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At least 37 records · Page 2Linked to original sources

Tools for assessing kinship, population structure, phylogeography, and interspecific hybridization in Asian carps invasive to the Mississippi River, USA: isolation and characterization of novel tetranucleotide microsatellite DNA loci in silver carp Hypophthalmichthys molitrix

We document the isolation and characterization of novel tetranucleotide microsatellite DNA markers for the invasive silver carp Hypophthalmichthys molitrix and provide the results of cross-species amplification for three additional invasive carp species: bighead (H. nobilis), grass (Ctenopharyngodon idella) and black (Mylopharyngodon piceus). In the target species these markers yielded levels of allelic diversity (average 4.4 alleles/locus) and heterozygosity (average 54.7%) sufficient to: (1) provide unique multilocus genotypes; (2) delineate kinship relationships; (3) differentiate populations/species; (4) estimate effective population sizes; and (5) provide unique demographic perspectives for control or eradication. Currently these markers are being utilized to determine the degree of introgressive hybridization between H. molitrix and H. nobilis, to quantify gene flow between different sub-basins established in the central United States, and to assess the demographic status of sub-basin groups. This information will be critically important in the management/control of these invasive species.

Mississippi River↗

Characterization of small microsatellite loci isolated in endangered Indiana bat ( Myotis sodalis ) for use in non-invasive sampling

Primers for 10 microsatellite loci were developed specifically to amplify low quantity and quality DNA in the endangered Indiana Bat ( Myotis sodalis ). In a screen of 20 individuals from a population in Missouri, the 10 loci were found to have levels of variability ranging from seven to 18 alleles. No loci were found to be linked, although two loci revealed significant departures from Hardy–Weinberg equilibrium. These microsatellite loci will be applicable for population genetic analyses and for use in mark-recapture studies that utilize DNA collected non-invasively from fecal pellets, which will ultimately aid in management efforts.

Indiana↗

Isolation of microsatellite loci from the lesser long-nosed bat (Leptonycteris yerbuenae)

Leptonycteris yerbabuenae is a nectarivore (subfamily: Glossophaginae, family: Phyllostomidae), is found from southern Arizona/southwestern New Mexico to southern Mexico including the Baja California peninsula (Ceballos et al.1997; Cockrum 1991). Leptonycteris yerbabuenae is listed as endangered in the United States (Shull 1988) and threatened in Mexico (SEMARNAT 2002). They migrate up to 1,800 km between wintering and breeding grounds (Fleming and Eby 2001). Females mate in the winter in southern Mexico, and migrate to maternity roosts in northern Mexico/southern Arizona to give birth in late spring-early summer (Ceballos et al.1997; Cockrum 1991). Wilkinson and Fleming (1996) have suggested two separate migration corridors where bats occupy southeastern Arizona and southwestern Arizona arrive and leave through separate corridors. We isolated 12 microsatellites loci to estimate gene flow between southwestern and southeastern Arizona roosts, as well as Sonora, Baja California, and Jalisco, Mexico. Genomic DNA was extracted using the DNeasy Blood & Tissue Kit (Qiagen). Approximately 5 μg of genomic DNA was digested with RsaI (NEB) and fragments were ligated to double-stranded SuperSNX-24 linkers to construct an enriched genomic DNA library using a modified version of Glenn and Schable (2005). Linker-ligated fragments ranging from 300–1400 bp were recovered using the polymerase chain reaction (PCR) with a SuperSNX-24 forward primer and Platinum high-fidelity Taq DNA polymerase (Invitrogen), and were hybridized to 5′-biotinylated microsatellite oligonucleotide probes (GT) 15 , (CT) 15 , (GATA) 10 and (GACA) 8 . Hybridized fragments were captured on streptavidin-coated paramagnetic beads (Dynal) and then recovered by PCR. These fragments were ligated into the vector PCR4-TOPO (Invitrogen), and transformed into TOP10 chemically competent E. coli cells (Invitrogen) following the manufacturer’s protocol.

Conservation Genetics Resources↗

Characterization of ten microsatellite loci in the Broad-tailed hummingbird (Selasphorus platycercus)

The Broad-tailed Hummingbird ( Selaphorus platycercus ) breeds at higher elevations in the central and southern Rockies, eastern California, and Mexico and has been studied for 8 years in Rocky Mountain National Park, Colorado. Questions regarding the relatedness of Broad-tailed Hummingbirds banded together and then recaptured in close time proximity in later years led us to isolate and develop primers for 10 polymorphic microsatellite loci. In a screen of 25 individuals from a population in Rocky Mountain National Park, the 10 loci were found to have levels of variability ranging from two to 16 alleles. No loci were found to depart from linkage disequilibrium, although two loci revealed significant departures from Hardy–Weinberg equilibrium. These 10 microsatellite loci will be applicable for population genetic analyses, investigation of mating systems and relatedness, and may help gain insight into the migration timing and routes for this species.

Conservation Genetics Resources↗

Isolation and characterization of 21 polymorphic microsatellite loci in the Japanese dace ( Tribolodon hakonensis )

Twenty one polymorphic microsatellite loci for the Japanese dace ( Tribolodon hakonensis ) were isolated and characterized. The number of observed alleles per locus in 32 individuals ranged from 3 to 30. The observed and expected heterozygosities ranged from 0.125 to 0.969 and from 0.175 to 0.973, respectively. All loci conformed to Hardy–Weinberg equilibrium, no linkage disequilibrium was observed between pairs of loci and no loci showed evidence of null alleles. These microsatellite loci will be useful for investigating the intraspecific genetic variation and population structure of this species.

Conservation Genetics Resources↗

CDFISH: an individual-based, spatially-explicit, landscape genetics simulator for aquatic species in complex riverscapes

We introduce Cost Distance FISHeries (CDFISH), a simulator of population genetics and connectivity in complex riverscapes for a wide range of environmental scenarios of aquatic organisms. The spatially-explicit program implements individual-based genetic modeling with Mendelian inheritance and k -allele mutation on a riverscape with resistance to movement. The program simulates individuals in subpopulations through time employing user-defined functions of individual migration, reproduction, mortality, and dispersal through straying on a continuous resistance surface.

Conservation Genetics Resources↗

Guidelines for collecting and maintaining archives for genetic monitoring

Rapid advances in molecular genetic techniques and the statistical analysis of genetic data have revolutionized the way that populations of animals, plants and microorganisms can be monitored. Genetic monitoring is the practice of using molecular genetic markers to track changes in the abundance, diversity or distribution of populations, species or ecosystems over time, and to follow adaptive and non-adaptive genetic responses to changing external conditions. In recent years, genetic monitoring has become a valuable tool in conservation management of biological diversity and ecological analysis, helping to illuminate and define cryptic and poorly understood species and populations. Many of the detected biodiversity declines, changes in distribution and hybridization events have helped to drive changes in policy and management. Because a time series of samples is necessary to detect trends of change in genetic diversity and species composition, archiving is a critical component of genetic monitoring. Here we discuss the collection, development, maintenance, and use of archives for genetic monitoring. This includes an overview of the genetic markers that facilitate effective monitoring, describes how tissue and DNA can be stored, and provides guidelines for proper practice.

Conservation Genetics Resources↗

Novel microsatellite loci for studies of Thamnophis Gartersnake genetic identity and hybridization

Butler’s Gartersnakes (BGS; Thamnophis butleri ) are confined to open and semi-open canopy wetlands and adjacent uplands, habitats under threat of development in Wisconsin. To address issues of species identity and putative hybridization with congeneric snakes, a suite of 18 microsatellite loci capable of cross-species amplification of Plains Gartersnakes ( T. radix ) and Common Gartersnakes ( T. sirtalis ) was developed. All loci were polymorphic in BGS with mean number of alleles per locus of 16.11 (range = 3–41) and mean observed heterozygosity of 0.659 (range = 0.311–0.978). Loci amplified efficiently in the congeneric species with high levels of intra- and inter-specific variation. These loci will aid ongoing efforts to effectively identify and manage BGS in Wisconsin.

Conservation Genetics Resources↗

Microsatellite marker isolation and development for the giant Pacific Octopus ( Enteroctopus dofleini )

We isolated and developed 18 novel microsatellite markers for the giant Pacific octopus ( Enteroctopus dofleini ) and examined them for 31 individuals from Prince William Sound (PWS), Alaska. These loci displayed moderate levels of allelic diversity (averaging 11 alleles per locus) and heterozygosity (averaging 65%). Seven loci deviated from Hardy–Weinberg Equilibrium (HWE) due to heterozygote deficiency for the PWS population, although deviations were not observed for all these loci in other populations, suggesting the PWS population is not in mutation-drift equilibrium. These novel microsatellite loci yielded sufficient genetic diversity for potential use in population genetics, individual identification, and parentage studies.

Conservation Genetics Resources↗

Development of polysomic microsatellite markers for characterization of population structuring and phylogeography in the shortnose sturgeon (Acipenser brevirostrum)

Shortnose sturgeon Acipenser brevirostrum is an endangered polyploid fish species for which no nuclear DNA markers previously existed. To address this need, 86 polysomic loci were developed and characterized in 20 A. brevirostrum from five river systems and eight members (parents and six progeny) of a captive-bred family. All markers proved to be polymorphic, polysomic, and demonstrated direct inheritance when tested in a captive family. Eleven loci were included in a range-wide survey of 561 fish sampled from 17 geographic collections. Allelic diversity at these markers ranged from 7 to 24 alleles/locus and averaged 16.5 alleles/locus; sufficient diversity to produce unique multilocus genotypes. In the range-wide survey, a Mantel comparison of an ecological (1-Jaccard’s) and genetic (Φ PT ; an analog to F ST ) distance metrics, identified a strong positive correlation (r = 0.98, P < 0.0001); suggesting Φ PT represents a viable metric for assessing genetic relatedness using this class of marker.

Conservation Genetics Resources↗

New microsatellite loci isolated via next-generation sequencing for two endangered pronghorn from the Sonoran Desert

We isolated 16 novel microsatellite loci in two subspecies of endangered desert pronghorns (Antilocapra americana sonoriensis and Antilocapra americana peninsularis) using a shotgun pyrosequencing approach. All and 87.5 % of the loci were polymorphic within each subspecies, respectively. The mean number of alleles per locus was 4.86 (range 2–8) and 2.5 alleles per locus (range 1–4 alleles), and observed heterozygosity ranged from 0.13 to 0.78 (mean 0.48) and 0.00 to 0.61 (mean 0.31), respectively. We did not find significant linkage disequilibrium among loci pairs and only one locus deviated significantly from Hardy–Weinberg equilibrium in peninsularis.

Conservation Genetics Resources↗

Development and characterization of thirteen microsatellite loci in Clark's nutcracker (Nucifraga columbiana)

Clark’s nutcrackers are important seed dispersers for two widely-distributed western North American conifers, whitebark pine and limber pine, which are declining due to outbreaks of mountain pine beetle and white pine blister rust. Because nutcracker seed dispersal services are key to maintaining viable populations of these imperiled pines, knowledge of movement patterns of Clark’s nutcrackers helps managers understand local extinction risks for these trees. To investigate population structure within Clark’s nutcracker, we developed primers for and characterized 13 polymorphic microsatellite loci. In a screen of 22 individuals from one population, levels of variability ranged from 6 to 15 alleles. No loci were found to be linked, although 4 loci revealed significant departures from Hardy–Weinberg equilibrium and evidence of null alleles. These microsatellite loci will enable population genetic analyses of Clark’s nutcrackers, which could provide insights into the spatial relationships between nutcrackers and the trees they help disperse.

Conservation Genetics Resources↗

Development and characterization of 21 polymorphic microsatellite markers for the barren-ground shrew, Sorex ugyunak (Mammalia: Sorcidae), through next-generation sequencing, and cross-species amplification in the masked shrew, S. cinereus

We used next generation shotgun sequencing to develop 21 novel microsatellite markers for the barren-ground shrew ( Sorex ugyunak ), which were polymorphic among individuals from northern Alaska. The loci displayed moderate allelic diversity (averaging 6.81 alleles per locus) and heterozygosity (averaging 70 %). Two loci deviated from Hardy–Weinberg equilibrium (HWE) due to heterozygote deficiency. While the population did not deviate from HWE overall, it showed significant linkage disequilibrium suggesting this population is not in mutation-drift equilibrium. Nineteen of 21 loci were polymorphic in masked shrews ( S. cinereus ) from interior Alaska and exhibited linkage equilibrium and HWE overall. All loci yielded sufficient variability for use in population studies.

Conservation Genetics Resources↗

Development and characterization of 16 polymorphic microsatellite loci for the Alaska blackfish (Esociformes: Dallia pectoralis )

Blackfishes (Esociformes: Esocidae: Dallia ), small fishes with relictual distributions, are unique in being the only primary freshwater fish genus endemic to Beringia. Although the number of species of Dallia is debated, disjunct populations and distinct mitochondrial divisions that predate the end of the last glacial maximum are apparent. We developed sixteen polymorphic microsatellites from the Alaska blackfish ( Dallia pectoralis ) to study genetic diversity in Dallia . Genotypes from two populations, Denali (n = 31) and Bethel (n = 35), demonstrated the usefulness of the loci for population-level investigation. Observed and expected heterozygosity averaged 18.6 and 19.8 % in Denali and 61.1 and 63.7 % in Bethel. Number of alleles at each locus averaged 3.50 in Denali and 9.63 in Bethel. The observed signature of variability and structuring between populations is consistent with mitochondrial data.

Conservation Genetics Resources↗

Development and characterization of 12 microsatellite markers for the Island Night Lizard ( Xantusia riversiana ), a threatened species endemic to the Channel Islands, California, USA

The Island Night Lizard is a federally threatened species endemic to the Channel Islands of California. Twelve microsatellite loci were developed for use in this species and screened in 197 individuals from across San Nicolas Island, California. The number of alleles per locus ranged from 6 to 21. Observed heterozygosities ranged from 0.520 to 0.843. These microsatellite loci will be used to investigate population structure, effective population size, and gene flow across the island, to inform protection and management of this species.

Conservation Genetics Resources↗

Development and characterization of microsatellite markers for the Hawaiian coot, Fulica alai , and Hawaiian gallinule, Gallinula galeata sandvicensis , through next-generation sequencing

We used next generation shotgun sequencing to develop novel microsatellite markers for two endangered waterbirds; the Hawaiian coot ( Fulica alai ) and Hawaiian gallinule ( Gallinula galeata sandvicensis ). The 20 loci polymorphic in the Hawaiian coot displayed moderate allelic diversity (average 3.8 alleles/locus) and heterozygosity (average 59.5 %). The 12 loci variable for the Hawaiian gallinule exhibited lower levels of allelic diversity (average 2.4 alleles/locus) and heterozygosity (average 47.5 %). Loci were in linkage equilibrium and only one locus deviated from Hardy&ndash;Weinberg equilibrium. These loci are sufficiently variable to assess levels of genetic diversity and will be useful for conservation genetic studies to aid in the management of these endangered waterbirds.

Conservation Genetics Resources↗

Development of eighteen microsatellite loci in walleye ( Sander vitreus )

A suite of tri- and tetra-nucleotide microsatellite loci were developed for walleye ( Sander vitreus ) from 454 pyrosequencing data. Eighteen of the 50 primer sets tested amplified consistently in 35 walleye from two lakes on Isle Royale, Lake Superior: Chickenbone Lake and Whittlesey Lake. The loci displayed moderate levels of allelic diversity (average 5.5 alleles/locus) and heterozygosity (average 35.8 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring as individuals assigned back to their population of origin. Cross-species amplification within S. canadensis (sauger) was successful for 15 loci, and 11 loci were diagnostic to species. The loci characterized here will be useful for detecting fine-scale spatial structuring, resolving the taxonomic status of Sander species and sub-species, and detecting walleye/sauger hybrids.

Michigan↗

Next-generation genomic shotgun sequencing indicates greater genetic variability in the mitochondria of Hypophthalmichthys molitrix relative to H. nobilis from the Mississippi River, USA and provides tools for research and detection

We characterized variation within the mitochondrial genomes of the invasive silver carp ( Hypophthalmichthys molitrix ) and bighead carp ( H. nobilis ) from the Mississippi River drainage by mapping our Next-Generation sequences to their publicly available genomes. Variant detection resulted in 338 single-nucleotide polymorphisms for H. molitrix and 39 for H. nobilis . The much greater genetic variation in H. molitrix mitochondria relative to H. nobilis may be indicative of a greater North American female effective population size of the former. When variation was quantified by gene, many tRNA loci appear to have little or no variability based on our results whereas protein-coding regions were more frequently polymorphic. These results provide biologists with additional regions of DNA to be used as markers to study the invasion dynamics of these species.

Conservation Genetics Resources↗