The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients

Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e. inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on (i) mean fitness of a population (relative to that of an outbred control population), (ii) within‐population inbreeding depression (reduction in fitness of offspring fro…

Additional file 6 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

The concatenated tree based on six housekeeping MLSA genes (including trpB; right) and five MLSA gene sequences (rpoD, dnaK, tuf, gyrB, atpA; left). The arrow shows disagreement concerning the position of strain G2 (B399) between the two trees. (PDF 77 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Fitness and viability of small populations : the effects of genetic drift, inbreeding, and interpopulation hybridization

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

The benefits of interpopulation hybridization diminish with increasing divergence of small populations.

Interpopulation hybridization can increase the viability of small populations suffering from inbreeding and genetic drift, but it can also result in outbreeding depression. The outcome of hybridization can depend on various factors, including the level of genetic divergence between the populations, and the number of source populations. Furthermore, the effects of hybridization can change between generations following the hybridization. We studied the effects of population divergence (low vs. high level of divergence) and the number of source populations (two vs. four source populations) on the viability of hybrid populations using experimental Drosophila littoralis populations. Population v…

Males Benefit from Mating with Outbred Females in Drosophila littoralis: Male Choice for Female Genetic Quality?

The evolution and expression of mate choice behaviour in either sex depends on the sex-specific combination of mating costs, benefits of choice and constraints on choice. If the benefits of choice are larger for one sex, we would expect that sex to be choosier, assuming that the mating costs and constraints on choice are equal between sexes. Because deliberate inbreeding is a powerful genetic method for experimental manipulation of the quality of study organisms, we tested the effects of both male and female inbreeding on egg and offspring production in Drosophila littoralis. Female inbreeding significantly reduced offspring production (mostly due to lower egg-to-adult viability), whereas m…

Sexual selection for genetic quality: disentangling the roles of male and female behaviour

According to the good genes model of sexual selection, females choose males of good heritable genetic quality to obtain offspring with high fitness. However, better mating success of high-quality males can also be brought about by direct interference competition between males, or simply through elevated activity of high-quality males. We examined the roles of different processes leading to sexual selection for genetic quality in Drosophila montana. We manipulated genetic quality of male flies by inducing mutations with ionizing radiation. We then recorded the effects of inherited heterozygous mutations on several aspects of mating behaviour of males and females in two experiments. We found …

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Additional file 1 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Site, year of isolation, source of isolation (fish or water), location of isolation, host species, sequence type (ST), and allelic profile data for the 83Â F. columnare strains from Finland analyzed by MLST. (DOCX 46 kb)

Laboratory relationships between adult lifetime reproductive success and fitness surrogates in a Drosophila littoralis population.

The difficulties in measuring total fitness of individuals necessitate the use of fitness surrogates in ecological and evolutionary studies. These surrogates can be different components of fitness (e.g. survival or fecundity), or proxies more uncertainly related to fitness (e.g. body size or growth rate). Ideally, fitness would be measured over the lifetime of individuals; however, more convenient short-time measures are often used. Adult lifetime reproductive success (adult LRS) is closely related to the total fitness of individuals, but it is difficult to measure and rarely included in fitness estimation in experimental studies. We explored phenotypic correlations between female adult LRS…

A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Background Columnaris disease caused by Flavobacterium columnare is a serious problem in aquaculture, annually causing large economic losses around the world. Despite considerable research, the molecular epidemiology of F. columnare remains poorly understood. Methods We investigated the population structure and spatiotemporal changes in the genetic diversity of F. columnare population in Finland by using a multilocus sequence typing (MLST) and analysis (MLSA) based on DNA sequence variation within six housekeeping genes. A total of 83 strains of F. columnare were collected from eight different areas located across the country between 2003 and 2012. Results Partial sequencing of six housekee…

Effect of resource availability on evolution of virulence and competition in an environmentally transmitted pathogen

Understanding ecological and epidemiological factors driving pathogen evolution in contemporary time scales is a major challenge in modern health management. Pathogens that replicate outside the hosts are subject to selection imposed by ambient environmental conditions. Increased nutrient levels could increase pathogen virulence by pre-adapting for efficient use of resources upon contact to a nutrient rich host or by favouring transmission of fast-growing virulent strains. We measured changes in virulence and competition in Flavobacterium columnare, a bacterial pathogen of freshwater fish, under high and low nutrient levels. To test competition between strains in genotype mixtures, we devel…

Additional file 4 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

The fluorescence peak profiles for the ARISA genotypes analysed with ABI Prism 3130xl Genetic Analyser and the GeneMapper v.5.0 software (Applied Biosystems, Carlsbad, California, USA). For the 83 strains isolated from Finland, we also determined the ARISA (automated ribosomal intergenic spacer analysis) genotypes following the procedure described by Suomalainen et al. [8]. However, the previously published method was modified so that ABI Prism 3130xl Genetic Analyser is used instead of LI-COR 4200 automatic sequencer The analysis revealed that ARISA genotypes associate uniformly with the clusters from the MLSA scheme. Briefly, the PCR reaction mixture (total volume 10 ul) contained 1X Drea…

Additional file 3 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Neighbor Joining phylogenetic trees based on the individual sequences of six MLST loci (trpB, rpoD, gyrB, dnaK, atpA,and tuf). MEGA v5.2 was used to evaluate the models for nucleotide substitution for each protein-coding locus and to construct the phylogenetic trees for Finnish F. columnare strains. The F. columnare type strain NCIMB 2248T isolated in the USA and two reference strains JIP39/87 and ATCC49512, both isolated in France, were also included in the phylogenetic analysis. The best model indicated by the lowest Bayesian Information Criterion (BIC) value was used to generate the Neighbor-Joining tree based on 1000 replicates. The T92 model was selected for dnaK, tuf, and gyrB, while …

Inbreeding rate modifies the dynamics of genetic load in small populations

The negative fitness consequences of close inbreeding are widely recognized, but predicting the long-term effects of inbreeding and genetic drift due to limited population size is not straightforward. As the frequency and homozygosity of recessive deleterious alleles increase, selection can remove (purge) them from a population, reducing the genetic load. At the same time, small population size relaxes selection against mildly harmful mutations, which may lead to accumulation of genetic load. The efficiency of purging and the accumulation of mutations both depend on the rate of inbreeding (i.e., population size) and on the nature of mutations. We studied how increasing levels of inbreeding …

Additional file 2 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Target genes and primers for the housekeeping genes of F. columnare. The loci used for the MLST/MLSA scheme are shown in bold font. Length refers to the length of the target sequence. * Reference for 16S rDNA primers [52]. (DOCX 20 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Additional file 2 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Target genes and primers for the housekeeping genes of F. columnare. The loci used for the MLST/MLSA scheme are shown in bold font. Length refers to the length of the target sequence. * Reference for 16S rDNA primers [52]. (DOCX 20 kb)

Additional file 5 of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Phylogenetic tree based on the 16Â s rDNA sequence data obtained from the representatives of Finnish F .columnare genotypes (A-H) studied in this study and other F .columnare sequences obtained from the GenBank. The tree was constructed by a UPGMA clustering method with a resampling of 1,000 bootstrap replicates and the Jukes Cantor model. Two strains representative of each ARISA genotype/MLSA cluster studied in this study were used for tree construction (identical sequences removed for clarity of representation). (PDF 191 kb)

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

of A multilocus sequence analysis scheme for characterization of Flavobacterium columnare isolates

Data from: The effect of inbreeding rate on fitness, inbreeding depression and heterosis over a range of inbreeding coefficients

Understanding the effects of inbreeding and genetic drift within populations and hybridization between genetically differentiated populations is important for many basic and applied questions in ecology and evolutionary biology. The magnitudes and even the directions of these effects can be influenced by various factors, especially by the current and historical population size (i.e., inbreeding rate). Using Drosophila littoralis as a model species, we studied the effect of inbreeding rate over a range of inbreeding levels on 1) mean fitness of a population (relative to that of an outbred control population), 2) within-population inbreeding depression (reduction in fitness of offspring from …