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1.
Gene ; 888: 147785, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37689222

RESUMO

Transposable elements (TEs) are mobile repetitive DNA sequences that can transfer horizontally between species. Due to their mutagenic characteristics, TEs are associated with different evolutionary events, including chromosomal rearrangements that are abundant in the beetle Euchroma gigantea. In order to understand more in depth the impact of TEs on the genomic evolution of E. gigantea, we characterized the E. gigantea mobilome and evaluated the horizontal transfer of Tc1-Mariner elements. Genomic sequencing data was generated on the Illumina Hiseq plataform, from a specimen (Northeast lineage) collected in Recife, Pernambuco - Brazil. The TEs were characterized by two independent approaches based on the clustering and assembly of highly repetitive sequences, the RepeatExplorer and dnaPipeTE. The sequences obtained were further characterized using ORFfinder and CD-Search, to obtain the TEs' potential coding proteins and verify the presence and integrity of known TE domains. Evidence for horizontal transfer was evaluated by nucleotide and protein genetic distance between TEs from E. gigantea and other species and phylogenetic incongruences detected between TEs and hosts phylogenetic trees. The mobilome of E. gigantea represents about 21 to 26% of its genome. This mobilome is composed of TEs from 31 superfamilies, belonging to different classes and most known orders of TEs. Several types of TEs with intact domains were observed with emphasis on Tc1-Mariner suggesting the presence of potentially autonomous elements. This superfamily also stands out for having the greatest abundance and diversity, with TEs being classified into four families. When compared to TEs deposited in databases, Mariner TEs stood out as having the highest nucleotide identity (above 90%) with TEs from phylogenetically distant species, such as ants and bees. Altogether these results suggest that E. gigantea Mariner TEs underwent multiple horizontal transfer events to other insect species.


Assuntos
Besouros , Humanos , Animais , Besouros/genética , Filogenia , Elementos de DNA Transponíveis/genética , Genômica , Nucleotídeos , Evolução Molecular
2.
Cytogenet Genome Res ; 162(7): 391-400, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36724740

RESUMO

In Dichotomius genus, transposable elements (TE) have been related to chromosome remodeling, genomic evolution, and, possibly, to the speciation process. The objective of this study was to verify the interpopulational and interspecific conservation/variation of Tc1-Mariner elements (possibly autonomous) in Dichotomius species, aiming to identify possible contributions in the speciation process of this group. The analysis was performed on four species of Dichotomius, belonging to the Selenocopris subgenus. We verified the presence of the DsPogo_8 and DsTc1_5 elements by PCR and sequencing. We also isolated and sequenced the 28S and 16S rRNA genes aiming at the phylogenetic reconstruction of the analyzed species. Chromosomal mapping of TEs DsTc1_5 and DsPogo_8 was performed by fluorescent in situ hybridization. The results revealed the presence of the elements in the different species analyzed, except for DsTc1_5 in D. (S.) geminatus. These results suggest a vertical inheritance, with the presence of these elements in the common ancestor of these species. In the analyzed species, the nucleotide similarity of DsTc1_5 was higher than that of the 28S and 16S rRNA genes, suggesting the occurrence of horizontal transfer. The phylogenetic tree indicated that the absence of DsTc1_5 in D. (S.) geminatus is related to stochastic loss of this TE. Chromosomal mapping revealed dispersed signals, with predominance in euchromatic regions and wide variation in the chromosomal localization pattern of DsTc1_5 and DsPogo_8, both interpopulational and interspecific. This variation indicates that DsTc1_5 and DsPogo_8 may have contributed to prezygotic and postzygotic isolation, thus contributing to the speciation of these species.


Assuntos
Besouros , Animais , Besouros/genética , Filogenia , Hibridização in Situ Fluorescente , RNA Ribossômico 16S/genética , Cromossomos , Elementos de DNA Transponíveis , Evolução Molecular
3.
Genet Mol Biol ; 43(3): e20190077, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32542305

RESUMO

The grasshopper Rhammatocerus brasiliensis shows polymorphism of B chromosomes, but the magnitude of B-chromosome occurrence and the factors that may contribute to their dispersion in the species remain unknown thus far. The present study analyzed the occurrence and dispersion of B chromosomes in R. brasiliensis individuals from 21 populations widely distributed in the Brazilian Northeast. The genetic connectivity between 10 populations was verified through analysis of ISSR markers from 200 individuals. Of the 21 populations, 19 presented individuals with one B chromosome, three with two, and one with three B chromosomes. The B chromosome is of medium size and constitutive heterochromatin (CH) located in the pericentromeric region. A variant B chromosome was observed in three populations, similar in size to that of chromosome X, gap and CH, and located in the terminal region. B chromosome frequencies in different populations varied from 0% to 18,8%, mean 8,5%. The wide distribution of the B chromosome is likely a consequence of the positive gene flow among the analyzed populations. B-chromosome occurrence in populations of R. brasiliensis possibly follows the population genetic structure of the species and, owing to the existence of a variant, its origin may not be recent.

4.
Genes (Basel) ; 9(11)2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30373193

RESUMO

Supernumerary (B) chromosomes are dispensable genomic elements occurring frequently among grasshoppers. Most B chromosomes are enriched with repetitive DNAs, including satellite DNAs (satDNAs) that could be implicated in their evolution. Although studied in some species, the specific ancestry of B chromosomes is difficult to ascertain and it was determined in only a few examples. Here we used bioinformatics and cytogenetics to characterize the composition and putative ancestry of B chromosomes in three grasshopper species, Rhammatocerus brasiliensis, Schistocerca rubiginosa, and Xyleus discoideus angulatus. Using the RepeatExplorer pipeline we searched for the most abundant satDNAs in Illumina sequenced reads, and then we generated probes used in fluorescent in situ hybridization (FISH) to determine chromosomal position. We used this information to infer ancestry and the events that likely occurred at the origin of B chromosomes. We found twelve, nine, and eighteen satDNA families in the genomes of R. brasiliensis, S. rubiginosa, and X. d. angulatus, respectively. Some satDNAs revealed clustered organization on A and B chromosomes varying in number of sites and position along chromosomes. We did not find specific satDNA occurring in the B chromosome. The satDNAs shared among A and B chromosomes support the idea of putative intraspecific ancestry from small autosomes in the three species, i.e., pair S11 in R. brasiliensis, pair S9 in S. rubiginosa, and pair S10 in X. d. angulatus. The possibility of involvement of other chromosomal pairs in B chromosome origin is also hypothesized. Finally, we discussed particular aspects in composition, origin, and evolution of the B chromosome for each species.

5.
Front Neurol ; 8: 73, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28321203

RESUMO

Musician's dystonia is a task-specific dystonia (TSD) worldwide disabling disorder, and most of the affected individuals may have severe difficulty to play their instrument. Many professional music players may have to quit working as a player. The objective of the present study was to evaluate the clinical characteristics and frequency of TSD in Brazilian music players and to promote awareness of this condition among musicians. We visited orchestras and music schools delivering lectures on TSD and about the scope of our survey. Musicians were invited to answer a questionnaire, and those with possible neurological dysfunction associated with musical performance were recorded by video while playing the instrument. We visited 51 orchestras and music schools in 19 Brazilian cities between March 2013 and March 2015. We collected 2,232 questionnaires, and 72 subjects with suspicion of dystonia were video recorded during specific tasks and evaluated regarding motor impairment. Forty-nine individuals (2.2%) were diagnosed as having TSD (mean age 36.4 years; 92% male). The instruments most associated with TSD were acoustic guitar (36.7%) and brass instruments (30.6%). We concluded that Brazilian TSD music players are mainly male, classical music professionals, around 30 years of age, with arms, hands, or oromandibular muscles affected. TSD is a neurological condition that can impair musical performance and should receive more attention from musicians, teachers, and health professionals.

6.
Mol Cytogenet ; 6(1): 54, 2013 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-24286129

RESUMO

BACKGROUND: With the aim to increase the knowledge on the evolution of coleopteran genomes, we investigated through cytogenetics and nucleotide sequence analysis Mariner transposons in three Scarabaeinae species (Coprophanaeus cyanescens, C. ensifer and Diabroctis mimas). RESULTS: The cytogenetic mapping revealed an accumulation of Mariner transposon in the pericentromeric repetitive regions characterized as rich in heterochromatin and C0t-1 DNA fraction (DNA enriched with high and moderately repeated sequences). Nucleotide sequence analysis of Mariner revealed the presence of two major groups of Mariner copies in the three investigated coleoptera species. CONCLUSIONS: The Mariner is accumulated in the centromeric area of the coleopteran chromosomes probably as a consequence of the absence of recombination in the heterochromatic regions. Our analysis detected high diversification of Mariner sequences during the evolutionary history of the group. Furthermore, comparisons between the coleopterans sequences with other insects and mammals, suggest that the horizontal transfer (HT) could have acted in the spreading of the Mariner in diverse non-related animal groups.

7.
Mol Cytogenet ; 4: 24, 2011 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-22075079

RESUMO

BACKGROUND: Supernumerary B chromosomes occur in addition to standard karyotype and have been described in about 15% of eukaryotes, being the repetitive DNAs the major component of these chromosomes, including in some cases the presence of multigene families. To advance in the understanding of chromosomal organization of multigene families and B chromosome structure and evolution, the distribution of rRNA and H3 histone genes were analyzed in the standard karyotype and B chromosome of three populations of the grasshopper Rhammatocerus brasiliensis. RESULTS: The location of major rDNA was coincident with the previous analysis for this species. On the other hand, the 5S rDNA mapped in almost all chromosomes of the standard complement (except in the pair 11) and in the B chromosome, showing a distinct result from other populations previously analyzed. Besides the spreading of 5S rDNA in the genome of R. brasiliensis it was also observed multiple sites for H3 histone genes, being located in the same chromosomal regions of 5S rDNAs, including the presence of the H3 gene in the B chromosome. CONCLUSIONS: Due to the intense spreading of 5S rRNA and H3 histone genes in the genome of R. brasiliensis, their chromosomal distribution was not informative in the clarification of the origin of B elements. Our results indicate a linked organization for the 5S rRNA and H3 histone multigene families investigated in R. brasiliensis, reinforcing previous data concerning the association of both genes in some insect groups. The present findings contribute to understanding the organization/evolution of multigene families in the insect genomes.

8.
BMC Genet ; 12: 88, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21999519

RESUMO

BACKGROUND: Scarabaeinae beetles show a high level of macro-chromosomal variability, although the karyotypic organization of heterochromatin and multigene families (rDNAs and histone genes) is poorly understood in this group. To better understand the chromosomal organization and evolution in this group, we analyzed the karyotypes, heterochromatin distribution and chromosomal locations of the rRNAs and histone H3 genes in beetles belonging to eight tribes from the Scarabaeinae subfamily (Coleoptera, Scarabaeidae). RESULTS: The number of 18S rRNA gene (a member of the 45S rDNA unit) sites varied from one to 16 and were located on the autosomes, sex chromosomes or both, although two clusters were most common. Comparison of the 45S rDNA cluster number and the diploid numbers revealed a low correlation value. However, a comparison between the number of 45S rDNA sites per genome and the quantity of heterochromatin revealed (i) species presenting heterochromatin restricted to the centromeric/pericentromeric region that contained few rDNA sites and (ii) species with a high quantity of heterochromatin and a higher number of rDNA sites. In contrast to the high variability for heterochromatin and 45S rDNA cluster, the presence of two clusters (one bivalent cluster) co-located on autosomal chromosomes with the 5S rRNA and histone H3 genes was highly conserved. CONCLUSIONS: Our results indicate that the variability of the 45S rDNA chromosomal clusters is not associated with macro-chromosomal rearrangements but are instead related to the spread of heterochromatin. The data obtained also indicate that both heterochromatin and the 45S rDNA loci could be constrained by similar evolutionary forces regulating spreading in the distinct Scarabaeinae subfamily lineages. For the 5S rRNA and the histone H3 genes, a similar chromosomal organization could be attributed to their association/co-localization in the Scarabaeinae karyotypes. These data provide evidence that different evolutionary forces act at the heterochromatin and the 45S rDNA loci compared to the 5S rRNA and histone H3 genes during the evolution of the Scarabainae karyotypes.


Assuntos
Besouros/genética , Histonas/genética , RNA Ribossômico 18S/genética , RNA Ribossômico 5S/genética , Animais , Mapeamento Cromossômico , Cromossomos de Insetos/genética , DNA Ribossômico/genética , Evolução Molecular , Variação Genética , Heterocromatina/genética , Hibridização in Situ Fluorescente , Proteínas de Insetos/genética , Cariótipo , Cariotipagem , Masculino , Família Multigênica
9.
Arq. bras. oftalmol ; 57(3): 167-9, jun. 1994. tab
Artigo em Português | LILACS | ID: lil-280048

RESUMO

Dez pacientes com queimaduras oculares unilaterais graves, oito por agentes químicos e dois por agentes térmicos, foram submetidos ao transplante de conjuntiva limbar autógena. A técnica cirúrgica consistiu em transferir dois retalhos da conjuntiva limbar autôgena. A técnica cirúrgica consistiu em transferir dois retalhos da conjuntiva limbar do olho contralateral, para regiöes comprometidas do olho acometido. O acompanhamento variou de 8 a 48 meses. Todos os pacientes apresentaram melhora da acuidade visual, estabilidade epitelial e regressäo da neovascularizaçäo estromal. O transplante de conjuntiva limbar autógeno parece ser indicado para o tratamento de queimaduras oculares químicas ou térmicas severas, associadas à perda de células primordiais limbares.


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Túnica Conjuntiva/cirurgia , Queimaduras Oculares , Traumatismos Oculares , Limbo da Córnea , Transplante
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