1
|
Graham CF, Boreham DR, Manzon RG, Stott W, Wilson JY, Somers CM. How "simple" methodological decisions affect interpretation of population structure based on reduced representation library DNA sequencing: A case study using the lake whitefish. PLoS One 2020; 15:e0226608. [PMID: 31978053 PMCID: PMC6980518 DOI: 10.1371/journal.pone.0226608] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 12/01/2019] [Indexed: 12/30/2022] Open
Abstract
Reduced representation (RRL) sequencing approaches (e.g., RADSeq, genotyping by sequencing) require decisions about how much to invest in genome coverage and sequencing depth, as well as choices of values for adjustable bioinformatics parameters. To empirically explore the importance of these “simple” methodological decisions, we generated two independent sequencing libraries for the same 142 individual lake whitefish (Coregonus clupeaformis) using a nextRAD RRL approach: (1) a larger number of loci at low sequencing depth based on a 9mer (library A); and (2) fewer loci at higher sequencing depth based on a 10mer (library B). The fish were selected from populations with different levels of expected genetic subdivision. Each library was analyzed using the STACKS pipeline followed by three types of population structure assessment (FST, DAPC and ADMIXTURE) with iterative increases in the stringency of sequencing depth and missing data requirements, as well as more specific a priori population maps. Library B was always able to resolve strong population differentiation in all three types of assessment regardless of the selected parameters, largely due to retention of more loci in analyses. In contrast, library A produced more variable results; increasing the minimum sequencing depth threshold (-m) resulted in a reduced number of retained loci, and therefore lost resolution at high -m values for FST and ADMIXTURE, but not DAPC. When detecting fine population differentiation, the population map influenced the number of loci and missing data, which generated artefacts in all downstream analyses tested. Similarly, when examining fine scale population subdivision, library B was robust to changing parameters but library A lost resolution depending on the parameter set. We used library B to examine actual subdivision in our study populations. All three types of analysis found complete subdivision among populations in Lake Huron, ON and Dore Lake, SK, Canada using 10,640 SNP loci. Weak population subdivision was detected in Lake Huron with fish from sites in the north-west, Search Bay, North Point and Hammond Bay, showing slight differentiation. Overall, we show that apparently simple decisions about library construction and bioinformatics parameters can have important impacts on the interpretation of population subdivision. Although potentially more costly on a per-locus basis, early investment in striking a balance between the number of loci and sequencing effort is well worth the reduced genomic coverage for population genetics studies. More conservative stringency settings on STACKS parameters lead to a final dataset that was more consistent and robust when examining both weak and strong population differentiation. Overall, we recommend that researchers approach “simple” methodological decisions with caution, especially when working on non-model species for the first time.
Collapse
Affiliation(s)
- Carly F. Graham
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - Douglas R. Boreham
- Medical Sciences, Northern Ontario School of Medicine, Greater Sudbury, Ontario, Canada
| | - Richard G. Manzon
- Department of Biology, University of Regina, Regina, Saskatchewan, Canada
| | - Wendylee Stott
- Department of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan, USA
| | - Joanna Y. Wilson
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | | |
Collapse
|
2
|
Díez-Del-Molino D, García-Berthou E, Araguas RM, Alcaraz C, Vidal O, Sanz N, García-Marín JL. Effects of water pollution and river fragmentation on population genetic structure of invasive mosquitofish. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 637-638:1372-1382. [PMID: 29801230 DOI: 10.1016/j.scitotenv.2018.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/13/2018] [Accepted: 05/01/2018] [Indexed: 06/08/2023]
Abstract
We analyzed variation at the GPI-2 locus and eleven microsatellite loci of eastern mosquitofish Gambusia holbrooki populations introduced to the Ebro River (Spain), sampling above and below a dam (Flix Reservoir) where severe chronic pollution has been well documented. Allele frequency changes at the GPI-2 locus in the sites nearest to the polluted sediments agree with previous results from studies in mercury-exposed populations of this highly invasive fish. Genetic distinction of the mosquitofish collected close to the polluted sediments was detected at the GPI locus but also at the presumptive neutral microsatellite loci. Recent migration rates estimated from microsatellites indicated that around 30% of fish collected in a specific location were immigrants from upstream and downstream sources. Such high migration rates probably contribute to the mosquitofish's invasive success and suggest that the consequences on the mosquitofish regional genetic structured of high levels of water toxicants could be mediated by immigration from other sites, but the effect of pollutants on local diversity might be higher than observed here.
Collapse
Affiliation(s)
- David Díez-Del-Molino
- Laboratori d'Ictiologia Genètica (LIG), University of Girona, Edifici AC-LEAR, Carrer M. Aurèlia Capmany, 40, 17003 Girona, Spain; Dept. of Bioinformatics and Genetics, Swedish Museum of Natural History, Box 50007, 104 05 Stockholm, Sweden.
| | | | - Rosa-Maria Araguas
- Laboratori d'Ictiologia Genètica (LIG), University of Girona, Edifici AC-LEAR, Carrer M. Aurèlia Capmany, 40, 17003 Girona, Spain.
| | - Carles Alcaraz
- IRTA Marine and Continental Waters, Carretera Poble Nou, km 5.5, 43540 Sant Carles de la Ràpita, Spain.
| | - Oriol Vidal
- Laboratori d'Ictiologia Genètica (LIG), University of Girona, Edifici AC-LEAR, Carrer M. Aurèlia Capmany, 40, 17003 Girona, Spain.
| | - Nuria Sanz
- Laboratori d'Ictiologia Genètica (LIG), University of Girona, Edifici AC-LEAR, Carrer M. Aurèlia Capmany, 40, 17003 Girona, Spain.
| | - Jose-Luis García-Marín
- Laboratori d'Ictiologia Genètica (LIG), University of Girona, Edifici AC-LEAR, Carrer M. Aurèlia Capmany, 40, 17003 Girona, Spain.
| |
Collapse
|
3
|
Eme J, Mueller CA, Lee AH, Melendez C, Manzon RG, Somers CM, Boreham DR, Wilson JY. Daily, repeating fluctuations in embryonic incubation temperature alter metabolism and growth of Lake whitefish (Coregonus clupeaformis). Comp Biochem Physiol A Mol Integr Physiol 2018; 226:49-56. [PMID: 30114471 DOI: 10.1016/j.cbpa.2018.07.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/11/2018] [Accepted: 07/29/2018] [Indexed: 01/01/2023]
Abstract
Lake whitefish (Coregonus clupeaformis) utilize overwintering embryonic development (up to 180 days), and such stenothermic, cold-water embryos may be particularly susceptible to thermal shifts. We incubated whitefish embryos in temperature treatments that were constant temperature (2.0 ± 0.1 °C, 5.0 ± 0.1 °C, and 8.0 ± 0.1 °C; mean ± SD) or variable temperature (VT, mean = 5.0 ± 0.3 °C). In the VT, a daily 2 °C temperature change followed a continuous pattern throughout development: 2-4-6-8-6-4-2 °C. Hatchling survival proportion from fertilization to hatch was significantly impacted by incubation temperature (P < 0.001): 2 °C (0.88 ± 0.01) and 5 °C (0.91 ± 0.01) showed higher survival than both the VT (0.83 ± 0.02) and 8 °C groups (0.15 ± 0.06), which were statistically distinct from each other. Time to hatch (dpf) was significantly different across all treatments (P < 0.001): 8 °C (68 ± 2 dpf), VT (111 ± 4 dpf), 5 °C (116 ± 4 dpf), 2 °C (170 ± 3 dpf). Likewise, hatchling yolk-free dry mass (mg) and total body length (mm) were significantly different across all treatments (P < 0.001): 8 °C (0.66 ± 0.08 mg; 11.1 ± 0.08 mm), VT (0.97 ± 0.06 mg; 11.7 ± 0.05 mm), 5 °C (1.07 ± 0.03 mg; 12.0 ± 0.02 mm), 2 °C (1.36 ± 0.04 mg; 12.8 ± 0.05 mm). Oxygen consumption rate (V̇o2) was significantly affected by the interaction between treatment and measurement temperature (P < 0.001). Hatchling VT whitefish showed mean V̇o2 that was higher compared to the 2 °C group measured at 2 °C, and lower compared to the 2 °C and 5 °C group measured at 8 °C. This study demonstrates that the VT incubation treatment produced fewer (increased mortality), smaller embryos that hatched earlier than 2 °C and 5 °C embryos. The plasticity of V̇o2 for this stenothermic-incubating fish species under variable incubation conditions reveals a metabolic cost to cycling thermal incubation conditions.
Collapse
Affiliation(s)
- John Eme
- Department of Biological Sciences, California State University San Marcos, 333 Twin Oaks Valley Road, San Marcos, CA 92096, United States; Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
| | - Casey A Mueller
- Department of Biological Sciences, California State University San Marcos, 333 Twin Oaks Valley Road, San Marcos, CA 92096, United States; Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
| | - Abigail H Lee
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
| | - Christopher Melendez
- Department of Biological Sciences, California State University San Marcos, 333 Twin Oaks Valley Road, San Marcos, CA 92096, United States.
| | - Richard G Manzon
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada.
| | - Christopher M Somers
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada.
| | - Douglas R Boreham
- Medical Sciences, Northern Ontario School of Medicine, Laurentian University, 935 Ramsey Lake Road, Sudbury, ON P3E 2C6, Canada; Bruce Power, Tiverton, Ontario, Canada; Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - Joanna Y Wilson
- Department of Biology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada.
| |
Collapse
|
4
|
Olsen JB, Brown RJ, Russ OL, Harper K, Wenburg JK. Contemporary factors influencing genetic diversity in the Alaska humpback whitefish Coregonus clupeaformis complex. JOURNAL OF FISH BIOLOGY 2018; 92:1065-1081. [PMID: 29479698 DOI: 10.1111/jfb.13568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
Thirteen microsatellite loci were used to address three hypotheses regarding genetic diversity in the humpback whitefish Coregonus clupeaformis complex in Alaska. The test results provided further insight into the factors influencing C. clupeaformis complex population structure and level of genetic variation. First, the microsatellite data did not provide evidence of two spatially distinct Beringian and Eurasian refugial groups as revealed in previous phylogeographic analyses of mitochondrial DNA variation. Rather, the population structure inferred from the microsatellite variation appears to reveal the influence of factors on a more recent time scale, including gene flow among the refugial groups and isolation of some anadromous and freshwater resident populations. Second, anadromous C. clupeaformis complex collections exhibited higher intra-population genetic diversity than freshwater resident collections. This outcome is consistent with previous meta analyses suggesting that freshwater resident populations probably have smaller historical effective population sizes and less conspecific gene flow because the habitat tends to be smaller and supports fewer and smaller populations. Finally, the analysis of contemporary immigration rates was consistent with, but did not provide statistical support for, the hypothesis that gene flow among anadromous C. clupeaformis complex populations along coastal Alaska is influenced by the Alaska Coastal Current. Further studies are needed to evaluate gene flow among coastal Alaska C. clupeaformis complex populations.
Collapse
Affiliation(s)
- J B Olsen
- Conservation Genetics Laboratory, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503, U.S.A
| | - R J Brown
- Fairbanks Fish and Wildlife Field Office, U.S. Fish and Wildlife Service, 101 12th Ave., Room 222, Fairbanks, Alaska, 99701, U.S.A
| | - O L Russ
- Conservation Genetics Laboratory, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503, U.S.A
| | - K Harper
- Kenai Fish and Wildlife Field Office, U.S. Fish and Wildlife Service, P.O. Box 1670, Kenai, Alaska, 99611, U.S.A
| | - J K Wenburg
- Conservation Genetics Laboratory, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 99503, U.S.A
| |
Collapse
|