scholarly journals Flow modification associated with reduced genetic health of a river-breeding frog, Rana boylii

2018 ◽  
Author(s):  
Ryan A. Peek ◽  
Sean M. O’Rourke ◽  
Michael R. Miller
Keyword(s):  
Genetic Diversity ◽  
Geographic Distance ◽  
Aquatic Organisms ◽  
Population Connectivity ◽  
Flow Alteration ◽  
Population Genetic Differentiation ◽  
Flow Modification ◽  
Diversity Loss ◽  
Rana Boylii

AbstractRiver regulation or flow modification—the hydrological alteration of flow by dams and diversions—has been implicated as a cause of fundamental change to downstream aquatic ecosystems. Flow modification changes the patterns and functionality of the natural flow regime, and has the potential to restrict population connectivity and gene flow in river-dependent organisms. Since population connectivity and the maintenance of genetic diversity are fundamental drivers of long-term persistence, understanding the extent flow modification impacts these critical attributes of genetic health is an important goal for long-term conservation. Foothill yellow-legged frogs (Rana boylii) were historically abundant throughout many western rivers but have declined since the onset of regulation. However, the extent to which R. boylii populations in rivers with altered flow regimes are maintaining connectivity and genetic diversity is unknown. Here we use genetic methods to investigate the impacts of flow alteration on R. boylii to explore their potential for long-term persistence under continued flow modification. We found R. boylii in rivers with flow modification showed striking patterns of isolation and trajectories of genetic diversity loss relative to unregulated rivers. For example, flow modification explained the greatest amount of variance in population genetic differentiation compared with other covariates including geographic distance. Importantly, patterns of connectivity and genetic diversity loss were observed regardless of flow alteration level but were most prominent in locations with the greatest flow modification intensity. Although our results do not bode well for long-term persistence of R. boylii populations under current flow regulation regimes, they do highlight the power of genetic monitoring for assessing population health in aquatic organisms.

Weak genetic structuring suggests historically high genetic connectivity among recently fragmented urban populations of the scincid lizard, Ctenotus fallens

2015 ◽  
Vol 63 (4) ◽  
pp. 279 ◽  
Author(s):  
Josef Krawiec ◽  
Siegfried L. Krauss ◽  
Robert A. Davis ◽  
Peter B. S. Spencer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Large Population ◽  
Geographic Distance ◽  
Genetic Erosion ◽  
Genetic Connectivity ◽  
Genetic Structuring ◽  
Low Genetic Diversity ◽  
Population Sizes

Populations in fragmented urban remnants may be at risk of genetic erosion as a result of reduced gene flow and elevated levels of inbreeding. This may have serious genetic implications for the long-term viability of remnant populations, in addition to the more immediate pressures caused by urbanisation. The population genetic structure of the generalist skink Ctenotus fallens was examined using nine microsatellite markers within and among natural vegetation remnants within a highly fragmented urban matrix in the Perth metropolitan area in Western Australia. These data were compared with samples from a large unfragmented site on the edge of the urban area. Overall, estimates of genetic diversity and inbreeding within all populations were similar and low. Weak genetic differentiation, and a significant association between geographic and genetic distance, suggests historically strong genetic connectivity that decreases with geographic distance. Due to recent fragmentation, and genetic inertia associated with low genetic diversity and large population sizes, it is not possible from these data to infer current genetic connectivity levels. However, the historically high levels of gene flow that our data suggest indicate that a reduction in contemporary connectivity due to fragmentation in C. fallens is likely to result in negative genetic consequences in the longer term.

scholarly journals Population connectivity buffers genetic diversity loss in a seabird

2013 ◽  
Vol 10 (1) ◽  
pp. 28 ◽  
Author(s):  
Oscar Ramírez ◽  
Elena Gómez-Díaz ◽  
Iñigo Olalde ◽  
Juan Illera ◽  
Juan Rando ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Connectivity ◽  
Diversity Loss

The influence of hydrographic structure and seasonal run timing on genetic diversity and isolation-by-distance in chum salmon (Oncorhynchus keta)

2008 ◽  
Vol 65 (9) ◽  
pp. 2026-2042 ◽  
Author(s):  
Jeffrey B. Olsen ◽  
Blair G. Flannery ◽  
Terry D. Beacham ◽  
Jeffrey F. Bromaghin ◽  
Penelope A. Crane ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Chum Salmon ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Population Connectivity ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
Yukon River ◽  
Run Timing

We used 20 microsatellite loci to compare genetic diversity and patterns of isolation-by-distance among three groups of chum salmon ( Oncorhynchus keta ) from two physically distinct watersheds in western Alaska, USA. The results were consistent with the hypothesis that gene flow decreases as the complexity of the hydrographic system increases. Specifically, higher gene flow was inferred among 11 populations from a nonhierarchical collection of short coastal rivers in Norton Sound compared with 29 populations from a complex hierarchical network of inland tributaries of the Yukon River. Within the Yukon River, inferred gene flow was highest among 15 summer-run populations that spawn in the lower drainage, compared with 14 fall-run populations that spawn in the upper drainage. The results suggest that the complexity of the hydrographic system may influence population connectivity and hence the level of genetic diversity of western Alaska chum salmon. Finally, evidence of isolation-by-time, when controlling for geographic distance, supported the hypothesis that genetic divergence in Yukon River chum salmon is influenced by seasonal run timing. However, evidence of isolation-by-distance, when controlling for season run timing, indicated the populations are not sufficiently isolated, spatially or temporally, to prevent gene flow. Dispersal among summer- and fall-run populations may play a role in maintaining genetic diversity.

scholarly journals Dots on Earth with huge genetic diversity: relict flatworm Crenobia alpinain the alpine lakes of Tatra Mountains

2021 ◽  
Vol 4 ◽  
Author(s):  
Kornélia Tuhrinová ◽  
Jana Bozáňová ◽  
Fedor Čiampor Jr ◽  
Zuzana Čiamporová-Zaťovičová
Keyword(s):  
Genetic Diversity ◽  
Aquatic Organisms ◽  
Alpine Lakes ◽  
Dispersal Ability ◽  
Population Stability ◽  
Tatra Mountains ◽  
Holistic View ◽  
Genetic Lineages ◽  
Glacial Origin

Mountain lakes, typical signs of an alpine landscape all around the world, were formed in the western part of the Carpathian Arch about 10,000-15,000 years ago, as remnants of the last continental glaciation. In the Tatra Mountains (Slovak-Polish border), more than 110 permanent lakes of glacial origin and many other small ponds exist. These (sub)alpine lakes, with their specific conditions, are very vulnerable and any change in their environment can largely impact their biodiversity, which is, despite long-term faunistic and ecological research, still not fully recognized. This shortcoming could be strongly improved by molecular approaches, which, even within population-genetic studies, often reveal unsuspected cryptic lineages or potential new species. Our long-term research is aimed at revealing the genetic diversity of aquatic macroinvertebrate species in the alpine environment of the Western Carpathians. One of the currently studied species is the glacial relict flatworm taxon Crenobia alpina (Dana, 1766) (Tricladida: Planariidae), representing an element of the permanent aquatic fauna. Totally, 88 COI haplotypes of C. alpina forming at least five well-separated genetic lineages were identified within 348 individuals collected from 45 lakes and ponds in theTatra Mts. Based on tests of selective neutrality and population stability, C. alpina populations in the Tatra lakes did not overcome recent population expansions or contractions. It seems that great genetic differences between localities and their population stability could be a consequence of the presence of natural topographic barriers (ridges, mountain peaks) dividing the mountains into small and relatively isolated valleys. Moreover, other important factors that could play a significant role are the limited dispersal ability of the species as well as its ability to reproduce asexually. Our findings were also compared with all publicly available sequences (Barcoding of Life Datasystems - BOLD and GenBank) in order to shift our data from a local to a holistic view on C. alpina. Our resultssupport the assumption of Brändle et al. 2017 that C. alpina represents a complex of cryptic lineages or species in Europe. As part of the AquaBOL.sk initiative, the data obtained contribute to the knowledge of genetic variability and barcoding of aquatic organisms in Slovakia.

scholarly journals Toxic or Not Toxic, That Is the Carbon Quantum Dot’s Question: A Comprehensive Evaluation with Zebrafish Embryo, Eleutheroembryo, and Adult Models

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1598
Author(s):  
Chih-Yu Chung ◽  
Yu-Ju Chen ◽  
Chia-Hui Kang ◽  
Hung-Yun Lin ◽  
Chih-Ching Huang ◽  
...  
Keyword(s):  
Zebrafish Embryo ◽  
Comprehensive Evaluation ◽  
Aquatic Organisms ◽  
Carbon Quantum Dots ◽  
Adult Zebrafish ◽  
Fish Embryo ◽  
Wide Range ◽  
Different Types ◽  
Low Toxicity

Carbon quantum dots (CQDs) are emerging novel nanomaterials with a wide range of applications and high biocompatibility. However, there is a lack of in-depth research on whether CQDs can cause acute or long-term adverse reactions in aquatic organisms. In this study, two different types of CQDs prepared by ammonia citrate and spermidine, namely CQDAC and CQDSpd, were used to evaluate their biocompatibilities. In the fish embryo acute toxicity test (FET), the LD50 of CQDAC and CQDSpd was about 500 and 100 ppm. During the stage of eleutheroembryo, the LD50 decreased to 340 and 55 ppm, respectively. However, both CQDs were quickly eliminated from embryo and eleutheroembryo, indicating a lack of bioaccumulation. Long-term accumulation of CQDs was also performed in this study, and adult zebrafish showed no adverse effects in 12 weeks. In addition, there was no difference in the hatchability and deformity rates of offspring produced by adult zebrafish, regardless of whether they were fed CQDs or not. The results showed that both CQDAC and CQDSpd have low toxicity and bioaccumulation to zebrafish. Moreover, the toxicity assay developed in this study provides a comprehensive platform to assess the impacts of CQDs on aquatic organisms in the future.

scholarly journals Genetic Consequences of Fence Confinement in a Population of White-Tailed Deer

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 126
Author(s):  
Emily K. Latch ◽  
Kenneth L. Gee ◽  
Stephen L. Webb ◽  
Rodney L. Honeycutt ◽  
Randy W. DeYoung ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Wildlife Management ◽  
Field Observations ◽  
Adaptive Potential ◽  
Population Isolation ◽  
Potential Benefits ◽  
Wildlife Populations ◽  
Mtdna Diversity

Fencing wildlife populations can aid wildlife management goals, but potential benefits may not always outweigh costs of confinement. Population isolation can erode genetic diversity and lead to the accumulation of inbreeding, reducing viability and limiting adaptive potential. We used microsatellite and mitochondrial DNA data collected from 640 white-tailed deer confined within a 1184 ha fence to quantify changes in genetic diversity and inbreeding over the first 12 years of confinement. Genetic diversity was sustained over the course of the study, remaining comparable to unconfined white-tailed deer populations. Uneroded genetic diversity suggests that genetic drift is mitigated by a low level of gene flow, which supports field observations that the fence is not completely impermeable. In year 9 of the study, we observed an unexpected influx of mtDNA diversity and drop in inbreeding as measured by FIS. A male harvest restriction imposed that year increased male survival, and more diverse mating may have contributed to the inbreeding reduction and temporary genetic diversity boost we observed. These data add to our understanding of the long-term impacts of fences on wildlife, but also highlight the importance of continued monitoring of confined populations.

Soil microbial dynamics and genetic diversity in soil under monoculture wheat grown in different long-term management systems

2007 ◽  
Vol 39 (6) ◽  
pp. 1391-1400 ◽  
Author(s):  
Carmine Crecchio ◽  
Maddalena Curci ◽  
Antonella Pellegrino ◽  
Patrizia Ricciuti ◽  
Nunzia Tursi ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Management Systems ◽  
Microbial Dynamics ◽  
Soil Microbial ◽  
Term Management

scholarly journals Microsatellite-Based Genetic Structure and Hybrid Detection in Alpacas Bred in Poland

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2193
Author(s):  
Angelika Podbielska ◽  
Katarzyna Piórkowska ◽  
Tomasz Szmatoła
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
First Generation ◽  
Expected Heterozygosity ◽  
Hybrid Detection ◽  
Average Coefficient ◽  
Mixed Origin ◽  
Generation Hybrid

This study aimed to characterize the population structure and genetic diversity of alpacas maintained in Poland using 17 microsatellite markers recommended by the International Society for Animal Genetics. The classification of llamas, alpacas, and hybrids of both based on phenotype is often difficult due to long-term admixture. Our results showed that microsatellite markers can distinguish alpacas from llamas and provide information about the level of admixture of one species in another. Alpacas admixed with llamas constituted 8.8% of the tested individuals, with the first-generation hybrid displaying only 7.4% of llama admixture. The results showed that Poland hosts a high alpaca genetic diversity as a consequence of their mixed origin. More than 200 different alleles were identified and the average observed heterozygosity and expected heterozygosity values were 0.745 and 0.768, respectively, the average coefficient of inbreeding was 0.034, and the average polymorphism information content value was 0.741. The probability of exclusion for one parent was estimated at 0.99995 and for two parents at 0.99999.

Genetic Structure and Diversity among Species of Salacia: An Endangered Medicinal Herb of Western Ghats, India

2019 ◽  
Vol 9 (1) ◽  
pp. 23-33
Author(s):  
Chandrashekhar G Patil ◽  
Sheetal Ganapati Kamat ◽  
R Vasudeva
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Issr Marker ◽  
Group Method ◽  
Population Genetic Differentiation ◽  
Expected Heterozygosity ◽  
Marker Analysis ◽  
Endangered Medicinal Herb ◽  
High Level ◽  
Genetic Structure And Diversity

Salacia is one of the medicinally valuable genus, distributed throughout tropical areas which include India, Sri Lanka, Southern China and other Southern Asian Countries. The genus Salacia is represented by 21 species in India, among them eight species are recorded from the state of Karnataka in the Southern part of India. Despite its pharmaceutical importance, very little information exists about the genetic diversity of Salacia at molecular level. Hence the present study was carried out to evaluate the genetic among six species of Salacia namely S. chinensis, S. malabarica, S. oblonga, S. macrosperma, S. reticulata and S. gambleana with the help of ISSR marker analysis. Dendrogram and genetic distance were generated adopting Unweighted Paired Group Method with Arithmetic mean (UPGMA) in the NTSYS-pc software. Basic genetic parameters were calculated by analysing the genetic data with Pop gene 1.32 and GenAlEx 6.2 software. The overall polymorphism across the ten primers screened revealed 26 % polymorphism. A 60% polymorphism was scored for the primer UBC 841, whereas, no polymorphism was observed for primer UBC 840 and ISSR 6. The average observed heterozygosity was more than expected heterozygosity. Observed heterozygosity (Ho) ranged from 0.15 (UBC 841) to 0.38 (ISSR 6) with an average of 0.25, whereas expected heterozygosity (He) ranged from 0.10 (UBC 843) to 0.35 (ISSR 6) with an average of 0.23 for Salacia species. The higher heterozygosity pointed towards increased genetic diversity amongst the species. ISSR marker analysis showed high level of inter and intra population genetic differentiation.

Detection of genetic diversity in rough fescue (Festuca campestris Rydb) populations of southern Alberta and British Columbia, Canada, using RAPD markers

2008 ◽  
Vol 88 (2) ◽  
pp. 307-312
Author(s):  
Zhao Mengli ◽  
Han Bing ◽  
Walter D Willms
Keyword(s):  
Genetic Diversity ◽  
British Columbia ◽  
Genetic Distance ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Gene Frequencies ◽  
Southern Alberta ◽  
Potential Adaptation ◽  
Rough Fescue

Mountain rough fescue (Festuca campestris Rydb.) is a tufted native grass in southern Alberta and British Columbia, Canada, and has attracted interest for use in reclamation. However, its seed is often available from only a few localized sources and may not be adapted for areas removed from the collection site. We conducted a study to determine the genetic variability among rough fescue populations to assess its potential adaptation. Thirty plants were collected from each of six populations and analyzed using Random Amplified Polymorphic DNA (RAPD). One population (Kamloops, BC) was separated by several mountain ranges from the five easterly Alberta populations.The Kamloops population was also separated from the Alberta populations by genetic distance in two clusters. Of the total genetic variation present in the data, 21% was found among populations while the remaining (79%) was found within populations. Nei’s genetic distances among populations were related to their geographical distances. Genetic differences among populations appeared to be caused primarily by differences in gene frequencies rather than rare genes. Also, genetic diversity appeared to increase from west to east suggesting that the more easterly populations had greater adaptation potential. We speculate that the more easterly populations are less likely to share genes since the prevailing winds are from the west. Germplasm from the more easterly populations may be used with suitable precautions within Alberta and possibly around Kamloops. Key words: Genetic distance, geographic distance, reclamation, potential adaptation

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