scholarly journals Morphological, Ecological, and Molecular Divergence of Conogethes pinicolalis from C. punctiferalis (Lepidoptera: Crambidae)

Insects ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 455
Author(s):  
Na Ra Jeong ◽  
Min Jee Kim ◽  
Sung-Soo Kim ◽  
Sei-Woong Choi ◽  
Iksoo Kim

Conogethes pinicolalis has long been considered as a Pinaceae-feeding type of the yellow peach moth, C. punctiferalis, in Korea. In this study, the divergence of C. pinicolalis from the fruit-feeding moth C. punctiferalis was analyzed in terms of morphology, ecology, and genetics. C. pinicolalis differs from C. punctiferalis in several morphological features. Through field observation, we confirmed that pine trees are the host plants for the first generation of C. pinicolalis larvae, in contrast to fruit-feeding C. punctiferalis larvae. We successfully reared C. pinicolalis larvae to adults by providing them pine needles as a diet. From a genetic perspective, the sequences of mitochondrial COI of these two species substantially diverged by an average of 5.46%; moreover, phylogenetic analysis clearly assigned each species to an independent clade. On the other hand, nuclear EF1α showed a lower sequence divergence (2.10%) than COI. Overall, EF1α-based phylogenetic analysis confirmed each species as an independent clade, but a few haplotypes of EF1α indicated incomplete lineage sorting between these two species. In conclusion, our results demonstrate that C. pinicolalis is an independent species according to general taxonomic criteria; however, analysis of the EF1α sequence revealed a short divergence time.

2022 ◽  
Author(s):  
XiaoXu Pang ◽  
Da-Yong Zhang

The species studied in any evolutionary investigation generally constitute a very small proportion of all the species currently existing or that have gone extinct. It is therefore likely that introgression, which is widespread across the tree of life, involves "ghosts," i.e., unsampled, unknown, or extinct lineages. However, the impact of ghost introgression on estimations of species trees has been rarely studied and is thus poorly understood. In this study, we use mathematical analysis and simulations to examine the robustness of species tree methods based on a multispecies coalescent model under gene flow sourcing from an extant or ghost lineage. We found that very low levels of extant or ghost introgression can result in anomalous gene trees (AGTs) on three-taxon rooted trees if accompanied by strong incomplete lineage sorting (ILS). In contrast, even massive introgression, with more than half of the recipient genome descending from the donor lineage, may not necessarily lead to AGTs. In cases involving an ingroup lineage (defined as one that diverged no earlier than the most basal species under investigation) acting as the donor of introgression, the time of root divergence among the investigated species was either underestimated or remained unaffected, but for the cases of outgroup ghost lineages acting as donors, the divergence time was generally overestimated. Under many conditions of ingroup introgression, the stronger the ILS was, the higher was the accuracy of estimating the time of root divergence, although the topology of the species tree is more prone to be biased by the effect of introgression.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jeffrey P. Rose ◽  
Ricardo Kriebel ◽  
Larissa Kahan ◽  
Alexa DiNicola ◽  
Jesús G. González-Gallegos ◽  
...  

Next-generation sequencing technologies have facilitated new phylogenomic approaches to help clarify previously intractable relationships while simultaneously highlighting the pervasive nature of incongruence within and among genomes that can complicate definitive taxonomic conclusions. Salvia L., with ∼1,000 species, makes up nearly 15% of the species diversity in the mint family and has attracted great interest from biologists across subdisciplines. Despite the great progress that has been achieved in discerning the placement of Salvia within Lamiaceae and in clarifying its infrageneric relationships through plastid, nuclear ribosomal, and nuclear single-copy genes, the incomplete resolution has left open major questions regarding the phylogenetic relationships among and within the subgenera, as well as to what extent the infrageneric relationships differ across genomes. We expanded a previously published anchored hybrid enrichment dataset of 35 exemplars of Salvia to 179 terminals. We also reconstructed nearly complete plastomes for these samples from off-target reads. We used these data to examine the concordance and discordance among the nuclear loci and between the nuclear and plastid genomes in detail, elucidating both broad-scale and species-level relationships within Salvia. We found that despite the widespread gene tree discordance, nuclear phylogenies reconstructed using concatenated, coalescent, and network-based approaches recover a common backbone topology. Moreover, all subgenera, except for Audibertia, are strongly supported as monophyletic in all analyses. The plastome genealogy is largely resolved and is congruent with the nuclear backbone. However, multiple analyses suggest that incomplete lineage sorting does not fully explain the gene tree discordance. Instead, horizontal gene flow has been important in both the deep and more recent history of Salvia. Our results provide a robust species tree of Salvia across phylogenetic scales and genomes. Future comparative analyses in the genus will need to account for the impacts of hybridization/introgression and incomplete lineage sorting in topology and divergence time estimation.


DNA Barcodes ◽  
2015 ◽  
Vol 3 (1) ◽  
Author(s):  
S. Behrens-Chapuis ◽  
F. Herder ◽  
H. R. Esmaeili ◽  
J. Freyhof ◽  
N. A. Hamidan ◽  
...  

AbstractDNA barcoding is a fast and reliable tool for species identification, and has been successfully applied to a wide range of freshwater fishes. The limitations reported were mainly attributed to effects of geographic scale, taxon-sampling, incomplete lineage sorting, or mitochondrial introgression. However, the metrics for the success of assigning unknown samples to species or genera also depend on a suited taxonomic framework. A simultaneous use of the mitochondrial COI and the nuclear RHO gene turned out to be advantageous for the barcode efficiency in a few previous studies. Here, we examine 14 cyprinid fish genera, with a total of 74 species, where standard DNA barcoding failed to identify closely related species unambiguously. Eight of the genera (Acanthobrama, Alburnus, Chondrostoma, Gobio, Mirogrex, Phoxinus, Scardinius, and Squalius) contain species that exhibit very low interspecific divergence, or haplotype sharing (12 species pairs) with presumed introgression based on mtCOI data. We aimed to test the utility of the nuclear rhodopsin marker to uncover reasons for the high similarity and haplotype sharing in these different groups. The included labeonine species belonging to Crossocheilus, Hemigrammocapoeta, Tylognathus and Typhlogarra were found to be nested within the genus Garra based on mtCOI. This specific taxonomic uncertainty was also addressed by the use of the additional nuclear marker. As a measure of the delineation success we computed barcode gaps, which were present in 75% of the species based on mtCOI, but in only 39% based on nuclear rhodopsin sequences. Most cases where standard barcodes failed to offer unambiguous species identifications could not be resolved by adding the nuclear marker. However, in the labeonine cyprinids included, nuclear rhodopsin data generally supported the lineages as defined by the mitochondrial marker. This suggests that mitochondrial patterns were not mislead by introgression, but are caused by an inadequate taxonomy. Our findings support the transfer of the studied species of Crossocheilus, Hemigrammocapoeta, Tylognathus and Typhlogarra to Garra.


2019 ◽  
Author(s):  
Lars Nauheimer ◽  
Lujing Cui ◽  
Charles Clarke ◽  
Darren M. Crayn ◽  
Greg Bourke ◽  
...  

Nepenthes is a genus of carnivorous plants consisting of ~160 species that are distributed in the paleotropics. Molecular systematics has so far not been able to resolve evolutionary relationships of most species because of the limited genetic divergence in previous studies. In the present study, we used a genome-skimming approach to infer phylogenetic relationships on the basis of 81 plastid genes and the highly repetitive rRNA (external transcribed spacer (ETS)–26S) for 39 accessions representing 34 species from eight sections. Maximum-likelihood analysis and Bayesian inference were performed separately for the nuclear and the plastid datasets. Divergence-time estimations were conducted on the basis of a relaxed molecular-clock model, using secondary calibration points. The phylogenetic analyses of the nuclear and plastid datasets yielded well resolved and supported phylogenies. Incongruences between the two datasets were detected, suggesting multiple hybridisation events or incomplete lineage sorting in the deeper and more recent evolutionary history of the genus. The inclusion of several known and suspected hybrids in the phylogenetic analysis provided insights into their parentage. Divergence-time estimations placed the crown diversification of Nepenthes in the early Miocene, c. 20 million years ago. This study showed that genome skimming provides well resolved nuclear and plastid phylogenies that provide valuable insights into the complex evolutionary relationships of Nepenthes.


2017 ◽  
Author(s):  
Graham Jones

AbstractAllopolyploid species are formed by genome doubling after hybridization between otherwise intersterile parental species. Allopolyploidy is a common speciation mechanism in land plants. Here we describe and evaluate a Bayesian approach to the phylogenetic analysis of species relationships when both ordinary speciation and allopolyploidy are present. The approach takes incomplete lineage sorting into account using the multi-species coalescent model, and extends this to deal with the extra complications due to allopolyploidy. The number of hybridizations is not assumed, which means that the number of parameters varies and a reversible-jump MCMC algorithm is needed to sample from the posterior. The main restriction is that only diploids and allotetraploids are considered. The model is implemented in the BEAST framework and is an extension of Jones et al. (2013). Simulations show that the topology of the network can be reliably inferred along with estimates of other parameters.


Author(s):  
Marco Cosimo Simeone ◽  
Guido W Grimm ◽  
Alessio Papini ◽  
Federico Vessella ◽  
Simone Cardoni ◽  
...  

Nucleotide sequences from the plastome are currently the main source for assessing taxonomic and phylogenetic relationships in flowering plants and their historical biogeography at all hierarchical levels. One exception is the large and economically important genus Quercus (oaks). Whereas differentiation patterns of the nuclear genome are in agreement with morphology and the fossil record, diversity patterns in the plastome are at odds with established taxonomic and phylogenetic relationships. However, the extent and evolutionary implications of this incongruence has yet to be fully uncovered. The DNA sequence divergence of four Euro-Mediterranean Group Ilex oak species (Quercus ilex L., Q. coccifera L., Q. aucheri Jaub. & Spach., Q. alnifolia Poech.) was explored at three chloroplast markers (rbcL, trnK-matK, trnH-psbA). Phylogenetic relationships were reconstructed including worldwide members of additional 55 species representing all Quercus subgeneric groups. Family and order sequence data were harvested from gene banks to better frame the observed divergence in larger taxonomic contexts. We found a strong geographic sorting in the focal group and the genus in general that is entirely decoupled from species boundaries. Main plastid haplotypes shared by distinct oak lineages from the same geographic region and high plastid diversity in members of Group Ilex are indicative for a polyphyletic origin of their plastomes. The results suggest that incomplete lineage sorting and repeated phases of unidirectional introgression among ancestral lineages of Group Ilex and two other main Groups of Eurasian oaks (Cyclobalanopsis and Cerris) caused this complex pattern. Comparison with the current phylogenetic synthesis also suggests an initial high- versus mid-latitude biogeographic split within Quercus. High plastome plasticity of Group Ilex reflects geographic area disruptions, possibly linked with high tectonic activity of past and modern distribution ranges, that did not leave imprints in the nuclear genome of modern species and infrageneric lineages.


2019 ◽  
Author(s):  
Rodney T. Richardson ◽  
Douglas B. Sponsler ◽  
Harper McMinn-Sauder ◽  
Reed M. Johnson

SummaryThe community-level analysis of samples containing diverse genetic material, via metabarcoding and metagenomic approaches, is increasingly popular. While the production of sequence data for such studies has become straightforward, questions remain about how best to analyze and taxonomically characterize sequence data. For many sequence classification approaches, an important component of the workflow involves the curation of reference sequences. Ideally, this involves trimming away extraneous sequence at the 3 prime and 5 prime ends of the target marker of interest, as well as the removal of reference sequence duplicates. Here, we present MetaCurator, a software package written in Python, designed for automated reference sequence curation and highly generalizable across markers and study systems. MetaCurator is organized in a modular fashion, so users can implement tools individually in addition to utilizing the automated and flexible MetaCurator parental code. Aside from modules used to organize and format taxonomic lineage data, MetaCurator contains two signature tools. IterRazor utilizes profile hidden Markov models and an iterative search framework to exhaustively identify and extract the precise amplicon marker of interest from available reference sequence data. DerepByTaxonomy then facilitates sequence dereplication using a taxonomically aware approach, removing duplicates only when they belong to the same taxon. This is important for cases of incomplete lineage sorting between species and for highly conserved markers, such as plantrbcLandtrnL, which often display no sequence divergence across taxa, even at the genus level.Availability and implementationMetaCurator is supported on OSX and Linux (RedHat/CentOS) and is freely available under a GPL v3.0 license athttps://github.com/RTRichar/[email protected] informationCode associated with this work is available athttps://github.com/RTRichar/MetabarcodeDBsV2and additional analysis is presented in supplementary files.


2008 ◽  
Vol 29 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Mario García-París ◽  
Iñigo Martínez-Solano ◽  
Guillermo Velo-Antón

AbstractThe generalized use of nuclear introns in combination with mitochondrial DNA data in molecular systematic and intraspecific phylogeographical studies is providing new insights into the complex evolutionary histories of taxa surviving the Quaternary glaciations. Previous studies have highlighted the suitability of the beta-fibrinogen intron 7 (β-fibint7) for phylogenetic and phylogeographic studies in a wide variety of taxa, including amphibians. Here we use sequences of this marker to assess inter- and intraspecific variation in Discoglossus (Discoglossidae), with special emphasis on geographic patterns of genetic structure in the Iberian Peninsula, where recent studies have questioned the taxonomic status of D. jeanneae. We obtained 81 sequences of β-fibint7 from samples including all currently recognized species except D. montalentii and 37 populations in the Iberian Peninsula and compared levels of genetic variation with those observed in a fragment of similar length of the mtDNA gene cytochrome b. The sequence of β-fibint7 in Discoglossus is the shortest described for amphibians so far, 378 base pairs. In general, we found low levels of variability (only 26 parsimony-informative sites in the dataset), with no alternatively fixed haplotypes in samples attributed to D. galganoi or D. jeanneae based on their mtDNA. Values of pairwise sequence divergence between non-Iberian species ranged from 1.1% to 4.5% (13.3% to 20.9% in mtDNA). The patterns observed in samples from the Iberian Peninsula are consistent with either incomplete lineage sorting or ongoing gene flow between D. galganoi and D. jeanneae. We conclude by reviewing the genetic evidence available to address the taxonomic status of Iberian species of Discoglossus.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1897 ◽  
Author(s):  
Marco Cosimo Simeone ◽  
Guido W. Grimm ◽  
Alessio Papini ◽  
Federico Vessella ◽  
Simone Cardoni ◽  
...  

Nucleotide sequences from the plastome are currently the main source for assessing taxonomic and phylogenetic relationships in flowering plants and their historical biogeography at all hierarchical levels. One major exception is the large and economically important genusQuercus(oaks). Whereas differentiation patterns of the nuclear genome are in agreement with morphology and the fossil record, diversity patterns in the plastome are at odds with established taxonomic and phylogenetic relationships. However, the extent and evolutionary implications of this incongruence has yet to be fully uncovered. The DNA sequence divergence of four Euro-Mediterranean Group Ilex oak species (Quercus ilexL.,Q. cocciferaL.,Q. aucheriJaub. & Spach.,Q. alnifoliaPoech.) was explored at three chloroplast markers (rbcL, trnK/matK, trnH-psbA). Phylogenetic relationships were reconstructed including worldwide members of additional 55 species representing allQuercussubgeneric groups. Family and order sequence data were harvested from gene banks to better frame the observed divergence in larger taxonomic contexts. We found a strong geographic sorting in the focal group and the genus in general that is entirely decoupled from species boundaries. High plastid divergence in members ofQuercusGroup Ilex, including haplotypes shared with related, but long isolated oak lineages, point towards multiple geographic origins of this group of oaks. The results suggest that incomplete lineage sorting and repeated phases of asymmetrical introgression among ancestral lineages of Group Ilex and two other main Groups of Eurasian oaks (Cyclobalanopsis and Cerris) caused this complex pattern. Comparison with the current phylogenetic synthesis also suggests an initial high- versus mid-latitude biogeographic split withinQuercus. High plastome plasticity of Group Ilex reflects geographic area disruptions, possibly linked with high tectonic activity of past and modern distribution ranges, that did not leave imprints in the nuclear genome of modern species and infrageneric lineages.


The Auk ◽  
2003 ◽  
Vol 120 (3) ◽  
pp. 889-907
Author(s):  
Kim T. Scribner ◽  
Sandra L. Talbot ◽  
John M. Pearce ◽  
Barbara J. Pierson ◽  
Karen S. Bollinger ◽  
...  

Abstract Using molecular genetic markers that differ in mode of inheritance and rate of evolution, we examined levels and partitioning of genetic variation for seven nominal subspecies (11 breeding populations) of Canada Geese (Branta canadensis) in western North America. Gene trees constructed from mtDNA control region sequence data show that subspecies of Canada Geese do not have distinct mtDNA. Large and small-bodied forms of Canada Geese were highly diverged (0.077 average sequence divergence) and represent monophyletic groups. A majority (65%) of 20 haplotypes resolved were observed in single breeding locales. However, within both large and small-bodied forms certain haplotypes occurred across multiple subspecies. Population trees for both nuclear (microsatellites) and mitochondrial markers were generally concordant and provide resolution of population and subspecific relationships indicating incomplete lineage sorting. All populations and subspecies were genetically diverged, but to varying degrees. Analyses of molecular variance, nested-clade and coalescencebased analyses of mtDNA suggest that both historical (past fragmentation) and contemporary forces have been important in shaping current spatial genetic distributions. Gene flow appears to be ongoing though at different rates, even among currently recognized subspecies. The efficacy of current subspecific taxonomy is discussed in light of hypothesized historical vicariance and current demographic trends of management and conservation concern.


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