting that different selection pressures (possibly resulting from variation in parasitic fauna) are acting in these different regions. The birds produced specific antibodies following injection with two novel antigens. Males that were chosen as mates, had higher antibody titers than their neighbouring males, suggesting that this ability may be important in female mate choice. Such choice could give the offspring an enhanced immune system or could favour females directly by avoidance of sexually transmitted diseases. Females choosing to mate with a male having a different set of MHC genes than their own could give the offspring immune system the ability to react to a wide range of parasites. No such mate choice could, however, be found in the great snipe. Instead, females preferred males with certain MHC alleles, irrespective of their own MHC type. If those alleles confer resistance to parasites currently prevailing in the population, such resistance would be inherited by the offspring, thereby enhancing their fitness.

The homeodomain leucine zipper (HDZip) proteins constitute a plant-specific family of transcription factors, that based on sequence criteria have been grouped into four classes, HDZip I-IV. This thesis describes the phylogeny, function, expression patterns and regulation of the HDZip class I genes in the model species Arabidopsis thaliana. The phylogenetic analyses, traced duplication history and exon/intron organisation of the 17 class I genes in Arabidopsis show that the genes form six monophyletic groups, clades, with an origin in early plant evolution. All genes are expressed in broad tissue distribution patterns and the majority are responsive to water availability and/or light conditions. The expression of the genes show different patterns and dependence on environmental stress conditions, indicating evolutionary changes within and between clades. Ectopic expression of the genes suggest that they regulate genes in part by conserved mechanisms. Therefore, different functional roles seem to have evolved by a divergence mainly in the regulatory properties of the genes. Detailed expression analyses of the paralogous HDZip I genes ATHB7 and ATHB12 show that they have essentially overlapping patterns of activity in response to abscisic acid, ABA, or water deficit in leaves, stems and roots. The water deficit response of ATHB7 and -12 is mediated by ABA and depends on the protein phosphateses ABI1 and ABI2. Transgenic plants with ectopic expression of ATHB7 and/or -12, and athb7 and athb12 mutants, reveal that the genes in roots mediate the growth inhibitory effects of ABA. In this aspect of their function they do not overlap. In leaves and stems, the genes might act as growth regulators redundantly with other factors. Taken together these data suggest that ATHB7 and -12 regulate growth in response water deficit and that other HDZip I genes have related functions in response to environmental stress conditions.

Viruses are very abundant in water and hence diseases caused by viruses are common in marine organisms. These diseases create great problems for the commercial farming of crustaceans and mussels. One of the most common and most disastrous diseases for shrimp is caused by the white spot syndrome virus (WSSV), which is spread all around the world and also is infecting many different species of crustaceans including freshwater crayfish. Although during recent years knowledge has been gathered on the ways in which invertebrates defend themselves against bacteria and fungi virtually nothing is known about the defence processes elicited by virus. The aim of this work was to develop a model to use for studies of virus-host interactions in vivo and in vitro. Temperature was found to be important for the virus infectivity and at lower temperature the virus apparently did not replicate, but if animals kept at low temperature for more than 40 days were transferred to higher temperatures they died quickly due to an increased virus replication. In crayfish infected with the virus it was found that hemocytes did not degranulate and the melanization reaction was also inhibited in the hemocyes. Thus it is apparent that this virus interacts with the immune system and hemocytes in particular and to be able to study this in some greater detail it was necessary to develop a cell culture to study virus-host interactions at the molecular level. Hence, we have developed a stem cell culture from the hematopoietic tissue (hpt) that will differentiate and mature into hemocytes and which can be used to replicate the WSSV in the presence of an endogenous cytokine, astakine. Astakine is the first cytokine like-factor described which is directly involved in hematopoiesis in an invertebrate.

This thesis focuses on the interactions among microbiota in clearwater lakes. Field sampling and field experiments were performed to evaluate interactions among microbiota and the importance of benthic versus pelagic microbiota in terms of biomass and production. In addition, carbon cycling in an oligotrophic clearwater lake was calculated. Biomass and production of microbiota was clearly focused to the benthic habitat. During natural nutrient concentrations growth of heterotrophic bacteria (benthic and pelagic) was coupled to production of microphytobenthos in Lake Eckarfjärden, indicating interactions between autotrophic and heterotrophic microbiota in, as well as between, habitats. At increased nutrient concentrations, growth of heterotrophic bacteria was not correlated to microphytobenthos production. This was explained by less release of dissolved organic carbon (DOC) from microphytobenthos when they got access to more nutrients. Further investigations showed different scenarios in oligotrophic clearwater lakes following increased nutrient concentrations. The interactions between microbiota may be altered following increased nutrient concentrations and the microbial mat either positively or negatively affect the pelagic microbiota. The most striking result was that the expected shift towards dominance of pelagic primary production does not necessarily occur. Major flows of carbon were identified between different habitats in the oligotrophic clearwater Lake Eckarfjärden, and the net result was that the benthic habitat provided carbon to the pelagial. High DOC concentrations in the lake together with low pelagic production are factors that would indicate net heterotrophy. Accordingly, the pelagial of Lake Eckarfjärden was net heterotrophic but when the benthic and littoral habitats were included in the calculations, the lake turned out to be net autotrophic. In conclusion, the benthic microbiota contributed significantly to the total production in the investigated lakes and had a major role in the lake metabolism. Thus, this thesis emphasises the importance of benthic microbiota in shallow clearwater lakes.

I have studied persistent environmental pollutants in herring (Clupea harengus), in adult guillemot (Uria aalge) and in guillemot eggs from the Baltic Sea. The studied contaminants were organochlorines (OCs); dichlorodiphenyltrichloroethanes (DDTs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), and brominated flame retardants (BFRs); polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCD). The highest concentration in both species was shown by p,p′DDE with a concentration in guillemot egg (geometric mean (GM) with 95% confidence interval) of 18200 (17000 – 19600) ng/g lipid weight. The BFR with the highest concentration in guillemot egg was HBCD with a GM concentration of 140 (120 – 160) ng/g lw. To extract additional and essential information from the data, not possible to obtain using only univariate or bivariate statistics, I used multivariate data analysis techniques; principal components analysis (PCA), partial least squares regression (PLS), soft independent modelling of class analogy (SIMCA), and PLS discriminant analysis (PLS-DA). I found e.g.; that there are significant negative correlations between egg weight and the concentrations of HCB and p,p'DDE; that concentrations of OCs and BFRs in the organisms co-varied so that concentrations of OCs can be used to calculate concentrations of BFRs; and, that several contaminants (e.g. HBCD) had higher concentration in guillemot egg than in guillemot muscle, that several (e.g. BDE47) showed no concentration difference between muscle and egg and that one contaminant (BDE154) showed higher concentration in the guillemot muscles than in egg. In this thesis I developed a new method, “randomly sampled ratios” (RSR), to calculate biomagnification factors (BMFs) i.e. the ratio between the concentration of a contaminant in an organism and the concentration of the same contaminant in its food. With this new method BMFs are denoted with an estimate of variation. Contaminants that biomagnify are e.g., p,p′DDE, CB118, HCB, βHCH and all of the BFRs. Those that do not biomagnify are e.g., p,p′DDT, αHCH and CB101. Lastly, to investigate which of the contaminants descriptors (physical-chemical/other properties and characteristics) that correlates to the biomagnification of the contaminants, I modeled the contaminants’ respective BMFRSR versus ~100 descriptors and showed that ~20 descriptors in combination were important, either favoring or counteracting biomagnification between herring and guillemot.

Speciation is the process describing the formation of new species and is at the heart of evolutionary biology. According to the biological species concept only reproductively isolated forms are regarded good species. This thesis aims at identifying evolutionary processes that cause population divergence and, ultimately, speciation. Natural and sexual selection are two major candidates driving changes in traits that could render populations reproductively incompatible. In recent years, biologists have recognized that most animal species are polygamous. Therefore, sexual selection does not end at mating but continues to include interactions between individuals after mating has occurred but before zygote formation. Male-male sperm competition and cryptic female choice are two main forms of postmating sexual selection shaping reproductive traits like behaviour. The studies presented in this thesis focus on laboratory experiments attempting to identify the role of postmating sexual selection in causing reproductive divergence across populations in beetles. The majority of studies were performed using a Bruchid beetle, Callosobruchus maculatus, a common, worldwide pest on stored leguminose seeds. I used two major methodological approaches. One approach seeks to identify the traces left by past selection among extant conspecific populations, by assessing the pattern of female reproductive responses to mating with males of decreasing relatedness. Second, I used a selection experiment to disentangle the joint effect of natural and sexual selection acting simultaneously on diverging replicated selection lines. In general, these experiments revealed that postmating sexual selection can be a powerful engine of incipient divergence between allopatric populations. Changes in traits underlying variables such as female reproductive output, female mating rate or male success in sperm competition evolved rapidly and could in some cases effectively reduce gene flow between conspecific populations. While postmating sexual selection per se can drive divergence, I found that interactions with natural selection can limit divergence in reproductive characters. Sexual selection tended to reinforce natural selection under strong directional selection. In contrast, sexual selection inflicted a reproductive load on populations under weak natural selection. Thus, the joint effects of natural and sexual selection on allopatric populations are non-trivial and should be considered in greater detail in future studies of early divergence.

Onychophorans are closely allied to the arthropods and possess a body organisation more similar to Middle Cambrian fossils than to recent arthropods. This means that onychophorans in some respects can be regarded as a model for the last common ancestor to both the Arthropoda and the Onychophora. This thesis mainly deals with the morphology of the head region of the Onychophora, but developmental investigations of the expression of a key regulatory gene, engrailed, are also carried out. The innervation of the head was found to differ from that reported in earlier investigations. The nerves that support the mouth were found to originate from three different regions of the brain. That innervation pattern suggests that present day onychophorans with a ventrally placed mouth, have evolved from an ancestor with a terminal mouth. Furthermore it was confirmed that the onychophoran structure with the unfortunately chosen term labrum is not homologous to the structure in arthropods that bears this name. Instead it is a muscular outgrowth from the pharynx. The embryological investigations gave further support for an ancestral and terminal mouth. The two most anterior oral lips are first located on the dorso-frontal side of the head, and later migrate to their final position at the ventral side. This phenomenon also explains their somewhat unexpected innervation from the dorsum. It was also established that the eye originates at a position posterior to the antenna. This is reversed compared to the condition in arthropods, were the eye is innervated from the protocerebrum and the first antenna from the dutocerebrum, and implies that the eye and antenna are not serially homologous between the two groups. A structure in the onychophoran head that has gained little attention is the hypocerebral organ, also termed infracerebral organ. It has been suggested as a corpora allata analog by earlier workers. Its ultrastructure was investigated, and great similarities to the corpora allata of the stick insect Carausius morosus were found. However, the lack of innervation of the hypocerebral organ of Onychophora poses a problem since the corpora allata of insects is controlled by nerves. Instead, cellular strands were found that connected the hypocerebral organ with the brain, and it is possible that these strands act as an alternative communication. The expression pattern of the segment polarity gene engrailed was found to be different from that reported in an earlier account of onychophorans. Engrailed was expressed in a subset of developing neurons in the brain anlage and in the ectoderm and mesoderm of the limb buds. The engrailed positive cells in the brain anlage were located in the area were the first commissure will form. This indicates that engrailed might have a function in axon guidance, as has been reported in other organisms. Later embryonic stages showed expression in the neuropile of the brain. There were no indications of this gene acting in determination of segment polarity. This suggests that there may be at least two copies of engrailed in onychophorans.

Med den här uppsatsen har jag velat diskutera relationen mellan utomhusdidaktik respektive inomhusdidaktik som utgångspunkt för undervisningen i den svenska skolan. Ett annat syfte är att med utgångspunkt i ovan nämnda didaktiker fördjupa kunskaperna i utbildningsmetodik för lärare i allmänhet och biologilärare i synnerhet. Studien utgår från två frågeställningar som jag genom intervjuer med två representanter för utomhusdidaktik och två representanter för inomhusdidaktik har försökt besvara. Resultatet av denna studie visar att utomhusdidaktik och inomhusdidaktik kan vara mycket lika i sina fokus på de didaktiska frågorna. Ett undantag är var-frågan som är av större betydelse för utomhusdidaktiken. Studien visar även att utomhusdidaktik berör många fler ämnen än biologiämnet. En viktig slutsats är att undervisningen i skolan ofta saknar verklighetsförankring. Utomhusdidaktik och science-center-didaktik, som representerar inomhudidaktik i denna studie kan båda hjälpa skolan att konkretisera den ofta teoretiska undervisningen och bidra till en ökad förståelse hos eleverna.

From interviews with biology teachers and pupils, some important factors are presented that motivates and interests pupils in biology. Some of these are varied education, commitment of the teacher, narrative skill and individually reachable goals. Other important factors are practical application and connection to daily life, as well as actuality of the subject and pupils experience of the use of learning. Circumstance around teacher and pupils will influence which factors that has the most impact. It´s up to each teacher to make a decision which factors to be used based on his or her own qualities and depending on the group they will teach. Teachers and pupils agreed about factors that will cause an interesting lesson. The pupils emphasize that variation is the most important factor. Their experience is that many teachers have theoretical introductions that are too long. / Utifrån intervjuer med biologilärare och elever presenteras ett antal punkter som viktiga, eller som grundförutsättningar, för att motivera och intressera elever för ämnet biologi. Några av dessa är varierad undervisning, lärarens engagemang och berättarförmåga samt individuella greppbara mål. Praktisk tillämpning och verklighetsanknytning, ämnets mediala aktualitet samt att eleverna upplever nytta av sitt lärande är andra exempel på viktiga faktorer. Omständigheter runt lärare och elever påverkar vilka faktorer som spelar mest in. Detta måste varje pedagog känna av, beroende på egna egenskaper och elevmålgrupp. Lärare och elever är eniga om vilka faktorer som är viktiga för att göra lektionen intressant. Eleverna betonar dock vikten av variation och menar att flertalet lärare har alltför långa teoretiska genomgångar.