Fitness Traits and Dispersal Ability in the Herb Tragopogon pratensis (Asteraceae): Decoupling the Role of Inbreeding Depression and Maternal Effects

Plant Biology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 522-530 ◽  
Author(s):  
F. X. Picó ◽  
N. J. Ouborg ◽  
J. M. Groenendael
Keyword(s):  
Maternal Effects ◽  
Inbreeding Depression ◽  
Dispersal Ability ◽  
Fitness Traits

scholarly journals Maternal effects alter the severity of inbreeding depression in the offspring

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161023 ◽  
Author(s):  
Natalie Pilakouta ◽  
Per T. Smiseth
Keyword(s):  
Maternal Effects ◽  
Inbreeding Depression ◽  
Potential Role ◽  
Causal Effect ◽  
Natural Populations ◽  
Larval Survival ◽  
Burying Beetle ◽  
Nicrophorus Vespilloides ◽  
Selection For

A maternal effect is a causal influence of the maternal phenotype on the offspring phenotype over and above any direct effects of genes. There is abundant evidence that maternal effects can have a major impact on offspring fitness. Yet, no previous study has investigated the potential role of maternal effects in influencing the severity of inbreeding depression in the offspring. Inbreeding depression is a reduction in the fitness of inbred offspring relative to outbred offspring. Here, we tested whether maternal effects due to body size alter the magnitude of inbreeding depression in the burying beetle Nicrophorus vespilloides . We found that inbreeding depression in larval survival was more severe for offspring of large females than offspring of small females. This might be due to differences in how small and large females invest in an inbred brood because of their different prospects for future breeding opportunities. To our knowledge, this is the first evidence for a causal effect of the maternal phenotype on the severity of inbreeding depression in the offspring. In natural populations that are subject to inbreeding, maternal effects may drive variation in inbreeding depression and therefore contribute to variation in the strength and direction of selection for inbreeding avoidance.

scholarly journals The role of dispersal for shaping phylogeographical structure of flightless beetles from the Andes

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7226 ◽  
Author(s):  
Sofia I. Muñoz-Tobar ◽  
Michael S. Caterino
Keyword(s):  
Mitochondrial Gene ◽  
Ground Beetle ◽  
Population Level ◽  
Population Subdivision ◽  
Dispersal Ability ◽  
Population Isolation ◽  
Small Areas ◽  
Maximum Entropy Models ◽  
The Andes

Background Páramo is a tropical alpine ecosystem present in the northern Andes. Its patchy distribution imposes limits and barriers to specialist inhabitants. We aim to assess the effects of this habitat distribution on divergence across two independently flightless ground beetle lineages, in the genera Dyscolus and Dercylus. Methods One nuclear and one mitochondrial gene from 110 individuals from 10 sites across the two lineages were sequenced and analyzed using a combination of phylogenetics, population genetic analyses, and niche modeling methods. Results The two lineages show different degrees of population subdivision. Low levels of gene flow were found in Dyscolus alpinus, where one dominant haplotype is found in four out of the six populations analyzed for both molecular markers. However, complete population isolation was revealed in species of the genus Dercylus, where high levels of differentiation exist at species and population level for both genes. Maximum entropy models of species in the Dercylus lineage show overlapping distributions. Still, species distributions appear to be restricted to small areas across the Andes. Conclusion Even though both beetle lineages are flightless, the dispersal ability of each beetle lineage appears to influence the genetic diversity across fragmented páramo populations, where Dyscolus alpinus appears to be a better disperser than species in the genus Dercylus.

scholarly journals Heterosis in the second and third generation affects litter size in a crossbreed mink (Neovison vison) population

2014 ◽  
Vol 66 (3) ◽  
pp. 1097-1103 ◽  
Author(s):  
Janne Thirstrup ◽  
Cino Pertoldi ◽  
Peter Larsen ◽  
Vivi Nielsen
Keyword(s):  
Litter Size ◽  
Maternal Effects ◽  
Inbreeding Depression ◽  
Neovison Vison ◽  
Parental Line ◽  
Third Generation ◽  
Black Line ◽  
Environmental Variations ◽  
The Mean ◽  
One Year

Litter sizes in a cross between Brown and Black mink color types were observed through six generations. Litter size was significantly affected by yearly environmental variations. After adjusting for year effects, we found significant increases in litter size in the second and third generations (F2 and F3) after crossing. Thereafter, in the following generations, litter size dropped to a level comparable to the mean litter size of the midparent. Increased litter size in F2 compared to F1 indicated that maternal effects influenced litter size more than non-maternal effects. The heterosis was mainly caused by an increase in litter size compared to the Black parental line. This indicates that the Black line was affected by inbreeding depression prior to crossing. We also found that two-year old F1 females had significantly more offspring compared to one-year old F1 females.

scholarly journals Explaining discrepancies in the study of maternal effects: the role of context and embryo

2020 ◽  
Vol 36 ◽  
pp. 185-192
Author(s):  
Ton GG Groothuis ◽  
Neeraj Kumar ◽  
Bin-Yan Hsu
Keyword(s):  
Maternal Effects

scholarly journals Point estimation and graphical inference of marginal dominance for two viability loci controlling inbreeding depression

1997 ◽  
Vol 70 (2) ◽  
pp. 143-153 ◽  
Author(s):  
YONG-BI FU ◽  
DEBORAH CHARLESWORTH ◽  
GENE NAMKOONG
Keyword(s):  
Inbreeding Depression ◽  
Gene Action ◽  
Marker Locus ◽  
Point Estimation ◽  
Relative Role ◽  
Selfed Progeny ◽  
Deterministic Analysis ◽  
Partial Dominance ◽  
Segregation Ratios

A deterministic analysis is conducted to examine marginal dominance for two linked viability loci influencing inbreeding depression and its graphical inferences. Four estimators of marginal dominance are derived, assuming a biallelic marker locus completely linked to one of the viability loci, and the biases in expected estimates due to the other deleterious locus are discussed. Three conditions under which apparent partial dominance or underdominance could occur are found, i.e. when two multiplicative, partially recessive loci are linked in coupling phase and when two synergistic, highly overdominant loci are linked in coupling or repulsion phases. Expected frequencies of the three marker genotypes in selfed progeny are derived, considering two linkage phases, two types of marker locus position with respect to the viability loci, and the multiplicative and synergistic fitness models. Segregation ratios are generated for the marker locus linked to either two overdominant or partially recessive loci and plotted in gene action graphs to examine the robustness of the graphical inferences of gene action due to the presence of an additional linked viability locus. Under a multiplicative fitness model, the presence of an additional partially recessive or overdominant locus in the vicinity of the marker locus does not greatly affect the graphical inferences of the relative role of partially recessive or overdominant genes in expression of inbreeding depression. A marker linked to two synergistic, highly overdominant loci can behave as though linked to a partially recessive, partially dominant or underdominant locus, even with relatively weak synergism.

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