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1.
The ecology and geographical distribution of disease vectors are major determinants of spatial and temporal variations in the transmission dynamics of vector‐borne pathogens. However, there are limited studies on the ecology of vectors that contribute to the natural transmission of most vector‐borne pathogens. Avian Plasmodium parasites are multihost mosquito‐borne pathogens transmitted by multiple mosquito species, which might regulate the diversity and persistence of these parasites. From 2007 to 2010, we conducted entomological surveys at Sakata wetland in central Japan, to investigate temporal variation in mosquito occurrence and prevalence of avian Plasmodium lineages in the mosquito populations. A polymerase chain reaction (PCR)‐based method was used to detect Plasmodium parasites and identify the blood sources of mosquitoes. Culex inatomii and C. pipiens pallens represented 60.0% and 34.8% of 11 mosquito species collected, respectively. Our results showed that the two dominant mosquito species most likely serve as principal vectors of avian Plasmodium parasites during June, which coincides with the breeding season of bird species nesting in the wetland reed beds. Fourteen animal species were identified as blood sources of mosquitoes, with the oriental reed warbler (Acrocephalus orientalis) being the commonest blood source. Although there was significant temporal variation in the occurrence of mosquitoes and prevalence of Plasmodium lineages in the mosquitoes, the dominant Plasmodium lineages shared by the two dominant mosquito species were consistently found at the same time during transmission seasons. Because vector competence cannot be confirmed solely by PCR approaches, experimental demonstration is required to provide definitive evidence of transmission suggested in this study. 相似文献
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Naima C. Starkloff Jeremy J. Kirchman Andrew W. Jones Benjamin M. Winger Yen‐Hua Huang Paulo C. Pulgarín‐R Wendy C. Turner 《Ecology and evolution》2020,10(12):5402-5415
The latitudinal diversity gradient (LDG) is an established macroecological pattern, but is poorly studied in microbial organisms, particularly parasites. In this study, we tested whether latitude, elevation, and host species predicted patterns of prevalence, alpha diversity, and community turnover of hemosporidian parasites. We expected parasite diversity to decrease with latitude, alongside the diversity of their hosts and vectors. Similarly, we expected infection prevalence to decrease with latitude as vector abundances decrease. Lastly, we expected parasite community turnover to increase with latitudinal distance and to be higher between rather than within host species. We tested these hypotheses by screening blood and tissue samples of three closely related avian species in a clade of North American songbirds (Turdidae: Catharus, n = 466) across 17.5° of latitude. We used a nested PCR approach to identify parasites in hemosporidian genera that are transmitted by different dipteran vectors. Then, we implemented linear‐mixed effects and generalized dissimilarity models to evaluate the effects of latitude, elevation, and host species on parasite metrics. We found high diversity of hemosporidian parasites in Catharus thrushes (n = 44 lineages) but no evidence of latitudinal gradients in alpha diversity or prevalence. Parasites in the genus Leucocytozoon were most prevalent and lineage rich in this study system; however, there was limited turnover with latitude and host species. Contrastingly, Plasmodium parasites were less prevalent and diverse than Leucocytozoon parasites, yet communities turned over at a higher rate with latitude and host species. Leucocytozoon communities were skewed by the dominance of one or two highly prevalent lineages with broad latitudinal distributions. The few studies that evaluate the hemosporidian LDG do not find consistent patterns of prevalence and diversity, which makes it challenging to predict how they will respond to global climate change. 相似文献
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Joshua G. Lynton‐Jenkins Aisha C. Bründl Maxime Cauchoix La A. Lejeune Louis Sall Alice C. Thiney Andrew F. Russell Alexis S. Chaine Camille Bonneaud 《Ecology and evolution》2020,10(12):6097-6111
Understanding the ecology and evolution of parasites is contingent on identifying the selection pressures they face across their infection landscape. Such a task is made challenging by the fact that these pressures will likely vary across time and space, as a result of seasonal and geographical differences in host susceptibility or transmission opportunities. Avian haemosporidian blood parasites are capable of infecting multiple co‐occurring hosts within their ranges, yet whether their distribution across time and space varies similarly in their different host species remains unclear. Here, we applied a new PCR method to detect avian haemosporidia (genera Haemoproteus, Leucocytozoon, and Plasmodium) and to determine parasite prevalence in two closely related and co‐occurring host species, blue tits (Cyanistes caeruleus, N = 529) and great tits (Parus major, N = 443). Our samples were collected between autumn and spring, along an elevational gradient in the French Pyrenees and over a three‐year period. Most parasites were found to infect both host species, and while these generalist parasites displayed similar elevational patterns of prevalence in the two host species, this was not always the case for seasonal prevalence patterns. For example, Leucocytozoon group A parasites showed inverse seasonal prevalence when comparing between the two host species, being highest in winter and spring in blue tits but higher in autumn in great tits. While Plasmodium relictum prevalence was overall lower in spring relative to winter or autumn in both species, spring prevalence was also lower in blue tits than in great tits. Together, these results reveal how generalist parasites can exhibit host‐specific epidemiology, which is likely to complicate predictions of host–parasite co‐evolution. 相似文献
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G. Schiavo M. G. Strillacci A. Ribani S. Bovo S. I. Roman‐Ponce S. Cerolini F. Bertolini A. Bagnato L. Fontanesi 《Animal genetics》2018,49(3):259-264
Mitochondrial DNA (mtDNA) insertions have been detected in the nuclear genome of many eukaryotes. These sequences are pseudogenes originated by horizontal transfer of mtDNA fragments into the nuclear genome, producing nuclear DNA sequences of mitochondrial origin (numt). In this study we determined the frequency and distribution of mtDNA‐originated pseudogenes in the turkey (Meleagris gallopavo) nuclear genome. The turkey reference genome (Turkey_2.01) was aligned with the reference linearized mtDNA sequence using last . A total of 32 numt sequences (corresponding to 18 numt regions derived by unique insertional events) were identified in the turkey nuclear genome (size ranging from 66 to 1415 bp; identity against the modern turkey mtDNA corresponding region ranging from 62% to 100%). Numts were distributed in nine chromosomes and in one scaffold. They derived from parts of 10 mtDNA protein‐coding genes, ribosomal genes, the control region and 10 tRNA genes. Seven numt regions reported in the turkey genome were identified in orthologues positions in the Gallus gallus genome and therefore were present in the ancestral genome that in the Cretaceous originated the lineages of the modern crown Galliformes. Five recently integrated turkey numts were validated by PCR in 168 turkeys of six different domestic populations. None of the analysed numts were polymorphic (i.e. absence of the inserted sequence, as reported in numts of recent integration in other species), suggesting that the reticulate speciation model is not useful for explaining the origin of the domesticated turkey lineage. 相似文献
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Robin Loveridge Oliver R. Wearn Marcus Vieira Henry Bernard Robert M. Ewers 《Biotropica》2016,48(3):373-380
Invasive species pose one of the greatest threats to biodiversity. This study investigates the extent to which human disturbance to natural ecosystems facilitates the spread of non‐native species, focusing on a small mammal community in selectively logged rain forest, Sabah, Borneo. The microhabitat preferences of the invasive Rattus rattus and three native species of small mammal were examined in three‐dimensional space by combining the spool‐and‐line technique with a novel method for quantifying fine‐scale habitat selection. These methods allowed the detection of significant differences for each species between the microhabitats used compared with alternative, available microhabitats that were avoided. Rattus rattus showed the greatest preference for heavily disturbed habitats, and in contrast to two native small mammals of the genus Maxomys, R. rattus showed high levels of arboreal behavior, frequently leaving the forest floor and traveling through the understory and midstory forest strata. This behavior may enable R. rattus to effectively utilize the complex three‐dimensional space of the lower strata in degraded forests, which is characterized by dense vegetation. The behavioral flexibility of R. rattus to operate in both terrestrial and arboreal space may facilitate its invasion into degraded forests. Human activities that generate heavily disturbed habitats preferred by R. rattus may promote the establishment of this invasive species in tropical forests in Borneo, and possibly elsewhere. We present this as an example of a synergistic effect, whereby forest disturbance directly threatens biodiversity and indirectly increases the threat posed by invasive species, creating habitat conditions that facilitate the establishment of non‐native fauna. 相似文献
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Maxine Zylberberg 《Ibis》2014,156(3):615-626
The scientific community has long recognized the importance of individual behaviour in pathogen spread in wild animals. Furthermore, recent studies have highlighted the potential for behaviour to act as a pathogen defence mechanism. In line with these studies, the pathogen defence optimization hypothesis (PDOH) posits that individuals balance investment in costly behavioural and immunological defences against pathogen infection. Here, I test the PDOH using data from observations of wild Galapagos finches (Medium Ground Finches Geospiza fortis and Small Ground Finches Geospiza fuliginosa) at feeders, combined with immune data collected in the field. Both within and between species, those groups engaging to a greater extent in high transmission‐risk behaviours (not investing in behavioural defences against pathogen exposure) invest more heavily in immune pathogen defences. These data provide the first support for the PDOH in a wild population. 相似文献
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Joel Ralston Lydia Lorenc Melissa Montes William V. DeLuca Jeremy J. Kirchman Bradley K. Woodworth Stuart A. Mackenzie Amy Newman Hilary A. Cooke Nikole E. Freeman Alex O. Sutton Lila Tauzer D. Ryan Norris 《Ecology and evolution》2019,9(15):8840-8855
Migratory behaviors such as the timing and duration of migration are genetically inherited and can be under strong natural selection, yet we still know very little about the specific genes or molecular pathways that control these behaviors. Studies in candidate genes Clock and Adcyap1 have revealed that both of these loci can be significantly correlated with migratory behaviors in birds, though observed relationships appear to vary across species. We investigated geographic genetic structure of Clock and Adcyap1 in four populations of blackpoll warblers (Setophaga striata), a Neotropical–Nearctic migrant that exhibits geographic variation in migratory timing and duration across its boreal breeding distribution. Further, we used data on migratory timing and duration, obtained from light‐level geolocator trackers to investigate candidate genotype–phenotype relationships at the individual level. While we found no geographic structure in either candidate gene, we did find evidence that candidate gene lengths are correlated with five of the six migratory traits. Maximum Clock allele length was significantly and negatively associated with spring arrival date. Minimum Adcyap1 allele length was significantly and negatively associated with spring departure date and positively associated with fall arrival date at the wintering grounds. Additionally, we found a significant interaction between Clock and Adcyap1 allele lengths on both spring and fall migratory duration. Adcyap1 heterozygotes also had significantly shorter migration duration in both spring and fall compared to homozygotes. Our results support the growing body of evidence that Clock and Adcyap1 allele lengths are correlated with migratory behaviors in birds. 相似文献
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Jemma Salmon Sally P. Ward Steven J. Hanley Ottoline Leyser Angela Karp 《Plant biotechnology journal》2014,12(4):480-491
Willows (Salix spp.) are important biomass crops due to their ability to grow rapidly with low fertilizer inputs and ease of cultivation in short‐rotation coppice cycles. They are relatively undomesticated and highly diverse, but functional testing to identify useful allelic variation is time‐consuming in trees and transformation is not yet possible in willow. Arabidopsis is heralded as a model plant from which knowledge can be transferred to advance the improvement of less tractable species. Here, knowledge and methodologies from Arabidopsis were successfully used to identify a gene influencing stem number in coppiced willows, a complex trait of key biological and industrial relevance. The strigolactone‐related More AXillary growth (MAX) genes were considered candidates due to their role in shoot branching. We previously demonstrated that willow and Arabidopsis show similar response to strigolactone and that transformation rescue of Arabidopsis max mutants with willow genes could be used to detect allelic differences. Here, this approach was used to screen 45 SxMAX1, SxMAX2, SxMAX3 and SxMAX4 alleles cloned from 15 parents of 11 mapping populations varying in shoot‐branching traits. Single‐nucleotide polymorphism (SNP) frequencies were locus dependent, ranging from 29.2 to 74.3 polymorphic sites per kb. SxMAX alleles were 98%–99% conserved at the amino acid level, but different protein products varying in their ability to rescue Arabidopsis max mutants were identified. One poor rescuing allele, SxMAX4D, segregated in a willow mapping population where its presence was associated with increased shoot resprouting after coppicing and colocated with a QTL for this trait. 相似文献
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Zorica S. Mitić Biljana M. Nikolić Mihailo S. Ristić Vele V. Tešević Srdjan R. Bojović Petar D. Marin 《化学与生物多样性》2017,14(8)
Comparative analysis of terpene diversity and differentiation of relict pines Pinus heldreichii, P. nigra, and P. peuce from the central Balkans was performed at the population level. Multivariate statistical analyses showed that the composition of needle terpenes reflects clear divergence among the pine species from different subgenera: P. peuce (subgenus Strobus) vs. P. nigra and P. heldreichii (subgenus Pinus). In addition, despite the described morphological similarities and the fact that P. nigra and P. heldreichii may spontaneously hybridize, our results indicated differentiation of their populations naturally growing in the same area. In accordance with recently proposed concept of ‘flavonic evolution’ in the genus Pinus, we assumed that the terpene profile of soft pine P. peuce, defined by high amounts of six monoterpenes, is more basal than those of hard pines P. nigra and P. heldreichii, which were characterized by high content levels of mainly sesquiterpenes. In order to establish precise positions of P. heldreichii, P. nigra and P. peuce within the taxonomic and phylogenetic tree, as well as develop suitable conservation strategies and future breeding efforts, it is necessary to perform additional morphological, biochemical, and genetic studies. 相似文献
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Cédric Berney Andreea Ciuprina Sara Bender Juliet Brodie Virginia Edgcomb Eunsoo Kim Jeena Rajan Laura Wegener Parfrey Sina Adl Stéphane Audic David Bass David A. Caron Guy Cochrane Lucas Czech Micah Dunthorn Stefan Geisen Frank Oliver Glöckner Frédéric Mahé Christian Quast Jonathan Z. Kaye Alastair G. B. Simpson Alexandros Stamatakis Javier del Campo Pelin Yilmaz Colomban de Vargas 《The Journal of eukaryotic microbiology》2017,64(3):407-411
Universal taxonomic frameworks have been critical tools to structure the fields of botany, zoology, mycology, and bacteriology as well as their large research communities. Animals, plants, and fungi have relatively solid, stable morpho‐taxonomies built over the last three centuries, while bacteria have been classified for the last three decades under a coherent molecular taxonomic framework. By contrast, no such common language exists for microbial eukaryotes, even though environmental ‘‐omics’ surveys suggest that protists make up most of the organismal and genetic complexity of our planet's ecosystems! With the current deluge of eukaryotic meta‐omics data, we urgently need to build up a universal eukaryotic taxonomy bridging the protist ‐omics age to the fragile, centuries‐old body of classical knowledge that has effectively linked protist taxa to morphological, physiological, and ecological information. UniEuk is an open, inclusive, community‐based and expert‐driven international initiative to build a flexible, adaptive universal taxonomic framework for eukaryotes. It unites three complementary modules, EukRef, EukBank, and EukMap, which use phylogenetic markers, environmental metabarcoding surveys, and expert knowledge to inform the taxonomic framework. The UniEuk taxonomy is directly implemented in the European Nucleotide Archive at EMBL‐EBI, ensuring its broad use and long‐term preservation as a reference taxonomy for eukaryotes. 相似文献
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Biljana M. Nikolić Zorica S. Mitić Vele V. Tešević Iris Ž. Đorđević Marina M. Todosijević Srdjan R. Bojović Petar D. Marin 《化学与生物多样性》2018,15(9)
The n‐alkane composition in the leaf cuticular waxes of natural populations of Bosnian pine (Pinus heldreichii), Austrian pine (P. nigra), and Macedonian pine (P. peuce) was compared for the first time. The range of n‐alkanes was wider in P. nigra (C16 – C33) than in P. heldreichii and P. peuce (C18 – C33). Species also diverged in abundance and range of dominant n‐alkanes (P. heldreichii: C23, C27, and C25; P. nigra: C25, C27, C29, and C23; P. peuce: C29, C25, C27, and C23). Multivariate statistical analyses (PCA, DA, and CA) generally pointed out separation of populations of P. nigra from populations of P. heldreichii and P. peuce (which were, to a greater or lesser extent, separated too). However, position of these species on the basis of n‐alkane composition was in accordance neither with infrageneric classification nor with recent molecular and terpene investigations. 相似文献
15.
Vithya Krishnan Nicole Robinson Jennifer Firn Grahame Applegate John Herbohn Susanne Schmidt 《Ecology and evolution》2019,9(3):1378-1393
Wet‐sclerophyll forests are unique ecosystems that can transition to dry‐sclerophyll forests or to rainforests. Understanding of the dynamics of these forests for conservation is limited. We evaluated the long‐term succession of wet‐sclerophyll forest on World Heritage listed K'gari (Fraser Island)—the world's largest sand island. We recorded the presence and growth of tree species in three 0.4 hectare plots that had been subjected to selective logging, fire, and cyclone disturbance over 65 years, from 1952 to 2017. Irrespective of disturbance regimes, which varied between plots, rainforest trees recruited at much faster rates than the dominant wet‐sclerophyll forest trees, narrowly endemic species Syncarpia hillii and more common Lophostemon confertus. Syncarpia hillii did not recruit at the plot with the least disturbance and recruited only in low numbers at plots with more prominent disturbance regimes in the ≥10 cm at breast height size. Lophostemon confertus recruited at all plots but in much lower numbers than rainforest trees. Only five L. confertus were detected in the smallest size class (<10 cm diameter) in the 2017 survey. Overall, we find evidence that more pronounced disturbance regimes than those that have occurred over the past 65 years may be required to conserve this wet‐sclerophyll forest, as without intervention, transition to rainforest is a likely trajectory. Fire and other management tools should therefore be explored, in collaboration with Indigenous landowners, to ensure conservation of this wet‐sclerophyll forest. 相似文献
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M. Ferencakovic I. Curik L. Pérez‐Pardal L. J. Royo V. Cubric‐Curik I. Fernández I. Álvarez A. Kostelic N. Sprem K. Krapinec F. Goyache 《Animal genetics》2013,44(2):184-192
Variation in mitochondrial DNA (mtDNA) and Y‐chromosome haplotypes was analysed in nine domestic sheep breeds (159 rams) and 21 mouflon ( Ovis musimon) sampled in the East Adriatic. Mitochondrial DNA analyses revealed a high frequency of type B haplotypes, predominantly in European breeds, and a very low frequency of type A haplotypes, which are more frequent in some Asian breeds. Mitochondrial haplotype Hmt‐3 was the most frequent (26.4%), and 37.1%, 20.8% and 7.6% of rams had haplotypes one, two and three mutations remote from Hmt‐3 respectively. In contrast, Y‐chromosome analyses revealed extraordinary paternal allelic richness: HY‐6, 89.3%; HY‐8, 5.0%; HY‐18, 3.1%; HY‐7, 1.3%; and HY‐5, 1.3%. In fact, the number of haplotypes observed is comparable to the number found in Turkish breeds and greater than the number found in European breeds so far. Haplotype HY‐18 (A‐oY1/135‐SRYM18), identified here for the first time, provides a link between the haplotype HY‐12 (A‐oY1/139‐SRYM18) found in a few rams in Turkey and haplotype HY‐9 (A‐oY1/131‐SRYM18) found in one ram in Ethiopia. All mouflons had type B mtDNA haplotypes, including the private haplotype (Hmt‐55), and all were paternally monomorphic for haplotype HY‐6. Our data support a quite homogeneous maternal origin of East Adriatic sheep, which is a characteristic of European breeds. At the same time, the high number of haplotypes found was surprising and intriguing, and it begs for further analysis. Simultaneous analysis of mtDNA and Y‐chromosome information allowed us to detect a large discrepancy between maternal and paternal lineages in some populations. This is most likely the result of breeder efforts to ‘upgrade’ local populations using rams with different paternal origins. 相似文献
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Christoph G. Jäger Tobias Vrede Lennart Persson Mats Jansson 《Freshwater Biology》2014,59(8):1596-1607
- Humic lakes with a high external supply of DOC and low input of nutrients can often support a high biomass of metazoan zooplankton. In such lakes, autotrophic algae compete with bacteria for inorganic nutrients, but bacteria support mixotrophic growth. Consequently, planktonic communities are often dominated by mixotrophic flagellates, while obligate autotrophic phytoplankton occurs in low numbers for extended periods.
- To test the importance of autotrophic phytoplankton and mixotrophic flagellates as food resources for metazoan grazers and, in turn, the feedback effects of grazers on basal food‐web interactions, we conducted a long‐term experiment where we simulated abiotic resource relationships of humic lakes (high DOC [glucose] and low P input). We examined the population dynamics of Daphnia galeata when inoculated in systems with autotrophic algae only, mixotrophic algae only and a mixture of autotrophic and mixotrophic algae, and how the systems changed after the inoculation of Daphnia. All combinations were run at high‐ and low‐light conditions to analyse the effects of light on food quantity and quality.
- Daphnia grew to high densities only when mixotrophs were present at high‐light conditions and showed no or only weak growth at low‐light conditions or with autotrophs as the only food source.
- Autotrophic algae and bacteria showed a strong competition for nutrients. Autotrophic algae were released from competition for nutrients after Daphnia grazed on bacteria, which led to a probable change of the bacteria community to less edible but less competitive taxa. As a consequence, there was a mutualistic interaction between autotrophs and mixotrophs before Daphnia were introduced which turned into competition after Daphnia inoculation.
- We suggest that mixotrophic flagellates can be a critical resource for cladocerans and thereby also have a cascading effect on higher trophic levels, and cladocerans, in turn, have important indirect effects on basal planktonic food webs; hence, both might affect whole lake ecosystems.
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Cesc Múrria Amanda T. Rugenski Matt R. Whiles Alfried P. Vogler 《Diversity & distributions》2015,21(8):938-949