Host-symbiont coevolution, cryptic structure, and bleaching susceptibility, in a coral species complex (Scleractinia; Poritidae)

Abstract The ‘species’ is a key concept for conservation and evolutionary biology, yet the lines between population and species-level variation are often blurred, especially for corals. The ‘Porites lobata species complex’ consists of branching and mounding corals that form reefs across the Pacific. We used reduced representation meta-genomic sequencing to examine genetic relationships within this species complex and to identify candidate loci associated with colony morphology, cryptic genetic structure, and apparent bleaching susceptibility. We compared existing Porites data with bleached and unbleached colonies of the branching coral P. compressa collected in Kāneʻohe Bay Hawaiʻi during the 2015 coral bleaching event. Loci that mapped to coral, symbiont, and microbial references revealed genetic structure consistent with recent host-symbiont co-evolution. Cryptic genetic clades were resolved that previous work has associated with distance from shore, but no genetic structure was associated with bleaching. We identified many candidate loci associated with morphospecies, including candidate host and symbiont loci with fixed differences between branching and mounding corals. We also found many loci associated with cryptic genetic structure, yet relatively few loci associated with bleaching. Recent host-symbiont co-evolution and rapid diversification suggests that variation and therefore the capacity of these corals to adapt may be underappreciated.

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Spatial genetic structure and asymmetrical gene flow within the Pacific walrus

Journal of Mammalogy ◽

10.1644/11-mamm-a-344.1 ◽

2012 ◽

Vol 93 (6) ◽

pp. 1512-1524 ◽

Cited By ~ 9

Author(s):

Sarah A. Sonsthagen ◽

Chadwick V. Jay ◽

Anthony S. Fischbach ◽

George K. Sage ◽

Sandra L. Talbot

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Genetic Structure ◽

Genetic Differentiation ◽

Spatial Genetic Structure ◽

Genetic Relationships ◽

Breeding Population ◽

Pacific Walrus ◽

Breeding Populations ◽

The Pacific

Abstract Pacific walruses (Odobenus rosmarus divergens) occupying shelf waters of Pacific Arctic seas migrate during spring and summer from 3 breeding areas in the Bering Sea to form sexually segregated nonbreeding aggregations. We assessed genetic relationships among 2 putative breeding populations and 6 nonbreeding aggregations. Analyses of mitochondrial DNA (mtDNA) control region sequence data suggest that males are distinct among breeding populations (ΦST = 0.051), and between the eastern Chukchi and other nonbreeding aggregations (ΦST = 0.336–0.449). Nonbreeding female aggregations were genetically distinct across marker types (microsatellite FST = 0.019; mtDNA ΦST = 0.313), as was eastern Chukchi and all other nonbreeding aggregations (microsatellite FST = 0.019–0.035; mtDNA ΦST = 0.386–0.389). Gene flow estimates are asymmetrical from St. Lawrence Island into the southeastern Bering breeding population for both sexes. Partitioning of haplotype frequencies among breeding populations suggests that individuals exhibit some degree of philopatry, although weak. High levels of genetic differentiation among eastern Chukchi and all other nonbreeding aggregations, but considerably lower genetic differentiation between breeding populations, suggest that at least 1 genetically distinct breeding population remained unsampled. Limited genetic structure at microsatellite loci between assayed breeding areas can emerge from several processes, including male-mediated gene flow, or population admixture following a decrease in census size (i.e., due to commercial harvest during 1880–1950s) and subsequent recovery. Nevertheless, high levels of genetic diversity in the Pacific walrus, which withstood prolonged decreases in census numbers with little impact on neutral genetic diversity, may reflect resiliency in the face of past environmental challenges.

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Autosomal Microsatellite Investigation Reveals Multiple Genetic Components of the Highlanders from Thailand

Genes ◽

10.3390/genes12030383 ◽

2021 ◽

Vol 12 (3) ◽

pp. 383

Author(s):

Aornpriya Mawan ◽

Nonglak Prakhun ◽

Kanha Muisuk ◽

Suparat Srithawong ◽

Metawee Srikummool ◽

...

Keyword(s):

Genetic Structure ◽

Genetic Relationships ◽

Forensic Investigation ◽

Northern Thailand ◽

Hill Tribe ◽

Genetic Components ◽

Large Populations ◽

Population Interactions ◽

Hill Tribes ◽

The Hill

The hill tribes of northern Thailand comprise nine officially recognized groups: the Austroasiatic-speaking (AA) Khmu, Htin and Lawa; the Hmong-Mien-speaking (HM) IuMien and Hmong; and the Sino-Tibetan-speaking (ST) Akha, Karen, Lahu and Lisu. Except the Lawa, the rest of the hill tribes migrated into their present habitats only very recently. The Thai hill tribes were of much interest to research groups focusing on study of cultural and genetic variation because of their unique languages and cultures. So far, there have been several genetic studies of the Thai hill tribes. However, complete forensic microsatellite database of the Thai hill tribes is still lacking. To construct such database, we newly generated 654 genotypes of 15 microsatellites commonly used in forensic investigation that belong to all the nine hill tribes and also non-hill tribe highlanders from northern Thailand. We also combined 329 genotypes from previous studies of northern Thai populations bringing to a total of 983 genotypes, which were then subjected to genetic structure and population relationships analyses. Our overall results indicated homogenous genetic structure within the HM- and Tai-Kadai (TK)-speaking groups, large genetic divergence of the HM-speaking Hmong but not IuMien from the other Thai groups, and genetic heterogeneity within the ST- and AA-speaking groups, reflecting different population interactions and admixtures. In addition to establishing genetic relationships within and among these populations, our finding, which provides a more complete picture of the forensic microsatellite database of the multiple Thai highland dwellers, would not only serve to expand and strengthen forensic investigation in Thailand, but would also benefit its neighboring countries of Laos and Myanmar, from which many of the Thai hill tribes originated and where large populations of these ethnic groups still reside.

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Comparing divergence landscapes from reduced‐representation and whole‐genome re‐sequencing in the yellow‐rumped warbler ( Setophaga coronata ) species complex

Molecular Ecology ◽

10.1111/mec.15940 ◽

2021 ◽

Author(s):

Stephanie J. Szarmach ◽

Alan Brelsford ◽

Christopher Witt ◽

David P.L. Toews

Keyword(s):

Species Complex ◽

Whole Genome ◽

Reduced Representation

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Genetic Relationships of Cory's Shearwater: Parentage, Mating Assortment, and Geographic Differentiation Revealed by DNA Fingerprinting

The Auk ◽

10.1093/auk/117.3.651 ◽

2000 ◽

Vol 117 (3) ◽

pp. 651-662 ◽

Cited By ~ 1

Author(s):

Corinne Rabouam ◽

Vincent Bretagnolle ◽

Yves Bigot ◽

Georges Periquet

Keyword(s):

Genetic Variation ◽

Genetic Structure ◽

Dna Fingerprinting ◽

Genetic Relatedness ◽

Isolation By Distance ◽

Genetic Relationships ◽

Cory’S Shearwater ◽

Genetic Structure Of Populations ◽

The Social ◽

Calonectris Diomedea

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.

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Genetic population structure of the monogenean parasite Gyrodactylus thymalli and its host European grayling (Thymallus thymallus) in a large Norwegian lake

Hydrobiologia ◽

10.1007/s10750-020-04431-7 ◽

2020 ◽

Author(s):

Ruben Alexander Pettersen ◽

Claudia Junge ◽

Kjartan Østbye ◽

Tor Atle Mo ◽

Leif Asbjørn Vøllestad

Keyword(s):

Genetic Structure ◽

Evolutionary Biology ◽

Isolation By Distance ◽

Genetic Structuring ◽

Thymallus Thymallus ◽

Homing Behavior ◽

Genetic Population ◽

Monogenean Parasite ◽

European Grayling ◽

Genetic Clusters

Abstract Understanding how populations are structured in space and time is a central question in evolutionary biology. Parasites and their hosts are assumed to evolve together, however, detailed understanding of mechanisms leading to genetic structuring of parasites and their hosts are lacking. As a parasite depends on its host, studying the genetic structure of both parasite and host can reveal important insights into these mechanisms. Here, genetic structure of the monogenean parasite Gyrodactylus thymalli and its host the European grayling (Thymallus thymallus) was investigated in 10 tributaries draining into the large Lake Mjøsa in Norway. The population genetic structure of spawning grayling was studied using microsatellite genotyping, while G. thymalli was studied by sequencing a mitochondrial DNA gene (dehydrogenase subunit 5). Two main genetic clusters were revealed in grayling, one cluster comprising grayling from the largest spawning population, while the remaining tributaries formed the second cluster. For both taxa, some genetic differentiation was observed among tributaries, but there was no clear isolation-by-distance signature. The structuring was stronger for the host than for the parasite. These results imply that moderate to high levels of gene flow occur among the sub-populations of both taxa. The high parasite exchange among tributaries could result from a lack of strong homing behavior in grayling as well as interactions among individual fish outside of the spawning season, leading to frequent mixing of both host and parasite.

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Genetic structure of four species in the Leptasterias hexactis complex along the Pacific coast of North America

Echinoderms through Time ◽

10.1201/9781003077831-66 ◽

2020 ◽

pp. 291-296

Author(s):

David W. Foltz ◽

William B. Stickle

Keyword(s):

Genetic Structure ◽

North America ◽

Pacific Coast ◽

The Pacific

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Pathogen emergence in changing ecosystems: RAD-seq reveals long evolutionary history of Phellinus noxius in east Asia, Australia, and the Pacific Islands

10.22541/au.162670289.98665561/v1 ◽

2021 ◽

Author(s):

Olga Kozhar ◽

Mee-Sook Kim ◽

Jorge Ibarra Caballero ◽

Ned Klopfenstein ◽

Phil Cannon ◽

...

Keyword(s):

East Asia ◽

Evolutionary History ◽

Pacific Islands ◽

Genetic Relationships ◽

Supervised Machine Learning ◽

Sequencing Data ◽

The Pacific ◽

Recent Emergence ◽

History Of ◽

Phellinus Noxius

Emerging pathogens have been increasing exponentially over the last century. The knowledge on whether these organisms are native to ecosystems or have been recently introduced is often of great importance. Understanding the ecological and evolutionary processes promoting emergence can help to control their spread and forecast epidemics. Using restriction site-associated DNA sequencing data, we studied genetic relationships, pathways of spread, and evolutionary history of Phellinus noxius, an emerging root-rotting fungus of unknown origin, in eastern Asia, Australia, and the Pacific Islands. We analyzed patterns of genetic variation using Bayesian inference, maximum likelihood phylogeny, populations splits and mixtures measuring correlations in allele frequencies and genetic drift, and finally applied coalescent based theory using approximate Bayesian computation (ABC) with supervised machine learning. Population structure analyses revealed five genetic groups with signatures of complex recent and ancient migration histories. The most probable scenario of ancient pathogen spread is movement from west to east: from Malaysia to the Pacific Islands, with subsequent spread to Taiwan and Australia. Furthermore, ABC analyses indicate that P. noxius spread occurred thousands of generations ago, contradicting previous assumptions that it was recently introduced in multiple areas. Our results suggest that recent emergence of P. noxius in east Asia, Australia, and the Pacific Islands is likely driven by anthropogenic and natural disturbances, including deforestation, land-use change, severe weather events, and introduction of exotic plants. This study provides a novel example of utilization of genome wide allele frequency data to unravel dynamics of pathogen emergence under conditions of changing ecosystems.

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Whole-genome SNP analysis elucidates the genetic population structure and diversity of Acrocomia species

10.1101/2020.10.08.331140 ◽

2020 ◽

Author(s):

Brenda G. Díaz ◽

Maria I. Zucchi ◽

Alessandro. Alves-Pereira ◽

Caléo P. de Almeida ◽

Aline C. L. Moraes ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Genetic Structure ◽

Genetic Relationships ◽

Geographical Area ◽

Taxonomic Classification ◽

Genomic Diversity ◽

Productive Capacity ◽

Snp Analysis ◽

Genetic Population

AbstractAcrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of seven species of Acrocomia including 117 samples of A. aculeata covering a wide geographical area of occurrence, using single nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS). The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.

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