HYBRIDIZATION BETWEEN TWO CYPRINID FISHES, HYBOPSIS PLUMBEA AND RHINICHTHYS CATARACTAE, IN ALBERTA

1966 ◽  
Vol 44 (5) ◽  
pp. 963-968 ◽  
Author(s):  
J. S. Nelson
Keyword(s):  
Environmental Changes ◽  
Parental Species ◽  
Rhinichthys Cataractae ◽  
Cyprinid Fishes ◽  
Physical Changes ◽  
Species Hybrids

Five hybrids between Hybopsis plumbea and Rhinichthys cataractae seined from Upper Kananaskis Reservoir, Alberta, were intermediate in most of the characters examined which differ between their parental species. Hybrids of each sex were present. Environmental changes may have been conducive to the hybridization. Marked physical changes occur annually in Upper Kananaskis Reservoir and Hybopsis plumbea and probably Rhinichthys cataractae were introduced.

scholarly journals Patterns of evolution of genes disrupted in expression in Drosophila species hybrids

2005 ◽  
Vol 85 (2) ◽  
pp. 119-125 ◽  
Author(s):  
MOHAMED A. F. NOOR
Keyword(s):  
Amino Acid ◽  
Parental Species ◽  
Species Group ◽  
Pure Species ◽  
X Chromosomes ◽  
Regulatory Pathways ◽  
Regulatory Architecture ◽  
Species Groups ◽  
Male Specific ◽  
Species Hybrids

Divergence between species in regulatory pathways may contribute to hybrid incompatibilities such as sterility. Consistent with this idea, genes involved in male fertility often evolve faster than most other genes both in amino acid sequence and in expression. Previously, we identified a panel of male-specific genes underexpressed in sterile male hybrids of Drosophila simulans and D. mauritiana relative to pure species, and we showed that this underexpression is associated with infertility. In a preliminary effort to assess the generalities in the patterns of evolution of these genes, I examined patterns of mRNA expression in three of these genes in sterile F1 hybrid males of D. pseudoobscura and D. persimilis. F1 hybrid males bearing D. persimilis X chromosomes underexpressed all these genes relative to the parental species, while hybrids bearing D. pseudoobscura X chromosomes underexpressed two of these three genes. Interestingly, the third gene, CG5762, has undergone extensive amino acid evolution within the D. pseudoobscura species group, possibly driven by positive natural selection. We conclude that some of the same genes exhibit disruptions in expression within each of the two species groups, which could suggest commonalities in the regulatory architecture of sterility in these groups. Alternative explanations are also considered.

scholarly journals Evaluation of High-Resolution Melting for Rapid Differentiation of Phytophthora Hybrids and Their Parental Species

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2295-2304
Author(s):  
Maria F. Ratti ◽  
Rhys A. Farrer ◽  
Liliana M. Cano ◽  
Roberto Faedda ◽  
Erica M. Goss
Keyword(s):  
High Resolution ◽  
Genome Sequencing ◽  
High Resolution Melting ◽  
Parental Species ◽  
Phytophthora Species ◽  
Wild Plants ◽  
Whole Genome ◽  
Advance Research ◽  
Species Hybrids ◽  
Rapid Tool

Phytophthora species hybrids have been repeatedly reported as causing damaging diseases to cultivated and wild plants. Two known hybrids, P. andina and P. × pelgrandis, are pathogens of Solanaceae and ornamentals, respectively, although the extent of their host ranges are unknown. P. andina emerged from hybridization of P. infestans and an unidentified related species, whereas P. × pelgrandis emerged from P. nicotianae and P. cactorum. Considering that hybrids and parental species can coexist in the same regions and to distinguish them usually requires cloning or whole genome sequencing, we aimed to develop a rapid tool to distinguish them. Specifically, we used high-resolution melting (HRM) assays to differentiate genotypes based on their amplicon melting profiles. We designed primers for P. × pelgrandis and parental species based on available sequences of P. nicotianae and P. cactorum nuclear genes containing polymorphisms between species. For P. andina, heterozygous sites from Illumina short reads were used for the same purpose. We identified multiple amplicons exhibiting differences in melting curves between parental species and hybrids. We propose HRM as a rapid method for differentiation of P. andina and P. × pelgrandis hybrids from parental species that could be employed to advance research on these pathogens.

scholarly journals An assessment of the functional variability of selected coastal ecosystems in the context of local environmental changes

2009 ◽  
Vol 66 (7) ◽  
pp. 1520-1527 ◽  
Author(s):  
Dan Baird
Keyword(s):  
Environmental Changes ◽  
System Organization ◽  
Coastal Ecosystems ◽  
System Throughput ◽  
Total System ◽  
Nutrient Input ◽  
Run Off ◽  
Carbon Recycling ◽  
Physical Changes ◽  
Selection Of

Abstract Baird, D. (2009) An assessment of the functional variability of selected coastal ecosystems in the context of local environmental changes. – ICES Journal of Marine Science, 66: 1520–1527. The functioning of coastal ecosystems is greatly dependent on a wide variety of external pulses (e.g. tides, freshwater influx, seasonal trends in temperature, nutrient input, etc.). Assessments of the effect of a selection of environmental characteristics driven by natural and/or anthropogenic forces on ecosystem function are given using selected ecosystem properties, such as total system throughput, system organization, productivity, recycling, and trophic efficiency, derived from ecological network analysis (ENA) of several coastal ecosystems on monthly, intra-seasonal, seasonal, and interdecadal scales. Each ecosystem was modelled depicting data of standing stocks, the flows between the constituent living and non-living components in the system, exports, and imports. Results from ENA revealed considerable differences of the same property (or properties) resulting from physical changes (e.g. temperature, salinity, oxygen, rate of freshwater inflow) over time. A small temperature increase in a Florida seagrass bed, for example, resulted in increases in system throughput, the P/B ratio, and in the rate of carbon recycling, but also in a significant decrease in system organization. The effect of seasonal increases in water temperature and of measured decrease/increase in river run-off to a few selected estuaries is discussed using ENA.

Land use change causes environmental homogeneity and low beta-diversity in Heteroptera of streams

2020 ◽  
Vol 56 ◽  
pp. 9 ◽  
Author(s):  
Karina Dias-Silva ◽  
Leandro Schlemmer Brasil ◽  
Geysa Kelly Oliveira Veloso ◽  
Helena Soares Ramos Cabette ◽  
Leandro Juen
Keyword(s):  
Beta Diversity ◽  
Riparian Vegetation ◽  
Environmental Changes ◽  
Aquatic Communities ◽  
Generalist Species ◽  
Environmental Variations ◽  
Environmental Integrity ◽  
Physical Changes ◽  
Topic Understanding ◽  
Better Than

Although species distribution pattern is a widely discussed topic, understanding the mechanisms that drive it in time and space is still one of the central goals of ecology. Moreover, it is of the most importance to discuss the maintenance of this biodiversity and the services it provides. Therefore, our aim is to test the following hypotheses: 1) Preserved environments have higher beta-diversity than environments with lower preservation values, since beta-diversity is determined by environmental variations between habitats; 2) Beta-diversity will be better than species richness to detect changes in community regarding environmental integrity gradients. This will occur because richness is not sensitive to changes in composition and this might mask results when sensitive species are lost and generalist species are introduced into the altered environments. In order to test these hypotheses, 20 points were sampled in five streams of the Brazilian Cerrado with different integrity conditions. Environmental change did not affect Heteroptera richness; however, it affected the beta-diversity of the group as a whole and of Nepomorpha, also negatively affecting both Gerromorpha beta-diversity and richness. Moreover, there was difference in variation of Gerromorpha composition in altered and degraded sites, but there was no effect on Nepomorpha. These results show that Gerromorpha is more sensitive to physical changes in streams caused by the loss of environmental integrity. Therefore, environmental changes with no regard to riparian vegetation boundaries causes shifts in stream conditions and changes aquatic communities, which places at risk the ecosystems services provided by these communities.

A Model-Based Method for Identifying Species Hybrids Using Multilocus Genetic Data

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1217-1229 ◽  
Author(s):  
E C Anderson ◽  
E A Thompson
Keyword(s):  
Parental Species ◽  
Probability Model ◽  
Simulated Data ◽  
Data Sets ◽  
Model Based Clustering ◽  
Model Based ◽  
Hybrid Classes ◽  
Allelic Differences ◽  
Using Data ◽  
Species Hybrids

Abstract We present a statistical method for identifying species hybrids using data on multiple, unlinked markers. The method does not require that allele frequencies be known in the parental species nor that separate, pure samples of the parental species be available. The method is suitable for both markers with fixed allelic differences between the species and markers without fixed differences. The probability model used is one in which parentals and various classes of hybrids (F1's, F2's, and various backcrosses) form a mixture from which the sample is drawn. Using the framework of Bayesian model-based clustering allows us to compute, by Markov chain Monte Carlo, the posterior probability that each individual belongs to each of the distinct hybrid classes. We demonstrate the method on allozyme data from two species of hybridizing trout, as well as on two simulated data sets.

Natural Hybridization between Arctic Char (Salvelinus alpinus) and Brook Trout (S. fontinalis): Evidence from Northern Labrador

1991 ◽  
Vol 48 (8) ◽  
pp. 1437-1445 ◽  
Author(s):  
Johan Hammar ◽  
J. Brian Dempson ◽  
Eric Verspoor
Keyword(s):  
Research And Development ◽  
Brook Trout ◽  
Parental Species ◽  
Salvelinus Alpinus ◽  
Electrophoretic Analysis ◽  
Arctic Char ◽  
Natural Hybridization ◽  
Gene Pools ◽  
Fraser River ◽  
Species Hybrids

Electrophoretic analysis of successive samples of Salvelinus collected in the Fraser River watershed of northern Labrador in 1984 and 1986 revealed the existence of natural hybrids between Arctic char (Salvelinus alpinus) and brook trout (S. fontinalis). We examined 11 electrophoretic loci in liver tissue; 10 loci were informative and six were diagnostic of the two species and their hybrids. The electrophoretic phenotypes of some hybrid specimens sugested that they were second-generation hybrids and/or backcrosses to the parental species. Hybrids were represented by six different year classes, indicating that crossing between the species in the system is a regular occurrence. The hybrids, although visually difficult to distinguish from brook trout, were meristicaîly intermediate or more closely resembled Arctic char. The observations raise a number of questions regarding the ecological circumstances promoting hybridization in the evolution of Arctic char and brook trout populations. The results stress the need for restrictions on introducing brook trout into systems with original populations of Arctic char. Further, Arctic char from the Fraser River are commonly used for aquaculture research and development; therefore, there is a clear need to screen fish carefully to determine whether or not they represent introgressed gene pools.

Multivariate analysis of hybridizing Cyprinidae from the Kananaskis Reservoirs, Alberta

1980 ◽  
Vol 58 (9) ◽  
pp. 1664-1673 ◽  
Author(s):  
G. A. Butcher
Keyword(s):  
Multivariate Analysis ◽  
Principal Components ◽  
Parental Species ◽  
Morphological Characters ◽  
Rhinichthys Cataractae ◽  
Canonical Variates ◽  
Couesius Plumbeus ◽  
Hybrid Group

Principal components and canonical variates analyses of hybridizing Couesius plumbeus (lake chub) and Rhinichthys cataractae (longnose dace) from Upper and Lower Kananaskis Reservoirs, Alberta, using 21 morphological characters, revealed two parental groups bridged continuously by an intermediate hybrid group. This morphological overlap between the hybrids and the parental species indicates that it is not always possible to positively identify "pure" parental individuals from the Kananaskis. Neither backcross nor hybrid F2 individuals could be identified from the analyses, although the Kananaskis R. cataractae showed effects suggestive of either selection or introgression, relative to known R. cataractae from widespread Alberta localities. Rhinichthys cataractae has also declined in numbers relative to C. plumbeus since last studied in 1961. Couesius plumbeus does not show similar effects suggestive of selection or introgression.

scholarly journals Additive and non-additive epigenetic signatures of hybridisation between fish species with different mating systems

2020 ◽  
Author(s):  
Waldir M. Berbel-Filho ◽  
Andrey Tatarenkov ◽  
George Pacheco ◽  
Helder M. V. Espírito-Santo ◽  
Mateus G. Lira ◽  
...  
Keyword(s):  
Mating Systems ◽  
Parental Species ◽  
Major Effect ◽  
F1 Hybrids ◽  
Introgressive Hybridisation ◽  
Evolutionary Innovation ◽  
Natural Hybridisation ◽  
Methylation Patterns ◽  
Epigenetic Signatures ◽  
Species Hybrids

AbstractHybridisation is a major source of evolutionary innovation. However, several prezygotic and postzygotic factors influence its likelihood and evolutionary outcomes. Differences in mating systems can have a major effect on the extent and direction of hybridisation and introgression. In plants, epigenetic mechanisms help to stabilize hybrid genomes and contribute to reproductive isolation, but the relationship between genetic and epigenetic changes in animal hybrids is unclear. We analysed the extent of a unique case of natural hybridisation between two genetically distant mangrove killifish species with different mating systems, Kryptolebias hermaphroditus (self-fertilising) and K. ocellatus (outcrossing), and the methylation patterns of their hybrids. Hybridisation rate between the species ranged between 14% and 26%. Although co-existing parental species displayed highly distinct genetic (microsatellites and SNPs) and methylation patterns (37,000 differentially methylated cytosines), our results indicate that F1 hybrids are viable and able to backcross with parental species. Hybrids had predominantly intermediate methylation patterns (88.5% of the sites) suggesting additive effects, as expected from hybridisation between genetically distant species. Differentially methylated cytosines between hybrids and both parental species (5,800) suggest that introgressive hybridisation may play a role in generating novel genetic and epigenetic variation which could lead to species diversification. We also found a small percentage of non-additive epigenetic effects which might act as an evolutionary bet-hedging strategy and increase fitness under environmental change.

Induction of tumor formation in Nicotiana amphiploids with triiodobenzoic acid

1970 ◽  
Vol 48 (12) ◽  
pp. 2209-2212 ◽  
Author(s):  
Ira H. Ames
Keyword(s):  
Nutrient Medium ◽  
Parental Species ◽  
Tumor Formation ◽  
Trigger Mechanism ◽  
Tumor Induction ◽  
Nicotiana Species ◽  
Triiodobenzoic Acid ◽  
Species Hybrids

Young seedlings of two tumorous Nicotiana amphiploids and the parental species, grown aseptically on nutrient medium, were treated with 2,3,5-triiodobenzoic acid. The incidence of tumor formation was scored for 18 days subsequent to exposure. Triiodobenzoic acid markedly accelerated the rate of tumorigenesis in both amphiploids, but it did not induce tumors in the parental species. The compound also induced tumor formation in a small percentage of seedlings of a non-tumorous mutant of the N. glauca × N. langsdorffii amphiploid. These results are discussed in relation to the problem of the trigger mechanism for tumor induction in Nicotiana species hybrids.<

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