Testing for parallel allochronic isolation in lake–stream stickleback

Hanson, Dieta; Barrett, Rowan D. H.; Hendry, Andrew P.

doi:10.1111/jeb.12761

Cited by 12 publications

(12 citation statements)

References 90 publications

(136 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Combining these two reproductive barriers sequentially (Coyne & Orr, ; Sobel & Chen, ), adaptive divergence drives total RI in the order of 0.8. This strong ecological barrier to gene flow offers an answer to the long‐standing question of how lake and stream stickleback can maintain (often striking) genetic and phenotypic differentiation in close contact (Reimchen et al ., ; Berner et al ., ; Bolnick et al ., ; Eizaguirre et al ., ; Hendry et al ., ; Hanson et al ., ).…”

Section: Discussionmentioning

confidence: 97%

Fitness differences between parapatric lake and stream stickleback revealed by a field transplant

Moser

Frey

Berner

2016

J of Evolutionary Biology

View full text Add to dashboard Cite

Molecular comparisons of populations diverging into ecologically different environments often reveal strong differentiation in localized genomic regions, with the remainder of the genome being weakly differentiated. This pattern of heterogeneous genomic divergence, however, is rarely connected to direct measurements of fitness differences among populations. We here do so by performing a field enclosure experiment in threespine stickleback fish residing in a lake and in three replicate adjoining streams, and displaying weak yet heterogeneous genomic divergence between these habitats. Tracking survival over 29 weeks, we consistently find that lake genotypes transplanted into the streams suffer greatly reduced viability relative to local stream genotypes and that the performance of F1 hybrid genotypes is intermediate. This observed selection against migrants and hybrids combines to a total reduction in gene flow from the lake into streams of around 80%. Overall, our study identifies a strong reproductive barrier between parapatric stickleback populations, and cautions against inferring weak fitness differences between populations exhibiting weak overall genomic differentiation.

show abstract

Section: Discussionmentioning

confidence: 97%

Fitness differences between parapatric lake and stream stickleback revealed by a field transplant

Moser

Frey

Berner

2016

J of Evolutionary Biology

View full text Add to dashboard Cite

show abstract

“…), whose breeding seasons overlap extensively (Hanson et al. ). Numerous transplant experiments or mark‐recapture studies have failed to find evidence of reciprocal local adaptation; both ecotypes do not clearly achieve higher fitness in their respective habitats.…”

Section: Discussionmentioning

confidence: 99%

Partitioning the effects of isolation by distance, environment, and physical barriers on genomic divergence between parapatric threespine stickleback

et al. 2016

View full text Add to dashboard Cite

Genetic divergence between populations is shaped by a combination of drift, migration, and selection, yielding patterns of isolation-by-distance (IBD) and isolation-by-environment (IBE). Unfortunately, IBD and IBE may be confounded when comparing divergence across habitat boundaries. For instance, parapatric lake and stream threespine stickleback (Gasterosteus aculeatus) may have diverged due to selection against migrants (IBE), or mere spatial separation (IBD). To quantitatively partition the strength of IBE and IBD, we used recently developed population genetic software (BEDASSLE) to analyze partial genomic data from three lake-stream clines on Vancouver Island. We find support for IBD within each of three outlet streams (unlike prior studies of lake-stream stickleback). In addition, we find evidence for IBE (controlling for geographic distance): the genetic effect of habitat is equivalent to geographic separation of ∼1.9 km of IBD. Remarkably, of our three lake-stream pairs, IBE is strongest where migration between habitats is easiest. Such microgeographic genetic divergence would require exceptionally strong divergent selection, which multiple experiments have failed to detect. Instead, we propose that nonrandom dispersal (e.g., habitat choice) contributes to IBE. Supporting this conclusion, we show that the few migrants between habitats are a nonrandom subset of the phenotype distribution of the source population.

show abstract

“…cry1ab is part of the cryptochrome protein family that is involved in regulation of the circadian clock in zebrafish (Kobayashi et al , 2000; Lahiri et al , 2005; Liu et al , 2015) and Atlantic cod (Lazado et al , 2014). Sexual maturation in stickleback is dependent on photoperiod (Borg, 1982; Baggerman, 1985; Borg et al , 2004) and the optimal time for breeding could differ between lake and stream (but see Hanson et al , 2016). Overall, the functional roles for the stream upregulated DEP genes are unclear, but future experiments examining expression of these genes in more detail would be valuable.…”

Section: Discussionmentioning

confidence: 99%

Heritable gene expression differences between lake and stream stickleback include both parallel and antiparallel components

Hanson

Hendry

et al. 2017

Heredity

View full text Add to dashboard Cite

The repeated phenotypic patterns that characterize populations undergoing parallel evolution provide support for a deterministic role of adaptation by natural selection. Determining the level of parallelism also at the genetic level is thus central to our understanding of how natural selection works. Many studies have looked for repeated genomic patterns in natural populations, but work on gene expression is less common. The studies that have examined gene expression have found some support for parallelism, but those studies almost always used samples collected from the wild that potentially confounds the effects of plasticity with heritable differences. Here we use two independent pairs of lake and stream threespine stickleback (Gasterosteus aculeatus) raised in common garden conditions to assess both parallel and antiparallel (that is, similar versus different directions of lake–stream expression divergence in the two watersheds) heritable gene expression differences as measured by total RNA sequencing. We find that more genes than expected by chance show either parallel (22 genes, 0.18% of expressed genes) or antiparallel (24 genes, 0.20% of expressed genes) lake–stream expression differences. These results correspond well with previous genomic studies in stickleback ecotype pairs that found similar levels of parallelism. We suggest that parallelism might be similarly constrained at the genomic and transcriptomic levels.

show abstract

Testing for parallel allochronic isolation in lake–stream stickleback

Cited by 12 publications

References 90 publications

Fitness differences between parapatric lake and stream stickleback revealed by a field transplant

Fitness differences between parapatric lake and stream stickleback revealed by a field transplant

Partitioning the effects of isolation by distance, environment, and physical barriers on genomic divergence between parapatric threespine stickleback

Heritable gene expression differences between lake and stream stickleback include both parallel and antiparallel components

Contact Info

Product

Resources

About