Genetic Variation Among Certain Fish Species in Terms of Evolution and Lineages

Three tests of phylogenetic including likelihood-joining tree, neighbour-joining tree, and minimum evolution tree have been used based on sox3 gene. Phylogenetic analysis was used to detect the genetic affinity and common ancestors for selected species that belong to the same or different families. This study showed the most appropriate methods for testing the genetic affinity among species and the methodology of each test according to the requirement of molecular applications. Secondary RNA predicted structure and minimum free energy were also included in this study because of their contribution to the detection of the orthologous gene and variance in RNA folding among species related to the different families. The genetic distance in the studied populations was calculated to know the most appropriate way to find out the genetic similarity among the studied species. The low distance-variance value of each group indicated significant genetic affinity among the species of the same family, this result is more consistent with the test of maximum-likelihood tree indicating the validity of this test to measure the genetic affinity among species that have common ancestors.

Molecular identification of common hard ticks (Acari: Ixodidae) in Xinjiang, China

We provide data on the cytochrome c oxidase subunit I (COI) and 16S rDNA genes for eight species of common hard ticks in Xinjiang: Dermacentor montanus, D. niveus, Haemaphysalis sulcate, Hyalomma asiaticum asiaticum, Hya. detritum, Hya. scupense, Rhipicephalus sanguineus and R. pumilio. Genetic distances, calculated based on the Kimura two-parameter (K2P) distance model, found the same trend of intraspecies level≤interspecies level<intragenus level. Phylogenetic trees, constructed with the neighbor-joining (NJ) and minimum-evolution (ME) methods, demonstrated that each species clustered into separate clades, thus confirming the usefulness of CO1 and 16S rDNA genes for tick species identification. The genera Dermacentor, Haemaphysalis and Rhipicephalus were all recovered in the phylogenetic analysis, as was the subfamily Rhipicephalinae, but a monophyletic Hyalomma was not.

Whole-genome doubling-aware copy number phylogenies for cancer evolution with MEDICC2

Chromosomal instability (CIN) and somatic copy number alterations (SCNA) play a key role in the evolutionary process that shapes cancer genomes. SCNAs comprise many classes of clinically relevant events, such as localised amplifications, gains, losses, loss-of-heterozygosity (LOH) events, and recently discovered parallel evolutionary events revealed by multi-sample phasing. These events frequently appear jointly with whole genome doubling (WGD), a transformative event in tumour evolution, which generates tetraploid or near-tetraploid cells. WGD events are often clonal, occuring before the emergence of the most recent common ancestor, and have been associated with increased CIN, poor patient outcome and are currently being investigated as potential therapeutic targets. While SCNAs can provide a rich source of phylogenetic information, so far no method exists for phylogenetic inference from SCNAs that includes WGD events. Here we present MEDICC2, a new phylogenetic algorithm for allele-specific SCNA data based on a minimum-evolution criterion that explicitly models clonal and subclonal WGD events and that takes parallel evolutionary events into account. MEDICC2 can identify WGD events and quantify SCNA burden in single-sample studies and infer phylogenetic trees and ancestral genomes in multi-sample scenarios. In this scenario, it accurately locates clonal and subclonal WGD events as well as parallel evolutionary events in the evolutionary history of the tumour, timing SCNAs relative to each other. We use MEDICC2 to detect WGD events in 2778 tumours with 98.8% accuracy and show its ability to correctly place subclonal WGD events in simulated and real-world multi-sample tumours, while accurately inferring its phylogeny and parallel SCNA events. MEDICC2 is implemented in Python 3 and freely available under GPLv3 at https://bitbucket.org/schwarzlab/medicc2.

Molecular characterization of Indian species of the genus Cornudiscoides Kulkarni, 1969 (Monogenoidea: Dactylogyridae)

Molecular characterization and phylogenetic study based on partial sequences of 28S and 18S ribosomal DNA (rDNA) of sixteen Indian species of the genus Cornudiscoides (Monogenoidea: Dactylogyridae) were conducted to decode the genetic relationship between them and with other members of the family Dactylogyridae. Blastn searches disclosed the significant similarity among the species of the Cornudiscoides for large ribosomal subunits as well as for small ribosomal subunit showing genetic relatedness. The phylogenetic tree using neighbour-joining (NJ) and minimum evolution (ME) methods for 28S ribosomal subunit depicted that all Cornudiscoides species clustering in a single clade and forming sister clade with other members of the family Dactylogyridae and similar results were obtained from 18S ribosomal subunit. Thus, the present study demonstrated that both 28S and 18S ribosomal subunits are very helpful in discriminating Cornudiscoides species (intra or interspecific variation) and in the establishment of the evolutionary relationship among them.

Politopos en filogenética

We introduce mathematical notions used in phylogenetics and three sorts of phylogenetics polytopes. The Tight span and the Lipschitz polytope are both associated to finite metric spaces and can be connected to distance-preserving embeddings, while the balanced minimum evolution (BME) polytope is associated to natural numbers.

Phylogenetic analysis of DNA sequence data.

The goal of phylogenetics is to construct relationships that are true representations of the evolutionary history of a group of organisms or genes. The history inferred from phylogenetic analysis is usually depicted as branching in tree-like diagrams or networks. In nematology, phylogenetic studies have been applied to resolve a wide range of questions dealing with improving classifications and testing evolution processes, such as co-evolution, biogeography and many others. There are several main steps involved in a phylogenetic study: (i) selection of ingroup and outgroup taxa for a study; (ii) selection of one or several gene fragments for a study; (iii) sample collection, obtaining PCR products and sequencing of gene fragments; (iv) visualization, editing raw sequence data and sequence assembling; (v) search for sequence similarity in a public database; (vi) making and editing multiple alignment of sequences; (vii) selecting appropriate DNA model for a dataset; (viii) phylogenetic reconstruction using minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference; (ix) visualization of tree files and preparation of tree for a publication; and (x) sequence submission to a public database. Molecular phylogenetic study requires particularly careful planning because it is usually relatively expensive in terms of the cost in reagents and time.

Phylogenetic analysis of DNA sequence data.

The goal of phylogenetics is to construct relationships that are true representations of the evolutionary history of a group of organisms or genes. The history inferred from phylogenetic analysis is usually depicted as branching in tree-like diagrams or networks. In nematology, phylogenetic studies have been applied to resolve a wide range of questions dealing with improving classifications and testing evolution processes, such as co-evolution, biogeography and many others. There are several main steps involved in a phylogenetic study: (i) selection of ingroup and outgroup taxa for a study; (ii) selection of one or several gene fragments for a study; (iii) sample collection, obtaining PCR products and sequencing of gene fragments; (iv) visualization, editing raw sequence data and sequence assembling; (v) search for sequence similarity in a public database; (vi) making and editing multiple alignment of sequences; (vii) selecting appropriate DNA model for a dataset; (viii) phylogenetic reconstruction using minimum evolution, maximum parsimony, maximum likelihood and Bayesian inference; (ix) visualization of tree files and preparation of tree for a publication; and (x) sequence submission to a public database. Molecular phylogenetic study requires particularly careful planning because it is usually relatively expensive in terms of the cost in reagents and time.

Dissecting molecular evolutionary relationship of Krameriaceae inferred from phylotranscriptomic analysis

The systematic relationships of Krameriaceae have changed considerably. The phylotranscriptomic data sets provide highly informative data for resolving deeper‐level phylogenetic relationships. The phylotranscriptomic analyses to infer evolutionary relationships of Krameriaceae in the order Zygophyllales using the Minimum Evolution, Maximum Parsimony and Maximum Likelihood methods recovered similar topology and taxon proximity. Under the Zygophyllales clade, Krameria lanceolata Torr. of the family Krameriaceae nested with Tribulus eichlerianus K.L. Wilson and Larrea tridentata (Sessé & Moc. ex DC.) Coville belonging to the family Zygophyllaceae with strong nodal support. The phylotranscriptomic analyses suggest that the family Krameriaceae is sister to Zygophyllaceae. Bangladesh J. Plant Taxon. 27(2): 427-433, 2020 (December)