The burst of satellite DNA in Leptidea wood white butterflies and their putative role in karyotype evolution.

Satellite DNAs (satDNAs) are abundant components of eukaryotic genomes, playing pivotal roles in chromosomal organization, genome stability, and evolution. Here, we combined cytogenetic and genomic methods to characterize the satDNAs in the genomes of Leptidea butterflies. Leptidea is characterized by the presence of a high heterochromatin content, large genomes, and extensive chromosomal reshuffling as well as the occurrence of cryptic species.

Differential amplification and contraction of satellite DNAs in the distinct lineages of the beetle Euchroma gigantea.

Satellite DNA (satDNA) consists of tandem repeat sequences that typically evolve rapidly through evolutionary mechanisms, including unequal crossover, transposition events, and others. The evolutionary history of Euchroma gigantea is marked by complex chromosomal evolution between lineages, making this species an interesting model for understanding satDNA evolution at intraspecies level. Therefore, our aim was to comprehend the potential contribution of satDNAs to the greater chromosomal differentiation of evolutionary lineages in E.

Comparative analysis of transposable elements dynamics in fish with different sex chromosome systems.

Transposable elements (TEs) are widespread genomic components with substantial roles in genome evolution and sex chromosome differentiation. In this study, we compared the TE composition of three closely related fish with different sex chromosome systems: (Z1Z1Z2Z2/Z1W1Z2W2), (ZZ/ZW) (both with highly differentiated W sex chromosomes), and (without heteromorphic sex chromosomes). We created custom TE libraries for each species using clustering methods and manual annotation and prediction, and we predicted TE temporal dynamics through divergence-based analysis.

Telomere organization and the interstitial telomeric sites involvement in insects and vertebrates chromosome evolution.

Telomere has a central role in chromosomal stability events. Chromosome ends organized in telomere-loop prevent activation of DNA damage response (DDR) mechanisms, thus keeping the chromosome structure organized. On the other hand, free chromosome ends, dysfunctional telomeres, and interstitial telomeric sequences (ITS) can trigger chromosome rearrangements.

Establishment and multiapproach characterization of Amblyomma sculptum (Acari: Ixodidae) cell line (ASE-14) from Brazil.

The establishment and characterization of the ASE-14 cell line derived from embryos of Amblyomma sculptum is described here. Primary cultures were started, and after 60 days of culturing a confluent monolayer was formed and the first subculture was then carried out. After this, new subcultures were carried out every 4 weeks.

Universal fluorescence in situ hybridization (FISH) protocol for mapping repetitive DNAs in insects and other arthropods.

Repetitive DNAs comprise large portion of eukaryote genomes. In genome projects, the assembly of repetitive DNAs is challenging due to the similarity between repeats, which generate ambiguities for alignment. Fluorescence in situ hybridization (FISH) is a powerful technique for the physical mapping of various sequences on chromosomes.

Analysis of Holhymenia histrio genome provides insight into the satDNA evolution in an insect with holocentric chromosomes.

Satellite DNAs (satDNA) are fast-evolving repetitive sequences organized in large tandem arrays, with characteristic enrichment in heterochromatin. Knowledge about evolutionary dynamics of this genome fraction is mostly restricted to its characterization in species with monocentric chromosomes, i.e.

Insights into the karyotype evolution and speciation of the beetle Euchroma gigantea (Coleoptera: Buprestidae).

Euchroma Dejean, 1833 (Buprestidae: Coleoptera) is a monotypic genus comprising the species Euchroma gigantea, with populations presenting a degree of karyotypic variation/polymorphism rarely found within a single taxonomic (specific) unit, as well as drastically incompatible meiotic configurations in populations from extremes of the species range. To better understand the complex karyotypic evolution of E. gigantea, the karyotypes of specimens from five populations in Brazil were investigated using molecular cytogenetics and phylogenetic approaches.

Uncovering the molecular organization of unusual highly scattered 5S rDNA: The case of Chariesterus armatus (Heteroptera).

One cluster of 5S rDNA per haploid genome is the most common pattern among Heteroptera. However, in Chariesterus armatus, highly scattered signals were noticed. We isolated and characterized the entire 5S rDNA unit of C.

Satellite DNAs are conserved and differentially transcribed among Gryllus cricket species.

Satellite DNA (satDNA) is an abundant class of non-coding repetitive DNA that is preferentially found as tandemly repeated arrays in gene-poor heterochromatin but is also present in gene-rich euchromatin. Here, we used DNA- and RNA-seq from Gryllus assimilis to address the content and transcriptional patterns of satDNAs. We also mapped RNA-seq libraries for other Gryllus species against the satDNAs found in G.

Centromeric enrichment of LINE-1 retrotransposons and its significance for the chromosome evolution of Phyllostomid bats.

Despite their ubiquitous incidence, little is known about the chromosomal distribution of long interspersed elements (LINEs) in mammalian genomes. Phyllostomid bats, characterized by lineages with distinct trends of chromosomal evolution coupled with remarkable ecological and taxonomic diversity, represent good models to understand how these repetitive sequences contribute to the evolution of genome architecture and its link to lineage diversification. To test the hypothesis that LINE-1 sequences were important modifiers of bat genome architecture, we characterized the distribution of LINE-1-derived sequences on genomes of 13 phyllostomid species within a phylogenetic framework.

The satellite DNA AflaSAT-1 in the A and B chromosomes of the grasshopper Abracris flavolineata.

Background: Satellite DNAs (satDNAs) are organized in repetitions directly contiguous to one another, forming long arrays and composing a large portion of eukaryote genomes. These sequences evolve according to the concerted evolution model, and homogenization of repeats is observed at the intragenomic level. Satellite DNAs are the primary component of heterochromatin, located primarily in centromeres and telomeres.

High-throughput analysis of the satellitome revealed enormous diversity of satellite DNAs in the neo-Y chromosome of the cricket Eneoptera surinamensis.

Satellite DNAs (satDNAs) constitute large portion of eukaryote genomes, comprising non-protein-coding sequences tandemly repeated. They are mostly found in heterochromatic regions of chromosomes such as around centromere or near telomeres, in intercalary heterochromatin, and often in non-recombining segments of sex chromosomes. We examined the satellitome in the cricket Eneoptera surinamensis (2n = 9, neo-XXY, males) to characterize the molecular evolution of its neo-sex chromosomes.

Highest Diploid Number Among Gymnotiformes: First Cytogenetic Insights into Rhabdolichops (Sternopygidae).

We report the first comparative cytogenetic analysis of two species from electrogenic fish of genus Rhabdolichops (Sternopygidae, Gymnotiformes): Rhabdolichops troscheli and Rhabdolichops cf eastwardi. R. troscheli has 2n = 54 (fundamental number [FN] = 66), whereas R.

Chromosomal evolutionary dynamics of four multigene families in Coreidae and Pentatomidae (Heteroptera) true bugs.

Previous chromosome mapping of multigene families in Pentatomomorpha (Heteroptera) insects, which was restricted to the major rDNA, revealed remarkable conservation of number of clusters and chromosomal positions. Aiming to understand the chromosomal organization and evolutionary patterns of multigene families in karyotypes of Heteroptera, we performed a chromosomal mapping using four distinct multigene families in representatives of Coreidae (ten species) and Pentatomidae (five species). A single pair of the major rDNA cluster (18S rDNA probe) and a single pair of the minor rDNA cluster (5S rDNA probe), both terminally located were primarily observed, being, in most species, located in distinct chromosomes.

Possible origin of B chromosome in Dichotomius sericeus (Coleoptera).

B chromosomes have so far been described in about 80 species of Coleoptera, mainly using conventional staining analysis. In this study, 152 individuals of the dung beetle Dichotomius sericeus (Coleoptera), collected from three isolated geographical areas in the State of Pernambuco, Brazil, were analyzed to determine the frequency, prevalence, distribution, meiotic behavior, and possible B chromosome origin. The cytogenetic analysis consisted of conventional staining, C-banding, triple fluorochrome staining (CMA3/DA/DAPI), and fluorescent in situ hybridization using ribosomal DNAs (rDNAs) and H3 histone gene as probes, as well as microdissection and chromosome painting of the B chromosome.

The 5S rDNA in two Abracris grasshoppers (Ommatolampidinae: Acrididae): molecular and chromosomal organization.

The 5S ribosomal DNA (rDNA) sequences are subject of dynamic evolution at chromosomal and molecular levels, evolving through concerted and/or birth-and-death fashion. Among grasshoppers, the chromosomal location for this sequence was established for some species, but little molecular information was obtained to infer evolutionary patterns. Here, we integrated data from chromosomal and nucleotide sequence analysis for 5S rDNA in two Abracris species aiming to identify evolutionary dynamics.

Toxicogenetic effects of low concentrations of the pesticides imidacloprid and sulfentrazone individually and in combination in in vitro tests with HepG2 cells and Salmonella typhimurium.

The insecticide imidacloprid and the herbicide sulfentrazone are two different classes of pesticides that are used for pest control in sugarcane agriculture. To evaluate the genotoxic potential of low concentrations of these two pesticides alone and in mixture, the comet assay and the micronucleus (MN) test employing fluorescence in situ hybridization (FISH) with a centromeric probe were applied in human hepatoma cell lines (HepG2), in a 24-h assay. Mutagenicity was assessed by Salmonella/microsome assay with TA98 and TA100 strains in the absence and presence of an exogenous metabolizing system (S9).

Heterochromatin and molecular characterization of DsmarMITE transposable element in the beetle Dichotomius schiffleri (Coleoptera: Scarabaeidae).

Cytogenetic studies of the Neotropical beetle genus Dichotomius (Scarabaeinae, Coleoptera) have shown dynamism for centromeric constitutive heterochromatin sequences. In the present work we studied the chromosomes and isolated repetitive sequences of Dichotomius schiffleri aiming to contribute to the understanding of coleopteran genome/chromosomal organization. Dichotomius schiffleri presented a conserved karyotype and heterochromatin distribution in comparison to other species of the genus with 2n = 18, biarmed chromosomes, and pericentromeric C-positive blocks.

Microsatellite organization in the grasshopper Abracris flavolineata (Orthoptera: Acrididae) revealed by FISH mapping: remarkable spreading in the A and B chromosomes.

With the aim of acquiring deeper knowledge about repetitive DNAs chromosomal organization in grasshoppers, we used fluorescent in situ hybridization (FISH) to map the distribution of 16 microsatellite repeats, including mono-, di-, tri- and tetra-nucleotides, in the chromosomes of the species Abracris flavolineata (Acrididae), which harbors B chromosome. FISH revealed two main patterns: (i) exclusively scattered signals, and (ii) scattered and specific signals, forming evident blocks. The enrichment was observed in both euchromatic and heterochromatic areas and only the motif (C)30 was absent in heterochromatin.

Chromosomal diversification of diploid number, heterochromatin and rDNAs in two species of Phanaeus beetles (Scarabaeidae, Scarabaeinae).

The genus Phanaeus is included in the tribe Phanaeini, one of the most diverse tribes within the subfamily Scarabaeinae in terms of chromosomal characteristics. However, so far the species of this genus were not studied with differential cytogenetic techniques, limiting any inference of the probable mechanisms responsible for this diversity. In this work, several techniques were applied with the aim of cytogenetically characterizing two Phanaeus species.

Chromosomal Mapping of Repetitive DNAs in the Grasshopper Abracris flavolineata Reveal Possible Ancestry of the B Chromosome and H3 Histone Spreading.

Supernumerary chromosomes (B chromosomes) occur in approximately 15% of eukaryote species. Although these chromosomes have been extensively studied, knowledge concerning their specific molecular composition is lacking in most cases. The accumulation of repetitive DNAs is one remarkable characteristic of B chromosomes, and the occurrence of distinct types of multigene families, satellite DNAs and some transposable elements have been reported.