scholarly journals Especies crípticas Lutzomyia longipalpis (Diptera: Phlebotominae) y sus implicaciones en la en la transmisión de leishmaniasis en Panamá.

Author(s):  
Anayansi Valderrama Cumbrera ◽  
Mileyka Santos ◽  
Angélica Castro ◽  
José Dilermando Andrade Filho

<p><em>[Cryptic Species Lutzomyia longipalpis (Diptera: Phlebotominae) and its Implications in the Transmission of Leishmaniasis in Panama]</em></p><p><em>RESUMEN</em></p><p><em>Lutzomyia</em><em>longipalpis</em>es el principal vector de una importante enfermedad desatendida en América. La diversidad genética de este vector se estimó en la población colectada en dos áreas geográficas separadas por hasta 37 km. Analizamos la secuencia CB3-PDR / N1N-PDR de 22 individuos obteniendo un parámetro de: h = 0.43 y π = 0.0017 (Bo-na), h = 0.89, π = 0.004 (El Limón) con una diferenciación genética de kst = 0.03; p&gt; 0.05 entre ellos. Ocho haplotipos fueron detectados, de los cuales fue compartido. Se detectó una diferenciación significativa entre las poblaciones Panamá-Colombia (kst = 0.98), Panamá-Costa Rica (kst = 0.98) y Panamá-Brasil (kst = 0.72) bajo el modelo de aislamiento. Las inferencias genéticas de esta población pueden complementar la información de la capacidad de dispersión y brindar pistas importantes para comprender la ecología de <em>Lu</em>. <em>longiplapis</em>en Panamá.</p><p>ABSTRACT</p><p class="CuerpoA"><span class="Ninguno"><em><span lang="EN-US">Lutzomyia longipalpis</span></em></span><span class="Ninguno"><span lang="EN-US">is the main vector-borne of important neglected disease in America. The genetic diversity of this vector was estimated in population collected from two geographic area separated by up to </span></span><span class="Ninguno"><span lang="ES-TRAD">37</span></span><span class="Ninguno"><span lang="EN-US">km. We analyzed the sequence CB3-PDR/N1N-PDR of 22 individuals and the resulted of parameter was: h = 0.43 and π = 0.0017 (Bona), h = 0.89, π = 0.004 (El Limón) and genetic differentiation was kst = 0.03; p &gt; 0.05 among them. Eight haplotypes were detected, and one was shared. Significant differentiation was detected among populations Panama-Colombia (kst = 0.98), Panama-Costa Rica (kst = 0.98) and Panama-Brazil (kst = 0.72) and these were genetically isolated by distance. The existence of shared haplotypes among the populations suggests a gene flow despite the distance and geographic separation. Nevertheless, showed isolation it contrasted with individuals very distant.</span></span><span class="Ninguno"><span lang="EN-US">The genetic inferences of this population can supplement the information of dispersal capacity and provided important clues to understand the ecology of sandflies.</span></span></p>

2015 ◽  
Author(s):  
Eric J Fuchs ◽  
Allan Meneses Martínez ◽  
Amanda Calvo ◽  
Melania Muñoz ◽  
Griselda Arrieta-Espinoza

Wild crop relatives are an important source of genetic diversity for crop improvement. However, gene flow from cultivated species into wild species may prove detrimental. Introgression may lead to changes in wild species by incorporating alleles from domesticated species, which may increase the likelihood of extinction. The objective of the present study is to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated if there is evidence of introgression between wild rice and commercial varieties of O. sativa since it is cultivated commonly in close proximity to wild rice populations. Individuals from all known O. glumaepatula populations in Costa Rica were collected. With the aid of 455 AFLP markers, we characterized the genetic diversity and structure among seven populations in northern Costa Rica. Given the dominant nature of our markers, Bayesian estimates of genetic structure were used. We also compared genetic diversity estimates between O. glumaepatula individuals and O. sativa commercial rice. Our results show that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. This is likely a result of large population size. Despite the restricted distributions of this wild species, in Costa Rica most populations are composed of several thousand individuals, thus reducing the effects of drift on genetic diversity. Our results also found low but significant structure (\theta=0.03±0.001) among populations that are separated by ~10 Km within a single river. The position of the population along the river did not influence genetic diversity estimates or differences among populations. This river does not have a strong current and meadows or seeds may easily move upstream, thus homogenizing genetic diversity across populations regardless of river position. Ample gene flow through pollen, seeds or detached culms within the same river reduces genetic structure. A Bayesian structure analysis showed that individuals from two populations share a significant proportion of their genomes with O. sativa genome. These results suggest that the low levels of genetic structure found in these populations are likely the result of introgression from cultivated O. sativa populations. These results expose an important biohazard as recurrent hybridization may reduce genetic diversity of this wild rice species. Introgression may transfer commercial traits into the only populations of O. glumaepatula in Costa Rica, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.


2017 ◽  
Vol 28 (1) ◽  
pp. 116-125 ◽  
Author(s):  
WAYNE A. HOUSTON ◽  
WILLIAM J. ASPDEN ◽  
ROD ELDER ◽  
ROBERT L. BLACK ◽  
LINDA E. NEAVES ◽  
...  

SummaryThe Yellow Chat Epthianura crocea is comprised of three disjunct subspecies. Subspecies E. c. macgregori (Capricorn Yellow Chat) is listed as Critically Endangered under the EPBC Act and has a distribution that also appears to be disjunct, with a limited geographic area of less than 7,000 ha. Some populations are threatened by rapid industrial development, and it is important for conservation of the subspecies to determine the extent to which the putative populations are connected. We used 14 microsatellite markers to measure genetic diversity and to determine the extent of gene flow between two disjunct populations at the northern and southern extremes of the subspecies’ range. No significant differences in genetic diversity (number of alleles and heterozygosity) were observed, but clear population structuring was apparent, with obvious differentiation between the northern and southern populations. The most likely explanation for reduced gene flow between the two populations is either the development of a geographic barrier as a consequence of shrinkage of the marine plains associated with the rise in sea levels following the last glacial maxima, or reduced connectivity across the largely unsuitable pasture and forest habitat that now separates the two populations, exacerbated by declining population size and fewer potential emigrants. Regardless of the mechanism, restricted gene flow between these two populations has important consequences for their ongoing conservation. The relative isolation of the smaller southern groups (the Fitzroy River delta and Curtis Island) from the much larger northern group (both sides of the Broad Sound) makes the southern population more vulnerable to local extinction. Conservation efforts should focus on nature refuge agreements with land owners agreeing to maintain favourable grazing management practices in perpetuity, particularly in the northern area where most chats occur. Supplemental exchanges of individuals from northern and southern populations should be explored as a way of increasing genetic diversity and reducing inbreeding.


Author(s):  
Eric J Fuchs ◽  
Allan Meneses Martínez ◽  
Amanda Calvo ◽  
Melania Muñoz ◽  
Griselda Arrieta-Espinoza

Wild crop relatives are an important source of genetic diversity for crop improvement. However, gene flow from cultivated species into wild species may prove detrimental. Introgression may lead to changes in wild species by incorporating alleles from domesticated species, which may increase the likelihood of extinction. The objective of the present study is to analyze how genetic diversity is distributed within and among populations of the wild rice species Oryza glumaepatula in Costa Rica. We also evaluated if there is evidence of introgression between wild rice and commercial varieties of O. sativa since it is cultivated commonly in close proximity to wild rice populations. Individuals from all known O. glumaepatula populations in Costa Rica were collected. With the aid of 455 AFLP markers, we characterized the genetic diversity and structure among seven populations in northern Costa Rica. Given the dominant nature of our markers, Bayesian estimates of genetic structure were used. We also compared genetic diversity estimates between O. glumaepatula individuals and O. sativa commercial rice. Our results show that O. glumaepatula populations in Costa Rica have moderately high levels of genetic diversity, comparable to those found in South American populations. This is likely a result of large population size. Despite the restricted distributions of this wild species, in Costa Rica most populations are composed of several thousand individuals, thus reducing the effects of drift on genetic diversity. Our results also found low but significant structure (\theta=0.03±0.001) among populations that are separated by ~10 Km within a single river. The position of the population along the river did not influence genetic diversity estimates or differences among populations. This river does not have a strong current and meadows or seeds may easily move upstream, thus homogenizing genetic diversity across populations regardless of river position. Ample gene flow through pollen, seeds or detached culms within the same river reduces genetic structure. A Bayesian structure analysis showed that individuals from two populations share a significant proportion of their genomes with O. sativa genome. These results suggest that the low levels of genetic structure found in these populations are likely the result of introgression from cultivated O. sativa populations. These results expose an important biohazard as recurrent hybridization may reduce genetic diversity of this wild rice species. Introgression may transfer commercial traits into the only populations of O. glumaepatula in Costa Rica, which in turn could alter genetic diversity and increase the likelihood of local extinction. These results have important implications for in situ conservation strategies of the only wild populations of O. glumaepatula in Costa Rica.


2019 ◽  
Vol 67 (2SUPL) ◽  
pp. S95-S111 ◽  
Author(s):  
Wendy Solís-Hernández ◽  
Eric-J. Fuchs

In tropical trees, forest fragmentation has been shown to affect mating and gene flow patterns. Mobile dispersal vectors should be less sensitive to fragmented landscapes and may ameliorate the genetic effects of forest fragmentation on plant populations. To test this hypothesis, we analyzed gene flow patterns in Symphonia globulifera, a tropical tree species with highly mobile pollinators and seed dispersers in the Osa Peninsula in southern Costa Rica. We used microsatellites to study genetic diversity and realized gene flow patterns between a continuous forest and a forest fragment. We found high levels of genetic diversity in adults and seedlings at both sites. Parentage analyses suggest near-neighbor matings and frequent long-distance gene flow events. Half the progeny beneath an adult was not sired by that tree and the majority of established seedlings were the result of long-distance gene dispersal. Gene flow from the forest into the fragment was more common than from the fragment into the continuous forests. Despite long distance gene flow events, seedling spatial genetic structure was stronger and extended further in the forest fragment likely due to limited seed dispersal. We conclude that fragmentation affects gene flow in this tropical tree and may compromise its genetic diversity in forest fragments even for a species with mobile pollen and seed vectors.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yong Wei ◽  
Jiatian Wang ◽  
Zhangyao Song ◽  
Yulan He ◽  
Zihao Zheng ◽  
...  

Abstract Background The Asian tiger mosquito, Aedes albopictus, is one of the 100 worst invasive species in the world and the vector for several arboviruses including dengue, Zika and chikungunya viruses. Understanding the population spatial genetic structure, migration, and gene flow of vector species is critical to effectively preventing and controlling vector-borne diseases. Little is known about the population structure and genetic differentiation of native Ae. albopictus in China. The aim of this study was to examine the patterns of the spatial genetic structures of native Ae. albopictus populations, and their relationship to dengue incidence, on a large geographical scale. Methods During 2016–2018, adult female Ae. albopictus mosquitoes were collected by human landing catch (HLC) or human-bait sweep-net collections in 34 localities across China. Thirteen microsatellite markers were used to examine the patterns of genetic diversity, population structure, and gene flow among native Ae. albopictus populations. The correlation between population genetic indices and dengue incidence was also examined. Results A total of 153 distinct alleles were identified at the 13 microsatellite loci in the tested populations. All loci were polymorphic, with the number of distinct alleles ranging from eight to sixteen. Genetic parameters such as PIC, heterozygosity, allelic richness and fixation index (FST) revealed highly polymorphic markers, high genetic diversity, and low population genetic differentiation. In addition, Bayesian analysis of population structure showed two distinct genetic groups in southern-western and eastern-central-northern China. The Mantel test indicated a positive correlation between genetic distance and geographical distance (R2 = 0.245, P = 0.01). STRUCTURE analysis, PCoA and GLS interpolation analysis indicated that Ae. albopictus populations in China were regionally clustered. Gene flow and relatedness estimates were generally high between populations. We observed no correlation between population genetic indices of microsatellite loci in Ae. albopictus populations and dengue incidence. Conclusion Strong gene flow probably assisted by human activities inhibited population differentiation and promoted genetic diversity among populations of Ae. albopictus. This may represent a potential risk of rapid spread of mosquito-borne diseases. The spatial genetic structure, coupled with the association between genetic indices and dengue incidence, may have important implications for understanding the epidemiology, prevention, and control of vector-borne diseases.


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