The population genomic signature of environmental association and gene flow in an ecologically divergent tree species Metrosideros polymorpha
 (Myrtaceae)

AbstractPopulation genomic approaches can characterise dispersal across a single generation through to many generations in the past, bridging the gap between individual movement and intergenerational gene flow. These approaches are particularly useful when investigating dispersal in recently altered systems, where they provide a way of inferring long-distance dispersal between newly established populations and their interactions with existing populations. Human-mediated biological invasions represent such altered systems which can be investigated with appropriate study designs and analyses. Here we apply temporally-restricted sampling and a range of population genomic approaches to investigate dispersal in a 2004 invasion of Aedes albopictus (the Asian tiger mosquito) in the Torres Strait Islands (TSI) of Australia. We sampled mosquitoes from 13 TSI villages simultaneously and genotyped 373 mosquitoes at genome-wide single nucleotide polymorphisms (SNPs): 331 from the TSI, 36 from Papua New Guinea (PNG), and 4 incursive mosquitoes detected in uninvaded regions. Within villages, spatial genetic structure varied substantially but overall displayed isolation by distance and a neighbourhood size of 232–577. Close kin dyads revealed recent movement between islands 31–203 km apart, and deep learning inferences showed incursive Ae. albopictus had travelled to uninvaded regions from both adjacent and non-adjacent islands. Private alleles and a coancestry matrix indicated direct gene flow from PNG into nearby islands. Outlier analyses also detected four linked alleles introgressed from PNG, with the alleles surrounding 12 resistance-associated cytochrome P450 genes. By treating dispersal as both an intergenerational process and a set of discrete events, we describe a highly interconnected invasive system.

Download Full-text

Open areas in a landscape enhance pollen-mediated gene flow of a tree species: evidence from northern Switzerland

Landscape Ecology ◽

10.1007/s10980-010-9468-z ◽

2010 ◽

Vol 25 (6) ◽

pp. 903-911 ◽

Cited By ~ 25

Author(s):

U. Kamm ◽

F. Gugerli ◽

P. Rotach ◽

P. Edwards ◽

R. Holderegger

Keyword(s):

Gene Flow ◽

Tree Species ◽

Northern Switzerland

Download Full-text

Decontamination of Ceratocystis Pathogens Responsible for Rapid ʻŌhiʻa Death

Plant Health Progress ◽

10.1094/php-06-20-0051-rs ◽

2020 ◽

Vol 21 (4) ◽

pp. 301-305

Author(s):

Kylle Roy ◽

Kelly A. Jaenecke ◽

Nikko Bjontegard ◽

Dan Mikros ◽

Ellen J. Dunkle ◽

...

Keyword(s):

Active Ingredient ◽

Tree Species ◽

Ambrosia Beetle ◽

Metrosideros Polymorpha ◽

The Public ◽

Native Tree ◽

Native Tree Species

Rapid ʻōhiʻa death (ROD) is caused by two recently described species of Ceratocystis, C. lukuohia and C. huliohia. These fungi are decimating ʻōhiʻa lehua (Metrosideros polymorpha), the keystone native tree species of Hawaiʻi. Viable Ceratocystis propagules can persist in ambrosia beetle frass (Coleoptera: Scolytinae), and movement of the frass may play a key role in the spread of the disease. In order to prevent the spread of ROD, we developed effective and practical surface (e.g., tools and shoes) decontamination methods to be used by researchers, managers, and the public alike. We first tested different household and laboratory disinfectants on the Ceratocystis fungi in culture, and then we applied the effective culture disinfectants to contaminated ambrosia beetle frass. Laboratory-grade ethanol (70, 80, and 95%), Clorox bleach (10%, 0.825% active ingredient [a.i.]), and isopropanol (70 and 91%), were all equally effective at decontaminating cultured C. lukuohia and C. huliohia. Although all concentrations of isopropanol (50, 70, and 90%) and ethanol (50, 70, and 90%) were effective disinfectants of Ceratocystis-contaminated frass, treatments of frass with up to 20% Clorox bleach (1.2% a.i.) were not completely adequate at killing the fungus. These data reveal that bleach is not a sufficient ROD disinfectant when frass is present, and isopropanol or ethanol are the more reliable options.

Download Full-text

Impacts of gene flow and logging history on the local genetic structure of a scattered tree species, Sorbus torminalis L. Crantz

Molecular Ecology ◽

10.1111/j.1365-294x.2004.02373.x ◽

2004 ◽

Vol 13 (12) ◽

pp. 3689-3702 ◽

Cited By ~ 51

Author(s):

SYLVIE ODDOU-MURATORIO ◽

BRIGITTE DEMESURE-MUSCH ◽

RAPHAËL PÉLISSIER ◽

PIERRE-HENRI GOUYON

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Tree Species ◽

Sorbus Torminalis

Download Full-text

POLLEN- VERSUS SEED-MEDIATED GENE FLOW IN A SCATTERED FOREST TREE SPECIES

Evolution ◽

10.1554/0014-3820(2001)055[1123:pvsmgf]2.0.co;2 ◽

2001 ◽

Vol 55 (6) ◽

pp. 1123 ◽

Cited By ~ 5

Author(s):

S. Oddou-Muratorio ◽

R. J. Petit ◽

B. Le Guerroue ◽

D. Guesnet ◽

B. Demesure

Keyword(s):

Gene Flow ◽

Tree Species ◽

Forest Tree ◽

Forest Tree Species ◽

Seed Mediated

Download Full-text

Whole genome duplication potentiates inter-specific hybridisation and niche shifts in Australian burrowing frogs Neobatrachus

10.1101/593699 ◽

2019 ◽

Cited By ~ 2

Author(s):

Polina Yu. Novikova ◽

Ian G. Brennan ◽

William Booker ◽

Michael Mahony ◽

Paul Doughty ◽

...

Keyword(s):

Gene Flow ◽

Sequence Data ◽

Diploid Species ◽

Exome Capture ◽

Polyploid Species ◽

Ploidy Levels ◽

Population Genomic ◽

Niche Shifts ◽

Inheritance Mode ◽

The Impact

Polyploidy has played an important role in evolution across the tree of life but it is still unclear how polyploid lineages may persist after their initial formation. While both common and well-studied in plants, polyploidy is rare in animals and generally less well-understood. The Australian burrowing frog genus Neobatrachus is comprised of six diploid and three polyploid species and offers a powerful animal polyploid model system. We generated exome-capture sequence data from 87 individuals representing all nine species of Neobatrachus to investigate species-level relationships, the origin and inheritance mode of polyploid species, and the population genomic effects of polyploidy on genus-wide demography. We resolve the phylogenetic relationships among Neobatrachus species and provide further support that the three polyploid species have independent autotetraploid origins. We document higher genetic diversity in tetraploids, resulting from widespread gene flow specifically between the tetraploids, asymmetric inter-ploidy gene flow directed from sympatric diploids to tetraploids, and current isolation of diploid species from each other. We also constructed models of ecologically suitable areas for each species to investigate the impact of climate variation on frogs with differing ploidy levels. These models suggest substantial change in suitable areas compared to past climate, which in turn corresponds to population genomic estimates of demographic histories. We propose that Neobatrachus diploids may be suffering the early genomic impacts of climate-induced habitat loss, while tetraploids appear to be avoiding this fate, possibly due to widespread gene flow into tetraploid lineages specifically. Finally, we demonstrate that Neobatrachus is an attractive model to study the effects of ploidy on the evolution of adaptation in animals.

Download Full-text

Fine scale population structure and extensive gene flow within an Eastern Nearctic snake complex (Pituophis melanoleucus)

10.1101/2021.09.28.462151 ◽

2021 ◽

Author(s):

Zachary L Nikolakis ◽

Richard Orton ◽

Brian I Crother

Keyword(s):

Gene Flow ◽

Isolation By Distance ◽

Genomic Structure ◽

Genomic Variation ◽

Genomic Diversity ◽

Evolutionary Relationships ◽

Population Genomic ◽

Isolation By Environment ◽

Pituophis Melanoleucus ◽

Lineage Divergence

Understanding the processes and mechanisms that promote lineage divergence is a central goal in evolutionary biology. For instance, studies investigating the spatial distribution of genomic variation often highlight biogeographic barriers underpinning geographic isolation, as well as patterns of isolation by environment and isolation by distance that can also lead to lineage divergence. However, the patterns and processes that shape genomic variation and drive lineage divergence may be taxa-specific, even across closely related taxa co-occurring within the same biogeographic region. Here, we use molecular data in the form of ultra-conserved elements (UCEs) to infer the evolutionary relationships and population genomic structure of the Eastern Pinesnake complex (Pituophis melanoleucus) – a polytypic wide-ranging species that occupies much of the Eastern Nearctic. In addition to inferring evolutionary relationships, population genomic structure, and gene flow, we also test relationships between genomic diversity and putative barriers to dispersal, environmental variation, and geographic distance. We present results that reveal shallow population genomic structure and ongoing gene flow, despite an extensive geographic range that transcends geographic features found to reduce gene flow among many taxa, including other squamate reptiles within the Eastern Nearctic. Further, our results indicate that the observed genomic diversity is spatially distributed as a pattern of isolation by distance and suggest that the current subspecific taxonomy do not adhere to independent lineages, but rather, show a significant amount of admixture across the entire P. melanoleucus range.

Download Full-text