Paleoclimate effects and geographic barriers shape regional population genetic structure of blackbrush (Coleogyne ramosissima: Rosaceae)

Botany ◽  
2012 ◽  
Vol 90 (4) ◽  
pp. 293-299 ◽  
Author(s):  
Bryce A. Richardson ◽  
Susan E. Meyer
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Mojave Desert ◽  
Population Genetic ◽  
Colorado Plateau ◽  
Demographic History ◽  
Future Climate Change ◽  
Surprising Result ◽  
Coleogyne Ramosissima

Coleogyne ramosissima Torr. (blackbrush) is a dominant xerophytic shrub species in the ecotone between the warm and cold deserts of interior western North America. Amplified fragment length polymorphisms (AFLPs) were used to survey genetic diversity and population genetic structure at 14 collection sites across the species range. Analysis revealed significant population differentiation (FST = 0.103, p < 0.0001) and reasonably high levels of genetic diversity (expected heterozygosity; HE = 0.26), a surprising result for a putative paleoendemic species. Model-based Bayesian clustering, principal coordinates analysis, and neighbor-joining analysis all produced support for the existence of two metapopulations, the first centered on the Mojave Desert and the second on the Colorado Plateau. These genetic data, coupled with information from Late Pleistocene and Holocene packrat (genus Neotoma Say and Ord, 1825) middens, illustrate a demographic history in which eastern and western distributions were disjunct during the Last Glacial Maximum and remained so through the Holocene, forming the present-day metapopulations in the Mojave Desert and Colorado Plateau. This strong regional genetic differentiation has implications for population persistence and migration in response to future climate change, as well as for shrubland restoration following anthropogenic disturbances such as annual grass invasion and wildfire.

scholarly journals Genomic epidemiology ofMycobacterium bovisinfection in sympatric badger and cattle populations in Northern Ireland

2021 ◽  
Author(s):  
Assel Akhmetova ◽  
Jimena Guerrero ◽  
Paul McAdam ◽  
Liliana C.M. Salvador ◽  
Joseph Crispell ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Spatial Distribution ◽  
Genetic Structure ◽  
Northern Ireland ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Transmission Dynamics ◽  
Data Set ◽  
Hair Samples ◽  
Disease Persistence

AbstractBackgroundBovine tuberculosis (bTB) is a costly epidemiologically complex, multi-host, endemic disease. Lack of understanding of transmission dynamics may undermine eradication efforts. Pathogen whole genome sequencing improves epidemiological inferences, providing a means to determine the relative importance of inter- and intra- species host transmission for disease persistence. We sequenced an exceptional data set of 619Mycobacterium bovisisolates from badgers and cattle in a 100km2bTB ‘hotspot’ in Northern Ireland. Historical molecular subtyping data permitted the targeting of an endemic pathogen lineage, whose long-term persistence provided a unique opportunity to study disease transmission dynamics in unparalleled detail. Additionally, to assess whether badger population genetic structure was associated with the spatial distribution of pathogen genetic diversity, we microsatellite genotyped hair samples from 769 badgers trapped in this area.ResultsGraph transmission tree methods and structured coalescent analyses indicated the majority of bacterial diversity was found in the local cattle population. Results pointed to transmission from cattle to badger being more common than badger to cattle. Furthermore, the presence of significant badger population genetic structure in the landscape was not associated with the spatial distribution ofM. bovisgenetic diversity, suggesting that badger-to-badger transmission may not be a key determinant of disease persistence.SignificanceOur data were consistent with badgers playing a smaller role in the maintenance ofM. bovisinfection in this study site, compared to cattle. Comparison to other areas suggests thatM. bovistransmission dynamics are likely to be context dependent, and the role of wildlife difficult to generalise.

scholarly journals Diverging Genetic Structure of Coexisting Populations of the Black Storm-Petrel and the Least Storm-Petrel in the Gulf of California

2020 ◽  
Vol 13 ◽  
pp. 194008292094917
Author(s):  
Misael D. Mancilla-Morales ◽  
Santiago Romero-Fernández ◽  
Araceli Contreras-Rodríguez ◽  
José J. Flores-Martínez ◽  
Víctor Sánchez-Cordero ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Mate Selection ◽  
Gulf Of California ◽  
Population Genetic ◽  
Life Histories ◽  
Gene Diversity ◽  
Isolation By Distance ◽  
Storm Petrel

Estimations on the influence of evolutionary and ecological forces as drivers of population gene diversity and genetic structure have been performed on a growing number of colonial seabirds, but many remain poorly studied. In particular, the population genetic structure of storm-petrels (Hydrobatidae) has been evaluated in only a few of the 24 recognized species. We assessed the genetic diversity and population structure of the Black Storm-Petrel ( Hydrobates melania) and the Least Storm-Petrel ( Hydrobates microsoma) in the Gulf of California. The two species were selected because they are pelagic seabirds with comparable ecological traits and breeding grounds. Recent threats such as introduced species of predators and human disturbance have resulted in a decline of many insular vertebrate populations in this region and affected many different aspects of their life histories (ranging from reproductive success to mate selection), with a concomitant loss of genetic diversity. To elucidate to what extent the population genetic structure occurs in H. melania and H. microsoma, we used 719 base pairs from the mitochondrial cytochrome oxidase c subunit I gene. The evaluation of their molecular diversity, genetic structure, and gene flow were performed through diversity indices, analyses of molecular and spatial variance, and isolation by distance (IBD) across sampling sites, respectively. The population genetic structure (via AMOVA and SAMOVA) and isolation by distance (pairwise p-distances and FST/1– FST (using ΦST) were inferred for H. microsoma. However, for H. melania evidence was inconclusive. We discuss explanations leading to divergent population genetic structure signatures in these species, and the consequences for their conservation.

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