Population genetic structure and the conservation of isolated populations of Acacia raddiana in the Negev Desert

Piabanha (Brycon insignis) is a freshwater fish species from the drainages in Southeastern Brazil. During the 1950s, it was an important economic and food resource for local populations, but dramatic and continuous environmental degradation seriously jeopardized the B. insignis populations in the region. Microsatellite markers were used to assess the genetic structure of wild populations of B. insignis and compare the genetic variability and integrity of the wild populations with a captive population. Samples of DNA from 208 specimens from geographically isolated populations were analyzed. Population genetic structure was investigated using F ST, R ST estimates as well as AMOVA. All five loci used in this study were polymorphic with observed heterozygosity ranging from 0.77 (± 0.15) to 0.88 (± 0.07) in the wild population and 0.90 (± 0.09) in the captive population and the allelic richness average were 7.56 (± 0.27) and 5.80 (± 1.02), respectively. Overall genetic differences were significantly partitioned among populations (F ST = 0.072, p = 0.034). Evidence of a genetic bottleneck was found in some of the wild populations, but especially in the captive population. The results showed that genetic variability still can be found in B. insignis populations which are currently structured possibly due to anthropic actions. The implications of these findings for the management and conservation of B. insignis populations are discussed.

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Resolving distribution and population fragmentation in two leaf-tailed gecko species of north-east Australia: key steps in the conservation of microendemic species

Australian Journal of Zoology ◽

10.1071/zo18036 ◽

2018 ◽

Vol 66 (2) ◽

pp. 152 ◽

Cited By ~ 1

Author(s):

Lorenzo V. Bertola ◽

Megan Higgie ◽

Conrad J. Hoskin

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Mitochondrial Gene ◽

Isolated Populations ◽

Distribution Models ◽

Genetic Structuring ◽

North East ◽

Management Actions ◽

Key Steps

North Queensland harbours many microendemic species. These species are of conservation concern due to their small and fragmented populations, coupled with threats such as fire and climate change. We aimed to resolve the distribution and population genetic structure in two localised Phyllurus leaf-tailed geckos: P. gulbaru and P. amnicola. We conducted field surveys to better resolve distributions, used Species Distribution Models (SDMs) to assess the potential distribution, and then used the SDMs to target further surveys. We also sequenced all populations for a mitochondrial gene to assess population genetic structure. Our surveys found additional small, isolated populations of both species, including significant range extensions. SDMs revealed the climatic and non-climatic variables that best predict the distribution of these species. Targeted surveys based on the SDMs found P. gulbaru at an additional two sites but failed to find either species at other sites, suggesting that we have broadly resolved their distributions. Genetic analysis revealed population genetic structuring in both species, including deeply divergent mitochondrial lineages. Current and potential threats are overlain on these results to determine conservation listings and identify management actions. More broadly, this study highlights how targeted surveys, SDMs, and genetic data can rapidly increase our knowledge of microendemic species, and direct management.

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Population genetic structure in the paddyfield warbler (Acrocephalus agricola Jerd.)

Current Zoology ◽

10.1093/czoolo/57.1.63 ◽

2011 ◽

Vol 57 (1) ◽

pp. 63-71 ◽

Cited By ~ 3

Author(s):

Pavel Zehtindjiev ◽

Mihaela Ilieva ◽

Bengt Hansson ◽

Olga Oparina ◽

Mihail Oparin ◽

...

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Bird Species ◽

Migratory Bird ◽

Isolated Populations ◽

Breeding Populations ◽

Bulgarian Population ◽

Migratory Strategy ◽

Degree Of Differentiation

Abstract Population genetic structure was studied in paddyfield warblers Acrocephalus agricola breeding in NE Bulgaria, SE Russia and S Kazakhstan. We were particularly interested in the degree of genetic differentiation and gene flow of the Bulgarian population due to its geographical isolation, recent origin and unique migratory strategy. Analyses of mitochondrial DNA (mtDNA) showed that there was no divergence between Bulgarian and Russian populations (FST = 0.007), whereas those in Kazakhstan differed significantly from the European breeding populations (Russia: FST = 0.058; Bulgaria: FST = 0.114). The degree of differentiation between populations at nuclear markers (five microsatellite loci; FST ≈ 0) was weaker than for mtDNA. We suggest that this relatively weak differentiation over the range of this species reflects a recent postglacial expansion, and results from mismatch distribution analyses and Fu’s FS tests are in agreement. Preservation of small and geographically isolated populations which may contain individuals with unique adaptive traits, such as the studied Bulgarian population of paddyfield warbler, is valuable for the long-term conservation of expanding migratory bird species.

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Population genetic structure in the insular Ryukyu flying fox, Pteropus dasymallus

10.1101/2020.03.05.979211 ◽

2020 ◽

Author(s):

Shiang-Fan Chen ◽

Chung-Hao Juan ◽

Stephen Rossiter ◽

Teruo Kinjo ◽

Dai Fukui ◽

...

Keyword(s):

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Isolation By Distance ◽

Restricted Gene Flow ◽

Negative Consequences ◽

Isolated Populations ◽

Genetic Management ◽

Pteropus Dasymallus ◽

Flying Fox

AbstractSmall isolated populations are vulnerable to both stochastic events and the negative consequences of genetic drift. For threatened species, the genetic management of such populations has therefore become a crucial aspect of conservation. Flying foxes (Pteropus spp, Chiroptera) are keystone species with essential roles in pollination and seed dispersal in tropical and subtropical ecosystems. Yet many flying fox species are also of conservation concern, having experienced dramatic population declines driven by habitat loss and hunting. The Ryukyu flying fox (Pteropus dasymallus) ranges from Japan and Taiwan to the northern Philippines, and has undergone precipitous population crashes on several islands in recent decades. To assess population genetic structure and diversity in P. dasymallus, and its likely causes, we analyzed mitochondrial and microsatellite DNA. Both markers showed significant genetic differentiation among most island populations with patterns of isolation-by-distance. However, while mitochondrial haplotypes showed some mixing across the region, likely reflecting historical colonization and/or dispersal events, microsatellites markers showed clear subdivisions corresponding to the position of deep ocean trenches. The current distribution of P. dasymallus and its subspecific diversity therefore appears to have arisen through vicariance coupled with a long history of restricted gene flow across oceanic barriers. We conclude that isolated island subgroups should be managed separately, with efforts directed at reducing further declines.

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