scholarly journals Genetic rescue in an inbred Arctic fox ( Vulpes lagopus ) population

2018 ◽  
Vol 285 (1875) ◽  
pp. 20172814 ◽  
Author(s):  
Malin Hasselgren ◽  
Anders Angerbjörn ◽  
Nina E. Eide ◽  
Rasmus Erlandsson ◽  
Øystein Flagstad ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
First Generation ◽  
Small Population ◽  
Arctic Fox ◽  
Vulpes Lagopus ◽  
Genetic Rescue ◽  
Individual Fitness ◽  
Fitness Traits ◽  
Population Average

Isolation of small populations can reduce fitness through inbreeding depression and impede population growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations. We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox ( Vulpes lagopus ), founded by six individuals and isolated for 9 years at an extremely small population size. Based on a long-term pedigree (105 litters, 543 individuals) combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene flow of three outbred males in 2010 resulted in a reduction in population average inbreeding coefficient ( f ), from 0.14 to 0.08 within 5 years. Genetic rescue was further supported by 1.9 times higher juvenile survival and 1.3 times higher breeding success in immigrant first-generation offspring compared with inbred offspring. Five years after immigration, the population had more than doubled in size and allelic richness increased by 41%. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness.

scholarly journals Low Persistence of Genetic Rescue Across Generations in the Arctic Fox (Vulpes lagopus)

2021 ◽  
Author(s):  
Anna Lotsander ◽  
Malin Hasselgren ◽  
Malin Larm ◽  
Johan Wallén ◽  
Anders Angerbjörn ◽  
...  
Keyword(s):  
Time Perspective ◽  
Chromosome Analysis ◽  
Small Population ◽  
The Arctic ◽  
Vulpes Lagopus ◽  
Long Term Effects ◽  
Genetic Rescue ◽  
Isolated Populations ◽  
Individual Fitness

Abstract Genetic rescue can facilitate the recovery of small and isolated populations suffering from inbreeding depression. Long-term effects are however complex, and examples spanning over multiple generations under natural conditions are scarce. The aim of this study was to test for long-term effects of natural genetic rescue in a small population of Scandinavian Arctic foxes (Vulpes lagopus). By combining a genetically verified pedigree covering almost 20 years with a long-term dataset on individual fitness (n = 837 individuals), we found no evidence for elevated fitness in immigrant F2 and F3 compared to native inbred foxes. Population inbreeding levels showed a fluctuating increasing trend and emergence of inbreeding within immigrant lineages shortly after immigration. Between 0–5 and 6–9 years post immigration, the average number of breeding adults decreased by almost 22% and the average proportion of immigrant ancestry rose from 14% to 27%. Y chromosome analysis revealed that 2 out of 3 native male lineages were lost from the gene pool, but all founders represented at the time of immigration were still contributing to the population at the end of the study period through female descendants. The results highlight the complexity of genetic rescue and suggest that beneficial effects can be brief. Continuous gene flow may be needed for small and threatened populations to recover and persist in a longer time perspective.

scholarly journals Mutation load decreases with haplotype age in wild Soay sheep

2021 ◽  
Author(s):  
M.A. Stoffel ◽  
S.E. Johnston ◽  
J.G. Pilkington ◽  
J.M Pemberton
Keyword(s):  
Inbreeding Depression ◽  
Purifying Selection ◽  
Small Population ◽  
First Year ◽  
Mutation Load ◽  
Soay Sheep ◽  
Recessive Mutations ◽  
Deleterious Alleles ◽  
Lower Population

AbstractRuns of homozygosity (ROH) are pervasive in diploid genomes and expose the effects of deleterious recessive mutations, but how exactly these regions contribute to variation in fitness remains unclear. Here, we combined empirical analyses and simulations to explore the deleterious effects of ROH with varying genetic map lengths in wild Soay sheep. Using a long-term dataset of 4,592 individuals genotyped at 417K SNPs, we found that inbreeding depression increases with ROH length. A 1% genomic increase in long ROH (>12.5cM) reduced the odds of first-year survival by 12%, compared to only 7% for medium ROH (1.56-12.5cM), while short ROH (<1.56cM) had no effect on survival. We show by forward genetic simulations that this is predicted: compared with shorter ROH, long ROH will have higher densities of deleterious alleles, with larger average effects on fitness and lower population frequencies. Taken together, our results are consistent with the idea that the mutation load decreases in older haplotypes underlying shorter ROH, where purifying selection has had more time to purge deleterious mutations. Finally, our study demonstrates that strong inbreeding depression can persist despite ongoing purging in a historically small population.

scholarly journals Inbreeding depression in maize populations of reduced size

2002 ◽  
Vol 59 (2) ◽  
pp. 335-340 ◽  
Author(s):  
Félix Alonso Astete Maldonado ◽  
José Branco de Miranda Filho
Keyword(s):  
Plant Height ◽  
Inbreeding Depression ◽  
Quantitative Traits ◽  
First Generation ◽  
Small Population ◽  
Yield Traits ◽  
Common System ◽  
Two Generations ◽  
Population Sizes ◽  
Ear Height

Inbreeding is a well known phenomenon in living beings and its immediate consequence is the decrease in the expression of quantitative traits, known as inbreeding depression. Selfing is the most common system of inbreeding in plant species; however, little has been studied with other less severe inbreeding systems, such that resulting from small population sizes. The present work consisted of the study of the inbreeding effect on quantitative traits as a consequence of reduced population size under panmixy. Three maize (Zea mays L.) populations were used in this study: P1 -- ITA, population derived from the variety IAC-Taiúba; P2 -- represented by 30 subpopulations already submmited to reduced size (N = 5); and P3 - population derived from the interpopulation cross ESALQ-PB2 x ESALQ-PB3. The subpopulations and the respective parental populations were evaluated in six experiments using completely randomized blocks with four replications in Piracicaba (SP) and Anhembi (SP), Brazil, from 1997 to 1999. Estimates of inbreeding depression and components of means were obtained for the two generations in the three populations for the following traits: plant height, ear height, ear length, ear diameter, and yield traits (total ear weight and total grain weight). In all populations and for all traits and sampling generations, means of subpopulations were always smaller than mean of the base populations, however the inbreeding depression levels were smaller than expected. The highest inbreeding depression was exhibited by the yield traits, while a very small depressive effect was observed for plant height and ear height in the first generation of reduced size in populations P1 and P3. The component A (expected mean of a random sample of completely homozygous lines) was always higher than d (contribution of the heterozygotes to the mean) for all traits and populations.

scholarly journals Reviewing the consequences of genetic purging on the success of rescue programs

2021 ◽  
Author(s):  
Noelia Perez-Pereira ◽  
Armando Caballero ◽  
Aurora Garcia-Dorado
Keyword(s):  
Inbreeding Depression ◽  
Extinction Risk ◽  
Conservation Strategy ◽  
Recessive Mutation ◽  
Stable Gene ◽  
Main Concern ◽  
Genetic Rescue ◽  
Genetic Purging ◽  
The Impact

Genetic rescue is increasingly considered a promising and underused conservation strategy to reduce inbreeding depression and restore genetic diversity in endangered populations, but the empirical evidence supporting its application is limited to a few generations. Here we discuss on the light of theory the role of inbreeding depression arising from partially recessive deleterious mutations and of genetic purging as main determinants of the medium to long-term success of rescue programs. This role depends on two main predictions: (1) The inbreeding load hidden in populations with a long stable demography increases with the effective population size; and (2) After a population shrinks, purging tends to remove its (partially) recessive deleterious alleles, a process that is slower but more efficient for large populations than for small ones. We also carry out computer simulations to investigate the impact of genetic purging on the medium to long term success of genetic rescue programs. For some scenarios, it is found that hybrid vigor followed by purging will lead to sustained successful rescue. However, there may be specific situations where the recipient population is so small that it cannot purge the inbreeding load introduced by migrants, which would lead to increased fitness inbreeding depression and extinction risk in the medium to long term. In such cases, the risk is expected to be higher if migrants came from a large non-purged population with high inbreeding load, particularly after the accumulation of the stochastic effects ascribed to repeated occasional migration events. Therefore, under the specific deleterious recessive mutation model considered, we conclude that additional caution should be taken in rescue programs. Unless the endangered population harbors some distinctive genetic singularity whose conservation is a main concern, restoration by continuous stable gene flow should be considered, whenever feasible, as it reduces the extinction risk compared to repeated occasional migration and can also allow recolonization events.

scholarly journals Reviewing the consequences of genetic purging on the success of rescue programs

2021 ◽  
Author(s):  
Noelia Pérez-Pereira ◽  
Armando Caballero ◽  
Aurora García-Dorado
Keyword(s):  
Inbreeding Depression ◽  
Extinction Risk ◽  
Conservation Strategy ◽  
Recessive Mutation ◽  
Stable Gene ◽  
Main Concern ◽  
Genetic Rescue ◽  
Genetic Purging ◽  
The Impact

AbstractGenetic rescue is increasingly considered a promising and underused conservation strategy to reduce inbreeding depression and restore genetic diversity in endangered populations, but the empirical evidence supporting its application is limited to a few generations. Here we discuss on the light of theory the role of inbreeding depression arising from partially recessive deleterious mutations and of genetic purging as main determinants of the medium to long-term success of rescue programs. This role depends on two main predictions: (1) The inbreeding load hidden in populations with a long stable demography increases with the effective population size; and (2) After a population shrinks, purging tends to remove its (partially) recessive deleterious alleles, a process that is slower but more efficient for large populations than for small ones. We also carry out computer simulations to investigate the impact of genetic purging on the medium to long term success of genetic rescue programs. For some scenarios, it is found that hybrid vigor followed by purging will lead to sustained successful rescue. However, there may be specific situations where the recipient population is so small that it cannot purge the inbreeding load introduced by migrants, which would lead to increased fitness inbreeding depression and extinction risk in the medium to long term. In such cases, the risk is expected to be higher if migrants came from a large non-purged population with high inbreeding load, particularly after the accumulation of the stochastic effects ascribed to repeated occasional migration events. Therefore, under the specific deleterious recessive mutation model considered, we conclude that additional caution should be taken in rescue programs. Unless the endangered population harbors some distinctive genetic singularity whose conservation is a main concern, restoration by continuous stable gene flow should be considered, whenever feasible, as it reduces the extinction risk compared to repeated occasional migration and can also allow recolonization events.

Do antiserotonergic antipsychotics induce OCD more frequently than first-generation antipsychotics in the long-term treatment of schizophrenia?

2005 ◽  
Vol 38 (05) ◽  
Author(s):  
X Schlenzig ◽  
J Rentzsch ◽  
SBD Bahri ◽  
H Danker-Hopfe ◽  
MC Jockers-Scherübl
Keyword(s):  
First Generation ◽  
Term Treatment ◽  
Long Term Treatment

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

Reports From the Field: “Vini Ansanm” Come Together for Inclusive Community Music Development in Port-au-Prince, Haiti

2020 ◽  
pp. 273-289
Author(s):  
Donald DeVito ◽  
Gertrude Bien-Aime ◽  
Hannah Ehrli ◽  
Jamie Schumacher
Keyword(s):  
Social Media ◽  
Inclusive Education ◽  
Children With Disabilities ◽  
Small Population ◽  
Significant Loss ◽  
Community Music ◽  
Music Learning ◽  
Loss Of Life

Haiti has experienced a series of catastrophic natural disasters in recent decades, resulting in significant loss of life and long-term damage to infrastructure. One critical outcome of these disasters is that there are approximately 400,000 orphans in the small population of just over 10 million. Throughout Haiti, children with disabilities are often considered cursed, and thus are rejected by the community in which they live. Haitian children with disabilities need creative and educational activities that will help them grow, develop, enjoy their lives, and become accepted members of the community. This chapter on the Haitian Center for Inclusive Education presents a case study of social media engagement and music learning, with an emphasis on social justice that has contributed to sustainable efforts.

The overabundance of resources leads to small but exclusive home ranges in Arctic fox (Vulpes lagopus) on Bering Island

Polar Biology ◽  
2021 ◽  
Author(s):  
Anton Pletenev ◽  
Elena Kruchenkova ◽  
Yulia Mikhnevich ◽  
Vyacheslav Rozhnov ◽  
Mikhail Goltsman
Keyword(s):  
Home Ranges ◽  
Arctic Fox ◽  
Vulpes Lagopus ◽  
Bering Island
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