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1.
In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.  相似文献   

2.
Most global hotspots of biodiversity and endemism are in montane regions. One explanation is that montane regions have intrinsically higher speciation rates than lowland regions because complex mountain topography and climate variation facilitate genetic isolation among populations. Here, we ask from an intraspecific perspective whether frog species whose haplotypes are connected by topographically/climatically complex regions display strong genetic isolation (greater scaled genetic distances), compared with species whose haplotypes are connected by less complex regions. We analysed published DNA sequences of several frog species from tropical Central and South America for the mitochondrial cob, cox1 and 16S rRNA genes. Pairwise genetic distances among haplotypes within each species were scaled to the geographic distances between each pair of haplotypes. Topographic complexity was positively correlated with scaled genetic distances, and isolation‐by‐resistance was supported only in species from more topographically complex regions. This suggests that heterogeneous topographies increase landscape resistance, which in turn favours the appearance of isolation‐by‐resistance. Moreover, we found that the potential barriers that restrict gene flow within species are more closely related to factors associated with temperature and topography than to precipitation.  相似文献   

3.
4.
The wild common bean (Phaseolus vulgaris) is widely but discontinuously distributed from northern Mexico to northern Argentina on both sides of the Isthmus of Panama. Little is known on how the species has reached its current disjunct distribution. In this research, chloroplast DNA polymorphisms in seven non-coding regions were used to study the history of migration of wild P. vulgaris between Mesoamerica and South America. A penalized likelihood analysis was applied to previously published Leguminosae ITS data to estimate divergence times between P. vulgaris and its sister taxa from Mesoamerica, and divergence times of populations within P. vulgaris. Fourteen chloroplast haplotypes were identified by PCR-RFLP and their geographical associations were studied by means of a Nested Clade Analysis and Mantel Tests. The results suggest that the haplotypes are not randomly distributed but occupy discrete parts of the geographic range of the species. The current distribution of haplotypes may be explained by isolation by distance and by at least two migration events between Mesoamerica and South America: one from Mesoamerica to South America and another one from northern South America to Mesoamerica. Age estimates place the divergence of P. vulgaris from its sister taxa from Mesoamerica at or before 1.3 Ma, and divergence of populations from Ecuador-northern Peru at or before 0.6 Ma. As these ages are taken as minimum divergence times, the influence of past events, such as the closure of the Isthmus of Panama and the final uplift of the Andes, on the migration history and population structure of this species cannot be disregarded.  相似文献   

5.
The identification of Dinophysis species with similar morphology but different toxic (Diarrhetic Shellfish Poisoning, DSP) potential is a crucial task in harmful algae monitoring programmes. The taxonomic assignment of Dinophysis species using molecular markers is a difficult task due to extremely low interspecific variability within their nuclear ribosomal genes and intergenic regions. Mitochondrial cox1 gene has been proposed as a better specific marker for Dinophysis species based on its higher resolution for two morphologically related species (Dinophysis acuminata and Dinophysis ovum) of the “Dinophysis acuminata complex”. In this study, the potential of two mitochondrial genes (mt cox1 and cob) to discriminate among six Dinophysis species (field isolates and cultures) associated with DSP events was explored. Neither mt cox1 nor cob genes provided enough resolution for all species of Dinophysis. The cob gene showed very poor resolution and grouped all Dinophysis spp. in a common clade. In contrast, the cox1 phylogeny distinguished 5 clades in the Dinophysiales – the “acuminata complex”, the “caudata group”, “acuta + norvegica” and Phalacromaspp. However, within the “D. acuminata complex” mtcox1 is so far the unique marker that differentiates D. acuminata from other species: isolates of D. ovum and Dinophysis sacculus had almost identical sequences (only four mismatches), but they were well separated from D. acuminata. D. acuminata and Dinophysis skagii (considered a life cycle stage of the former) showed identical cox1 sequences. Probes towards this gene can be useful in Mediterranean and Western Iberia sites where the co-occurrence of close morphotypes of D. acuminata and D. sacculus pose a problem for monitoring analyses. This is the first report on cultures of D. sacculus and its phylogenetic relation with other species of the D. acuminata complex.  相似文献   

6.
Echinococcus multilocularis (Em) is a zoonotic parasite considered a global emergent pathogen. Recent findings indicate that the parasite is expanding its range in North America and that European-type haplotypes are circulating in western Canada. However, genetic analyses are usually conducted only on a few parasites out of thousands of individuals within each definitive host, likely underestimating the prevalence of less common haplotypes. Moreover, mixed infections with several mtDNA haplotypes in the same host have been reported, but their relative abundance within the host was never estimated. We aimed to 1) estimate the frequency of co-infections of different Em haplotypes in coyotes (Canis latrans) and red foxes (Vulpes vulpes) from western Canada and their relative abundance within the definitive hosts, 2) detect less prevalent haplotypes by sampling a larger proportion of the parasite subpopulation per host, and 3) investigate differences in the distribution of Em haplotypes in these main definitive hosts; foxes and coyotes. We extracted DNA from ~10% of the worm subpopulation per host (20 foxes and 47 coyotes) and used deep amplicon sequencing (NGS technology) on four loci, targeting the most polymorphic regions from the mitochondrial genes cox1 (814 bp), nad1 (344 bp), and cob (387 bp). We detected the presence of mixed infections with multiple Em haplotypes and with different Echinococcus species including Em and E. granulosus s.l. genotypes G8/G10, low intraspecific diversity of Em, and a higher abundance of the European-type haplotypes in both hosts. Our results suggest a population expansion of the European over the North American strain in Alberta and a limited distribution of some European-type haplotypes. Our findings indicate that deep amplicon sequencing represents a valuable tool to characterize Em in multiple hosts, to assess the current distribution and possible origins of the European strain in North America. The potential use of next-generation sequencing technologies is particularly important to understand the patterns of geographic expansion of this parasite.  相似文献   

7.
Plant disjunctions between the temperate regions of the northern and southern hemisphere, commonly called amphitropical or bipolar disjunctions, have been discussed by numerous authors but very little attention has been paid to the occurrence of such disjunctive ranges in the complex thalloids (Marchantiidae). A perusal of the literature revealed 20 species of Marchantiidae with amphitropical ranges, in eight genera (Asterella, Clevea, Corsinia, Cryptomitrium, Oxymitra, Riccia, Riella and Sphaerocarpos). These amphitropical species are distributed in subtropical and Mediterranean regions of the northern and southern hemisphere but not, or rarely, in the tropics. The majority are disjunctive between North America and southern South America and between Eurasia and South Africa. Long-distance dispersal of spores via birds is considered the most plausible natural cause of these amphitropical ranges. About two-third of the species have bisexual spores, which should be advantageous to long-distance dispersal. Extinction due to past climatic fluctuations may also have played a role but fossil evidence is lacking. A few species have attained their amphitropical range by human-mediated introduction: Riccia warnstorfii Limpr. and Sphaerocarpos texanus Austin were presumably introduced in the southern hemisphere whereas S. stipitatus Bisch. ex Lindenb. from Central Chile and South Africa is adventive in the northern hemisphere. The amphitropical ranges exhibited by a number of complex thalloid species are solely based on morphological, floristic and ecological evidence and have not been tested by molecular analysis. Careful comparisons of the northern and southern populations based on an integrated molecular-phylogenetic, morphological-anatomical and chemical approach should be carried out.  相似文献   

8.
9.
Chuquiraga is a genus of 23 species of evergreen shrubs endemic to South America. It is distributed principally along the Andes from Colombia to Chile and Argentina, and it is especially diversified in the Central Andes and in the deserts and semideserts of southern South America. The genus exhibits a wide array of leaf-morphology types and two different head and floral types apparently related to hummingbird and insect pollination. In this study, phylogenetic relationships amongChuquiraga species were resolved by parsimony cladistic analysis using morphological characters. The resulting cladogram was used to interpret morphological, ecological, and biogeographical patterns in a historical context. Biotic and abiotic environmental factors hypothesized to have exerted selective pressure on morphological traits of its species were optimized onto the phylogeny to suggest how and when these factors may have affected the evolution and diversification of the genus. Results suggest an origin of the genus in southern South America, with two major evolutionary radiations, one more northern in the Central and Northern Andes, and the other in the Southern Andes and the North Chilean, Patagonia and Monte Deserts. Pollination by hummingbirds seems to have been an important factor in the origin of the northern clade, affecting floral morphology. Herbivory by vertebrates and increased aridity seem to have been important selective forces in the evolution and diversification of the southern clade, especially affecting leaf morphology. These changes were probably associated with the major elevation of the Andes in late Tertiary and with the hyperaridization and climatic fluctuations of Pleistocene and Holocene times.
Resumen   Chuquiraga es un género con 23 especies de arbustos perennifolios endémico de América del Sur. Se distribuye principalmente a lo largo de los Andes desde Colombia hasta Chile y Argentina y está especialmente diversificado en los desiertos y semidesiertos de América del Sur. El género presenta un amplio espectro de tipos de morfología foliar y dos tipos florales y de capítulos aparentemente relacionados con la polinización por colibríes y por insectos. En este trabajo las relaciones filogenéticas entre las especies deChuquiraga se resolvieron mediante análisis cladístico de parsimonia utilizando caracteres morfológicos. El cladograma resultante se empleó para interpretar patrones morfológicos, ecológicos y biogeográficos de las especies en un contexto histórico. Factures bióticos y abióticos que se han hipotetizado que han ejercido presión selectiva sobre los caracteres morfológicos fueron optimizados sobre la filogenia para sugerir cómo y cuándo podrían haber afectado la evolución y la diversificación del género. Los resultados obtenidos sugieren un origen del género en el sur de América del Sur, y dos principales radiaciones evolutivas, una más al norte en los Andes Centrales y en los Andes del Norte, y la otra más al sur en los Andes del Sur y en los desiertos del norte de Chile, la Patagonia y el Monte. La polinización por colibríes parece haber sido un factor importante en el origen del clado del norte, afectando la morfología floral. La herbivoría por vertebrados y el incremento en la aridez parecen haber sido fuerzas selectivas importantes en la evolución y diversificación del clado austral, afectando especialmente la morfología foliar. Estos cambios probablemente estuvieron asociados a la elevación máxima de los Andes a fines del Terciario y a la hiperaridización y fiuctuaciones climáticas del Pleistoceno y Holoceno.
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10.
ABSTRACT

The brightly blue shallow water species Terpios fugax Duchassaing and Michelotti, 1864 was originally described from the Caribbean and has been extensively recorded in the Atlantic Ocean, but rarely found in the Indian and Pacific Oceans. In the Pacific Ocean it has been only reported from Sulawesi, Indonesia and from the Caroline and Marshall Islands. Here we report the first record of Terpios in the Eastern Pacific, based on the presence of T. fugax at Caldera, Región de Atacama, northern Chile. Although this species may have been inadvertently introduced to the area by human activity, it should also be considered that the geographically distant populations of this sponge (from the Caribbean to the Eastern Pacific) may represent different species.  相似文献   

11.
Malesherbiaceae are xerophytic plants of Chile, Peru, and Argentina. The 24 species of the only genus,Malesherbia, live in a variety of arid habitats in the Pacific coastal desert and adjacent Andes of Peru, Chile, and neighboring Argentina. Taxa with distributions in both Peru and Chile are rare; for this reason the family provides an excellent case study for the biogeography of this region of western South America. Phylogenetic analysis of ITS sequence data using Turneraceae as an outgroup shows a correlation between the phylogeny and the distribution of Malesherbiaceae. The origin of the family is placed in the late Miocene to early Pliocene, when the region became permanently arid. The five major clades of the family likely diverged during the Pliocene. A single clade consisting of species native to Peru and the Atacama Desert indicates that the family was introduced to Peru once. Most modern species appear to have evolved in response to Pleistocene climatic fluctuations.
Resumen  Las Malesherbiaceae son plantas xerófitas de Chile, el Perú, y Argentina. Las 24 especies del genero único,Malesherbia, viven en una variedad de hábitats en el desierto costero del Pacífico y en la zona andina vecina en el Perú, Chile, y Argentina. Los taxones con distribuciones tanto en el Perú como en Chile son raros; por eso la familia es un buen ejemplo para el estudio de la biogeografía de esta región del oeste de América del Sur. El análisis filogenético de datos de secuencias de ITS usando Turneraceae como un grupo extemo muestra una correlación entre la filogenia y la distribución de Malesherbiaceae. La familia se originó en el Mioceno tardío o Plioceno temprano, cuando la región se volvió permanentemente árida. Los cinco clados mayores de la familia probablemente divergieron en el Plioceno. Un solo clado que tiene especies nativas a Perú y el Desierto de Atacama indica que la familia llegó al Perú una vez. La mayoría de las especies modernas probablemente evolucionaron en respuesta a las fluctuaciones climáticas en el Pleistoceno.
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12.
Human diphyllobothriasis, caused by Dibothriocephalus nihonkaiensis, is prevalent globally, especially in regions where raw fish is consumed. Recent molecular diagnostic techniques have made species identification of tapeworm parasites and the determination of genetic variations among parasite populations possible. However, only a few studies done over a decade ago, have reported on the genetic variation among D. nihonkaiensis in Japan. The present study employed PCR-based mitochondrial DNA analysis to specifically detect D. nihonkaiensis from archived clinical samples, and to determine any genetic variation that may exist among the Japanese broad tapeworms from patients of Kanagawa Prefecture, Japan. Target genes were amplified from DNA extracted from the ethanol- or formaldehyde-fixed samples by PCR. Further sequencing and comparative phylogenetic analyses based on mitochondrial COI and ND1 sequences were also performed. In our results, all PCR-amplified and sequenced samples were identified as D. nihonkaiensis. Analysis of COI sequences revealed two haplotype lineages. However, clustering of almost all COI (and ND1) sample sequences into one of the two haplotype clades, together with reference sequences from different countries worldwide, revealed a common haplotype among D. nihonkaiensis samples in our study. Our results suggest a possible presence of a dominant D. nihonkaiensis haplotype, with a global distribution circulating in Japan. Results from this study have the potential to improve the management of clinical cases and establish robust control measures to reduce the burden of human diphyllobothriasis in Japan.  相似文献   

13.
Alveolar echinococcosis (AE) is a parasitosis that is expanding worldwide, including in Europe. The development of genotypic markers is essential to follow its spatiotemporal evolution. Sequencing of the commonly used mitochondrial genes cob, cox1, and nad2 shows low discriminatory power, and analysis of the microsatellite marker EmsB does not allow nucleotide sequence analysis. We aimed to develop a new method for the genotyping of Echinococcus multilocularis based on whole mitochondrial genome (mitogenome) sequencing, to determine the genetic diversity among 30 human visceral samples from French patients, and compare this method with those currently in use. Sequencing of the whole mitochondrial genome was carried out after amplification by PCR, using one uniplex and two multiplex reactions to cover the 13,738 bp of the mitogenome, combined with Illumina technology. Thirty complete mitogenome sequences were obtained from AE lesions. One showed strong identity with Asian genotypes (99.98% identity) in a patient who had travelled to China. The other 29 mitogenomes could be differentiated into 13 haplotypes, showing higher haplotype and nucleotide diversity than when using the cob, cox1, and nad2 gene sequences alone. The mitochondrial genotyping data and EmsB profiles did not overlap, probably because one method uses the mitochondrial genome and the other the nuclear genome. The pairwise fixation index (Fst) value between individuals living inside and those living outside the endemic area was high (Fst = 0.222, P = 0.002). This is consistent with the hypothesis of an expansion from historical endemic areas to peripheral regions.  相似文献   

14.
Adalia bipunctata Linnaeus, 1758 is a classical object for studying polymorphism of natural populations. Application of genetic markers significantly increased the possibilities of analysis of natural populations of ladybirds and opened the possibility of studying ecological adaptations at the genetic level. We analyze the geographical distribution of the mitochondrial haplotypes of A. bipunctata, determined on the basis of the variability of the mitochondrial cox1 gene in the natural populations of Norway. Two new mitochondrial haplotypes of A. bipunctata are described. We observe a geographical cline in the haplotypes frequencies from south to north. The main haplotype H1 of the central Europe is gradually replaced in the north by the haplotype H7. A possible reason for the observed geographical cline is a selective advantage of beetles with haplotype H7 in areas with a northern coastal climate.  相似文献   

15.
A case of abdominal dioctophymosis in a domestic cat was found in San Juan Bautista district, the Peruvian rainforest, in the Loreto department of Peru. The pet went to a veterinary clinic for a routine ovariohysterectomy during which a large nematode was found in the abdominal cavity. The nematode was morphologically identified as an adult female of Dioctophyme sp. A few morphological parameters, such as the vagina distance from the anterior part and the egg size, were different than D. renale. Partial sequences of the cytochrome c oxidase subunit I (cox1) and the small subunit 18S ribosomal RNA genes were compared with the references from public sequence database and showed a genetic identifies of 89.25% and 99.65% with D. renale, respectively. This is the first mitochondrial molecular analysis of a Dioctophyme specimen from South America and the results showed up to 12.5% nucleotide sequence variation in cox 1 gene of D. renale.  相似文献   

16.
Human diphyllobothriosis is caused by at least 14 species of cestodes belonging to the genus Diphyllobothrium. Molecular analysis by sequencing of nuclear and mitochondrial targets identifies some species at inter- and intra-specific level, and helps to reconstruct their phylogenetic relationships. Nevertheless, the suitability of further molecular targets deserves to be widened, and the comparison of samples of different geographical origin could allow their intra-specific characterization, which could also be useful for epidemiological purposes. In this study, we investigated inter- and intra-specific variability among tapeworms of the genus Diphyllobothrium, with focus on Diphyllobothrium latum, originated from Switzerland. Samples were analyzed by comparing the sequences of two nuclear and two mitochondrial DNA targets. We analyzed 27 samples belonging to 4 species (D. latum, Diphyllobothrium nihonkaiense, Diphyllobothrium dendriticum and Diphyllobothrium ditremum), 15 of which isolated from clinical cases (adults and eggs), 2 from wild canines, and 2 from fish of Swiss lakes (plerocercoid larvae); 8 samples of homologous species from other geographic origins were also sequenced and compared with the Swiss ones. Sequences of partial small subunit ribosomal RNA (18S rRNA) gene and partial internal transcribed spacers 1 and 2 (ITS1-2) were not useful even in inter-specific identification, whereas sequences of complete cytochrome c oxidase subunit 1 (cox1) and cytochrome b (cob) genes allowed us to assess inter- and intra-specific variations among the samples. Cox1 and cob could differentiate 3 and 5 haplotypes within the species D. latum. The results are discussed in the light of the anamneses provided by part of the patients.  相似文献   

17.
18.
The intergenic region of spliced-leader (SL-IR) genes from 105 Trypanosoma cruzi I (Tc I) infected biological samples, culture isolates and stocks from 11 endemic countries, from Argentina to the USA were characterised, allowing identification of 76 genotypes with 54 polymorphic sites from 123 aligned sequences. On the basis of the microsatellite motif proposed by Herrera et al. (2007) to define four haplotypes in Colombia, we could classify these genotypes into four distinct Tc I SL-IR groups, three corresponding to the former haplotypes Ia (11 genotypes), Ib (11 genotypes) and Id (35 genotypes); and one novel group, Ie (19 genotypes). Genotypes harbouring the Tc Ic motif were not detected in our study. Tc Ia was associated with domestic cycles in southern and northern South America and sylvatic cycles in Central and North America. Tc Ib was found in all transmission cycles from Colombia. Tc Id was identified in all transmission cycles from Argentina and Colombia, including Chagas cardiomyopathy patients, sylvatic Brazilian samples and human cases from French Guiana, Panama and Venezuela. Tc Ie gathered five samples from domestic Triatoma infestans from northern Argentina, nine samples from wild Mepraia spinolai and Mepraia gajardoi and two chagasic patients from Chile and one from a Bolivian patient with chagasic reactivation. Mixed infections by Tc Ia + Tc Id, Tc Ia + Tc Ie and Tc Id + Tc Ie were detected in vector faeces and isolates from human and vector samples. In addition, Tc Ia and Tc Id were identified in different tissues from a heart transplanted Chagas cardiomyopathy patient with reactivation, denoting histotropism. Trypanosoma cruzi I SL-IR genotypes from parasites infecting Triatoma gerstaeckeri and Didelphis virginiana from USA, T. infestans from Paraguay, Rhodnius nasutus and Rhodnius neglectus from Brazil and M. spinolai and M. gajardoi from Chile are to our knowledge described for the first time.  相似文献   

19.
Toxoplasma gondii is one of the most successful protozoan parasites given its ability to manipulate the immune system and establish a chronic infection. It is a parasite with a significant impact on human health, mainly in immunocompromised patients. In Europe and North America, only a few clonal genotypes (I, II and III) seem to be responsible for the vast majority of Toxoplasma infections. Surface antigen 2 gene (SAG2) has been extensively used for genotyping T. gondii isolates. The analysis of this locus reveals that in Northern hemisphere, human disease causing isolates are mainly type II, whereas T. gondii isolated from different animals are both type II and III. Since the immune response depends on parasite genotype, it seems relevant to characterize parasites producing human toxoplasmosis in different geographical areas. The growing information about the prevalent T. gondii genotypes in South America mostly refers to domestic animals. This is the first report of genetic characterization of T. gondii isolates from clinical samples in Chile, South America. All the samples analyzed corresponded to SAG2 type I isolates, and they differ from classic SAG2 type I by genetic polymorphisms. This study contributes to the scarce available information on T. gondii at South America, and reinforces an emerging concept suggesting that SAG2 type I, rather than II, parasites are a frequent cause of clinical toxoplasmosis in this continent.  相似文献   

20.
《Journal of Asia》2022,25(4):101988
Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating invasive pest worldwide, causing severe damage to tomatoes. Recently, it has been recorded in the northwestern and southwestern parts of China. Here, the mitogenomes and genetic variation of two newly invaded T. absoluta populations in Xinjiang and Yunnan, were determined. The results showed that the complete mitogenome size of T. absoluta is 15298 bp for the individual from Xinjiang and 15296 bp for the individual from Yunnan, which were both longer than the reported mitogenome from Spain (15290 bp). The mitogenome sequences of individuals collected from three locations showed high levels of sequence similarity, except for 8 polymorphic sites, which were in genes cox2 (1 site), cox3 (2 sites), cob (1 site), atp6 (1 site), nad1 (2 sites) and nad5 (1 site). Tuta absoluta mitogenomes share many features with other 6 Gelechiidae mitogenomes, except for several differences in the start and stop codons of protein-coding genes and the length of intergenic spacers. Seven partial mitochondrial genes (cox1, cox2, cox3, atp6, cob, nad1, and nad5) were used for genetic variation analysis, and significant population differentiation was found between the two populations based on cox2, atp6, nad1, and nad5. The complete mitogenomes and sensitive mitochondrial gene markers reported here provide useful data for further population genetics study of this pest.  相似文献   

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