| multiple cryptic species of sympatric generalists within the avian blood parasite haemoproteus majoris. | the avian haemosporidian parasite haemoproteus majoris has been reported to infect a wide range of passerine birds throughout the holarctic ecozone. five cytochrome b (cyt b) lineages have been described as belonging to the morphological species h. majoris, and these form a tight phylogenetic cluster together with 13 undescribed lineages that differ from each other by < 1.2% in sequence divergence. records in a database (malavi) that contains global findings of haemosporidian lineages generated ... | 2016 | 27262030 |
| mhc-i affects infection intensity but not infection status with a frequent avian malaria parasite in blue tits. | host resistance against parasites depends on three aspects: the ability to prevent, control and clear infections. in vertebrates the immune system consists of innate and adaptive immunity. innate immunity is particularly important for preventing infection and eradicating established infections at an early stage while adaptive immunity is slow, but powerful, and essential for controlling infection intensities and eventually clearing infections. major histocompatibility complex (mhc) molecules are ... | 2013 | 24023631 |
| molecular phylogenetic and morphological analysis of haemosporidian parasites (haemosporida) in a naturally infected european songbird, the blackcap sylvia atricapilla, with description of haemoproteus pallidulus sp. nov. | the blackcap (sylvia atricapilla) is a common palearctic migratory warbler, and haemosporidian parasites are common in this species. however, genetic and phenotypic diversity of haemosporidians in warblers has been insufficiently investigated and poorly linked. we addressed this issue by combining molecular and microscopy data for detection of pigment-forming haemosporidians of the genera haemoproteus and plasmodium. blood samples from 498 blackcaps were collected at 7 different sites in europe ... | 2010 | 19765350 |
| variation in host specificity between species of avian hemosporidian parasites: evidence from parasite morphology and cytochrome b gene sequences. | a parasite's shift to a new host may have serious evolutionary consequences, since host switching usually is associated with a change in virulence and may lead to the evolution of emerging diseases. this phenomenon remains insufficiently studied in wildlife. here, we combine microscopic examination of blood films and pcr-based methods to investigate the natural host specificity of haemoproteus and plasmodium spp. in birds of 4 families of the passeriformes within a small geographic area. the mat ... | 2006 | 17304814 |
| changes in haemoproteus sex ratios: fertility insurance or differential sex lifespan? | there is little direct evidence of the fitness effects of changes in malaria gametocyte sex ratio. gametocyte sex ratios in haemospororin parasites (phylum apicomplexa) are usually female skewed. however, in some cases and especially in haemoproteus parasites, less female-biased and even male-biased sex ratios are encountered. the 'fertility insurance hypothesis' tries to explain these biases as an evolutionary strategy to facilitate gamete encounter. thus, the hypothesis predicts that, if there ... | 2004 | 15306307 |
| are avian blood parasites pathogenic in the wild? a medication experiment in blue tits (parus caeruleus). | the hamilton and zuk hypothesis on haemoparasite-mediated sexual selection and certain studies of reproductive costs are based on the assumption that avian blood parasite infections are detrimental to their hosts. however, there is no experimental evidence demonstrating harmful effects of blood parasites on fitness in wild populations, it even having been suggested that they may be non-pathogenic. only an experimental manipulation of natural blood parasite loads may reveal their harmful effects. ... | 2000 | 11197126 |
| maximum host survival at intermediate parasite infection intensities. | although parasitism has been acknowledged as an important selective force in the evolution of host life histories, studies of fitness effects of parasites in wild populations have yielded mixed results. one reason for this may be that most studies only test for a linear relationship between infection intensity and host fitness. if resistance to parasites is costly, however, fitness may be reduced both for hosts with low infection intensities (cost of resistance) and high infection intensities (c ... | 2008 | 18560544 |