抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201

The Theory of Island Biogeography

I. the origin of species by means of natural selection

We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

A new species

What is ecological speciation

On the bi-centenary of his birth and coincidentally, on the 150th anniversary of publication of the most important publication in the science of biology (‘‘On the Origin of Species’’), it was appropriate that scientists gathered to discuss advances in research on a group of fishes that exemplify the variation in form, function and ecology that inspired Charles Darwin. Fish in the genus Salvelinus, collectively known as charr, thrive where no other fish live, in freshwaters of the highest northern latitudes, the highest altitudes and the greatest water depths, as well as freshwater and marine systems; charr specialise in the extreme. For the 6th time since 1981, biologists covering a broad range of disciplines gathered to share their most recent studies on this genus in the 6th International Charr Symposium. The 5 previous meetings were held in Winnipeg (1981), Sapporo (1988), Trondheim (1994) Trois-Rivières (2000) and Rejkavik (2006). Over 4 days in June in 2009, 120 biologists from 17 countries met in Stirling, Scotland, to listen to 86 verbal presentations, to read 30 poster presentations and to discuss, plan and occasionally argue over, past present and future research. Guest editors: C. Adams, E. Brännas, B. Dempson, R. Knudsen, I. McCarthy, M. Power, I. Winfield / Developments in the Biology, Ecology and Evolution of Charr

A perspective on Salvelinus research

– We explored the incidence of individual feeding specialisation among a naive predator (non-native rainbow trout postsmolts) and two native experienced predators (sea-run Arctic charr and sea-trout) in a subarctic Norwegian fjord. Interindividual foraging niche stability was obtained by combining information on stomach contents (recent dietary niche) with trophically transmitted parasite infestation (time-integrated historical dietary niche) of individual predators. Individual fish showed a high degree of resource specialisation as prey items such as gammarids and small fish (both potential intermediate host of parasites) rarely co-occurred in stomachs. In both naive and veteran predators, positive associations between the intensity of a specific parasite species and the occurrence of their respective intermediate host (gammarids or fish) in the stomachs of individual predators demonstrated temporally interindividual feeding specialisations. Several behavioural phenotypes clearly co-existed in both naive and veteran predator populations, including gammaridivore (benthic feeders), piscivore (pelagic feeders) or insectivore (pleuston feeders) individuals. The likely mechanism of this observed interindividual resource specialisation in the non-native naive predators involves a behavioural component of which rapid learning seems to be a key factor.

Individual feeding specialisation of a naïve vs. veteran predators.

Røye som langtidsvert og smittereservoar for Gyrodactylus salaris i Skibotnelva i Troms

The European whitefish Coregonus lavaretus complex represents one of the most diverse radiations within salmonids, with extreme morphological and genetic differentiation across its range. Such variation has led to the assignment of many populations to separate species. In Great Britain, the seven native populations of C. lavaretus (two in Scotland, four in England, one in Wales) were previously classified into three species, and recent taxonomic revision resurrected the previous nomenclature. Here we used a dataset of 15 microsatellites to: (1) investigate the genetic diversity of British populations, (2) assess the level of population structure and the relationships between British populations. Genetic diversity was highest in Welsh (HO = 0.50, AR = 5.29), intermediate in English (HO = 0.41–0.50, AR = 2.83–3.88), and lowest in Scottish populations (HO = 0.28–0.35, AR = 2.56–3.04). Population structure analyses indicated high genetic differentiation (global FST = 0.388) between all populations but for the two Scottish populations (FST = 0.063) and two English populations (FST = 0.038). Principal component analysis and molecular ANOVA revealed separation between Scottish, English, and Welsh populations, with the Scottish populations being the most diverged. We argue that the data presented here are not sufficient to support a separation of the British European whitefish populations into three separate species, but support the delineation of different ESUs for these populations.

/pdf/geographic-hierarchical-population-genetic-structuring-in-4mtzlnr5fd.pdf

Geographic hierarchical population genetic structuring in British European whitefish ( Coregonus lavaretus ) and its implications for conservation

In this study from Fjellfrosvatn, an oligotrophic lakc in northern Norway, the parasite communities in two sympatric Arctic charr populations were compared. 'The dwarf morph, which inhabits the profundal zone, exhibited the lowest parasite diversity, seven species, and 72% of these charr harboured only one or two parasite species. In contrast, 10 parasite species were encountered in the larger normal charr. and between 5 and 8 species were present in 73% of these fish, which also utilised a broader food and habitat niche. Proteoc~c~phulus sp. was by far the most abundant species in the dwarf charr, probably because this morph fed intensively upon the benthic copepod Acanthocyc.1op.s gigas. On the other hand, parasites that are transmitted with littoral benthic prey (i.e., Phyllodistornum umblae, Cyathocephalus truncutus, Cystidicola furionis, and Crepiclostornurn spp.) were almost absent in the dwarf charr, though they were common in the normal morph. Also, Diphyllobothriurn spp. were more prevalent in the normal charr, and this was attributed to their feeding upon limnetic copepods in the pelagic zone. The only recorded parasite with a direct life cycle, the copepod Salmincola edwardsii, had relatively similar abundances in the two morphs. The considerable differences in parasite community structure and abundance between the two charr populations were closely related to differences in the width and composition of the habitat and food niches between the morphs.

Rune Knudsen

Papers

A perspective on Salvelinus research

Individual feeding specialisation of a naïve vs. veteran predators.

Røye som langtidsvert og smittereservoar for Gyrodactylus salaris i Skibotnelva i Troms

Geographic hierarchical population genetic structuring in British European whitefish ( Coregonus lavaretus ) and its implications for conservation

Parasite communities in two sympatric morphs