scholarly journals Phylogenomics of the major tropical plant family Annonaceae using targeted enrichment of nuclear genes

2018 ◽  
Author(s):  
Thomas L.P. Couvreur ◽  
Andrew J. Helmstetter ◽  
Erik J.M. Koenen ◽  
Kevin Bethune ◽  
Rita D. Brandão ◽  
...  

AbstractTargeted enrichment and sequencing of hundreds of nuclear loci for phylogenetic reconstruction is becoming an important tool for plant systematics and evolution. Annonaceae is a major pantropical plant family with 109 genera and ca. 2450 species, occurring across all major and minor tropical forests of the world. Baits were designed by sequencing the transcriptomes of five species from two of the largest Annonaceae subfamilies. Orthologous loci were identified. The resulting baiting kit was used to reconstruct phylogenetic relationships at two different levels using concatenated and gene tree approaches: a family wide Annonaceae analysis sampling 65 genera and a species level analysis of tribe Piptostigmateae sampling 29 species with multiple individuals per species. DNA extraction was undertaken mainly on silicagel dried leaves, with two samples from herbarium dried leaves. Our kit targets 469 exons (364 653 bp of sequence data), successfully capturing sequences from across Annonaceae. Silicagel dried and herbarium DNA worked eaually well. We present for the first time a nuclear gene-based phylogenetic tree at the generic level based on 317 supercontigs. Results mainly confirm previous chloroplast based studies. However, several new relationships are found and discussed. We show significant differences in branch lengths between the two large subfamilies Annonoideae and Malmeoideae. A new tribe, Annickieae, is erected containing a single African genus Annickia. We also reconstructed a well resolved species-level phylogenetic tree of the Piptostigmteae tribe. Our baiting kit is useful for reconstructing well supported phylogenetic relationships within Annonaceae at different taxonomic levels. The nuclear genome is mainly concordant with plastome information with a few exceptions. Moreover, we find that substitution rate heterogeneity between the two subfamilies is also found within the nuclear compartment, and not just plastomes and ribosomal DNA as previously shown. Our results have implications for understanding the biogeography, molecular dating and evolution of Annonaceae.

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 339 ◽  
Author(s):  
Tshifhiwa G. Matumba ◽  
Jody Oliver ◽  
Nigel P. Barker ◽  
Christopher D. McQuaid ◽  
Peter R. Teske

Background: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality. Methods: DNA sequences were generated for the mtDNA COI gene and the nuclear 28S rRNA of two closely related rocky shore snails, and species-level variation was compared. Nuclear rRNA is not usually used to study intraspecific variation in species that are not spatially structured, presumably because this marker is assumed to evolve so slowly that it is more suitable for phylogenetics.  Results: Even though high inter-specific divergence reflected the faster evolutionary rate of COI, intraspecific genetic variation was similar for both markers. As a result, estimates of population expansion times based on mismatch distributions differed between the two markers by millions of years. Conclusions: Assuming that 28S evolution is more clock-like, these findings can be explained by variation-reducing purifying selection in mtDNA at the species level, and an elevated divergence rate caused by diversifying selection between the two species. Although these two selective forces together make mtDNA suitable as a marker for species identifications by means of DNA barcoding because they create a ‘barcoding gap’, estimates of demographic change based on this marker can be expected to be highly unreliable. Our study contributes to the growing evidence that the utility of mtDNA sequence data beyond DNA barcoding is limited.


2008 ◽  
Vol 363 (1508) ◽  
pp. 3427-3437 ◽  
Author(s):  
Renae C Pratt ◽  
Mary Morgan-Richards ◽  
Steve A Trewick

New Zealand taxa from the Orthopteran family Anostostomatidae have been shown to consist of three broad groups, Hemiandrus (ground weta), Anisoura/Motuweta (tusked weta) and Hemideina – Deinacrida (tree–giant weta). The family is also present in Australia and New Caledonia, the nearest large land masses to New Zealand. All genera are endemic to their respective countries except Hemiandrus that occurs in New Zealand and Australia. We used nuclear and mitochondrial DNA sequence data to study within genera and among species-level genetic diversity within New Zealand and to examine phylogenetic relationships of taxa in Australasia. We found the Anostostomatidae to be monophyletic within Ensifera, and justifiably distinguished from the Stenopelmatidae among which they were formerly placed. However, the New Zealand Anostostomatidae are not monophyletic with respect to Australian and New Caledonian species in our analyses. Two of the New Zealand groups have closer allies in Australia and one in New Caledonia. We carried out maximum-likelihood and Bayesian analyses to reveal several well supported subgroupings. Our analysis included the most extensive sampling to date of Hemiandrus species and indicate that Australian and New Zealand Hemiandrus are not monophyletic. We used molecular dating approaches to test the plausibility of alternative biogeographic hypotheses for the origin of the New Zealand anostostomatid fauna and found support for divergence of the main clades at, or shortly after, Gondwanan break-up, and dispersal across the Tasman much more recently.


2009 ◽  
Vol 21 (6) ◽  
pp. 565-570 ◽  
Author(s):  
Kristen L. Kuhn ◽  
Thomas J. Near

AbstractThe biota of Antarctica is amazingly rich and highly endemic. The phylogenetics of notothenioid fishes has been extensively investigated through analyses of morphological characters, DNA sequences from mitochondrial genes, and single copy nuclear genes. These phylogenetic analyses have produced reasonably similar phylogenetic trees of notothenioids, however a number of phylogenetic questions remain. The nototheniid clade Trematomus is an example of a group where phylogenetic relationships remain unresolved. In this paper we revisit the phylogenetic relationships of Trematomus using both increased taxon sampling and an expanded dataset which includes DNA sequences from two mitochondrial genes (ND2 and 16S rRNA) and one single-copy nuclear gene (RPS7). The Bayesian phylogeny resulting from the analysis of the combined mitochondrial and nuclear gene datasets was well resolved and contained more interspecific nodes supported with significant Bayesian posteriors than either the mitochondrial or nuclear gene phylogenies alone. This demonstrates that the addition of nuclear gene sequence data to mitochondrial data can enhance phylogenetic resolution and increase node support. Additionally, the results of the combined mitochondrial and nuclear Bayesian analyses provide further support for the inclusion of species previously classified as Pagothenia and Cryothenia in Trematomus.


2022 ◽  
Author(s):  
Laura P Lagomarsino ◽  
Lauren Frankel ◽  
Simon Uribe-Convers ◽  
Alexandre Antonelli ◽  
Nathan Muchhala

Background and Aims- The centropogonid clade (Lobelioideae: Campanulaceae) is an Andean-centered rapid radiation characterized by repeated convergent evolution of morphological traits, including fruit type and pollination syndromes. While previous studies have resolved relationships of lineages with fleshy fruits into subclades, relationships among capsular species remain unresolved. This lack of resolution has impeded reclassification of non-monophyletic genera, whose current taxonomy relies heavily on traits that have undergone convergent evolution. Methods- Targeted sequence capture using a probeset recently developed for the centropogonid clade was used to obtain phylogenomic data from DNA extracted from both silica-dried and herbarium leaf tissue. These data were used to infer relationships among species using concatenated and partitioned species tree methods, and to quantify gene tree discordance. Key Results- While silica-dried leaf tissue resulted in more and longer sequence data, the inclusion of herbarium samples improved phylogenetic reconstruction. Relationships among baccate lineages are similar previous studies, though differ within and among capsular lineages. We improve phylogenetic resolution of Siphocampylus, which forms ten groups of closely related species which we informally name. Two subclades of Siphocampylus and two individual species are rogue taxa whose placement differs widely across analyses. Gene tree discordance (including cytonuclear discordance) is rampant. Conclusions- The first phylogenomic study of the centropogonid clade considerably improves our understanding of relationships in this rapid radiation. Differences across analyses and the possibility of additional lineage discoveries still hamper a solid and stable reclassification. Rapid morphological innovation corresponds with a high degree of phylogenomic complexity, including cytonuclear discordance, nuclear gene tree conflict, and well-supported differences between analyses based on different nuclear loci. Taken together, these results point to a potential role of hemiplasy underlying repeated convergent evolution. This hallmark of rapid radiations is likely present in many other species-rich Andean plant radiations.


Therya ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 139-148
Author(s):  
Maria A. Gutiérrez-Costa ◽  
Francisco X. González-Cózatl ◽  
María Magdalena Ramírez-Martínez, ◽  
Luis Ignacio Iñiguez-Dávalos ◽  
Duke S. Rogers

Recent collecting surveys in the Sierra de Manantlán Biosphere Reserve, Jalisco (México), uncovered the existence of a new population of the Mexican spiny pocket mouse, Heteromys irroratus.  Because the subspecies H. i. bulleri and H. i. jaliscensis occur nearby, our objective was to properly determine the taxonomic identity of the novel sample.  Also, we evaluate its distinctiveness, both in terms of genetic divergence and phylogenetic placement, relative to other members of H. irroratus.  Preliminary, we compared external and cranial measurements of recently collected individuals to those reported for representatives of the subspecies of H. irroratus occurring close by.  In addition, we examined levels of genetic differentiation and phylogenetic relationships, based on sequence data of the Cytochrome b, among this population and other members of H. irroratus, including an individual from Sierra de Juanacatlán, Jalisco, the type locality of H. i. bulleri. Phylogenetic relationships were estimated using Maximum Likelihood and Bayesian Inference methods and levels of genetic divergence were assessed employing Kimura-2-parameters genetic distances.  Samples from Sierra de Manantlán and Sierra de Juanacatlán were grouped together in a well-supported haplogroup and genetic distances between them were lower than < 1.02 %.  Our phylogenetic hypothesis shows that H. i. bulleri represents the sister group to all other samples of H. irroratus but that, genetically, is a very divergent lineage.  Distances values between H. i. bulleri to any of the other groups were > 10.05 %.  Comparison of external and cranial measurements showed that, in average, individuals from Sierra de Manantlán are larger than those of H. i. jaliscensis, but more similar in size to H. i. bulleri.  Our results show that the new population of the Mexican spiny pocket mouse from Sierra de Manantlán belongs to H. i. bulleri.  In addition, the phylogenetic separation and the high levels of genetic divergence of H. i. bulleri, relative to other members of H. irroratus, suggest that the first should be recognized as a species-level taxon.  Considering the scarce collecting records of H. i. bulleri and the known area of occurrence, that is very restricted, this taxon may warrant special conservation status.


F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 339 ◽  
Author(s):  
Tshifhiwa G. Matumba ◽  
Jody Oliver ◽  
Nigel P. Barker ◽  
Christopher D. McQuaid ◽  
Peter R. Teske

Background: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality. Methods: DNA sequences were generated for the mtDNA COI gene and the nuclear 28S rRNA of two closely related rocky shore snails, and species-level variation was compared. To our knowledge, this is the first study to use nuclear rRNA at this taxonomic level, presumably because this marker is assumed to evolve so slowly that it is only suitable for phylogenetics.   Results: Even though high inter-specific divergence reflected the faster evolutionary rate of COI, intraspecific genetic variation was similar for both markers. As a result, estimates of population expansion times based on mismatch distributions differed between the two markers by millions of years. Conclusions: Assuming that 28S evolves effectively clock-like, these findings can be explained by variation-reducing purifying selection in mtDNA at the species level, and an elevated divergence rate caused by diversifying selection between the two species. Although these two selective forces together make mtDNA suitable as a marker for species identifications by means of DNA barcoding because they create a ‘barcoding gap’, estimates of demographic change based on this marker can be expected to be highly unreliable. Our study contributes to the growing evidence that the utility of mtDNA sequence data beyond DNA barcoding is limited.


2021 ◽  
Vol 71 ◽  
pp. 747-763
Author(s):  
V. Deepak ◽  
Samuel Lalronunga ◽  
Esther Lalhmingliani ◽  
Abhijit Das ◽  
Surya Narayanan ◽  
...  

Xenodermidae is a generally poorly known lineage of caenophidian snakes found in South, East and Southeast Asia. We report molecular phylogenetic analyses for a multilocus data set comprising all five currently recognised genera and including new mitochondrial and nuclear gene sequence data for the recently described Stoliczkia vanhnuailianai. Our phylogenetic results provide very strong support for the non-monophyly of Stoliczkia, as presently constituted, with S. borneensis being more closely related to Xenodermus than to the Northeast Indian S. vanhnuailianai. Based on phylogenetic relationships and morphological distinctiveness, we transfer Stoliczkia borneensis to a new monotypic genus endemic to Borneo, Paraxenodermusgen. nov. We also present new morphological data for P. borneensis.


2006 ◽  
Vol 54 (5) ◽  
pp. 353 ◽  
Author(s):  
Denise Raterman ◽  
Robert W. Meredith ◽  
Luis A. Ruedas ◽  
Mark S. Springer

The family Phalangeridae comprises approximately two dozen extinct and extant species that include the brushtail possums (Trichosurus), scaly-tailed possum (Wyulda) and cuscuses (Phalanger, Strigocuscus, Spilocuscus and Ailurops). Morphological studies have suggested that Ailurops ursinus is the sister taxon to all other phalangerids. Another species of interest is Strigocuscus celebensis, whose morphologically based taxonomic affinity has habitually been with trichosurins. Mitochondrial 12S rRNA results, however, found moderate support for an Ailurops and Strigocuscus celebensis clade and placed A. ursinus and S. celebensis as sister to Phalanger and Spilocuscus. This study uses nuclear sequence data from the breast cancer and ovarian cancer susceptibility gene 1 (BRCA1) to test previous mitochondrial DNA results and uses relaxed molecular clock methods to estimate divergence dates. The results support Ailurops as sister taxon to S. celebensis and this clade as sister to Phalangerini. Relaxed molecular-dating methods suggest a date of 23–29 million years for the split between Trichosurini and the remaining phalangerids and 19–24 million years for the split between Ailurops + Strigocuscus celebensis and Phalangerini. Several vicariant/dispersal events are necessary to explain the geographic distribution of the Phalangeridae and our estimated molecular divergence dates are congruent with previously proposed south-east Asian geological events.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bobby Lim-Ho Kong ◽  
Hyun-Seung Park ◽  
Tai-Wai David Lau ◽  
Zhixiu Lin ◽  
Tae-Jin Yang ◽  
...  

AbstractIlex is a monogeneric plant group (containing approximately 600 species) in the Aquifoliaceae family and one of the most commonly used medicinal herbs. However, its taxonomy and phylogenetic relationships at the species level are debatable. Herein, we obtained the complete chloroplast genomes of all 19 Ilex types that are native to Hong Kong. The genomes are conserved in structure, gene content and arrangement. The chloroplast genomes range in size from 157,119 bp in Ilex graciliflora to 158,020 bp in Ilex kwangtungensis. All these genomes contain 125 genes, of which 88 are protein-coding and 37 are tRNA genes. Four highly varied sequences (rps16-trnQ, rpl32-trnL, ndhD-psaC and ycf1) were found. The number of repeats in the Ilex genomes is mostly conserved, but the number of repeating motifs varies. The phylogenetic relationship among the 19 Ilex genomes, together with eight other available genomes in other studies, was investigated. Most of the species could be correctly assigned to the section or even series level, consistent with previous taxonomy, except Ilex rotunda var. microcarpa, Ilex asprella var. tapuensis and Ilex chapaensis. These species were reclassified; I. rotunda was placed in the section Micrococca, while the other two were grouped with the section Pseudoaquifolium. These studies provide a better understanding of Ilex phylogeny and refine its classification.


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