scholarly journals Population Genetics and Spawning Time of Lake Taupo Rainbow Trout

2021 ◽  
Author(s):  
◽  
Elizabeth Rose Heeg
Keyword(s):  
Genetic Variation ◽  
Rainbow Trout ◽  
Microsatellite Markers ◽  
Population Genetic ◽  
Allele Frequencies ◽  
Migration Time ◽  
Spawning Migration ◽  
Spatial Population ◽  
Significant Difference ◽  
Spawning Time

<p>The rainbow trout (Oncorhynchus mykiss) of Lake Taupo, New Zealand provide an exceptional opportunity to explore the contemporary adaptation of an introduced aquatic species. Recently it has become evident that their spawning migration time has shifted to later in the season. I investigated the genetic basis of these changes in spawning time by (1) using genetic markers to determine the origins of Taupo trout in California, (2) determining the pattern and extent of spatial population genetic variation throughout the Lake Taupo catchment and in comparison to nearby Lake Tarawera in the Rotorua district, (3) analysing genetic variation at the OtsClock1b spawning time gene in temporal replicates from several sites from Taupo, and (4) comparing contemporary genetic variation at this gene and microsatellite markers to genetic variation from three Taupo tributaries in 1980s. I compared the ability of single nucleotide polymorphism (SNP) and microsatellite markers to determine the origins of Lake Taupo rainbow trout, translocated from California around 120 years ago. Data were collected from 15 microsatellite and 93 SNP markers, using samples from the Lake Taupo population and ten populations throughout California, which included all historically indicated populations of origin. Results revealed that the Lake Taupo population has significantly diverged from Californian populations at both microsatellite and SNP loci. These analyses also showed that the Lake Taupo population was probably derived from several sources in California (the most likely origins being the McCloud River and Lake Almanor), and an indeterminate California coastal population. This conclusion was supported with simulations of founder events, which suggested that the genetic patterns of a single source of introduction would still be detectable 100 years post-founding, but with multiple introductions exact source populations become more difficult to detect. Approximately 50 individuals from 10 locations throughout the catchment were then analysed using 15 microsatellite loci to determine if there was any spatial population genetic differentiation. There was no significant difference in genetic distance between locations within Lake Taupo, although there was a significant difference between these populations and Rotorua and Waipakihi, which are isolated by geographic barriers. Lake Taupo rainbow trout do appear to diverge at markers potentially under selection, though, because genotyping of the poly-Q region of the timing locus OtsClock1b shows significant differentiation between individuals sampled at different times in the Waipa River. Two other sites, however, did not show the same pattern of significant seasonal variation in OtsClock1b allele frequencies. This suggests that genotypes at this locus could be influencing spawning migration time, but that this variation could also be site specific, and therefore have a strong environmental component. Scale samples from the 1980s show no significant divergence at 5 microsatellites and OtsClock1b, indicating that allele frequencies have not changed significantly over the last 20 years at neutral markers or markers under selection. I therefore conclude that while Taupo rainbow trout have diverged from their origins in California, they have only slightly diverged within their new environment, and do not show a consistent pattern of genetic change over time. This information will contribute not only to the management of the Taupo fishery but also to the current understanding of the population genetic structuring of introduced salmonids.</p>

scholarly journals Population Genetics and Spawning Time of Lake Taupo Rainbow Trout

2021 ◽  
Author(s):  
◽  
Elizabeth Rose Heeg
Keyword(s):  
Genetic Variation ◽  
Rainbow Trout ◽  
Microsatellite Markers ◽  
Population Genetic ◽  
Allele Frequencies ◽  
Migration Time ◽  
Spawning Migration ◽  
Spatial Population ◽  
Significant Difference ◽  
Spawning Time

<p>The rainbow trout (Oncorhynchus mykiss) of Lake Taupo, New Zealand provide an exceptional opportunity to explore the contemporary adaptation of an introduced aquatic species. Recently it has become evident that their spawning migration time has shifted to later in the season. I investigated the genetic basis of these changes in spawning time by (1) using genetic markers to determine the origins of Taupo trout in California, (2) determining the pattern and extent of spatial population genetic variation throughout the Lake Taupo catchment and in comparison to nearby Lake Tarawera in the Rotorua district, (3) analysing genetic variation at the OtsClock1b spawning time gene in temporal replicates from several sites from Taupo, and (4) comparing contemporary genetic variation at this gene and microsatellite markers to genetic variation from three Taupo tributaries in 1980s. I compared the ability of single nucleotide polymorphism (SNP) and microsatellite markers to determine the origins of Lake Taupo rainbow trout, translocated from California around 120 years ago. Data were collected from 15 microsatellite and 93 SNP markers, using samples from the Lake Taupo population and ten populations throughout California, which included all historically indicated populations of origin. Results revealed that the Lake Taupo population has significantly diverged from Californian populations at both microsatellite and SNP loci. These analyses also showed that the Lake Taupo population was probably derived from several sources in California (the most likely origins being the McCloud River and Lake Almanor), and an indeterminate California coastal population. This conclusion was supported with simulations of founder events, which suggested that the genetic patterns of a single source of introduction would still be detectable 100 years post-founding, but with multiple introductions exact source populations become more difficult to detect. Approximately 50 individuals from 10 locations throughout the catchment were then analysed using 15 microsatellite loci to determine if there was any spatial population genetic differentiation. There was no significant difference in genetic distance between locations within Lake Taupo, although there was a significant difference between these populations and Rotorua and Waipakihi, which are isolated by geographic barriers. Lake Taupo rainbow trout do appear to diverge at markers potentially under selection, though, because genotyping of the poly-Q region of the timing locus OtsClock1b shows significant differentiation between individuals sampled at different times in the Waipa River. Two other sites, however, did not show the same pattern of significant seasonal variation in OtsClock1b allele frequencies. This suggests that genotypes at this locus could be influencing spawning migration time, but that this variation could also be site specific, and therefore have a strong environmental component. Scale samples from the 1980s show no significant divergence at 5 microsatellites and OtsClock1b, indicating that allele frequencies have not changed significantly over the last 20 years at neutral markers or markers under selection. I therefore conclude that while Taupo rainbow trout have diverged from their origins in California, they have only slightly diverged within their new environment, and do not show a consistent pattern of genetic change over time. This information will contribute not only to the management of the Taupo fishery but also to the current understanding of the population genetic structuring of introduced salmonids.</p>

scholarly journals Genetic variation analysis of superior cotton varieties of Gossypium hirsutum through microsatellite markers

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Dede Nuraida ◽  
Yusuf Abdurrajak ◽  
Moh Amin ◽  
Utami S. Hastutik
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Gossypium Hirsutum ◽  
Microsatellite Markers ◽  
Size Range ◽  
Allele Frequencies ◽  
Variation Analysis ◽  
Ctab Method

This study was conducted in order to obtain information on genetic variation in populations rated as superior cotton (<em>Gossypium</em> <em>hirsutum</em> L.) varieties in Balittas Malang, Indonesia. The samples used 10 varieties of cotton Kanesia series and 2 other superior varieties that are LRA 5166 and ISA 205A. Indicators of genetic diversity are the number of alleles per <em>locus</em>, allele frequencies, and heterozygosity values. DNA was isolated from the leaves of 3- week-old seedlings using the CTAB method. Amplification was performed using 5 SSRs primer pairs of the JESPR series. The results showed five microsatellite <em>loci</em>, yielding 12 alleles with a size range of 80–500 bp, with an average number of alleles per <em>locus</em> of 4.60. The average values of heterozygosity of the five loci was high, at 0.71. Based on the number of alleles, allele frequencies and heterozygosity values, the genetic variation sampled in the superior cotton varieties studied here is quite high.

scholarly journals Development of microsatellite markers for the house cricket, Acheta domesticus (Orthoptera: Gryllidae)

2020 ◽  
Vol 21 (9) ◽  
Author(s):  
Yash Munnalal Gupta ◽  
SUPATCHAREE TANASARNPAIBOON ◽  
KITTISAK BUDDHACHAT ◽  
SURIN PEYACHOKNAGUL ◽  
PHATTHARAPORN INTHIM ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Analysis ◽  
Microsatellite Markers ◽  
Population Genetic ◽  
Acheta Domesticus ◽  
House Cricket ◽  
Population Genetic Analysis ◽  
Closely Related Species ◽  
Genetic Studies ◽  
Future Population

Abstract. Gupta YM, Tanasarnpaiboon S, Buddhachat K, Peyachoknagul S, Inthim P, Homchan S. 2020. Development of microsatellite markers for the house cricket, Acheta domesticus (Orthoptera: Gryllidae). Biodiversitas 21: 4094-4099. The house cricket, Acheta domesticus, is one of the species of crickets commonly found in Thailand. Insect breeders in Thailand prefer to breed house cricket as food due to its better taste and popularity among local people. Moreover, largescale breeding industries also breed house cricket to produce cricket-based edible products. Insect breeding industry is growing rapidly and requires primary precaution for sustainable production. To facilitate breeding system to maintain genetic variation in the captive population, we have sequenced the whole genome of A. domesticus to search for simple sequence repeats (SSRs) in order to develop polymorphic microsatellite markers for preliminary population genetic analysis. A total of 112,157 SSRs with primer pairs were identified in our analysis.  Of these, 91 were randomly selected to check for amplification of microsatellite polymorphisms. From these, nine microsatellites were used to check genetic variation in forty-five individuals of A. domesticus from the Phitsanulok population (Thailand).  These microsatellite markers also showed cross-amplification with other three species of edible crickets, specifically Gryllus bimaculatus, Gryllus testaceus, and Brachytrupes portentosus. The microsatellite markers presented herein will facilitate future population genetic analysis of A. domesticus populations. Moreover, the transferability of these makers would also enable researchers to conduct genetic studies for other closely related species.

Gene Flow and Genetic Differentiation among California Coastal Rainbow Trout Populations

1988 ◽  
Vol 45 (1) ◽  
pp. 122-131 ◽  
Author(s):  
W. J. Berg ◽  
G. A. E. Gall
Keyword(s):  
Gene Flow ◽  
Rainbow Trout ◽  
Genetic Variability ◽  
Population Genetic ◽  
Quantitative Methods ◽  
Gene Diversity ◽  
Allele Frequencies ◽  
Qualitative And Quantitative Methods ◽  
Total Gene Diversity ◽  
Population Genetic Variation

Present levels of genetic variability and estimates of historical rates of gene flow were obtained by analyses of allele frequency data from 31 California coastal rainbow trout populations. Genetic variability was higher than seen in most salmonid species. Seventy-one electrophoretic alleles were segregating at 24 loci. Seven loci were monomorphic. Between-population genetic indentities were high and there was only a weak relationship between geographic proximity of populations and genetic identity. Average within-population heterozygosity and percent polymorphic loci were 0.092 and 35.1, respectively. Estimated total heterozygosity was 0.106; therefore, 86.8% of the total gene diversity could be ascribed to within-population genetic variation. The remaining 13.2% of the total gene diversity represented genetic differences between rainbow trout populations. Both qualitative and quantitative methods of analyses suggested that historical rates of gene flow were high; realized gene flow was estimated to be at least 1.7 migrants per population per generation. It is argued that each population's allele frequencies may simply be expression of temporal fluctuations around the panmictic allele frequencies of the greater global population.

Temperature Selection of Rainbow Trout (Salmo gairdneri) Fingerlings in Vertical and Horizontal Gradients

1971 ◽  
Vol 28 (11) ◽  
pp. 1801-1804 ◽  
Author(s):  
R. W. McCauley ◽  
W. L. Pond
Keyword(s):  
Rainbow Trout ◽  
Salmo Gairdneri ◽  
Temperature Preference ◽  
Temperature Selection ◽  
Horizontal Gradients ◽  
Significant Difference ◽  
Preferred Temperatures ◽  
Laboratory Investigations ◽  
Horizontal Temperature Gradients ◽  
Selection Of

Preferred temperatures of underyearling rainbow trout (Salmo gairdneri) were determined in both vertical and horizontal temperature gradients. No statistically significant difference was found between the preferred temperatures by the two different methods. This suggests that the nature of the gradient plays a lesser role than generally believed in laboratory investigations of temperature preference.

scholarly journals Long-Term Experimental Evolution in Escherichia coli. VI. Environmental Constraints on Adaptation and Divergence

Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Michael Travisano
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Experimental Evolution ◽  
Population Genetic ◽  
Environmental Constraints ◽  
Asymmetric Pattern ◽  
Nutrient Environment ◽  
Mean Fitness ◽  
Population Genetic Variation

The effect of environment on adaptation and divergence was examined in two sets of populations of Escherichia coli selected for 1000 generations in either maltose- or glucose-limited media. Twelve replicate populations selected in maltose-limited medium improved in fitness in the selected environment, by an average of 22.5%. Statistically significant among-population genetic variation for fitness was observed during the course of the propagation, but this variation was small relative to the fitness improvement. Mean fitness in a novel nutrient environment, glucose-limited medium, improved to the same extent as in the selected environment, with no statistically significant among-population genetic variation. In contrast, 12 replicate populations previously selected for 1000 generations in glucose-limited medium showed no improvement, as a group, in fitness in maltose-limited medium and substantial genetic variation. This asymmetric pattern of correlated responses suggests that small changes in the environment can have profound effects on adaptation and divergence.

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