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1.
Oecologia ; 202(1): 29-40, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37087699

RESUMEN

Early life for animals is often a time of rapid growth and development. In a resource-limited environment, life history theory predicts that there must be trade-offs between resource sinks in ways that optimize future survival and reproductive success. Telomeres have emerged as putative indicators of these early life trade-offs, but there are conflicting accounts as to how developmental traits and conditions impact telomere length and dynamics. For 2 years, we studied the nestlings of a breeding population of barn swallows from day 6 to day 12 of life, measuring various ontogenetic factors to understand to what extent they explain variation in telomere length and dynamics. We unexpectedly found that telomeres lengthened between the two sampling points. Nestlings in large broods had shorter telomeres, but surprisingly, individuals that grew faster from day 6 to day 12 had longer telomeres and more telomere lengthening. Nestlings with higher mass relative to their nestmates on d6 had shorter telomeres, suggesting that the relatively fast growth barn swallows experience early in development is more costly than the relatively slower growth later in development. These effects were only found in the first year of study. Telomere lengthening may be due to the initiation of new hematopoietic cell lines during development or the expression of telomerase early in life. Favorable early life conditions and high parental investment could allow for more growth with little to no cost to telomere length or dynamics.


Asunto(s)
Golondrinas , Animales , Homeostasis del Telómero , Telómero , Reproducción , Acortamiento del Telómero
2.
Mol Ecol Resour ; 21(2): 355-362, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33037786

RESUMEN

The polymerase chain reaction (PCR) is a very powerful method to detect and identify pathogens. The high sensitivity of the method, however, comes with a cost; any of the millions of artificial DNA copies generated by PCR can serve as a template in a following experiment. If not identified as contaminations, these may result in erroneous conclusions on the occurrence of the pathogen, thereby inflating estimates of host range and geographic distribution. In the present paper, we evaluate whether several published records of avian haemosporidian parasites, in either unusual host species or geographical regions, might stem from PCR contaminations rather than novel biological findings. The detailed descriptions of these cases are shedding light upon the steps in the work process that might lead to PCR contaminations. By increasing the awareness of this problem, it will aid in developing procedures that keep these to a minimum. The examples in the present paper are from haemosporidians of birds, however the problem of contaminations and suggested actions should apply generally to all kinds of PCR-based identifications, not just of parasites and pathogens.


Asunto(s)
Enfermedades de las Aves , Aves/parasitología , Bases de Datos Genéticas , Haemosporida , Animales , Enfermedades de las Aves/parasitología , ADN Protozoario , Haemosporida/genética , Filogenia , Reacción en Cadena de la Polimerasa
3.
Trends Ecol Evol ; 34(6): 497-501, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31079944

RESUMEN

We propose an application of network analysis to determine which traits and behaviors predict fertilizations within and between populations. This approach quantifies how reproductive behavior between individuals shapes patterns of selection and gene flow, filling an important gap in our understanding of the connection between evolutionary processes and emergent patterns.


Asunto(s)
Especiación Genética , Conducta Reproductiva , Evolución Biológica , Flujo Génico , Fenotipo , Aislamiento Reproductivo
4.
Sci Rep ; 8(1): 15533, 2018 10 19.
Artículo en Inglés | MEDLINE | ID: mdl-30341385

RESUMEN

Animals use morphological signals such as ornamental traits or weaponry to mediate social interactions, and the extent of signal trait elaboration is often positively associated with reproductive success. By demonstrating relationships between signal traits and fitness, researchers often make inferences about how behaviour operates to shape those outcomes. However, detailed information about fine-scale individual behaviour, and its physiological basis, can be difficult to obtain. Here we show that experimental manipulations to exaggerate a signal trait (plumage colour) and concomitant changes in testosterone and stress-induced corticosterone levels altered social interactivity between manipulated males and their social mates. On average, darkened males did not have higher levels of interactivity than unmanipulated males; however, males who experienced a greater shift in colour (pale to dark), a larger, positive change in testosterone levels, and a dampened stress-induced corticosterone response had a larger increase in the number of interactions with their social mate post-manipulation compared to pre-manipulation. This work provides new insights into the integration and real-time flexibility of multivariate phenotypes and direct evidence for the role of social interactions in pair bond maintenance.


Asunto(s)
Aves/fisiología , Fenotipo , Conducta Sexual Animal , Animales , Tamaño Corporal , Color , Corticosterona/sangre , Plumas/anatomía & histología , Testosterona/sangre
5.
Ecol Evol ; 7(11): 3724-3731, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28616169

RESUMEN

Parasite lineages commonly diverge when host lineages diverge. However, when large clades of hosts and parasites are analyzed, some cases suggest host switching as another major diversification mechanism. The first step in host switching is the appearance of a parasite on an atypical host, or "straggling." We analyze the conditions associated with straggling events. We use five species of colonially nesting seabirds from the Galapagos Archipelago and two genera of highly specific ectoparasitic lice to examine host switching. We use both genetic and morphological identification of lice, together with measurements of spatial distribution of hosts in mixed breeding colonies, to test: (1) effects of local host community composition on straggling parasite identity; (2) effects of relative host density within a mixed colony on straggling frequency and parasite species identity; and (3) how straggling rates are influenced by the specifics of louse attachment. Finally, we determine whether there is evidence of breeding in cases where straggling adult lice were found, which may indicate a shift from straggling to the initial stages of host switching. We analyzed more than 5,000 parasite individuals and found that only ~1% of lice could be considered stragglers, with ~5% of 436 host individuals having straggling parasites. We found that the presence of the typical host and recipient host in the same locality influenced straggling. Additionally, parasites most likely to be found on alternate hosts are those that are smaller than the typical parasite of that host, implying that the ability of lice to attach to the host might limit host switching. Given that lice generally follow Harrison's rule, with larger parasites on larger hosts, parasites infecting the larger host species are less likely to successfully colonize smaller host species. Moreover, our study supports the general perception that successful colonization of a novel host is extremely rare, as we found only one nymph of a straggling species, which may indicate successful reproduction.

6.
Biol Lett ; 12(6)2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27354713

RESUMEN

Theory predicts that social interactions are dynamically linked to phenotype. Yet because social interactions are difficult to quantify, little is known about the precise details on how interactivity is linked to phenotype. Here, we deployed proximity loggers on North American barn swallows (Hirundo rustica erythrogaster) to examine intercorrelations among social interactions, morphology and features of the phenotype that are sensitive to the social context: stress-induced corticosterone (CORT) and gut microbial diversity. We analysed relationships at two spatial scales of interaction: (i) body contact and (ii) social interactions occurring between 0.1 and 5 m. Network analysis revealed that relationships between social interactions, morphology, CORT and gut microbial diversity varied depending on the sexes of the individuals interacting and the spatial scale of interaction proximity. We found evidence that body contact interactions were related to diversity of socially transmitted microbes and that looser social interactions were related to signalling traits and CORT.


Asunto(s)
Microbioma Gastrointestinal , Conducta Social , Golondrinas/microbiología , Golondrinas/fisiología , Animales , Corticosterona/sangre , ADN Bacteriano/análisis , Plumas/anatomía & histología , Plumas/química , Femenino , Masculino , Pigmentación/fisiología , ARN Ribosómico 16S/análisis , Caracteres Sexuales , Estrés Fisiológico , Golondrinas/anatomía & histología
7.
Ecol Evol ; 6(3): 716-26, 2016 02.
Artículo en Inglés | MEDLINE | ID: mdl-26865960

RESUMEN

Oceanic archipelagos are vulnerable to natural introduction of parasites via migratory birds. Our aim was to characterize the geographic origins of two Plasmodium parasite lineages detected in the Galapagos Islands and in North American breeding bobolinks (Dolichonyx oryzivorus) that regularly stop in Galapagos during migration to their South American overwintering sites. We used samples from a grassland breeding bird assemblage in Nebraska, United States, and parasite DNA sequences from the Galapagos Islands, Ecuador, to compare to global data in a DNA sequence registry. Homologous DNA sequences from parasites detected in bobolinks and more sedentary birds (e.g., brown-headed cowbirds Molothrus ater, and other co-occurring bird species resident on the North American breeding grounds) were compared to those recovered in previous studies from global sites. One parasite lineage that matched between Galapagos birds and the migratory bobolink, Plasmodium lineage B, was the most common lineage detected in the global MalAvi database, matching 49 sequences from unique host/site combinations, 41 of which were of South American origin. We did not detect lineage B in brown-headed cowbirds. The other Galapagos-bobolink match, Plasmodium lineage C, was identical to two other sequences from birds sampled in California. We detected a close variant of lineage C in brown-headed cowbirds. Taken together, this pattern suggests that bobolinks became infected with lineage B on the South American end of their migratory range, and with lineage C on the North American breeding grounds. Overall, we detected more parasite lineages in bobolinks than in cowbirds. Galapagos Plasmodium had similar host breadth compared to the non-Galapagos haemosporidian lineages detected in bobolinks, brown-headed cowbirds, and other grassland species. This study highlights the utility of global haemosporidian data in the context of migratory bird-parasite connectivity. It is possible that migratory bobolinks bring parasites to the Galapagos and that these parasites originate from different biogeographic regions representing both their breeding and overwintering sites.

8.
Ecol Evol ; 5(16): 3264-71, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26380662

RESUMEN

Parasites comprise a significant percentage of the biodiversity of the planet and are useful systems to test evolutionary and ecological hypotheses. In this study, we analyze the effect of host species identity and the immediate local species assemblage within mixed species colonies of nesting seabirds on patterns of genetic clustering within two species of multihost ectoparasitic lice. We use three genetic markers (one mitochondrial, COI, and two nuclear, EF1-α and wingless) and maximum likelihood phylogenetic trees to test whether (1) parasites show lineage sorting based on their host species; and (2) switching of lineages to the alternate host species depends on the immediate local species assemblage of individual hosts within a colony. Specifically, we examine the genetic structure of two louse species: Eidmanniella albescens, infecting both Nazca (Sula granti) and blue-footed boobies (Sula nebouxii), and Fregatiella aurifasciata, infecting both great (Fregata minor) and magnificent frigatebirds (Fregata magnificens). We found that host species identity was the only factor explaining the patterns of genetic structure in both parasites. In both cases, there is evident genetic differentiation depending on the host species. Thus, a revision of the taxonomy of these louse species is needed. One possible explanation of this pattern is extremely low louse migration rates between host species, perhaps influenced by fine-scale spatial separation of host species within mixed colonies, and low parasite infrapopulation numbers.

9.
PLoS One ; 10(9): e0137242, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26348329

RESUMEN

Proximity logging is a new tool for understanding social behavior as it allows for accurate quantification of social networks. We report results from field calibration and deployment tests of miniaturized proximity tags (Encounternet), digital transceivers that log encounters between tagged individuals. We examined radio signal behavior in relation to tag attachment (tag, tag on bird, tag on saline-filled balloon) to understand how radio signal strength is affected by the tag mounting technique used for calibration tests. We investigated inter-tag and inter-receiver station variability, and in each calibration test we accounted for the effects of antennae orientation. Additionally, we used data from a live deployment on breeding barn swallows (Hirundo rustica erythrogaster) to analyze the quality of the logs, including reciprocal agreement in dyadic logs. We evaluated the impact (in terms of mass changes) of tag attachment on the birds. We were able to statistically distinguish between RSSI values associated with different close-proximity (<5 m) tag-tag distances regardless of antennae orientation. Inter-tag variability was low, but we did find significant inter-receiver station variability. Reciprocal agreement of dyadic logs was high and social networks were constructed from proximity tag logs based on two different RSSI thresholds. There was no evidence of significant mass loss in the time birds were wearing tags. We conclude that proximity loggers are accurate and effective for quantifying social behavior. However, because RSSI and distance cannot be perfectly resolved, data from proximity loggers are most appropriate for comparing networks based on specific RSSI thresholds. The Encounternet system is flexible and customizable, and tags are now light enough for use on small animals (<50 g).


Asunto(s)
Conducta Social , Golondrinas/fisiología , Vocalización Animal/fisiología , Animales
10.
Gen Comp Endocrinol ; 213: 65-73, 2015 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-25712433

RESUMEN

Rufous-collared sparrows (Zonotrichia capensis peruviensis) from valleys in the Atacama Desert of Chile, live in an extremely stable environment, and exhibit overlap in molt and reproduction, with valley-specific differences in the proportion of birds engaged in both. To better understand the mechanistic pathways underlying the timing of life-history transitions, we examined the relationships among baseline and stress-induced levels of corticosterone (CORT), testosterone, and bacteria-killing ability of the blood plasma (BKA), as well as haemosporidian parasite infections and the genetic structure of two groups of sparrows from separate valleys over the course of a year. Birds neither molting nor breeding had the lowest BKA, but there were no differences among the other three categories of molt-reproductive stage. BKA varied over the year, with birds in May/June exhibiting significantly lower levels of BKA than the rest of the year. We also documented differences in the direction of the relationship between CORT and BKA at different times during the year. The direction of these relationships coincides with some trends in molt and reproductive stage, but differs enough to indicate that these birds exhibit individual-level plasticity, or population-level variability, in coordinating hypothalamo-pituitary-adrenal axis activity with life-history stage. We found weak preliminary evidence for genetic differentiation between the two populations, but not enough to indicate genetic isolation. No birds were infected with haemosporidia, which may be indicative of reduced parasite pressure in deserts. The data suggest that these birds may not trade off among different life-history components, but rather are able to invest in multiple life-history components based on their condition.


Asunto(s)
Enfermedades de las Aves/inmunología , Haemosporida/inmunología , Estadios del Ciclo de Vida/fisiología , Muda , Infecciones por Protozoos/inmunología , Reproducción , Gorriones/inmunología , Animales , Enfermedades de las Aves/parasitología , Cruzamiento , Corticosterona/sangre , Ambiente , Interacciones Huésped-Parásitos , Sistema Hipófiso-Suprarrenal/metabolismo , Infecciones por Protozoos/parasitología , Estaciones del Año , Gorriones/metabolismo , Gorriones/parasitología , Testosterona/sangre
11.
J Parasitol ; 100(5): 569-77, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24911632

RESUMEN

In this paper we describe the ectoparasitic lice (Insecta: Phthiraptera) found on 5 species of seabirds (magnificent frigatebird Fregata magnificens; great frigatebird Fregata minor ; Nazca booby Sula granti ; blue-footed booby Sula nebouxii ; and red-footed booby Sula sula ) on the Galapagos Archipelago. We found 9 species of ectoparasitic lice: 5 species of Pectinopygus ischnocerans, 1 infesting each host; 2 species of Colpocephalum amblyceran lice, 1 on each frigatebird species; and 2 shared amblycerans, Eidmanniella albescens (Piaget, 1880) found on Nazca and blue-footed boobies and Fregatiella aurifasciata (Kellogg, 1899) found on the 2 frigatebirds. We tested the relative importance and interactions of host sex, body size, host, island, host family, and breeding status and found that inter-island differences were the main predictors of prevalence and infestation intensity. These differences could be related to host density or weather, but further evidence is needed.


Asunto(s)
Amblycera/crecimiento & desarrollo , Enfermedades de las Aves/parasitología , Ischnocera/crecimiento & desarrollo , Infestaciones por Piojos/veterinaria , Amblycera/clasificación , Amblycera/genética , Animales , Enfermedades de las Aves/epidemiología , Aves , ADN/química , ADN/aislamiento & purificación , Código de Barras del ADN Taxonómico , Ecuador/epidemiología , Femenino , Interacciones Huésped-Parásitos , Ischnocera/clasificación , Ischnocera/genética , Infestaciones por Piojos/epidemiología , Infestaciones por Piojos/parasitología , Masculino , Ninfa , Prevalencia , Factores Sexuales , Razón de Masculinidad , Especificidad de la Especie
12.
Mol Ecol ; 23(4): 947-53, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24215498

RESUMEN

Haemosporidian parasites, which require both a vertebrate and invertebrate host, are most commonly studied in the life stages occurring in the vertebrate. However, aspects of the vector's behaviour and biology can have profound effects on parasite dynamics. We explored the effects of a haemosporidian parasite, Haemoproteus iwa, on a hippoboscid fly vector, Olfersia spinifera. Olfersia spinifera is an obligate ectoparasite of the great frigatebird, Fregata minor, living among bird feathers for all of its adult life. This study examined the movements of O. spinifera between great frigatebird hosts. Movement, or host switching, was inferred by identifying host (frigatebird) microsatellite genotypes from fly bloodmeals that did not match the host from which the fly was collected. Such host switches were analysed using a logistic regression model, and the best-fit model included the H. iwa infection status of the fly and the bird host sex. Uninfected flies were more likely to have a bird genotype in their bloodmeal that was different from their current host's genotype (i.e. to have switched hosts) than infected flies. Flies collected from female birds were more likely to have switched hosts than those collected on males. Reduced movement of infected flies suggests that there may be a cost of parasitism for the fly. The effect of host sex is probably driven by differences in the sex ratio of bird hosts available to moving flies.


Asunto(s)
Enfermedades de las Aves/transmisión , Aves/parasitología , Dípteros/genética , Haemosporida , Animales , Enfermedades de las Aves/parasitología , Aves/genética , Dípteros/parasitología , Infestaciones Ectoparasitarias/transmisión , Femenino , Genotipo , Modelos Logísticos , Masculino , Repeticiones de Microsatélite , Modelos Genéticos
13.
Parasitology ; 140(9): 1061-9, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23659306

RESUMEN

Parasites often have shorter generation times and, in some cases, faster mutation rates than their hosts, which can lead to greater population differentiation in the parasite relative to the host. Here we present a population genetic study of two ectoparasitic flies, Olfersia spinifera and Olfersia aenescens compared with their respective bird hosts, great frigatebirds (Fregata minor) and Nazca boobies (Sula granti). Olfersia spinifera is the vector of a haemosporidian parasite, Haemoproteus iwa, which infects frigatebirds throughout their range. Interestingly, there is no genetic differentiation in the haemosporidian parasite across this range despite strong genetic differentiation between Galapagos frigatebirds and their non-Galapagos conspecifics. It is possible that the broad distribution of this one H. iwa lineage could be facilitated by movement of infected O. spinifera. Therefore, we predicted more gene flow in both fly species compared with the bird hosts. Mitochondrial DNA sequence data from three genes per species indicated that despite marked differences in the genetic structure of the bird hosts, gene flow was very high in both fly species. A likely explanation involves non-breeding movements of hosts, including movement of juveniles, and movement by adult birds whose breeding attempt has failed, although we cannot rule out the possibility that closely related host species may be involved.


Asunto(s)
Enfermedades de las Aves/parasitología , Dípteros/genética , Infestaciones Ectoparasitarias/veterinaria , Interacciones Huésped-Parásitos/genética , Insectos Vectores/genética , Animales , Secuencia de Bases , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Aves , ADN Mitocondrial/química , ADN Mitocondrial/genética , Dípteros/parasitología , Infestaciones Ectoparasitarias/epidemiología , Infestaciones Ectoparasitarias/parasitología , Ecuador/epidemiología , Flujo Génico , Estructuras Genéticas , Genética de Población , Haemosporida/genética , Haemosporida/fisiología , Haplotipos , Humanos , Insectos Vectores/parasitología , Datos de Secuencia Molecular , Infecciones Protozoarias en Animales/parasitología , Infecciones Protozoarias en Animales/transmisión , Análisis de Secuencia de ADN/veterinaria
14.
Ecol Evol ; 2(11): 2775-87, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23170212

RESUMEN

Seabirds are considered highly mobile, able to fly great distances with few apparent barriers to dispersal. However, it is often the case that seabird populations exhibit strong population genetic structure despite their potential vagility. Here we show that Galapagos Nazca booby (Sula granti) populations are substantially differentiated, even within the small geographic scale of this archipelago. On the other hand, Galapagos great frigatebird (Fregata minor) populations do not show any genetic structure. We characterized the genetic differentiation by sampling five colonies of both species in the Galapagos archipelago and analyzing eight microsatellite loci and three mitochondrial genes. Using an F-statistic approach on the multilocus data, we found significant differentiation between nearly all island pairs of Nazca booby populations and a Bayesian clustering analysis provided support for three distinct genetic clusters. Mitochondrial DNA showed less differentiation of Nazca booby colonies; only Nazca boobies from the island of Darwin were significantly differentiated from individuals throughout the rest of the archipelago. Great frigatebird populations showed little to no evidence for genetic differentiation at the same scale. Only two island pairs (Darwin - Wolf, N. Seymour - Wolf) were significantly differentiated using the multilocus data, and only two island pairs had statistically significant φ(ST) values (N. Seymour - Darwin, N. Seymour - Wolf) according to the mitochondrial data. There was no significant pattern of isolation by distance for either species calculated using both markers. Seven of the ten Nazca booby migration rates calculated between island pairs were in the south or southeast to north or northwest direction. The population differentiation found among Galapagos Nazca booby colonies, but not great frigatebird colonies, is most likely due to differences in natal and breeding philopatry.

15.
J Parasitol ; 98(5): 924-9, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22509857

RESUMEN

The prevalence of hemosporidian parasites varies among different host species, geographic locations, habitats, and host life histories, and yet we do not have a firm understanding of the ultimate causes of the variation. Seabirds are not typically found infected with hemosporidian parasites; however, frigatebird species have been repeatedly documented with Hemoproteus spp. infections. Hemoproteus iwa in Galapagos great frigatebirds (Fregata minor) is vectored by a hippoboscid fly, Olfersia spinifera , an obligate ectoparasite of the bird host. Five populations of Galapagos great frigatebirds, and flies collected from the birds, were sampled and tested for H. iwa . Prevalence did not differ across 4 yr or between 5 islands, but males were found to have a significantly higher prevalence of infection than did females. Additionally, juveniles were more likely to be infected than were adults and chicks. Because the invertebrate vector is an obligate parasite, we were able to estimate prevalence in the vector as well as in the particular host upon which it fed, a task that is impossible, or nearly impossible, in hemosporidian parasites vectored by midges or mosquitoes. We tested the correlation between the infection status of the bird host and the infection status of the fly collected from the bird. More often than not the 2 were correlated, but some mismatches were found. Using the occurrence of infected flies on uninfected birds (12/99) as a proxy for transmission potential, we can estimate the transmission rate to be between 5 and 20% (95% confidence intervals) among individual vertebrate hosts.


Asunto(s)
Enfermedades de las Aves/parasitología , Dípteros/parasitología , Haemosporida/aislamiento & purificación , Insectos Vectores/parasitología , Infecciones Protozoarias en Animales/epidemiología , Distribución por Edad , Animales , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , Aves , ADN Protozoario/química , ADN Protozoario/aislamiento & purificación , Dípteros/clasificación , Infestaciones Ectoparasitarias/complicaciones , Infestaciones Ectoparasitarias/parasitología , Infestaciones Ectoparasitarias/veterinaria , Ecuador/epidemiología , Femenino , Insectos Vectores/clasificación , Masculino , Reacción en Cadena de la Polimerasa/veterinaria , Prevalencia , Infecciones Protozoarias en Animales/parasitología , Infecciones Protozoarias en Animales/transmisión , Distribución por Sexo
16.
J Parasitol ; 98(4): 847-54, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22324933

RESUMEN

Haemoproteus (Haemoproteus) jenniae n. sp. (Haemosporida: Haemoproteidae) is described from a Galapagos bird, the swallow-tailed gull Creagrus furcatus (Charadriiformes, Laridae), based on the morphology of its blood stages and segments of the mitochondrial cytochrome b (cyt b) gene. The most distinctive features of H. jenniae development are the circumnuclear gametocytes occupying all cytoplasmic space in infected erythrocytes and the presence of advanced, growing gametocytes in which the pellicle is closely appressed to the erythrocyte envelope but does not extend to the erythrocyte nucleus. This parasite is distinguishable from Haemoproteus larae, which produces similar gametocytes and parasitizes closely related species of Laridae. Haemoproteus jenniae can be distinguished from H. larae primarily due to (1) the predominantly amoeboid outline of young gametocytes, (2) diffuse macrogametocyte nuclei which do not possess distinguishable nucleoli, (3) the consistent size and shape of pigment granules, and (4) the absence of rod-like pigment granules from gametocytes. Additionally, fully-grown gametocytes of H. jenniae cause both the marked hypertrophy of infected erythrocytes in width and the rounding up of the host cells, which is not the case in H. larae. Phylogenetic analyses identified the DNA lineages that are associated with H. jenniae and showed that this parasite is more closely related to the hippoboscid-transmitted (Hippoboscidae) species than to the Culicoides spp.-transmitted (Ceratopogonidae) species of avian hemoproteids. Genetic divergence between morphologically well-differentiated H. jenniae and the hippoboscid-transmitted Haemoproteus iwa, the closely related parasite of frigatebirds (Fregatidae, Pelecaniformes), is only 0.6%; cyt b sequences of these parasites differ only by 1 base pair. This is the first example of such a small genetic difference in the cyt b gene between species of the subgenus Haemoproteus. In a segment of caseinolytic protease C gene (ClpC), genetic divergence is 4% between H. jenniae and H. iwa. This study corroborates the conclusion that hippoboscid-transmitted Haemoproteus parasites infect not only Columbiformes birds but also infect marine birds belonging to Pelecaniformes and Charadriiformes. We conclude that the vertebrate host range should be used cautiously in identification of subgenera of avian Haemoproteus species and that the phylogenies based on the cyt b gene provide evidence for determining the subgeneric position of avian hemoproteids.


Asunto(s)
Enfermedades de las Aves/parasitología , Charadriiformes/parasitología , Dípteros/parasitología , Haemosporida/clasificación , Insectos Vectores/parasitología , Infecciones Protozoarias en Animales/parasitología , Animales , Secuencia de Bases , Teorema de Bayes , Enfermedades de las Aves/epidemiología , Enfermedades de las Aves/transmisión , ADN Protozoario/química , Ecuador/epidemiología , Eritrocitos/parasitología , Variación Genética , Haemosporida/genética , Haemosporida/fisiología , Funciones de Verosimilitud , Datos de Secuencia Molecular , Filogenia , Prevalencia , Infecciones Protozoarias en Animales/epidemiología , Infecciones Protozoarias en Animales/transmisión , Caracteres Sexuales
17.
Int J Parasitol ; 41(10): 1019-27, 2011 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-21683082

RESUMEN

Haemosporidian parasites are widely distributed and common parasites of birds, and the application of molecular techniques has revealed remarkable diversity among their lineages. Four haemosporidian genera infect avian hosts (Plasmodium, Haemoproteus, Leucocytozoon and Fallisia), and Haemoproteus is split into two sub-genera based on morphological evidence and phylogenetic support for two divergent sister clades. One clade (Haemoproteus (Parahaemoproteus)) contains parasites developing in birds belonging to several different orders, except pigeons and doves (Columbiformes), while the other (Haemoproteus (Haemoproteus)) has previously been shown to only infect dove hosts. Here we provide molecular and morphological identification of Haemoproteus parasites from several seabird species that are closely related to those found in dove hosts. We also document a deeply divergent clade with two haemosporidian lineages recovered primarily from frigatebirds (Fregatidae, Pelecaniformes) that is sister to the hippoboscid-(Hippoboscidae) transmitted dove parasites. One of the lineages in this new clade of parasites belongs to Haemoproteus iwa and is distributed in two species of frigatebird (Fregata) hosts from Hawaii, the Galapagos Islands, the eastern Pacific and throughout the Caribbean Basin. Haemosporidian parasites are often considered rare in seabirds due in part to the lack or low activity of some dipteran vectors (e.g., mosquitos, biting midges) in marine and coastal environments; however, we show that H. iwa is prevalent and is very likely vectored among frigatebirds by hippoboscid flies which are abundant on frigatebirds and other seabirds. This study supports the existence of two sister clades of avian Haemoproteus in accord with the subgeneric classification of avian hemoproteids. Description of H. iwa from Galapagos Fregata minor is given based on morphology of blood stages and segments of the mitochondrial cytochrome b gene, which can be used for identification. This study shows that hippoboscid flies warrant more attention as vectors of avian Haemoproteus spp., particularly in marine and coastal environments.


Asunto(s)
Enfermedades de las Aves/parasitología , Haemosporida/clasificación , Haemosporida/aislamiento & purificación , Infecciones Protozoarias en Animales/parasitología , Animales , Enfermedades de las Aves/transmisión , Aves , Ceratopogonidae/parasitología , Análisis por Conglomerados , Citocromos b/genética , ADN Protozoario/química , ADN Protozoario/genética , Vectores de Enfermedades , Haemosporida/genética , Datos de Secuencia Molecular , Filogeografía , Infecciones Protozoarias en Animales/transmisión , Proteínas Protozoarias/genética , Análisis de Secuencia de ADN
18.
Proc Biol Sci ; 278(1707): 817-25, 2011 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-20861041

RESUMEN

The Galapagos Islands are renowned for their high degree of endemism. Marine taxa inhabiting the archipelago might be expected to be an exception, because of their utilization of pelagic habitats-the dispersal barrier for terrestrial taxa-as foraging grounds. Magnificent frigatebirds (Fregata magnificens) have a highly vagile lifestyle and wide geographical distribution around the South and Central American coasts. Given the potentially high levels of gene flow among populations, the species provides a good test of the effectiveness of the Galapagos ecosystem in isolating populations of highly dispersive marine species. We studied patterns of genetic (mitochondrial DNA, microsatellites and nuclear introns) and morphological variation across the distribution of magnificent frigatebirds. Concordant with predictions from life-history traits, we found signatures of extensive gene flow over most of the range, even across the Isthmus of Panama, which is a major barrier to gene flow in other tropical seabirds. In contrast, individuals from the Galapagos were strongly differentiated from all conspecifics, and have probably been isolated for several hundred thousand years. Our finding is a powerful testimony to the evolutionary uniqueness of the taxa inhabiting the Galapagos archipelago and its associated marine ecosystems.


Asunto(s)
Aves/genética , Ambiente , Aislamiento Social , Migración Animal , Animales , Aves/anatomía & histología , ADN Mitocondrial/química , Ecuador , Flujo Génico , Genotipo , Intrones , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Dinámica Poblacional , Análisis de Secuencia de ADN
19.
J Parasitol ; 96(4): 783-92, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20486741

RESUMEN

Haemoproteus (Haemoproteus) multipigmentatus n. sp. (Haemosporida, Haemoproteidae) was found in the endemic Galapagos dove Zenaida galapagoensis . It is described based on the morphology of its blood stages and segments of the mitochondrial cytochrome b gene, which can be used for molecular identification and diagnosis of this species. Haemoproteus multipigmentatus can be readily distinguished from all species of hemoproteids of the subgenus Haemoproteus , primarily due to numerous (approximately 40 on average) small pigment granules in its mature gametocytes. Illustrations of blood stages of the new species are given, and phylogenetic analysis identifies DNA lineages closely related to this parasite, which is prevalent in the Galapagos dove and also has been recorded in other species of Columbiformes in Mexico, Guatemala, and Peru, and so seems to be widespread in countries in the New World with warm climates. Cytochrome b lineages of H. multipigmentatus cluster with hippoboscid-transmitted lineages of Haemoproteus columbae . The same lineages of H. multipigmentatus were recorded in thoraxes of the hippoboscid fly Microlynchia galapagoensis , which likely is a natural vector of this parasite in Galapagos. Because different primers might amplify different parasites if they have a better match during a simultaneous infection, it is important that researchers standardize the genetic marker of choice for molecular typing of hemosporidian species. This study shows that more discussion among researchers is needed to clearly establish the sequence length and number of genes used for identification of hemosporidian parasites at different taxonomic levels. We point to the need of using both morphology and gene markers in studies of hemosporidian parasites, particularly in wildlife.


Asunto(s)
Enfermedades de las Aves/parasitología , Columbidae/parasitología , Haemosporida/clasificación , Infecciones Protozoarias en Animales/parasitología , Animales , Secuencia de Bases , Teorema de Bayes , Enfermedades de las Aves/epidemiología , Citocromos b/genética , ADN Protozoario/química , Dípteros/parasitología , Ecuador/epidemiología , Haemosporida/genética , Haemosporida/ultraestructura , Insectos Vectores/parasitología , Datos de Secuencia Molecular , Filogenia , Prevalencia , Infecciones Protozoarias en Animales/epidemiología
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