scholarly journals Early diversification and permeable species boundaries in the Mediterranean firs

2019 ◽  
Vol 125 (3) ◽  
pp. 495-507 ◽  
Author(s):  
Francisco Balao ◽  
María Teresa Lorenzo ◽  
José Manuel Sánchez-Robles ◽  
Ovidiu Paun ◽  
Juan Luis García-Castaño ◽  
...  

Abstract Background and Aims Inferring the evolutionary relationships of species and their boundaries is critical in order to understand patterns of diversification and their historical drivers. Despite Abies (Pinaceae) being the second most diverse group of conifers, the evolutionary history of Circum-Mediterranean firs (CMFs) remains under debate. Methods We used restriction site-associated DNA sequencing (RAD-seq) on all proposed CMF taxa to investigate their phylogenetic relationships and taxonomic status. Key Results Based on thousands of genome-wide single nucleotide polymorphisms (SNPs), we present here the first formal test of species delimitation, and the first fully resolved, complete species tree for CMFs. We discovered that all previously recognized taxa in the Mediterranean should be treated as independent species, with the exception of Abies tazaotana and Abies marocana. An unexpectedly early pulse of speciation in the Oligocene–Miocene boundary is here documented for the group, pre-dating previous hypotheses by millions of years, revealing a complex evolutionary history encompassing both ancient and recent gene flow between distant lineages. Conclusions Our phylogenomic results contribute to shed light on conifers’ diversification. Our efforts to resolve the CMF phylogenetic relationships help refine their taxonomy and our knowledge of their evolution.

2018 ◽  
Vol 78 (09) ◽  
pp. 866-870 ◽  
Author(s):  
Marlena Fejzo ◽  
Daria Arzy ◽  
Rayna Tian ◽  
Kimber MacGibbon ◽  
Patrick Mullin

Abstract Introduction Hyperemesis gravidarum (HG), a pregnancy complication characterized by severe nausea and vomiting in pregnancy, occurs in up to 2% of pregnancies. It is associated with both maternal and fetal morbidity. HG is highly heritable and recurs in approximately 80% of women. In a recent genome-wide association study, it was shown that placentation, appetite, and the cachexia gene GDF15 are linked to HG. The purpose of this study was to explore whether GDF15 alleles linked to overexpression of GDF15 protein segregate with the condition in families, and whether the GDF15 risk allele is associated with recurrence of HG. Methods We analyzed GDF15 overexpression alleles for segregation with disease using exome-sequencing data from 5 HG families. We compared the allele frequency of the GDF15 risk allele, rs16982345, in patients who had recurrence of HG with its frequency in those who did not have recurrence. Results Single nucleotide polymorphisms (SNPs) linked to higher levels of GDF15 segregated with disease in HG families. The GDF15 risk allele, rs16982345, was associated with an 8-fold higher risk of recurrence of HG. Conclusion The findings of this study support the hypothesis that GDF15 is involved in the pathogenesis of both familial and recurrent cases of HG. The findings may be applicable when counseling women with a familial history of HG or recurrent HG. The GDF15-GFRAL brainstem-activated pathway was recently identified and therapies to treat conditions of abnormal appetite are under development. Based on our findings, patients carrying GDF15 variants associated with GDF15 overexpression should be included in future studies of GDF15-GFRAL-based therapeutics. If safe, this approach could reduce maternal and fetal morbidity.


2015 ◽  
Author(s):  
Evangelos Vlachos ◽  
Adán Pérez-García ◽  
Márton Rabi

Background. Large-sized testudinids had a long evolutionary history in Europe during the last 50 million years before becoming extinct in the beginning of the Pleistocene. Despite a 150-year long history in research and a decent fossil record, the European large testudinids have received limited attention so far. Methods. New excavations, descriptions of new specimens from Greece, Spain and Germany, revisions of previously published European taxa and comparative studies with extant testudinids now provide a major advancement in understanding the anatomy and evolutionary history of these turtles. This contribution aims to provide an updated summary of the accumulated knowledge on European large tortoises and to explore in detail their phylogenetic relationships in a global context (including small-sized extinct and extant taxa). The phylogenetic analysis is based on a new character/taxon matrix of morphological characters. Parsimony analysis was performed both with and without molecular backbone constraints. Results. We describe new material of large testudinids from Greece, Spain and Germany and revise most of the available material that has been previously published. Our morphology-based results are promising since they are consistent with recent molecular studies in identifying large testudinids traditionally referred to the Geochelone complex as polyphyletic. Furthermore, we were able to reproduce the molecular phylogeny of Mediterranean tortoises (Testudona). Discussion. The phylogenetic framework presented here allows addressing several open questions of the history of testudinids. First of all, it hints to a more complex biogeographic history of European testudinids than previously recognized. Although the early Paleogene history of testudinids cannot be accurately traced at the moment it seems probable that, besides Asia and North America, Europe also played a major role in the early diversification of Testudinidae. We demonstrate that large European testudinids do not form a monophyletic lineage. The widely recognized genus Cheirogaster should only include the Eocene type species, and exclude other large Paleogene or giant Neogene taxa so far known. Our analysis reveals that large size evolved independently in several clades and in several continents during warmer parts of the Cenozoic. Besides this general scheme other factors might have played a role regionally (e.g. changes in vegetation, island isolation).


2018 ◽  
Vol 5 (6) ◽  
pp. 172125 ◽  
Author(s):  
Sean J. Buckley ◽  
Fabricius M. C. B. Domingos ◽  
Catherine R. M. Attard ◽  
Chris J. Brauer ◽  
Jonathan Sandoval-Castillo ◽  
...  

Pygmy perches (Percichthyidae) are a group of poorly dispersing freshwater fishes that have a puzzling biogeographic disjunction across southern Australia. Current understanding of pygmy perch phylogenetic relationships suggests past east–west migrations across a vast expanse of now arid habitat in central southern Australia, a region lacking contemporary rivers. Pygmy perches also represent a threatened group with confusing taxonomy and potentially cryptic species diversity. Here, we present the first study of the evolutionary history of pygmy perches based on genome-wide information. Data from 13 991 ddRAD loci and a concatenated sequence of 1 075 734 bp were generated for all currently described and potentially cryptic species. Phylogenetic relationships, biogeographic history and cryptic diversification were inferred using a framework that combines phylogenomics, species delimitation and estimation of divergence times. The genome-wide phylogeny clarified the biogeographic history of pygmy perches, demonstrating multiple east–west events of divergence within the group across the Australian continent. These results also resolved discordance between nuclear and mitochondrial data from a previous study. In addition, we propose three cryptic species within a southwestern species complex. The finding of potentially new species demonstrates that pygmy perches may be even more susceptible to ecological and demographic threats than previously thought. Our results have substantial implications for improving conservation legislation of pygmy perch lineages, especially in southwestern Western Australia.


2020 ◽  
Vol 12 (12) ◽  
pp. 2245-2257
Author(s):  
Boon-Peng Hoh ◽  
Xiaoxi Zhang ◽  
Lian Deng ◽  
Kai Yuan ◽  
Chee-Wei Yew ◽  
...  

Abstract North Borneo (NB) is home to more than 40 native populations. These natives are believed to have undergone local adaptation in response to environmental challenges such as the mosquito-abundant tropical rainforest. We attempted to trace the footprints of natural selection from the genomic data of NB native populations using a panel of ∼2.2 million genome-wide single nucleotide polymorphisms. As a result, an ∼13-kb haplotype in the Major Histocompatibility Complex Class II region encompassing candidate genes TSBP1–BTNL2–HLA-DRA was identified to be undergoing natural selection. This putative signature of positive selection is shared among the five NB populations and is estimated to have arisen ∼5.5 thousand years (∼220 generations) ago, which coincides with the period of Austronesian expansion. Owing to the long history of endemic malaria in NB, the putative signature of positive selection is postulated to be driven by Plasmodium parasite infection. The findings of this study imply that despite high levels of genetic differentiation, the NB populations might have experienced similar local genetic adaptation resulting from stresses of the shared environment.


2020 ◽  
Author(s):  
Mizuki Horoiwa ◽  
Ixchel F. Mandagi ◽  
Nobu Sutra ◽  
Javier Montenegro ◽  
Fadly Y. Tantu ◽  
...  

AbstractSulawesi, an island located in a biogeographical transition zone between Indomalaya and Australasia, is famous for its high levels of endemism. Ricefishes (family Adrianichthyidae) are an example of taxa that have uniquely diversified on this island. It was demonstrated that habitat fragmentation due to the Pliocene juxtaposition among tectonic subdivisions of this island was the primary factor that promoted their divergence; however, it is also equally probable that habitat fusions and resultant admixtures between phylogenetically distant species may have frequently occurred. Previous studies revealed that some individuals of Oryzias sarasinorum endemic to a tectonic lake in central Sulawesi have mitochondrial haplotypes that are similar to the haplotypes of O. eversi, which is a phylogenetically related but geologically distant (ca. 190 km apart) adrianichthyid endemic to a small lake. In this study, we tested if this reflects ancient admixture of O. eversi and O. sarasinorum. Population genomic analyses of genome-wide single-nucleotide polymorphisms revealed that O. eversi and O. sarasinorum are substantially reproductively isolated from each other. Comparison of demographic models revealed that the models assuming ancient admixture from O. eversi to O. sarasinorum was more supported than the models assuming no admixture; this supported the idea that the O. eversi-like mitochondrial haplotype in O. sarasinorum was introgressed from O. eversi. This study is the first to demonstrate ancient admixture of lacustrine organisms in Sulawesi beyond 100 km. The complex geological history of this island enabled such island-wide admixture of lacustrine organisms, which usually experience limited migration.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245316
Author(s):  
Mizuki Horoiwa ◽  
Ixchel F. Mandagi ◽  
Nobu Sutra ◽  
Javier Montenegro ◽  
Fadly Y. Tantu ◽  
...  

Sulawesi, an island located in a biogeographical transition zone between Indomalaya and Australasia, is famous for its high levels of endemism. Ricefishes (family Adrianichthyidae) are an example of taxa that have uniquely diversified on this island. It was demonstrated that habitat fragmentation due to the Pliocene juxtaposition among tectonic subdivisions of this island was the primary factor that promoted their divergence; however, it is also equally probable that habitat fusions and resultant admixtures between phylogenetically distant species may have frequently occurred. Previous studies revealed that some individuals of Oryzias sarasinorum endemic to a tectonic lake in central Sulawesi have mitochondrial haplotypes that are similar to the haplotypes of O. eversi, which is a phylogenetically related but geologically distant (ca. 190 km apart) adrianichthyid endemic to a small fountain. In this study, we tested if this reflects ancient admixture of O. eversi and O. sarasinorum. Population genomic analyses of genome-wide single-nucleotide polymorphisms revealed that O. eversi and O. sarasinorum are substantially reproductively isolated from each other. Comparison of demographic models revealed that the models assuming ancient admixture from O. eversi to O. sarasinorum was more supported than the models assuming no admixture; this supported the idea that the O. eversi-like mitochondrial haplotype in O. sarasinorum was introgressed from O. eversi. This study is the first to demonstrate ancient admixture of lacustrine or pond organisms in Sulawesi beyond 100 km. The complex geological history of this island enabled such island-wide admixture of lacustrine organisms, which usually experience limited migration.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Mai F. Minamikawa ◽  
Miyuki Kunihisa ◽  
Koji Noshita ◽  
Shigeki Moriya ◽  
Kazuyuki Abe ◽  
...  

AbstractHaplotypes provide useful information for genomics-based approaches, genomic prediction, and genome-wide association study. As a small number of superior founders have contributed largely to the breeding history of fruit trees, the information of founder haplotypes may be relevant for performing the genomics-based approaches in these plants. In this study, we proposed a method to estimate 14 haplotypes from 7 founders and automatically trace the haplotypes forward to apple parental (185 varieties) and breeding (659 F1 individuals from 16 full-sib families) populations based on 11,786 single-nucleotide polymorphisms, by combining multiple algorithms. Overall, 92% of the single-nucleotide polymorphisms information in the parental and breeding populations was characterized by the 14 founder haplotypes. The use of founder haplotype information improved the accuracy of genomic prediction in 7 traits and the resolution of genome-wide association study in 13 out of 27 fruit quality traits analyzed in this study. We also visualized the significant propagation of the founder haplotype with the largest genetic effect in genome-wide association study over the pedigree tree of the parental population. These results suggest that the information of founder haplotypes can be useful for not only genetic improvement of fruit quality traits in apples but also for understanding the selection history of founder haplotypes in the breeding program of Japanese apple varieties.


2015 ◽  
Author(s):  
Evangelos Vlachos ◽  
Adán Pérez-García ◽  
Márton Rabi

Background. Large-sized testudinids had a long evolutionary history in Europe during the last 50 million years before becoming extinct in the beginning of the Pleistocene. Despite a 150-year long history in research and a decent fossil record, the European large testudinids have received limited attention so far. Methods. New excavations, descriptions of new specimens from Greece, Spain and Germany, revisions of previously published European taxa and comparative studies with extant testudinids now provide a major advancement in understanding the anatomy and evolutionary history of these turtles. This contribution aims to provide an updated summary of the accumulated knowledge on European large tortoises and to explore in detail their phylogenetic relationships in a global context (including small-sized extinct and extant taxa). The phylogenetic analysis is based on a new character/taxon matrix of morphological characters. Parsimony analysis was performed both with and without molecular backbone constraints. Results. We describe new material of large testudinids from Greece, Spain and Germany and revise most of the available material that has been previously published. Our morphology-based results are promising since they are consistent with recent molecular studies in identifying large testudinids traditionally referred to the Geochelone complex as polyphyletic. Furthermore, we were able to reproduce the molecular phylogeny of Mediterranean tortoises (Testudona). Discussion. The phylogenetic framework presented here allows addressing several open questions of the history of testudinids. First of all, it hints to a more complex biogeographic history of European testudinids than previously recognized. Although the early Paleogene history of testudinids cannot be accurately traced at the moment it seems probable that, besides Asia and North America, Europe also played a major role in the early diversification of Testudinidae. We demonstrate that large European testudinids do not form a monophyletic lineage. The widely recognized genus Cheirogaster should only include the Eocene type species, and exclude other large Paleogene or giant Neogene taxa so far known. Our analysis reveals that large size evolved independently in several clades and in several continents during warmer parts of the Cenozoic. Besides this general scheme other factors might have played a role regionally (e.g. changes in vegetation, island isolation).


2014 ◽  
Vol 17 (4) ◽  
Author(s):  
Raymond K. Walters ◽  
Charles Laurin ◽  
Gitta H. Lubke

Epistasis is a growing area of research in genome-wide studies, but the differences between alternative definitions of epistasis remain a source of confusion for many researchers. One problem is that models for epistasis are presented in a number of formats, some of which have difficult-to-interpret parameters. In addition, the relation between the different models is rarely explained. Existing software for testing epistatic interactions between single-nucleotide polymorphisms (SNPs) does not provide the flexibility to compare the available model parameterizations. For that reason we have developed an R package for investigating epistatic and penetrance models, EpiPen, to aid users who wish to easily compare, interpret, and utilize models for two-locus epistatic interactions. EpiPen facilitates research on SNP-SNP interactions by allowing the R user to easily convert between common parametric forms for two-locus interactions, generate data for simulation studies, and perform power analyses for the selected model with a continuous or dichotomous phenotype. The usefulness of the package for model interpretation and power analysis is illustrated using data on rheumatoid arthritis.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 363
Author(s):  
Sulochana K. Wasala ◽  
Dana K. Howe ◽  
Louise-Marie Dandurand ◽  
Inga A. Zasada ◽  
Dee R. Denver

Globodera pallida is among the most significant plant-parasitic nematodes worldwide, causing major damage to potato production. Since it was discovered in Idaho in 2006, eradication efforts have aimed to contain and eradicate G. pallida through phytosanitary action and soil fumigation. In this study, we investigated genome-wide patterns of G. pallida genetic variation across Idaho fields to evaluate whether the infestation resulted from a single or multiple introduction(s) and to investigate potential evolutionary responses since the time of infestation. A total of 53 G. pallida samples (~1,042,000 individuals) were collected and analyzed, representing five different fields in Idaho, a greenhouse population, and a field in Scotland that was used for external comparison. According to genome-wide allele frequency and fixation index (Fst) analyses, most of the genetic variation was shared among the G. pallida populations in Idaho fields pre-fumigation, indicating that the infestation likely resulted from a single introduction. Temporal patterns of genome-wide polymorphisms involving (1) pre-fumigation field samples collected in 2007 and 2014 and (2) pre- and post-fumigation samples revealed nucleotide variants (SNPs, single-nucleotide polymorphisms) with significantly differentiated allele frequencies indicating genetic differentiation. This study provides insights into the genetic origins and adaptive potential of G. pallida invading new environments.


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