scholarly journals Phylogeography and hybridization of corvid birds in the Palearctic Region

2019 ◽  
Vol 23 (2) ◽  
pp. 232-238
Author(s):  
A. P. Kryukov
Keyword(s):  
Dna Sequences ◽  
Habitat Preferences ◽  
Natural Hybridization ◽  
Hybrid Zones ◽  
Positive Assortative Mating ◽  
Palearctic Species ◽  
Glacial Refuge ◽  
Genomic Regions ◽  
Hooded Crows ◽  
Group Species

Natural hybridization increases a lot phenotypic and genetic diversity and shapes intra-species patterns, which is a subject of phylogeography. We studied mitochondrial and complete genome variation in the bird family Corvidae, genera Corvus, Pica, Cyanopica, Perisoreus and Nucifraga. In the classic case of natural hybridization between carrion and hooded crows in Siberia, we found no decreased fitness of hybrids, but instead positive assortative mating which should restrict hybrid zone width. Several genetic markers were unable to discriminate between pure carrion and hooded crows. Mitochondrial DNA sequences revealed no difference between carrion and hooded crows, but instead two diverged haplogroups within the eastern part of the distribution range of the carrion crow. NGS resulted in a clear pattern of diversification of pure forms and hybrids (by using SNPs), and showed genomic regions of increased variability, the so-called “speciation islands”. Comparing European and Siberian crow hybrid zones, differences in genome regions bearing genes of melanogenesis supposedly under divergent selection were found. Comparative phylogeographic analysis of 10 widely distributed Palearctic species revealed two kinds of patterns: one with a division into two haplogroups, western and eastern, and another one without such a division. These two phylogeographic patterns might be explained by different habitat preferences: mainly open fields for the first group and forests for the second one. One glacial refuge was assigned to the latter group, while west-east group species might have survived in several refuges. One of such species, the Eurasian magpie (Pica pica) has a gap in its range in Transbaikalia, which is currently shrinking before our eyes. The two subspecies divided by this gap differ in phenotype, mtDNA and vocalization. In their young contact zone, some hybridization occurs with small introgression limited by certain post-zygotic isolation.

scholarly journals Genomic testing of landlocked Kildin cod (Gadus morhua kildinensis) for its ancestral state: stationary or migratory ecotype?

2016 ◽  
Author(s):  
Anastasia A Teterina ◽  
Lev A Zhivotovsky
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Habitat Preferences ◽  
Genomic Testing ◽  
Ancestral State ◽  
Genome Diversity ◽  
Effective Population ◽  
Marine Population ◽  
Genomic Regions ◽  
Kildin Cod

Kildin cod is a small landlocked population of Atlantic cod reproductively isolated from marine counterparts for around 1500-2000 years. The Kildin cod lives in a shallow meromictic lake in the five-meter intermediate layer of water with sharp gradients of oxygen and salinity. The cod had an effective population size of around one hundred individuals and evolved unique physiological, morphological and behavioral features. The marine Atlantic cod has two ecologically distinct forms: the stationary (coastal) and migratory (deep-water) ecotypes that differ in migratory behavior and habitat preferences (the depth, oxygen content, salinity and temperature). To understand the origin and genetic properties of Kildin cod, we scrutinized genomic regions associated with the cod ecotypes differentiation (LG1, LG2, and LG7) and found out that Kildin cod’s regions LG2 and LG7 were fixed with the migratory variants, whereas polymorphic LG1 had a higher frequency of the stationary variant, that could be explained by the possible strong genetic drift. The lake cod investigated had four times lesser genome diversity than marine population. Our finding suggests that Kildin cod originated from the migratory ecotype of the marine cod.

scholarly journals Making of fusion genes in cancer: An in-silico study of mechanism of chromosomal translocations

2018 ◽  
Author(s):  
Kiran Lalwani ◽  
Shivani Sheth ◽  
Inayatullah Sheikh ◽  
Afzal Ansari ◽  
Fulesh Kunwar ◽  
...  
Keyword(s):  
Dna Sequences ◽  
In Silico ◽  
Molecular Mechanisms ◽  
Fusion Gene ◽  
Genetic Material ◽  
Chromosomal Translocations ◽  
In Silico Study ◽  
Clinical Consequences ◽  
The Stability ◽  
Genomic Regions

Chromosomal translocations involve exchange of genetic material between non- homologous chromosomes leading to the formation of a fusion gene with altered function. The clinical consequences of non-random and recurrent chromosomal translocations have been so well understood in carcinogenesis that they serve as diagnostic and prognostic markers and also help in therapy decisions, mainly in leukemia and lymphoma. However, the molecular mechanisms underlying these recurrent genetic exchanges are yet to be understood. Various approaches employed include the extent of the vicinity of the partner chromosomes in the nucleus, DNA sequences at the breakpoints, etc. The present study addresses the stability of DNA sequences at the breakpoint regions using in-silico approach in terms of physicochemical properties such as; AT%, flexibility, melting temperature, enthalpy, entropy, stacking energy and free energy. Changes in these properties may lead to instability of DNA which could affect gene expression in particular and genome organization in general. Our study indicates that the fusion sequences are comparatively more unstable and hence, more prone to breakage. Current study along with others could lead to developing a model for predicting breakage prone genomic regions using this novel in-silico approach.

scholarly journals Population genomics of parallel hybrid zones in the mimetic butterflies, H. melpomene and H. erato

2013 ◽  
Author(s):  
Nicola Nadeau ◽  
Mayte Ruiz ◽  
Patricio Salazar ◽  
Brian Counterman ◽  
Jose Alejandro Medina ◽  
...  
Keyword(s):  
Population Genomics ◽  
De Novo ◽  
Reference Sequence ◽  
Colour Pattern ◽  
Adaptive Divergence ◽  
Population Divergence ◽  
Hybrid Zones ◽  
Data Alignment ◽  
Parallel Hybrid ◽  
Genomic Regions

Hybrid zones can be valuable tools for studying evolution and identifying genomic regions responsible for adaptive divergence and underlying phenotypic variation. Hybrid zones between subspecies of Heliconius butterflies can be very narrow and are maintained by strong selection acting on colour pattern. The co-mimetic species H. erato and H. melpomene have parallel hybrid zones where both species undergo a change from one colour pattern form to another. We use restriction associated DNA sequencing to obtain several thousand genome wide sequence markers and use these to analyse patterns of population divergence across two pairs of parallel hybrid zones in Peru and Ecuador. We compare two approaches for analysis of this type of data; alignment to a reference genome and de novo assembly, and find that alignment gives the best results for species both closely (H. melpomene) and distantly (H. erato, ~15% divergent) related to the reference sequence. Our results confirm that the colour pattern controlling loci account for the majority of divergent regions across the genome, but we also detect other divergent regions apparently unlinked to colour pattern differences. We also use association mapping to identify previously unmapped colour pattern loci, in particular the Ro locus. Finally, we identify within our sample a new cryptic population of H. timareta in Ecuador, which occurs at relatively low altitude and is mimetic with H. melpomene malleti.

Are polymorphic species of Uropodina (Acari: Mesostigmata) more successful evolutionarily?—A case study of closely related species from the genus Oodinychus Berlese, 1917 based on DNA sequences

2019 ◽  
Vol 24 (5) ◽  
pp. 866
Author(s):  
Jerzy Błoszyk ◽  
Katarzyna Buczkowska ◽  
Anna Maria Bobowicz ◽  
Alina Bączkiewicz ◽  
Zbigniew Adamski ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Related Species ◽  
Habitat Preferences ◽  
Abundant Species ◽  
Systematic Position ◽  
Genetic Differences ◽  
Similar Species ◽  
Closely Related Species ◽  
Wide Range

The study presented in this research paper is the first taxonomic investigation focusing on Uropodina (Acari: Mesostigmata) mites with a brief discussion of the genetic differences of two very closely related species from the genus Oodinychus Berlese, 1917, i.e. O. ovalis (C.L. Koch, 1839) and O. karawaiewi (Berlese, 1903). These two morphologically similar species are quite common and they have a wide range of occurrence in Europe. They also live in almost the same types of habitat. However, O. ovalis usually exhibits higher abundance and frequency of occurrence. The major aim of the study was to carry out a comparative analysis of the systematic position, morphological and biological differences, as well as habitat preferences and distribution of O. ovalis and O. karawaiewi. The next aim was to ascertain whether the differences in number and frequency of these species may stem from the genetic differences at the molecular level (16S rDNA and COI). The study shows that O. ovalis, which is a more abundant species than O. karawaiewi, turned out to be genetically more polymorphic.

scholarly journals Reference Genome Assembly for Australian Ascochyta rabiei Isolate ArME14

2020 ◽  
Vol 10 (7) ◽  
pp. 2131-2140
Author(s):  
Ramisah Mohd Shah ◽  
Angela H. Williams ◽  
James K. Hane ◽  
Julie A. Lawrence ◽  
Lina M. Farfan-Caceres ◽  
...  
Keyword(s):  
Secondary Metabolite ◽  
Dna Sequences ◽  
Genome Assembly ◽  
Ascochyta Blight ◽  
Ascochyta Rabiei ◽  
Causal Organism ◽  
Protein Coding ◽  
Putative Protein ◽  
Genomic Regions ◽  
Genome Assemblies

Ascochyta rabiei is the causal organism of ascochyta blight of chickpea and is present in chickpea crops worldwide. Here we report the release of a high-quality PacBio genome assembly for the Australian A. rabiei isolate ArME14. We compare the ArME14 genome assembly with an Illumina assembly for Indian A. rabiei isolate, ArD2. The ArME14 assembly has gapless sequences for nine chromosomes with telomere sequences at both ends and 13 large contig sequences that extend to one telomere. The total length of the ArME14 assembly was 40,927,385 bp, which was 6.26 Mb longer than the ArD2 assembly. Division of the genome by OcculterCut into GC-balanced and AT-dominant segments reveals 21% of the genome contains gene-sparse, AT-rich isochores. Transposable elements and repetitive DNA sequences in the ArME14 assembly made up 15% of the genome. A total of 11,257 protein-coding genes were predicted compared with 10,596 for ArD2. Many of the predicted genes missing from the ArD2 assembly were in genomic regions adjacent to AT-rich sequence. We compared the complement of predicted transcription factors and secreted proteins for the two A. rabiei genome assemblies and found that the isolates contain almost the same set of proteins. The small number of differences could represent real differences in the gene complement between isolates or possibly result from the different sequencing methods used. Prediction pipelines were applied for carbohydrate-active enzymes, secondary metabolite clusters and putative protein effectors. We predict that ArME14 contains between 450 and 650 CAZymes, 39 putative protein effectors and 26 secondary metabolite clusters.

scholarly journals A genomic perspective on the taxonomy of the subtribe Carcharodina (Lepidoptera: Hesperiidae: Carcharodini)

Zootaxa ◽  
2020 ◽  
Vol 4748 (1) ◽  
pp. 182-194 ◽  
Author(s):  
JING ZHANG ◽  
ERNST BROCKMANN ◽  
QIAN CONG ◽  
JINHUI SHEN ◽  
NICK V. GRISHIN
Keyword(s):  
Dna Sequences ◽  
Type Species ◽  
Phylogenetic Trees ◽  
Type Specimens ◽  
African Species ◽  
Protein Coding ◽  
Coding Regions ◽  
As Species ◽  
Close Relatives ◽  
Genomic Regions

We obtained whole genome shotgun sequences and phylogenetically analyzed protein-coding regions of representative skipper butterflies from the genus Carcharodus Hübner, [1819] and its close relatives. Type species of all available genus-group names were sequenced. We find that species attributed to four exclusively Old World genera (Spialia Swinhoe, 1912, Gomalia Moore, 1879, Carcharodus Hübner, [1819] and Muschampia Tutt, 1906) form a monophyletic group that we call a subtribe Carcharodina Verity, 1940. In the phylogenetic trees built from various genomic regions, these species form 7 (not 4) groups that we treat as genera. We find that Muschampia Tutt, 1906 is not monophyletic, and the 5th group is formed by currently monotypic genus Favria Tutt, 1906 new status (type species Hesperia cribrellum Eversmann, 1841), which is sister to Gomalia. The 6th and 7th groups are composed of mostly African species presently placed in Spialia. These groups do not have names and are described here as Ernsta Grishin, gen. n. (type species Pyrgus colotes Druce, 1875) and Agyllia Grishin, gen. n. (type species Pyrgus agylla Trimen, 1889). Two subgroups are recognized in Ernsta: the nominal subgenus and a new one: Delaga Grishin, subgen. n. (type species Pyrgus delagoae Trimen, 1898). Next, we observe that Carcharodus is not monophyletic, and species formerly placed in subgenera Reverdinus Ragusa, 1919 and Lavatheria Verity, 1940 are here transferred to Muschampia. Furthermore, due to differences in male genitalia or DNA sequences, we reinstate Gomalia albofasciata Moore, 1879 and Gomalia jeanneli (Picard, 1949) as species, not subspecies or synonyms of Gomalia elma (Trimen, 1862), and Spialia bifida (Higgins, 1924) as a species, not subspecies of Spialia zebra (Butler, 1888). Sequencing of the type specimens reveals 2.2-3.2% difference in COI barcodes, the evidence that combined with wing pattern differences suggests a new status of a species for Spialia lugens (Staudinger, 1886) and Spialia carnea (Reverdin, 1927), formerly subspecies of Spialia orbifer (Hübner, [1823]). 

Genome-wide profiling of histone 3 lysine 36 trimethylation in clear cell renal cell carcinoma.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 464-464
Author(s):  
Thai Huu Ho ◽  
Jeong-Heon Lee ◽  
Rafael Nunez Nateras ◽  
Erik P. Castle ◽  
Melissa L. Stanton ◽  
...  
Keyword(s):  
Cell Lines ◽  
Dna Sequences ◽  
Open Chromatin ◽  
Sequencing Analysis ◽  
Gene Desert ◽  
Cell Renal Cell Carcinoma ◽  
Chip Sequencing ◽  
Genome Wide ◽  
A Genome ◽  
Genomic Regions

464 Background: Although the von Hippel-Lindau (VHL) tumor suppressor gene is mutated in 60% of ccRCC, deletion of VHL in mice is insufficient for tumorigenesis. Sequencing of ccRCC tumors identified mutations in SETD2, a histone H3 lysine 36 (H3K36) trimethyltransferase. We hypothesize that loss of SETD2 methyltransferase activity alters the genome wide pattern of H3K36 trimethylation (H3K36me3) in ccRCC, and contributes to the cancer phenotype. Methods: To generate a genome-wide profile of H3K36me3 in frozen nephrectomy samples and RCC cell lines, we optimized a chromatin immunoprecipitation (ChIP) protocol for the isolation of DNA associated with H3K36me3. H3K36me3 is associated with open chromatin and an H3K36me3-specific antibody was used for immunoprecipitation of endogenous H3K36me3-bound DNA. ChIP PCR primers were optimized for active genes, such as actin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a “gene desert” on chromosome 12 (negative control). ChIP libraries were then generated from 3 paired uninvolved kidney and RCC and 2 RCC cell lines. In order to identify H3K36Me3 upregulated regions in uninvolved kidney and RCC, reads from the ChIP sequencing were mapped to the human genome using Burrows-Wheeler Aligner and SICER algorithms. Results: Using ChIP PCR, we found that active genomic regions were enriched 15-30 fold over the negative controls indicating that the quality and yield of immunoprecipitated DNA/chromatin complexes from frozen tissue was sufficient for ChIP sequencing. A preliminary ChIP sequencing analysis of RCC cell lines and frozen ccRCC tissue indicates that H3K36me3 enriched DNA sequences were mapped to exons (31.3%) compared to introns (13.5%, p<0.001), consistent with the role of H3K36me3 in transcription. Conclusions: Genomic regions enriched for H3K36Me3 binding were identified from patient-derived tissue and RCC cell lines. Current efforts are focused on comparing the H3K36me3 profiles between matched tumor and uninvolved kidney ChIP libraries to generate a genome wide map of dysregulated H3K36me3 modifications.

Biology, immature and adult morphology, and molecular characterization of a new species of the genusEntedon(Hymenoptera: Eulophidae) associated with the invasive pestSpecularius impressithorax(Coleoptera: Chrysomelidae, Bruchinae) onErythrinaplants

2011 ◽  
Vol 101 (6) ◽  
pp. 715-739 ◽  
Author(s):  
A.V. Gumovsky ◽  
M.M. Ramadan
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Early Embryo ◽  
Invasive Pest ◽  
Young Larva ◽  
Preimaginal Stages ◽  
Undifferentiated Cells ◽  
Palearctic Species ◽  
Coral Tree

AbstractEntedon erythrinaesp. n. (Hymenoptera: Eulophidae), a gregarious egg-larval endoparasitoid of the Erythrina bruchineSpecularius impressithorax, an invasive pest of the coral tree seeds (Erythrinaspp.), is described from the Hawaiian Islands and Africa (South Africa, Tanzania and Mozambique). The biology and morphology of preimaginal stages of this new species are described in details.It is remarkable that the early embryo of the parasitoid represents a mass of undifferentiated cells surrounded by a peculiar membrane formed by the peripheral enlarged polygonal cells. The young larva developing inside this membrane corresponds morphologically to the second instar of congeneric species. Various peculiarities of the parasitoid-host relationships in gregarious and solitaryEntedonparasitoids are discussed. The DNA sequences of 28S D2 (nuclear), Cytochrome Oxidase I (COI, mitochondrial) and Cytochrome B (CytB, mitochondrial) genes are provided for this new species and compared with the sequences of some other Afrotropical and Palearctic species of the genus.

scholarly journals The dominant hepatitis B virus genotype identified in Tibet is a C/D hybrid

2002 ◽  
Vol 83 (11) ◽  
pp. 2773-2777 ◽  
Author(s):  
Chaoyin Cui ◽  
Jinxiu Shi ◽  
Lijian Hui ◽  
Huifeng Xi ◽  
Zhuoma ◽  
...  
Keyword(s):  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Dna Sequences ◽  
The Other ◽  
Virus Genotype ◽  
Hbv Genotypes ◽  
B Virus ◽  
Genotype C ◽  
Genomic Regions ◽  
Positive Population

There are no reports on DNA sequences of hepatitis B virus (HBV) strains from Tibet, although this highland area has a high HBsAg-positive population. We characterized HBV isolates from sera of 26 HBsAg-positive Tibetans. To determine the HBV genotypes and their phylogenetic relationships, we sequenced two genomic regions, one including the pre-S1/pre-S2/S region and the other including the pre-C/C region. The sequences were classified into two different genotypes based on different regions of the genome, except for one isolate. To clarify this finding, two complete HBV genomes that represented the two groups of isolates were sequenced. From the sequencing results, we concluded that HBV strains in Tibet may be classified as genotype C, and there are at least two subgroups. The dominant subgroup is a C/D hybrid with serotype ayw2, and the other is genotype C with serotype adw. This is the first report of complete nucleotide sequences of HBV from Tibet. These results contribute to the investigation of recombinant HBV strains throughout the world and should encourage further study of genotypes and recombination in HBV from this particular region.

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