scholarly journals Characterisation of microsatellites for Litoria nannotis (Amphibia : Hylidae), an endangered waterfall frog endemic to the Australian Wet Tropics

2016 ◽  
Vol 64 (6) ◽  
pp. 390
Author(s):  
Robert Puschendorf ◽  
Erica V. Todd ◽  
Michael G. Gardner
Keyword(s):  
Genetic Variation ◽  
Microsatellite Loci ◽  
Population Sample ◽  
Pcr Primers ◽  
Fungal Disease ◽  
Shotgun Sequencing ◽  
Population Declines ◽  
Polymorphic Loci ◽  
Amplification Success ◽  
Wet Tropics

Litoria nannotis is an endangered waterfall frog from the wet tropics region in north Queensland that has suffered significant population declines due to the emerging fungal disease known as chytridiomycosis. The species has two deeply divergent lineages, and we used 454 shotgun sequencing of DNA extracted from one individual of the northern lineage to identify and design PCR primers for 576 microsatellite loci. Thirty markers were tested for amplification success and variability in a population sample from each lineage. Of these, 17 were found to be polymorphic in the northern lineage and 10 loci were polymorphic in the southern lineage. Numbers of alleles per locus ranged from 2 to 14 (mean = 6.47, s.d. = 4.02) for the northern lineage (17 polymorphic loci), and from 2 to 8 (mean = 5.40, s.d. = 2.55) in the southern lineage (10 polymorphic loci). Levels of heterozygosity were high in both lineages (northern mean HE = 0.63, s.d. = 0.21, range = 0.27–0.89; southern mean HE = 0.57, s.d. = 0.25, range = 0.18–0.81). These loci will be useful in understanding the genetic variation and connectivity amongst populations of this species recovering from mass population declines due to disease.

Isolation, via 454 sequencing, and characterisation of microsatellites for Phalacrocorax fuscescens, the black-faced cormorant (Aves : Phalacrocoracidae)

2012 ◽  
Vol 60 (5) ◽  
pp. 340
Author(s):  
Julie Riordan ◽  
Michael G. Gardner ◽  
Alison J. Fitch ◽  
Gregory R. Johnston
Keyword(s):  
Family Structure ◽  
Microsatellite Loci ◽  
Genomic Dna ◽  
454 Sequencing ◽  
South Australia ◽  
Breeding Colony ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Amplification Success ◽  
The Mean

The black-faced cormorant, Phalacrocorax fuscescens, is a brood-reducing seabird endemic to the southern waters of Australia. Microsatellite loci were isolated from genomic DNA using 454 shotgun sequencing. Thirty-one loci were tested and, of these, 16 were found to be polymorphic. Further characterisation was conducted on seven loci that were genotyped in 42 adult individuals from a single breeding colony in South Australia. The number of alleles per locus ranged from three to eight (s.d. ± 2.16), and the mean observed and expected heterozygosity was 0.66 (s.d. ± 0.249) and 0.62 (s.d. ± 0.178) respectively. We confirm that four loci conformed to Hardy–Weinberg expectations. Four other Phalacrocorax species were trialled for amplification of these four polymorphic loci. Amplification success varied between loci and species. These loci will be useful in determining genetic family structure and exploring nestling relatedness to further understand how relatedness influences competitive behaviours in brood-reducing species.

Isolation and characterisation of microsatellites for the endangered Slater’s skink, Liopholis slateri (Squamata : Scincidae), via next-generation sequencing

2017 ◽  
Vol 65 (3) ◽  
pp. 200 ◽  
Author(s):  
Michael G. Gardner ◽  
Mina H. Ansari ◽  
Claire E. Treilibs ◽  
Angharad Johnston ◽  
Chris R. Pavey ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Next Generation Sequencing ◽  
Microsatellite Loci ◽  
Shotgun Sequencing ◽  
Next Generation ◽  
Central Australia ◽  
Polymorphic Microsatellite ◽  
Generation Sequencing

We characterised 14 new polymorphic microsatellite loci for the endangered lizard Liopholis slateri. Initially, 454 shotgun sequencing was used to identify 46 loci, which were trialled for amplification. Subsequently, 14 of these loci were screened for variation in 21 individuals from scat-derived DNA samples collected from Owen Springs Reserve in central Australia. All 14 loci were polymorphic, with observed heterozygosity ranging from 0.19 to 0.86 and the number of alleles per locus ranging from 2 to 10. These loci will be useful in understanding the genetic variation and connectivity within and among extant L. slateri populations.

Population Genetics ofCaenorhabditis elegans: The Paradox of Low Polymorphism in a Widespread Species

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Arjun Sivasundar ◽  
Jody Hey
Keyword(s):  
Genetic Variation ◽  
Microsatellite Loci ◽  
Population Expansion ◽  
Widespread Species ◽  
C Elegans ◽  
Model Research ◽  
The World ◽  
Natural Isolates ◽  
History Of ◽  
Low Levels

AbstractCaenorhabditis elegans has become one of the most widely used model research organisms, yet we have little information on evolutionary processes and recent evolutionary history of this widespread species. We examined patterns of variation at 20 microsatellite loci in a sample of 23 natural isolates of C. elegans from various parts of the world. One-half of the loci were monomorphic among all strains, and overall genetic variation at microsatellite loci was low, relative to most other species. Some population structure was detected, but there was no association between the genetic and geographic distances among different natural isolates. Thus, despite the nearly worldwide occurrence of C. elegans, little evidence was found for local adaptation in strains derived from different parts of the world. The low levels of genetic variation within and among populations suggest that recent colonization and population expansion might have occurred. However, the patterns of variation are not consistent with population expansion. A possible explanation for the observed patterns is the action of background selection to reduce polymorphism, coupled with ongoing gene flow among populations worldwide.

scholarly journals POPULATION GENETIC CONSEQUENCES OF FEEDING HABITS IN SOME FOREST LEPIDOPTERA

Genetics ◽  
1979 ◽  
Vol 92 (3) ◽  
pp. 1005-1021
Author(s):  
Charles Mitter ◽  
Douglas J Futuyma
Keyword(s):  
Genetic Variation ◽  
Environmental Heterogeneity ◽  
Feeding Habits ◽  
Functional Relation ◽  
Allozyme Variation ◽  
Unexpected Result ◽  
Polymorphic Loci ◽  
Allozyme Loci ◽  
Race Formation ◽  
Relationship Of

ABSTRACT By surveying variation at allozyme loci in several phytophagous lepidopteran species (Geometridae), we have tested two hypotheses about the relationship of genetic variation to environmental heterogeneity: (1) that allozyme polymorphisms may exist because of associations between genotypes and "niches" (different host plants, in this instance), and (2) that the overall genetic variation of a species is correlated with environmental heterogeneity (or breadth of the species' overall ecological niche) .—Genetic differentiation among samples of oligophagous or polyphagous species taken from different host species was observed in one of three species, at only one of seven polymorphic loci. The data thus provide no evidence for pronounced genetic sub-structuring, or "host race" formation in these sexually reproducing species, although host plant-genotype associations in a parthenogenetic moth give evidence of the potential for diversifying selection.—In a comparison of allozyme variation in polyphagous ("generalized") and oligophagous ("specialized") species, heterozygosity appeared to be higher in specialized species, at all polymorphic loci but one. I t is possible that this unexpected result arises from a functional relation between breadth of diet and genetic variation.

scholarly journals Revisiting Ophidiomycosis (Snake Fungal Disease) After a Decade of Targeted Research

2021 ◽  
Vol 8 ◽  
Author(s):  
Christina M. Davy ◽  
Leonard Shirose ◽  
Doug Campbell ◽  
Rachel Dillon ◽  
Christina McKenzie ◽  
...  
Keyword(s):  
Large Scale ◽  
Sublethal Effects ◽  
Clinical Signs ◽  
Fungal Disease ◽  
Host Susceptibility ◽  
Current Evidence ◽  
Molecular Testing ◽  
Population Declines ◽  
Snake Fungal Disease ◽  
Free Ranging

Emerging infectious diseases (EIDs) are typically characterized by novelty (recent detection) and by increasing incidence, distribution, and/or pathogenicity. Ophidiomycosis, also called snake fungal disease, is caused by the fungus Ophidiomyces ophidiicola (formerly “ophiodiicola”). Ophidiomycosis has been characterized as an EID and as a potential threat to populations of Nearctic snakes, sparking over a decade of targeted research. However, the severity of this threat is unclear. We reviewed the available literature to quantify incidence and effects of ophidiomycosis in Nearctic snakes, and to evaluate whether the evidence supports the ongoing characterization of ophidiomycosis as an EID. Data from Canada remain scarce, so we supplemented the literature review with surveys for O. ophidiicola in the Canadian Great Lakes region. Peer-reviewed reports of clinical signs consistent with ophidiomycosis in free-ranging, Nearctic snakes date back to at least 1998, and retrospective molecular testing of samples extend the earliest confirmed record to 1986. Diagnostic criteria varied among publications (n = 33), confounding quantitative comparisons. Ophidiomycosis was diagnosed or suspected in 36/121 captive snakes and was fatal in over half of cases (66.7%). This result may implicate captivity-related stress as a risk factor for mortality from ophidiomycosis, but could also reflect reporting bias (i.e., infections are more likely to be detected in captive snakes, and severe cases are more likely to be reported). In contrast, ophidiomycosis was diagnosed or suspected in 441/2,384 free-ranging snakes, with mortality observed in 43 (9.8 %). Ophidiomycosis was only speculatively linked to population declines, and we found no evidence that the prevalence of the pathogen or disease increased over the past decade of targeted research. Supplemental surveys and molecular (qPCR) testing in Ontario, Canada detected O. ophidiicola on 76 of 657 free-ranging snakes sampled across ~136,000 km2. The pathogen was detected at most sites despite limited and haphazard sampling. No large-scale mortality was observed. Current evidence supports previous suggestions that the pathogen is a widespread, previously unrecognized endemic, rather than a novel pathogen. Ophidiomycosis may not pose an imminent threat to Nearctic snakes, but further research should investigate potential sublethal effects of ophidiomycosis such as altered reproductive success that could impact population growth, and explore whether shifting environmental conditions may alter host susceptibility.

scholarly journals Генотипирование сортов винограда селекции Института «Магарач» на основе анализа аллельного полиморфизма SSR локусов

2019 ◽  
pp. 289-293
Author(s):  
Svetlana Gorislavets ◽  
Vitalii Volodin ◽  
Gennadii Spotar ◽  
Valentina Risovannaya ◽  
Yakov Alekseev
Keyword(s):  
Genetic Variation ◽  
Simple Sequence Repeats ◽  
Microsatellite Loci ◽  
Molecular Genetic ◽  
Information Value ◽  
International Standards ◽  
Agricultural Crops ◽  
Ssr Analysis ◽  
Short Period ◽  
Simple Sequence

Обязательными условиями успешного сохранения и использования различных сортов сельскохозяйственных культур является идентификация и контроль генетической изменчивости сортов, для изучения которой используются различные методы, в том числе методы молекулярно-генетического анализа. В связи с быстрым развитием селекции, ежегодно появляются десятки новых сортов винограда, требующих паспортизации. Молекулярные маркеры могут способствовать подбору родительских пар для скрещивания, повышению точности и ускорению селекционного процесса, так как идентификация исходного материала с использованием молекулярных маркеров и анализ результатов скрещивания могут быть выполнены в достаточно короткий период. К наиболее информативным молекулярным маркерам относятся микросателлитные маркеры, основанные на анализе простых повторяющихся повторов (simple sequence repeats, SSR). Анализ полиморфизма SSR локусов позволяет изучить генетическую изменчивость сельскохозяйственных культур на уровне генома. Цель нашего исследования - генотипирование, оценка аллельного разнообразия и ДНК-паспортизация ряда сортов винограда селекции Института «Магарач» на основе SSR анализа. Основной метод, использованный в работе, - полимеразная цепная реакция (ПЦР) и фрагментный анализ продуктов ПЦР на генетическом анализаторе ABI 3130. В результате фрагментного анализа были генотипированы 8 селекционных сортов Института «Магарач» по 9 ядерным микросателлитным локусам (nSSR). Размеры аллелей оценены с помощью программы Gene Mapper v. 4.0. Полиморфизм микросателлитных локусов и генетическое разнообразие рассчитано с использованием программы Popgene (v. 1.32). Сравнительный анализ nSSR профилей ДНК изученных сортов позволил установить, что все сорта имеют уникальные профили. Всего идентифицировано 69 аллелей, среднее число аллелей - 7,67 аллелей/локус. На основании размеров аллелей составлены индивидуальные молекулярно-генетические паспорта в соответствии с международными стандартами.Identification and control of genetic variation of different varieties of agricultural crops enter as prerequisites for their efficient conservation and use. Genetic variation is investigated by means of a wide set of methods, including those relying on molecular-genetic analysis. Every year, dozens of new breedings of grapevine come into being, and their passportization is necessary. Molecular markets can promote selection of parent pairs for crossing, improve efficiency of breeding and accelerate the process as enable both identification of the initial material and analysis of crossing results to be done in a sufficiently short period of time. The highest information value is associated with microsatellite markers consisting of simple sequence repeats (SSR). Analysis of polymorphism of SSR loci allows to investigate genetic variation of agricultural crops at the level of genome. The goals of the study were to conduct genotyping of a number of grape breedings developed by the Institute Magarach, to assess their allelic diversity and to achieve DNA passportization based on SSR analysis. Polymerase chain reaction (PCR) and fragment analysis of PCR products with the use of a genetic analizer ABI 3130 were the main methods the study relied upon. As a result of the aforesaid analysis, eight new breedings of the Institute were genotyped for nine nuclear microsatellite loci (nSSR). The sizes of alleles were assessed using Gene Mapper v. 4.0 software. Popgene (v. 1.32) software was used to calculate polymorphism of microsatellite loci and genetic diversity. A comparative nSSR-analysis of DNA-profiles of the study varieties indicated that all of them had unique profiles. A total of 69 alleles were identified, with 7.67 alleles per locus on an average. Based on the sizes of the alleles, individual molecular-genetic passports of the varieties were made, in accordance with international standards.

scholarly journals Genetic analysis of silver-fir populations in the Beskids

2011 ◽  
Vol 72 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Leon Mejnartowicz
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Abies Alba ◽  
Genetic Distances ◽  
Silver Fir ◽  
Geographical Distance ◽  
Polymorphic Loci ◽  
Expected Heterozygosity ◽  
Rare Alleles

Twenty-eight isozymic loci were studied in the Beskid Mts., in four populations of common silver-fir (<em>Abies alba</em>): one in Beskid Makowski (BM) and three populations in Beskid Sądecki (BS). Their genetic variation and diversity were analyzed, and Nei's genetic distances between the populations were calculated. The results show that the geographical distance between the BM population and the three BS populations is reflected in genetic distances. The BM population is clearly distinct from the others. It has the lowest genetic diversity (<em>I</em> = <em>0.42</em>), percentage of polymorphic loci <em>(%PoL </em>= <em>64.29</em>) and number of rare alleles (<em>NoRa </em>= <em>5</em>). Besides, the BM population has the highest observed heterozygosity (<em>Ho </em>= <em>0.291</em>), which exceeds the expected heterozygosity (<em>He </em>= <em>0.254</em>), estimated on the basis of the Hardy-Weinberg Principle. On the contrary, BS populations are in the state of equilibrium, which is manifested, in similar values of <em>He </em>= <em>0.262 </em>and <em>Ho </em>= <em>0.264</em>.

scholarly journals Identification of microsatellite loci in sea anemones Aulactinia stella and Cribrinopsis albopunctata (family Actiniidae)

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 232
Author(s):  
Ekaterina S. Bocharova ◽  
Alexey A. Sergeev ◽  
Aleksandr A. Volkov
Keyword(s):  
Population Genetics ◽  
Microsatellite Loci ◽  
Sea Anemone ◽  
Sea Anemones ◽  
Polymorphic Loci ◽  
Dna Libraries

From the DNA libraries enriched by the repeat motifs (AAAC)6, (AATC)6, (ACAG)6, (ACCT)6, (ACTC)6, ACTG)6, (AAAT)8, (AACT)8, (AAGT)8, (AGAT)8, for two viviparous sea anemones Aulactinia stella and Cribrinopsis albopunctata, 41 primer pairs were developed. These primer pairs resulted in the identification of 41 candidate microsatellite loci in either A. stella or C. albopunctata. Polymorphic loci were identified in both sea anemone species for 13 of the primer pairs and can be applicable for population genetics researches.

scholarly journals Inter- and intra-population variation of local maize (Zea mays L.) populations from Slovakia and Czech Republic

2008 ◽  
Vol 43 (No. 1) ◽  
pp. 7-15 ◽  
Author(s):  
P. Múdry ◽  
J. Kraic
Keyword(s):  
Zea Mays ◽  
Genetic Variation ◽  
Czech Republic ◽  
Population Variation ◽  
Polymorphic Loci ◽  
Maize Populations ◽  
Expected Heterozygosity ◽  
Isoenzyme Polymorphism ◽  
New Alleles

Evaluation of genetic variation was performed within 62 local maize populations originating from Slovakia and Czech Republic. In total 48 alleles at 22 analyzed isoenzyme loci with an average of 2.2 alleles per locus were revealed. The percentage of polymorphic loci ranged from 14% to 59% and the frequencies of detected alleles varied from null to four per locus. No polymorphism was detected at the loci <i>Dia2</i>, <i>Got3</i>, <i>Mdh4</i>, <i>Mmm</i>, and <i>Pgm1</i>. The highest number of alleles (four) was detected at loci <i>Acp1</i>, <i>Cat3</i>, <i>Pgm2</i>. No new alleles were identified, nevertheless the frequency of seven alleles was only about 1%. The expected heterozygosity ranged from null to 0.492 with an average of 0.197. The revealed isoenzyme polymorphism confirmed that all analyzed populations were heterogeneous and as many as 17 of them were completely heterogeneous. None of the analyzed populations was identical in the frequency of alleles at all 22 analyzed loci.

Sign in / Sign up

Export Citation Format

Share Document