High genetic variation in marginal fragmented populations at extreme climatic conditions of the Patagonian Cypress Austrocedrus chilensis

2010 ◽  
Vol 54 (3) ◽  
pp. 941-949 ◽  
Author(s):  
María Verónica Arana ◽  
Leonardo A. Gallo ◽  
Giovanni G. Vendramin ◽  
Mario J. Pastorino ◽  
Federico Sebastiani ◽  
...  
2003 ◽  
Vol 12 (3) ◽  
pp. 675-683 ◽  
Author(s):  
Ronald A. Van Den Bussche ◽  
Steven R. Hoofer ◽  
David A. Wiedenfeld ◽  
Donald H. Wolfe ◽  
Steve K. Sherrod

2018 ◽  
Author(s):  
Willem G Coetzer ◽  
Trudy R Turner ◽  
Christopher A Schmitt ◽  
J Paul Grobler

Vervet monkeys (Chlorocebus pygerythrus) are one of the most widely distributed non-human primate species found in South Africa. They occur across all the South African provinces, inhabiting a large variety of habitats. These habitats vary sufficiently that it can be assumed that various factors such as pathogen diversity could influence populations in different ways. In turn, these factors could lead to varied levels of selection at specific fitness linked loci. The Toll-like Receptor (TLR) gene family, which play an integral role in vertebrate innate immunity, is a group of fitness linked loci which has been the focus of much research. In this study, we assessed the level of genetic variation at partial sequences of two TLR loci (TLR4 and 7) and a reproductively linked gene, acrosin (ACR), across the different habitat types within the vervet monkey distribution range. Gene variation and selection estimates were also made among 11 – 21 primate species. Low levels of genetic variation for all three gene regions were observed within vervet monkeys , with only two polymorphic sites identified for TLR4, three sites for TLR7 and one site for ACR . TLR7 variation was positively correlated with high mean annual rainfall, which was linked to increased pathogen abundance. The observed genetic variation at TLR4 might have been influenced by numerous factors including pathogens and climatic conditions. The ACR exonic regions showed no variation in vervet monkeys, which could point to the occurrence of a selective sweep. The TLR4 and TLR7 results for the among primate analyses was mostly in line with previous studies, indicating a higher rate of evolution for TLR4. Within primates, ACR also showed signs of positive selection, which was congruent with previous reports on mammals. Important additional information to the already existing vervet monkey knowledge base was gained from this study, which can guide future research projects on this highly researched taxon as well as help conservation agencies with future management planning involving possible translocations of this species.


2020 ◽  
Vol 125 (6) ◽  
pp. 969-980 ◽  
Author(s):  
Silvia Matesanz ◽  
Marina Ramos-Muñoz ◽  
Mario Blanco-Sánchez ◽  
Adrián Escudero

Abstract Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.


2014 ◽  
Vol 281 (1790) ◽  
pp. 20140370 ◽  
Author(s):  
Dylan J. Fraser ◽  
Paul V. Debes ◽  
Louis Bernatchez ◽  
Jeffrey A. Hutchings

Whether and how habitat fragmentation and population size jointly affect adaptive genetic variation and adaptive population differentiation are largely unexplored. Owing to pronounced genetic drift, small, fragmented populations are thought to exhibit reduced adaptive genetic variation relative to large populations. Yet fragmentation is known to increase variability within and among habitats as population size decreases. Such variability might instead favour the maintenance of adaptive polymorphisms and/or generate more variability in adaptive differentiation at smaller population size. We investigated these alternative hypotheses by analysing coding-gene, single-nucleotide polymorphisms associated with different biological functions in fragmented brook trout populations of variable sizes. Putative adaptive differentiation was greater between small and large populations or among small populations than among large populations. These trends were stronger for genetic population size measures than demographic ones and were present despite pronounced drift in small populations. Our results suggest that fragmentation affects natural selection and that the changes elicited in the adaptive genetic composition and differentiation of fragmented populations vary with population size. By generating more variable evolutionary responses, the alteration of selective pressures during habitat fragmentation may affect future population persistence independently of, and perhaps long before, the effects of demographic and genetic stochasticity are manifest.


2018 ◽  
Author(s):  
Willem G Coetzer ◽  
Trudy R Turner ◽  
Christopher A Schmitt ◽  
J Paul Grobler

Vervet monkeys (Chlorocebus pygerythrus) are one of the most widely distributed non-human primate species found in South Africa. They occur across all the South African provinces, inhabiting a large variety of habitats. These habitats vary sufficiently that it can be assumed that various factors such as pathogen diversity could influence populations in different ways. In turn, these factors could lead to varied levels of selection at specific fitness linked loci. The Toll-like Receptor (TLR) gene family, which play an integral role in vertebrate innate immunity, is a group of fitness linked loci which has been the focus of much research. In this study, we assessed the level of genetic variation at partial sequences of two TLR loci (TLR4 and 7) and a reproductively linked gene, acrosin (ACR), across the different habitat types within the vervet monkey distribution range. Gene variation and selection estimates were also made among 11 – 21 primate species. Low levels of genetic variation for all three gene regions were observed within vervet monkeys , with only two polymorphic sites identified for TLR4, three sites for TLR7 and one site for ACR . TLR7 variation was positively correlated with high mean annual rainfall, which was linked to increased pathogen abundance. The observed genetic variation at TLR4 might have been influenced by numerous factors including pathogens and climatic conditions. The ACR exonic regions showed no variation in vervet monkeys, which could point to the occurrence of a selective sweep. The TLR4 and TLR7 results for the among primate analyses was mostly in line with previous studies, indicating a higher rate of evolution for TLR4. Within primates, ACR coding regions also showed signs of positive selection, which was congruent with previous reports on mammals. Important additional information to the already existing vervet monkey knowledge base was gained from this study, which can guide future research projects on this highly researched taxon as well as help conservation agencies with future management planning involving possible translocations of this species.


Author(s):  
SHARMILA S. ◽  
AKILANDESWARI D. ◽  
RAMYA E. K. ◽  
MOWNIKA S.

Objective: To investigate the ecological and genetic diversity, climatic factors, edaphic factors morphological and reproductive characters and RAPD analysis of medicinal plant species Pterolobium hexapetalum in two hills viz., Maruthamalai (arid) and Chennimalai (very arid), which is located in Coimbatore and Erode districts, Tamil Nadu. Methods: The present research was carried out by using a random amplified polymorphic DNA (RAPD) analysis was made to determine the genetic variation between the two populations of the medicinal shrub, Pterolobium hexapetalum in an environmental gradient. Among the five primers tested, the OPN7 (80 %) and OPN17 (71.4 %) produced higher polymorphism was used in RAPD analysis. Results: The results of RAPD analysis showed the presence of 51 individual bands were formed, out of which, 29 were polymorphic bands which showed the existence of genetic variation between populations. A dendrogram was constructed based on Jaccard’s coefficient to determine the degree of genetic relationship among the two populations and analysed. The primers OPN7 and OPN17 were clustered together at a genetic distance level 10. Considering the elevation and proximity, the temperature ranges from 18 °C to 37.6 °C in Maruthamalai hill and 20 °C to 39.4 °C in Chennimalai hill. Conclusion: From the morphoecological studies the results indicated that both arid and very arid climatic conditions showed slight differences in their vegetative and reproductive characters.


2014 ◽  
Vol 281 (1777) ◽  
pp. 20132472 ◽  
Author(s):  
Jean-Baptiste Leducq ◽  
Guillaume Charron ◽  
Pedram Samani ◽  
Alexandre K. Dubé ◽  
Kayla Sylvester ◽  
...  

Exploring the ability of organisms to locally adapt is critical for determining the outcome of rapid climate changes, yet few studies have addressed this question in microorganisms. We investigated the role of a heterogeneous climate on adaptation of North American populations of the wild yeast Saccharomyces paradoxus . We found abundant among-strain variation for fitness components across a range of temperatures, but this variation was only partially explained by climatic variation in the distribution area. Most of fitness variation was explained by the divergence of genetically distinct groups, distributed along a north–south cline, suggesting that these groups have adapted to distinct climatic conditions. Within-group fitness components were correlated with climatic conditions, illustrating that even ubiquitous microorganisms locally adapt and harbour standing genetic variation for climate-related traits. Our results suggest that global climatic changes could lead to adaptation to new conditions within groups, or changes in their geographical distributions.


2018 ◽  
Author(s):  
Willem G Coetzer ◽  
Trudy R Turner ◽  
Christopher A Schmitt ◽  
J Paul Grobler

Vervet monkeys (Chlorocebus pygerythrus) are one of the most widely distributed non-human primate species found in South Africa. They occur across all the South African provinces, inhabiting a large variety of habitats. These habitats vary sufficiently that it can be assumed that various factors such as pathogen diversity could influence populations in different ways. In turn, these factors could lead to varied levels of selection at specific fitness linked loci. The Toll-like Receptor (TLR) gene family, which play an integral role in vertebrate innate immunity, is a group of fitness linked loci which has been the focus of much research. In this study, we assessed the level of genetic variation at partial sequences of two TLR loci (TLR4 and 7) and a reproductively linked gene, acrosin (ACR), across the different habitat types within the vervet monkey distribution range. Gene variation and selection estimates were also made among 11 – 21 primate species. Low levels of genetic variation for all three gene regions were observed within vervet monkeys , with only two polymorphic sites identified for TLR4, three sites for TLR7 and one site for ACR . TLR7 variation was positively correlated with high mean annual rainfall, which was linked to increased pathogen abundance. The observed genetic variation at TLR4 might have been influenced by numerous factors including pathogens and climatic conditions. The ACR exonic regions showed no variation in vervet monkeys, which could point to the occurrence of a selective sweep. The TLR4 and TLR7 results for the among primate analyses was mostly in line with previous studies, indicating a higher rate of evolution for TLR4. Within primates, ACR also showed signs of positive selection, which was congruent with previous reports on mammals. Important additional information to the already existing vervet monkey knowledge base was gained from this study, which can guide future research projects on this highly researched taxon as well as help conservation agencies with future management planning involving possible translocations of this species.


Sign in / Sign up

Export Citation Format

Share Document