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1.
Mol Ecol ; 29(22): 4457-4472, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32974981

RESUMEN

South American dry forests have a complex and poorly understood biogeographic history. Based on the fragmented distribution of many Neotropical dry forest species, it has been suggested that this biome was more widely distributed and contiguous under drier climate conditions in the Pleistocene. To test this scenario, known as the Pleistocene Arc Hypothesis, we studied the phylogeography of the Rufous-fronted Thornbird (Phacellodomus rufifrons), a widespread dry forest bird with a disjunct distribution closely matching that of the biome itself. We sequenced mtDNA and used ddRADseq to sample 7,167 genome-wide single-nucleotide polymorphisms from 74 P. rufifrons individuals across its range. We found low genetic differentiation over two prominent geographic breaks - particularly across a 1,000 km gap between populations in Bolivia and Northern Peru. Using demographic analyses of the joint site frequency spectrum, we found evidence of recent divergence without subsequent gene flow across those breaks. By contrast, parapatric morphologically distinct populations in northeastern Brazil show high genetic divergence with evidence of recent gene flow. These results, in combination with our paleoclimate species distribution modelling, support the idea that currently disjunct patches of dry forest were more connected in the recent past, probably during the Middle and Late Pleistocene. This notion fits the major predictions of the Pleistocene Arc Hypothesis and illustrates the importance of comprehensive genomic and geographic sampling for examining biogeographic and evolutionary questions in complex ecosystems like Neotropical dry forests.


Asunto(s)
Aves , Ecosistema , Polimorfismo de Nucleótido Simple , Animales , Aves/genética , Bolivia , Brasil , Bosques , Variación Genética , Perú , Filogenia , Filogeografía , Polimorfismo de Nucleótido Simple/genética
2.
PeerJ ; 8: e8956, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32341898

RESUMEN

Synthetic molecules that mimic the function of natural enzymes or molecules have untapped potential for use in the next generation of drugs. Cyclic compounds that contain aromatic rings are macrocyclic cyclophanes, and when they coordinate iron ions are of particular interest due to their antioxidant and biomimetic properties. However, little is known about the molecular responses at the cellular level. This study aims to evaluate the changes in immune gene expression in human cells exposed to the cyclophanes Fe2PO and Fe2PC. Confluent human embryonic kidney cells were exposed to either the cyclophane Fe2PO or Fe2PC before extraction of RNA. The expression of a panel of innate and adaptive immune genes was analyzed by quantitative real-time PCR. Evidence was found for an inflammatory response elicited by the cyclophane exposures. After 8 h of exposure, the cells increased the relative expression of inflammatory mediators such as interleukin 1; IRAK, which transduces signals between interleukin 1 receptors and the NFκB pathway; and the LPS pattern recognition receptor CD14. After 24 h of exposure, regulatory genes begin to counter the inflammation, as some genes involved in oxidative stress, apoptosis and non-inflammatory immune responses come into play. Both Fe2PO and Fe2PC induced similar immunogenetic changes in transcription profiles, but equal molar doses of Fe2PC resulted in more robust responses. These data suggest that further work in whole animal models may provide more insights into the extent of systemic physiological changes induced by these cyclophanes.

3.
Microb Genom ; 4(8)2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30052174

RESUMEN

Salmonella enterica serovar Montevideo has been linked to recent foodborne illness outbreaks resulting from contamination of products such as fruits, vegetables, seeds and spices. Studies have shown that Montevideo also is frequently associated with healthy cattle and can be isolated from ground beef, yet human salmonellosis outbreaks of Montevideo associated with ground beef contamination are rare. This disparity fuelled our interest in characterizing the genomic differences between Montevideo strains isolated from healthy cattle and beef products, and those isolated from human patients and outbreak sources. To that end, we sequenced 13 Montevideo strains to completion, producing high-quality genome assemblies of isolates from human patients (n=8) or from healthy cattle at slaughter (n=5). Comparative analysis of sequence data from this study and publicly available sequences (n=72) shows that Montevideo falls into four previously established clades, differentially occupied by cattle and human strains. The results of these analyses reveal differences in metabolic islands, environmental adhesion determinants and virulence factors within each clade, and suggest explanations for the infrequent association between bovine isolates and human illnesses.


Asunto(s)
Genómica , Salmonella enterica/genética , Salmonella enterica/patogenicidad , Serogrupo , Factores de Virulencia/genética , Animales , Bovinos , Brotes de Enfermedades , Ecosistema , Humanos , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/genética , Intoxicación Alimentaria por Salmonella/microbiología , Salmonella enterica/aislamiento & purificación , Especificidad de la Especie , Uruguay/epidemiología
4.
BMC Evol Biol ; 17(1): 210, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28863778

RESUMEN

BACKGROUND: Pleistocene climatic fluctuations are known to be an engine of biotic diversification at higher latitudes, but their impact on highly diverse tropical areas such as the Andes remains less well-documented. Specifically, while periods of global cooling may have led to fragmentation and differentiation at colder latitudes, they may - at the same time - have led to connectivity among insular patches of montane tropical habitat with unknown consequences on diversification. In the present study we utilized ~5.5 kb of DNA sequence data from eight nuclear loci and one mitochondrial gene alongside diagnostic morphological and bioacoustic markers to test the effects of Pleistocene climatic fluctuations on diversification in a complex of Andean tyrant-flycatchers of the genus Elaenia. RESULTS: Population genetic and phylogenetic approaches coupled with coalescent simulations demonstrated disparate levels of gene flow between the taxon chilensis and two parapatric Elaenia taxa predominantly during the last glacial period but not thereafter, possibly on account of downward shifts of montane forest habitat linking the populations of adjacent ridges. Additionally, morphological and bioacoustic analyses revealed a distinct pattern of character displacement in coloration and vocal traits between the two sympatric taxa albiceps and pallatangae, which were characterized by a lack of gene flow. CONCLUSION: Our study demonstrates that global periods of cooling are likely to have facilitated gene flow among Andean montane Elaenia flycatchers that are more isolated from one another during warm interglacial periods such as the present era. We also identify a hitherto overlooked case of plumage and vocal character displacement, underpinning the complexities of gene flow patterns caused by Pleistocene climate change across the Andes.


Asunto(s)
Flujo Génico , Pájaros Cantores/genética , Animales , Biodiversidad , Cambio Climático , Ecosistema , Especiación Genética , Filogenia , Recombinación Genética , América del Sur
5.
Mol Ecol ; 26(17): 4483-4496, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28664998

RESUMEN

Identifying the genetic basis of phenotypic variation and its relationship with the environment is key to understanding how local adaptations evolve. Such patterns are especially interesting among populations distributed across habitat gradients, where genetic structure can be driven by isolation by distance (IBD) and/or isolation by environment (IBE). Here, we used variation in ~1,600 high-quality SNPs derived from paired-end sequencing of double-digest restriction site-associated DNA (ddRAD-Seq) to test hypotheses related to IBD and IBE in the Yucatan jay (Cyanocorax yucatanicus), a tropical bird endemic to the Yucatán Peninsula. This peninsula is characterized by a precipitation and vegetation gradient-from dry to evergreen tropical forests-that is associated with morphological variation in this species. We found a moderate level of nucleotide diversity (π = .008) and little evidence for genetic differentiation among vegetation types. Analyses of neutral and putatively adaptive SNPs (identified by complementary genome-scan approaches) indicate that IBD is the most reliable explanation to account for frequency distribution of the former, while IBE has to be invoked to explain those of the later. These results suggest that selective factors acting along a vegetation gradient can promote local adaptation in the presence of gene flow in a vagile, nonmigratory and geographically restricted species. The putative candidate SNPs identified here are located within or linked to a variety of genes that represent ideal targets for future genomic surveys.


Asunto(s)
Adaptación Fisiológica/genética , Ecosistema , Genética de Población , Passeriformes/genética , Animales , Cruzamiento , Flujo Génico , Variación Genética , Genómica , México , Polimorfismo de Nucleótido Simple
7.
Ecol Evol ; 6(20): 7475-7489, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-28725414

RESUMEN

Identifying genomic signatures of natural selection can be challenging against a background of demographic changes such as bottlenecks and population expansions. Here, we disentangle the effects of demography from selection in the House Finch (Haemorhous mexicanus) using samples collected before and after a pathogen-induced selection event. Using ddRADseq, we genotyped over 18,000 SNPs across the genome in native pre-epizootic western US birds, introduced birds from Hawaii and the eastern United States, post-epizootic eastern birds, and western birds sampled across a similar time span. We found 14% and 7% reductions in nucleotide diversity, respectively, in Hawaiian and pre-epizootic eastern birds relative to pre-epizootic western birds, as well as elevated levels of linkage disequilibrium and other signatures of founder events. Despite finding numerous significant frequency shifts (outlier loci) between pre-epizootic native and introduced populations, we found no signal of reduced genetic diversity, elevated linkage disequilibrium, or outlier loci as a result of the epizootic. Simulations demonstrate that the proportion of outliers associated with founder events could be explained by genetic drift. This rare view of genetic evolution across time in an invasive species provides direct evidence that demographic shifts like founder events have genetic consequences more widespread across the genome than natural selection.

8.
Arch Environ Occup Health ; 71(6): 338-346, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26666397

RESUMEN

Exposure to As, Cd, Pb, and U among older Hispanic adults residing in underserved communities in southern New Mexico was investigated. Personal information was obtained by standardized interview from 188 adults aged 40-85 years. Urinary metal concentrations were measured and compared to results from the National Health and Nutritional Examination Survey (NHANES). Urinary As and U in study participants significantly (p < .05) exceeded NHANES reference values. Elevated urinary As concentration was significantly associated with older age, Latin American birthplace, clinic site, private-well drinking water, higher self-rated health, and diabetes. Higher urinary Cd was significantly associated with older age, clinic site, female sex, agricultural work, and current cigarette smoking. No personal characteristics were significantly associated with urinary Pb or U. Our results suggest elevated levels of As and U in this population.


Asunto(s)
Exposición a Riesgos Ambientales , Contaminantes Ambientales/orina , Metales Pesados/orina , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Monitoreo del Ambiente , Femenino , Humanos , Masculino , Persona de Mediana Edad , New Mexico , Encuestas Nutricionales , Factores de Riesgo
9.
BMC Genomics ; 15: 305, 2014 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-24758272

RESUMEN

BACKGROUND: With its plumage color dimorphism and unique history in North America, including a recent population expansion and an epizootic of Mycoplasma gallisepticum (MG), the house finch (Haemorhous mexicanus) is a model species for studying sexual selection, plumage coloration and host-parasite interactions. As part of our ongoing efforts to make available genomic resources for this species, here we report a transcriptome assembly derived from genes expressed in spleen. RESULTS: We characterize transcriptomes from two populations with different histories of demography and disease exposure: a recently founded population in the eastern US that has been exposed to MG for over a decade and a native population from the western range that has never been exposed to MG. We utilize this resource to quantify conservation in gene expression in passerine birds over approximately 50 MY by comparing splenic expression profiles for 9,646 house finch transcripts and those from zebra finch and find that less than half of all genes expressed in spleen in either species are expressed in both species. Comparative gene annotations from several vertebrate species suggest that the house finch transcriptomes contain ~15 genes not yet found in previously sequenced vertebrate genomes. The house finch transcriptomes harbour ~85,000 SNPs, ~20,000 of which are non-synonymous. Although not yet validated by biological or technical replication, we identify a set of genes exhibiting differences between populations in gene expression (n = 182; 2% of all transcripts), allele frequencies (76 FST ouliers) and alternative splicing as well as genes with several fixed non-synonymous substitutions; this set includes genes with functions related to double-strand break repair and immune response. CONCLUSIONS: The two house finch spleen transcriptome profiles will add to the increasing data on genome and transcriptome sequence information from natural populations. Differences in splenic expression between house finch and zebra finch imply either significant evolutionary turnover of splenic expression patterns or different physiological states of the individuals examined. The transcriptome resource will enhance the potential to annotate an eventual house finch genome, and the set of gene-based high-quality SNPs will help clarify the genetic underpinnings of host-pathogen interactions and sexual selection.


Asunto(s)
Empalme Alternativo , Pinzones/genética , Variación Genética , Transcriptoma , Animales , Polimorfismo de Nucleótido Simple , ARN Mensajero/genética , Especificidad de la Especie
10.
Mol Ecol ; 22(15): 3996-4013, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23786305

RESUMEN

The Atlantic Forest (AF) harbours one of the most diverse vertebrate faunas of the world, including 199 endemic species of birds. Understanding the evolutionary processes behind such diversity has become the focus of many recent, primarily single locus, phylogeographic studies. These studies suggest that isolation in forest refugia may have been a major mechanism promoting diversification, although there is also support for a role of riverine and geotectonic barriers, two sets of hypotheses that can best be tested with multilocus data. Here we combined multilocus data (one mtDNA marker and eight anonymous nuclear loci) from two species of parapatric antbirds, Myrmeciza loricata and M. squamosa, and Approximate Bayesian Computation to determine whether isolation in refugia explains current patterns of genetic variation and their status as independent evolutionary units. Patterns of population structure, differences in intraspecific levels of divergence and coalescent estimates of historical demography fit the predictions of a recently proposed model of refuge isolation in which climatic stability in the northern AF sustains higher diversity and demographic stability than in the southern AF. However, a pre-Pleistocene divergence associated with their abutting range limits in a region of past tectonic activity also suggests a role for rivers or geotectonic barriers. Little or no gene flow between these species suggests the development of reproductive barriers or competitive exclusion. Our results suggests that limited marker sampling in recent AF studies may compromise estimates of divergence times and historical demography, and we discuss the effects of such sampling on this and other studies.


Asunto(s)
Biodiversidad , ADN Mitocondrial/genética , Variación Genética , Passeriformes/genética , Animales , Ecosistema , Evolución Molecular , Marcadores Genéticos/genética , Haplotipos/genética , Filogeografía , Aislamiento Reproductivo , Análisis de Secuencia de ADN
11.
Ecol Evol ; 3(3): 655-66, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23532859

RESUMEN

Characterization of the genetic basis of fitness traits in natural populations is important for understanding how organisms adapt to the changing environment and to novel events, such as epizootics. However, candidate fitness-influencing loci, such as regulatory regions, are usually unavailable in nonmodel species. Here, we analyze sequence data from targeted resequencing of the cis-regulatory regions of three candidate genes for disease resistance (CD74, HSP90α, and LCP1) in populations of the house finch (Carpodacus mexicanus) historically exposed (Alabama) and naïve (Arizona) to Mycoplasma gallisepticum. Our study, the first to quantify variation in regulatory regions in wild birds, reveals that the upstream regions of CD74 and HSP90α are GC-rich, with the former exhibiting unusually low sequence variation for this species. We identified two SNPs, located in a GC-rich region immediately upstream of an inferred promoter site in the gene HSP90α, that were significantly associated with Mycoplasma pathogen load in the two populations. The SNPs are closely linked and situated in potential regulatory sequences: one in a binding site for the transcription factor nuclear NFYα and the other in a dinucleotide microsatellite ((GC)6). The genotype associated with pathogen load in the putative NFYα binding site was significantly overrepresented in the Alabama birds. However, we did not see strong effects of selection at this SNP, perhaps because selection has acted on standing genetic variation over an extremely short time in a highly recombining region. Our study is a useful starting point to explore functional relationships between sequence polymorphisms, gene expression, and phenotypic traits, such as pathogen resistance that affect fitness in the wild.

12.
Mol Biol Evol ; 30(5): 1046-50, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23429858

RESUMEN

Identifying genes influenced by natural selection can provide information about lineage-specific adaptations, and transcriptomes generated by next-generation sequencing are a useful resource for identifying such genes. Here, we utilize a spleen transcriptome for the house finch (Haemorhous mexicanus), an emerging model for sexual selection and disease ecology, together with previously sequenced avian genomes (chicken, turkey, and zebra finch), to investigate lineage-specific adaptations within birds. An analysis of 4,398 orthologous genes revealed a significantly higher ratio of nonsynonymous to synonymous substitutions and significantly higher GC content in passerines than in galliforms, an observation deviating from strictly neutral expectations but consistent with an effect of biased gene conversion on the evolutionary rate in passerines. These data also showed that genes exhibiting signs of positive selection and fast evolution in passerines have functional roles related to fat metabolism, neurodevelopment, and ion binding.


Asunto(s)
Evolución Molecular , Pinzones/genética , Bazo/metabolismo , Transcriptoma/genética , Animales , Pinzones/clasificación
13.
J Am Water Resour Assoc ; 47(5): 1061-1086, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22457582

RESUMEN

SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were developed to estimate nutrient inputs [total nitrogen (TN) and total phosphorus (TP)] to the northwestern part of the Gulf of Mexico from streams in the South-Central United States (U.S.). This area included drainages of the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf hydrologic regions. The models were standardized to reflect nutrient sources and stream conditions during 2002. Model predictions of nutrient loads (mass per time) and yields (mass per area per time) generally were greatest in streams in the eastern part of the region and along reaches near the Texas and Louisiana shoreline. The Mississippi River and Atchafalaya River watersheds, which drain nearly two-thirds of the conterminous U.S., delivered the largest nutrient loads to the Gulf of Mexico, as expected. However, the three largest delivered TN yields were from the Trinity River/Galveston Bay, Calcasieu River, and Aransas River watersheds, while the three largest delivered TP yields were from the Calcasieu River, Mermentau River, and Trinity River/Galveston Bay watersheds. Model output indicated that the three largest sources of nitrogen from the region were atmospheric deposition (42%), commercial fertilizer (20%), and livestock manure (unconfined, 17%). The three largest sources of phosphorus were commercial fertilizer (28%), urban runoff (23%), and livestock manure (confined and unconfined, 23%).

14.
Evolution ; 61(2): 346-67, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17348945

RESUMEN

The Andean uplift played important roles in the historical diversification of Neotropical organisms, both by producing new high-elevation habitats that could be colonized and by isolating organisms on either side of the mountains. Here, we present a molecular phylogeny of Thamnophlius antshrikes, a clade of 30 species whose collective distribution spans nearly the entirety of lowland habitats in tropical South America, the eastern slope foothills of the Andes, and the tepuis of northern South America. Our goal was to examine the role of the Andes in the diversification of lowland and foothill species. Using parsimony and Bayesian ancestral state reconstructions of a three-state distribution character (lowland-restricted, lowland-to-highland, highland-restricted), we found that the Andes were colonized twice independently and the tepuis once from lowland-restricted ancestors. Over the entire evolutionary history of Thamnophilus, the highest transition rates were between highland-restricted and lowland-to-highland distributions, with extremely low rates into and out of lowland-restricted distributions. This pattern suggests lowland-restricted distributions are limited not by physiological constraints, but by other forces, such as competition. These results highlight the need for additional comparative studies in elucidating processes associated with the colonization of high-elevation habitats and the differentiation of populations within them.


Asunto(s)
Evolución Biológica , Ecosistema , Geografía , Passeriformes/genética , Passeriformes/fisiología , Animales , Teorema de Bayes , Demografía , Variación Genética , Passeriformes/clasificación , América del Sur
15.
Genetica ; 129(2): 217-25, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17103248

RESUMEN

We present molecular data documenting how introduction to the eastern United States and an epizootic involving a bacterial pathogen has affected the genetic diversity of house finches, a cardueline songbird. Population bottlenecks during introduction can cause loss of genetic variation and may negatively affect a population's ability to adapt to novel stressors such as disease. Although a genome-wide survey using Amplified Fragment Length Polymorphism (AFLP) markers suggests little loss of genetic diversity in introduced populations, an epizootic of bacterial Mycoplasma has nonetheless caused dramatic declines in the eastern US population. Sequence analysis of a candidate gene for pathogen resistance in the Major Histocompatibity Complex (MHC) in pre- and post-epizootic population samples reveals allele frequency shifts since introduction of the pathogen, but similar shifts are also observed in control populations not exposed to the bacteria, and in a neutral non-coding locus. Expression studies using a novel subtractive hybridization approach indicate decreased expression of the class II MHC locus upon exposure to Mycoplasma, a pattern also seen in MHC class I loci in mice infected with cytomegalovirus and consistent with manipulation of the finch immune system by Mycoplasma. These results will be further expanded using experimental studies as well as examination of evolution of the pathogen genome itself.


Asunto(s)
Evolución Biológica , Pinzones/genética , Pinzones/microbiología , Mycoplasma gallisepticum/patogenicidad , Adaptación Fisiológica , Alelos , Animales , Secuencia de Bases , Conducta Animal , Enfermedades de las Aves/genética , Enfermedades de las Aves/inmunología , Enfermedades de las Aves/microbiología , ADN Complementario/genética , Ecosistema , Femenino , Pinzones/inmunología , Pinzones/fisiología , Expresión Génica , Frecuencia de los Genes , Variación Genética , Complejo Mayor de Histocompatibilidad , Masculino , Estados Unidos
16.
Biol Lett ; 2(3): 466-9, 2006 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-17148432

RESUMEN

We used ancient DNA analysis of seven museum specimens of the endangered North American ivory-billed woodpecker (Campephilus principalis) and three specimens of the species from Cuba to document their degree of differentiation and their relationships to other Campephilus woodpeckers. Analysis of these mtDNA sequences reveals that the Cuban and North American ivory bills, along with the imperial woodpecker (Campephilus imperialis) of Mexico, are a monophyletic group and are roughly equidistant genetically, suggesting each lineage may be a separate species. Application of both internal and external rate calibrations indicates that the three lineages split more than one million years ago, in the Mid-Pleistocene. We thus can exclude the hypothesis that Native Americans introduced North American ivory-billed woodpeckers to Cuba. Our sequences of all three woodpeckers also provide an important DNA barcoding resource for identification of non-invasive samples or remains of these critically endangered and charismatic woodpeckers.


Asunto(s)
Evolución Biológica , Aves/genética , Aves/fisiología , Animales , Teorema de Bayes , Conservación de los Recursos Naturales , Cuba , ADN Mitocondrial/metabolismo , Ecología , Funciones de Verosimilitud , Modelos Biológicos , América del Norte , Filogenia , Reacción en Cadena de la Polimerasa
17.
J Pediatr ; 143(5): 582-6, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14615726

RESUMEN

OBJECTIVES: To test whether iron supplementation affects hematologic, biochemical, and developmental status in term breast-fed infants. STUDY DESIGN: Term breast-fed infants (n=77) were randomly selected to receive either 7.5 mg per day of elemental iron as ferrous sulfate or placebo from 1 to 6 months of age. Investigators and families were unaware of group assignment. Complete blood count and ferritin, red cell superoxide dismutase, catalase, plasma ferric reducing antioxidant power, and zinc and copper levels were analyzed at 1, 3.5, 6, and 12 months of age. Bayley mental and psychomotor developmental indexes (MDI and PDI) and visual acuity (with the use of Teller acuity cards) were assessed from 12 to 18 months of age. Analysis performed by analysis of variance and t tests was by intention to treat. RESULTS: Iron supplementation resulted in higher hemoglobin and mean corpuscular volume at 6 months of age and significantly higher visual acuity and PDI at 13 months of age (100+/-12 vs 93+/-9 [+/-SD]). Treatment and placebo groups did not differ in anthropometric indexes, compliance, biochemical status, or demographic characteristics. CONCLUSIONS: Iron supplementation of breast-fed infants appears safe and might have beneficial hematologic and developmental effects for some infants.


Asunto(s)
Lactancia Materna , Suplementos Dietéticos , Fenómenos Fisiológicos Nutricionales del Lactante , Hierro/administración & dosificación , Anemia Ferropénica/epidemiología , Anemia Ferropénica/prevención & control , Peso Corporal , Lactancia Materna/estadística & datos numéricos , Catalasa/sangre , Cognición/efectos de los fármacos , Cobre/sangre , Método Doble Ciego , Femenino , Ferritinas/sangre , Humanos , Lactante , Recién Nacido , Hierro/farmacología , Masculino , Destreza Motora/efectos de los fármacos , Desempeño Psicomotor/efectos de los fármacos , Superóxido Dismutasa/sangre , Agudeza Visual/efectos de los fármacos , Zinc/sangre
18.
Evolution ; 57(12): 2852-64, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14761063

RESUMEN

The house finch (Carpodacus mexicanus) is a native songbird of western North America that was introduced to the eastern United States and Hawaiian Islands in historic times. As such, it provides an unusually good opportunity to test the ability of molecular markers to recover recent details of a known population history. To investigate this prospect, genetic variation in 172 individuals from 16 populations in the western and eastern United States, southeastern Canada, Hawaiian Islands, and Mexico, as well as genetic variation in the closely related purple finch (Carpodacus purpureus) and Cassin's finch (Carpodacus cassinii) was studied by a semi-automated fluorescence-labeled amplified fragment length polymorphism (AFLP) marker system. A total of 363 markers were generated, of which 258 (71.2%) were polymorphic among species, 166 (61.4%) polymorphic among house finch subspecies, and 157 (60.2%) polymorphic among populations within the frontalis subspecies complex. Heterozygosities and interpopulation divergences revealed by the analysis appeared relatively low at all taxonomic levels, but there are few similar studies in avian populations with which to compare results. Whereas the known population history predicts that both eastern and Hawaiian finches should have been derived from within western populations, tree analysis using both populations and individuals as units suggests weak monophyly of eastern populations and indicates that Hawaiian populations are not clearly derived from California populations. However, the genetic distinctiveness of native and recently founded populations was disclosed by analyses of molecular variance as well as by a model-based assignment approach in which 98%, 94%, and 99% individuals from western, Hawaiian, and eastern regions, respectively, were assigned correctly to their populations without using prior information on population of origin, suggesting that these recent introductions have resulted in detectable differentiation without substantial loss of AFLP diversity. Our results indicate that AFLPs are a useful tool for population genetic and evolutionary studies of birds, particularly as a prelude to finding molecular markers linked to traits subjected to recent adaptive evolution.


Asunto(s)
Variación Genética , Genética de Población , Modelos Genéticos , Pájaros Cantores/genética , Análisis de Varianza , Animales , Frecuencia de los Genes , Geografía , América del Norte , Filogenia , Polimorfismo de Longitud del Fragmento de Restricción
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