Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 2.927
Filtrar
1.
Medicine (Baltimore) ; 99(1): e18695, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895838

RESUMO

RATIONALE: Jacobsen syndrome (JBS) is a rare chromosomal disorder with variable phenotypic expressivity, which is usually diagnosed in infancy and childhood based on clinical examination and hematological and cytogenetic findings. Prenatal diagnosis and fetal ultrasonographic findings of JBS are rare. PATIENT CONCERNS: A 38-year-old, gravida 3, para 1, pregnant woman underwent clinical ultrasound examination at 22 weeks of gestation. DIAGNOSES: Ultrasonographic findings indicated an interventricular septal defect, the presence of septal blood flow, dilation of the left renal pelvis, and a single umbilical artery. Amniocentesis was performed to evaluate possible genetic causes of this diagnosis by cytogenetic and single nucleotide polymorphism (SNP) array analysis. INTERVENTIONS: After genetic counseling and informed consent, the couple elected to terminate the pregnancy. OUTCOMES: Karyotype analysis showed that the fetal karyotype was 46,XX,del(11)(q23). The SNP array revealed a 6.118 Mb duplication of 11q23.2q23.3 and a 15.03 Mb deletion of 11q23.3q25. LESSONS: Ultrasonographic findings of fetal JBS, including an interventricular septal defect, dilation of the left renal pelvis, and a single umbilical artery, may be associated with a 15.03 Mb deletion of 11q23.3q25. Further cases correlating phenotype and genotype are required to predict the postnatal phenotype.


Assuntos
Síndrome da Deleção Distal 11q de Jacobsen/diagnóstico por imagem , Adulto , Feminino , Humanos , Cariótipo , Gravidez , Ultrassonografia Pré-Natal
2.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 37(1): 37-40, 2020 Jan 10.
Artigo em Chinês | MEDLINE | ID: mdl-31922593

RESUMO

OBJECTIVE: To determine the frequency, common chromosomal karyotypes and breakpoints, and involved regions among carriers of reciprocal translocations from Henan Province, and to explore the influence of common breakpoint regions on pregnancy and fetal development. METHODS: For 586 carriers of reciprocal translocations, the above features were retrospectively analyzed. RESULTS: The 586 reciprocal translocations were identified among 62 477 subjects, which yielded a frequency of 0.94%. Among these, 572 (0.92%) had abnormal fertility, and 14 (0.02%) had a history of abnormal fetal development. Statistical analysis showed that chromosomes 1, 4, 7 and 11 were most frequently involved, with t(11;22)(q25;q13) being the most common type of translocation. In total 437 breakpoint regions were identified, with 11q23, 22q13 and 1p36 being most frequently involved, which resulted in infertility, abortion, embryo death, congenital malformation, development delay, mental retardation or a normal phenotype. CONCLUSION: Above results indicated a 0.92% carrier rate for reciprocal chromosomal translocations in Henan. The location of breakpoint regions may affect the pregnancy and/or fetal development. Discovery of such regions may enable more accurate genetic, reproductive and developmental counseling for carriers, and provide reference for delineation of function and pathogenetic mechanism of the relevant genes.


Assuntos
Pontos de Quebra do Cromossomo , Translocação Genética , Feminino , Heterozigoto , Humanos , Cariótipo , Cariotipagem , Gravidez , Estudos Retrospectivos , Translocação Genética/genética
3.
Mol Genet Genomics ; 295(1): 195-207, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31624915

RESUMO

The origin of supernumerary (B) chromosomes is clearly conditioned by their ancestry from the standard (A) chromosomes. Sequence similarity between A and B chromosomes is thus crucial to determine B chromosome origin. For this purpose, we compare here the DNA sequences from A and B chromosomes in the characid fish Characidium gomesi using two main approaches. First, we found 59 satellite DNA (satDNA) families constituting the satellitome of this species and performed FISH analysis for 18 of them. This showed the presence of six satDNAs on the B chromosome: one shared with sex chromosomes and autosomes, two shared with sex chromosomes, one shared with autosomes and two being B-specific. This indicated that B chromosomes most likely arose from the sex chromosomes. Our second approach consisted of the analysis of five repetitive DNA families: 18S and 5S ribosomal DNA (rDNA), the H3 histone gene, U2 snDNA and the most abundant satDNA (CgoSat01-184) on DNA obtained from microdissected B chromosomes and from B-lacking genomes. PCR and sequence analysis of these repetitive sequences was successful for three of them (5S rDNA, H3 histone gene and CgoSat01-184), and sequence comparison revealed that DNA sequences obtained from the B chromosomes displayed higher identity with C. gomesi genomic DNA than with those obtained from other Characidium species. Taken together, our results support the intraspecific origin of B chromosomes in C. gomesi and point to sex chromosomes as B chromosome ancestors, which raises interesting prospects for future joint research on the genetic content of sex and B chromosomes in this species.


Assuntos
Characidae/genética , Caraciformes/genética , DNA Satélite/genética , Cromossomos Sexuais/genética , Animais , Mapeamento Cromossômico/métodos , DNA Ribossômico/genética , Evolução Molecular , Histonas/genética , Cariótipo , Sequências Repetitivas de Ácido Nucleico/genética
4.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(6): 1717-1721, 2019 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-31839028

RESUMO

OBJECTIVE: To investigate the efficacy and prognosis of acute myeloid leukemia (AML) patients with chromosome karyotype abnormalities. METHODS: The clinical features and treatment responses of 91 patients with AML were collected and analyzed retrospectively. The efficacy and survival rate of the AML patients with normal and abnormal chromosome karyotype were compared. RESULTS: Chromosome translocations and monosomal karyotypes were the main heterogeneity of AML. There was no significant difference in complete remission rate and overall response rate between the normal and abnormal karyotype groups, but the recurrence rate was higher in abnormal karyotype group. There was no significant difference in response of AML patients received the standard "3+7 regimen" and pre-excitation chemotherapy in the treatment of normal and abnormal karyotype groups. The relapse free survival time (RFS) was longer in the normal karyotype group, but there was no significant difference in overall survival time (OS). CONCLUSION: The abnormal karyotype of AML is an independent prognostic factor, monosomal karyotype shows a poor prognosis, and the recurrence rate in AML patients with monosomal karyotype is higher.


Assuntos
Leucemia Mieloide Aguda , Adulto , Aberrações Cromossômicas , Humanos , Cariótipo , Cariotipagem , Prognóstico , Estudos Retrospectivos
5.
BMC Bioinformatics ; 20(Suppl 20): 641, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31842730

RESUMO

BACKGROUND: Many cancer genomes are extensively rearranged with highly aberrant chromosomal karyotypes. Structural and copy number variations in cancer genomes can be determined via abnormal mapping of sequenced reads to the reference genome. Recently it became possible to reconcile both of these types of large-scale variations into a karyotype graph representation of the rearranged cancer genomes. Such a representation, however, does not directly describe the linear and/or circular structure of the underlying rearranged cancer chromosomes, thus limiting possible analysis of cancer genomes somatic evolutionary process as well as functional genomic changes brought by the large-scale genome rearrangements. RESULTS: Here we address the aforementioned limitation by introducing a novel methodological framework for recovering rearranged cancer chromosomes from karyotype graphs. For a cancer karyotype graph we formulate an Eulerian Decomposition Problem (EDP) of finding a collection of linear and/or circular rearranged cancer chromosomes that are determined by the graph. We derive and prove computational complexities for several variations of the EDP. We then demonstrate that Eulerian decomposition of the cancer karyotype graphs is not always unique and present the Consistent Contig Covering Problem (CCCP) of recovering unambiguous cancer contigs from the cancer karyotype graph, and describe a novel algorithm CCR capable of solving CCCP in polynomial time. We apply CCR on a prostate cancer dataset and demonstrate that it is capable of consistently recovering large cancer contigs even when underlying cancer genomes are highly rearranged. CONCLUSIONS: CCR can recover rearranged cancer contigs from karyotype graphs thereby addressing existing limitation in inferring chromosomal structures of rearranged cancer genomes and advancing our understanding of both patient/cancer-specific as well as the overall genetic instability in cancer.


Assuntos
Cromossomos/genética , Rearranjo Gênico/genética , Cariótipo , Neoplasias/genética , Algoritmos , Sequência de Bases , Genoma , Humanos
6.
Cytogenet Genome Res ; 159(2): 88-96, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31593945

RESUMO

The bush dog (Speothos venaticus, 2n = 74) is a near threatened species taxonomically classified among South American canids. We revised the bush dog karyotype and performed a comparative sequence analysis of satellite and satellite-like DNAs in 6 canids: the bush dog, domestic dog (Canis familiaris, 2n = 78), grey wolf (C. lupus, 2n = 78), Chinese raccoon dog (Nyctereutes procyonoides procyonoides, 2n = 54+B), red fox (Vulpes vulpes, 2n = 34+B), and arctic fox (V. lagopus, 2n = 48-50) to specify the species position among Canidae. Using FISH with painting and BAC probes, we found that the distribution of canid evolutionarily conserved chromosome segments in the bush dog karyotype is similar to that of the domestic dog and grey wolf. The bush dog karyotype differs by 2 acrocentric chromosome pairs formed by tandem fusions of the canine (29;34) and (26;35) orthologues. An interstitial signal of the telomeric probe was observed in the (26;35) fusion site in the bush dog indicating a recent evolutionary origin of this rearrangement. Sequences and hybridisation patterns of satellite DNAs were compared, and a phylogenetic tree of the 6 canid species was constructed which confirmed the bush dog position close to the wolf-like canids, and apart from the raccoon dog and foxes.


Assuntos
Cromossomos/genética , DNA Satélite/genética , Animais , Bandeamento Cromossômico/métodos , Cães , Evolução Molecular , Raposas/genética , Cariótipo , Cariotipagem/métodos , Filogenia , Lobos/genética
7.
Cytogenet Genome Res ; 159(1): 39-47, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31593951

RESUMO

Greenhouse gas emissions are known to influence the planet's temperature, mainly due to human activities. To allow hypothesis testing, as well as to seek viable alternatives for mitigation, the Intergovernmental Panel on Climate Change (IPCC) suggested 3 main scenarios for changes projected for the year 2100. In this paper, we subjected Colossoma macropomum Cuvier, 1818 (tambaqui) individuals in a microcosm to IPCC scenarios B1 (mild), A1B (intermediate), and A2 (extreme) to test possible impacts on their genome. We found chromosome heterochromatinization in specimens exposed to the A2 scenario, where terminal blocks and interstitial bands were detected on several chromosome pairs. The behavior of Rex1 and Rex3 sequences differed between the test scenarios. Hybridization of Rex1 resulted in diffuse signals which showed a gradual increase in the tested scenarios. For Rex3, an increase was observed in the A2 scenario with blocks on several chromosomes, some of which coincided with heterochromatin. Heterochromatinization is an epigenetic process, which may have occurred as a mechanism for regulating Rex3 activity. The signal pattern of Rex6 did not change, suggesting that other mechanisms are acting to regulate its activity.


Assuntos
Caraciformes/genética , Mudança Climática , Gases de Efeito Estufa/efeitos adversos , Retroelementos/genética , Estresse Fisiológico/genética , Animais , Mapeamento Cromossômico , Cariótipo , Temperatura Ambiente
8.
BMC Evol Biol ; 19(1): 184, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601183

RESUMO

BACKGROUND: The Neacomys genus is predominantly found in the Amazon region, and belongs to the most diverse tribe of the Sigmodontinae subfamily (Rodentia, Cricetidae, Oryzomyini). The systematics of this genus and questions about its diversity and range have been investigated by morphological, molecular (Cytb and COI sequences) and karyotype analysis (classic cytogenetics and chromosome painting), which have revealed candidate species and new distribution areas. Here we analyzed four species of Neacomys by chromosome painting with Hylaeamys megacephalus (HME) whole-chromosome probes, and compared the results with two previously studied Neacomys species and with other taxa from Oryzomyini and Akodontini tribes that have been hybridized with HME probes. Maximum Parsimony (MP) analyses were performed with the PAUP and T.N.T. software packages, using a non-additive (unordered) multi-state character matrix, based on chromosomal morphology, number and syntenic blocks. We also compared the chromosomal phylogeny obtained in this study with molecular topologies (Cytb and COI) that included eastern Amazonian species of Neacomys, to define the phylogenetic relationships of these taxa. RESULTS: The comparative chromosome painting analysis of the seven karyotypes of the six species of Neacomys shows that their diversity is due to 17 fusion/fission events and one translocation, pericentric inversions in four syntenic blocks, and constitutive heterochromatin (CH) amplification/deletion of six syntenic autosomal blocks plus the X chromosome. The chromosomal phylogeny is consistent with the molecular relationships of species of Neacomys. We describe new karyotypes and expand the distribution area for species from eastern Amazonia and detect complex rearrangements by chromosome painting among the karyotypes. CONCLUSIONS: Our phylogeny reflects the molecular relationships of the Akodontini and Oryzomyini taxa and supports the monophyly of Neacomys. This work presents new insights about the chromosomal evolution of this group, and we conclude that the karyotypic divergence is in accord with phylogenetic relationships.


Assuntos
Coloração Cromossômica , Cromossomos de Mamíferos/genética , Filogenia , Sigmodontinae/genética , Animais , Brasil , Sondas de DNA , Geografia , Cariótipo , Sintenia
9.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1380-1386, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607287

RESUMO

OBJECTIVE: To investigate the effect of chromosomal karyotype on the prognosis of patients with acute promyelocytic leukemia (APL) in condition of the maintenance treatment based on arsenic trioxide. METHODS: The patients with acute promyelocytic leukemia for last 12 years in our hospital were retrospectively collected. The patients mainly treated with arsenic trioxide in maintenance protocol were selected and followed up. All the patients were divided into 3 groups according to cytogenetic data: single t (15; 17) group, t (15; 17) with additional chromosomal abnormality (ACA) group, and normal karyotype group. Then, the prognostic significance of ACAs and complex karyotype were investigated in APL patients. RESULTS: There were 57 cases in the single t (15; 17) group, in which 8 cases died in the first month after induction treatment with early mortality rate of 14%. There were 21 patients in t (15; 17) with ACA group, in which 4 cases died in the first month with early mortality rate of 19%. There were 15 cases in normal chromosome group, in which 5 cases died in the first month with the early mortality rate of 33.3%. There was no statistical difference in the early mortality among 3 groups. All the remaining 76 patients achieved complete hematological remission. These patients were followed up. The median follow-up time was 43.9 months. Among them, only 2 patients in single t (15; 17) group and 1 patient in t (15; 17) with ACA group relapsed. No patient relapsed in normal karyotype group. The relapse rate was 3.5% in single t (15; 17) group and 4.2% in t (15; 17) with ACA group, respectively. There was no statistical difference in the overall survival and disease-free survival rates among 3 groups. Further analysis showed that the patients with complex chromosome karyotypes had lower relapse-free survival rates, but overall survival rates were not significantly different in 3 group. CONCLUSION: In general, ACA can not affect the prognosis of patients with acute promyelocytic leukemia in condition of the maintenance treatment based on arsenic trioxide, but the complex chromosomal karyotype may reduce the relapse-free survival rates.


Assuntos
Trióxido de Arsênio/uso terapêutico , Leucemia Promielocítica Aguda , Humanos , Cariótipo , Leucemia Promielocítica Aguda/tratamento farmacológico , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Resultado do Tratamento , Tretinoína
10.
J Insect Sci ; 19(5)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31587063

RESUMO

In this study, chromosomal characteristics of Eratigena agrestris (Agelenidae) were investigated for the first time. Karyotype features including diploid chromosome number, sex chromosome system, chromosome morphology, and meiotic behavior were obtained from specimens collected in two localities of Mediterranean region. A spreading method including dissection, hypotonization, fixation, and staining was used to prepare the chromosome slides. In a total, 10 adult males were used due to having high numbers of dividing cells. Cytogenetical results showed that the diploid chromosome number and sex chromosome system was 2n♂ = 42 (X1X20). The sex chromosomes were identified tentatively. All chromosomes were telocentric. Relative chromosome lengths of autosomal pairs ranged between 5.65 and 3.32%, and relative chromosome lengths of X1 and X2 were 5.33 and 4.19%, respectively. In the first meiotic division stages, bivalents usually had one chiasma, but some had two chiasmata. At the end of the meiosis, two kinds of nuclei, with or without sex chromosomes, have occurred. These results contribute to a better characterization of the Agelenidae cytogenetic.


Assuntos
Análise Citogenética , Aranhas/genética , Animais , Feminino , Cariótipo , Masculino , Cromossomos Sexuais , Turquia
11.
Cytogenet Genome Res ; 159(1): 32-38, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31542782

RESUMO

Despite the variation observed in the diploid chromosome number of storks (Ciconiiformes, Ciconiidae), from 2n = 52 to 2n = 78, most reports have relied solely on analyses by conventional staining. As most species have similar macrochromosomes, some authors propose that karyotype evolution involves mainly fusions between microchromosomes, which are highly variable in species with different diploid numbers. In order to verify this hypothesis, in this study, the karyotypes of 2 species of storks from South America with different diploid numbers, the jabiru (Jabiru mycteria, 2n = 56) and the maguary stork (Ciconia maguary, 2n = 72), were analyzed by chromosome painting using whole chromosome probes from the macrochromosomes of Gallus gallus (GGA) and Leucopternis albicollis (LAL). The results revealed that J. mycteria and C. maguary share synteny within chromosome pairs 1-9 and Z. The syntenies to the macrochromosomes of G. gallus are conserved, except for GGA4, which is homologous to 2 different pairs, as in most species of birds. A fusion of GGA8 and GGA9 was observed in both species. Additionally, chromosomes corresponding to GGA4p and GGA6 are fused to other segments that did not hybridize to any of the macrochromosome probes used, suggesting that these segments correspond to microchromosomes. Hence, our data corroborate the proposed hypothesis that karyotype evolution is based on fusions involving microchromosomes. In view of the morphological constancy of the macrochromosome pairs in most Ciconiidae, we propose a putative ancestral karyotype for the family, including the GGA8/GGA9 fusion, and a diploid number of 2n = 78. The use of probes for microchromosome pairs should be the next step in identifying other synapomorphies that may help to clarify the phylogeny of this family.


Assuntos
Aves/genética , Coloração Cromossômica/veterinária , Cromossomos/genética , Variação Genética/genética , Cariótipo , Animais , Brasil , Diploide , Evolução Molecular , Feminino , Filogenia
12.
Clinics (Sao Paulo) ; 74: e771, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508719

RESUMO

OBJECTIVES: To evaluate the effects of epoetin (EPO) alfa treatment on overall survival, event-free survival and response duration in patients with myelodysplastic syndrome (MDS) who were treated at a haematological referral centre in northeastern Brazil. METHODS: This was a retrospective cohort study of 36 patients diagnosed with MDS and treated with EPO alfa at 30,000 to 60,000 IU per week. Clinical data were collected from medical records. The events assessed were non-response to treatment and progression to acute myeloid leukaemia (AML). Statistical analyses were performed using GraphPad Prism 7 and SPSS 24 software. RESULTS: The overall survival of patients who received EPO alfa treatment was 51.64%, with a median of 65 months of treatment, and the overall survival of this group was 100% during the first 24 months. We detected a 43.5-month median event-free survival, with a response rate of 80.5%. We observed responses from 25 to 175 months. Patients with transfusion dependence and those with a high-risk stratification, as determined by the International Prognostic Scoring System (IPSS), the Revised International Prognostic Scoring System (IPSS-R), the WHO classification-based Prognostic Scoring System (WPSS) and the WHO 2016, had a lower event-free survival than other patients. CONCLUSIONS: Despite the wide use of EPO alfa in the treatment of anaemia in patients with MDS, the median response duration is approximately only 24 months. Our data provide encouraging results concerning the benefits of using EPO alfa for the improvement of the quality of life, as patients treated with EPO showed higher overall survival, event-free survival rates and longer response durations than have been previously described in the literature.


Assuntos
Epoetina alfa/uso terapêutico , Hematínicos/uso terapêutico , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/mortalidade , Idoso , Idoso de 80 Anos ou mais , Transfusão de Sangue , Brasil , Progressão da Doença , Feminino , Hemoglobinas/análise , Humanos , Estimativa de Kaplan-Meier , Cariótipo , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Intervalo Livre de Progressão , Valores de Referência , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
13.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(9): 857-861, 2019 Sep 10.
Artigo em Chinês | MEDLINE | ID: mdl-31515775

RESUMO

OBJECTIVE: To carry out mutation analysis for patients with myelodysplastic syndromes (MDS) and a normal karyotype. METHODS: Targeted capture and next-generation sequencing (NGS) was carried out using a customized 49-gene panel. FLT3 internal tandem duplication (FLT3-ITD), CALR, NPM1 and CEBPA mutations were detected by PCR and Sanger sequencing. RESULTS: Sixty-two patients (80.5%) were found to harbor at least one mutation. Each patient has carried 2.21 mutations in average. Coexistence of ≥ 3 mutations was common (43.7%). The most commonly mutated genes were RUNX1 (23.4%, 18/77), ASXL1 (18.2%, 14/77), NPM1 (15.6%, 12/77), U2AF1 (15.6%, 12/77), DNMT3A (11.7%, 9/77). Patients with SF3B1 mutations were significantly older than those with ASXL1 mutations (P=0.023). Mutations of the DNMT3A gene were significantly associated with the blood platelet level compared with BCOR mutations (P=0.02). No significant difference was found in the number and rate of mutations between those under or above 60-year-old. Among 67 patients with clinical follow-up, 20 (29.8%) has transformed to acute myeloid leukemia, and the time of transformation has ranged from 1 to 44 months, with a average of 5.3 months. RUNX1, U2AF1 and FLT3 mutations are associated with leukemic transformation. CONCLUSION: Coexistence of ≥ 3 mutations are frequent among patients with normal-karyotype MDS. Certain mutations are associated with age and leukemic transformation.


Assuntos
Análise Mutacional de DNA , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Fatores Etários , Humanos , Cariótipo , Pessoa de Meia-Idade , Mutação , Prognóstico
14.
BMC Bioinformatics ; 20(1): 467, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31510921

RESUMO

BACKGROUND: Cytogenetic nomenclature is used to describe chromosomal aberrations (or lack thereof) in a collection of cells, referred to as the cells' karyotype. The nomenclature identifies locations on chromosomes using a system of cytogenetic bands, each with a unique name and region on a chromosome. Each band is microscopically visible after staining, and encompasses a large portion of the chromosome. More modern analyses employ genomic coordinates, which precisely specify a chromosomal location according to its distance from the end of the chromosome. Currently, there is no tool to convert cytogenetic nomenclature into genomic coordinates. Since locations of genes and other genomic features are usually specified by genomic coordinates, a conversion tool will facilitate the identification of the features that are harbored in the regions of chromosomal gain and loss that are implied by a karyotype. RESULTS: Our tool, termed CytoConverter, takes as input either a single karyotype or a file consisting of multiple karyotypes from several individuals. All net chromosomal gains and losses implied by the karyotype are returned in standard genomic coordinates, along with the numbers of cells harboring each aberration if included in the input. CytoConverter also returns graphical output detailing areas of gains and losses of chromosomes and chromosomal segments. CONCLUSIONS: CytoConverter is available as a web-based application at https://jxw773.shinyapps.io/Cytogenetic__software/ and as an R script at https://sourceforge.net/projects/cytoconverter/ . Supplemental Material detailing the underlying algorithms is available.


Assuntos
Aberrações Cromossômicas , Citogenética/métodos , Genômica/métodos , Internet/instrumentação , Cariótipo , Humanos
15.
Cytogenet Genome Res ; 159(1): 26-31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31527379

RESUMO

Karyotypes of 3 male Talpa specimens from northern Spain were analyzed. The mesostyles of upper molars and cytochrome b sequence analysis identified these specimens as belonging to Talpa aquitania, a new Talpa species recently described from northern Spain and southern France. We describe here for the first time the karyotype of Talpa aquitania. Its diploid number is 2n = 34 and NFa = 64, and all chromosomes including the sex chromosomes are biarmed, either metacentric or submetacentric. G-banding demonstrated that the karyotypes of T. aquitania and T. occidentalis (the most closely related species) are almost identical. However, the karyotype of T. aquitania differs from the karyotypes of both T. europaea and T. occidentalis in that it has a medium-sized biarmed Y chromosome rather than a dot-like chromosome and that chromosome 16 is submetacentric in T. aquitania but has a small p-arm in both T. europaea and T. occidentalis. Pericentromeric C-bands were scarce and only clearly visible in a few chromosomal pairs. In addition, C-banding demonstrated that half of the 14p, the 16p, and the Y chromosome are all heterochromatic. rDNA genes were located at the secondary constriction in autosomal pair 3, a common feature in the karyotypes of all Talpa species. Hybridization signals for telomeric repeats were found on the telomeres and the pericentric regions of some chromosomes and co-localized in the secondary constriction of pair 3 with the rDNA genes. In conclusion, the karyotype of T. aquitania from northern Spain is very similar to the karyotype of other species belonging to the genus Talpa.


Assuntos
Eutérios/classificação , Eutérios/genética , Insetívoros/classificação , Insetívoros/genética , Cariótipo , Animais , Bandeamento Cromossômico , Citocromos b/genética , Cariotipagem , Masculino , Dente Molar/anatomia & histologia , Espanha
16.
Int J Mol Sci ; 20(17)2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31480228

RESUMO

Karyotypic data from Australian native freshwater fishes are scarce, having been described from relatively few species. Golden perch (Macquaria ambigua) and Murray cod (Maccullochella peelii) are two large-bodied freshwater fish species native to Australia with significant indigenous, cultural, recreational and commercial value. The arid landscape over much of these fishes' range, coupled with the boom and bust hydrology of their habitat, means that these species have potential to provide useful evolutionary insights, such as karyotypes and sex chromosome evolution in vertebrates. Here we applied standard and molecular cytogenetic techniques to characterise karyotypes for golden perch and Murray cod. Both species have a diploid chromosome number 2n = 48 and a male heterogametic sex chromosome system (XX/XY). While the karyotype of golden perch is composed exclusively of acrocentric chromosomes, the karyotype of Murray cod consists of two submetacentric and 46 subtelocentric/acrocentric chromosomes. We have identified variable accumulation of repetitive sequences (AAT)10 and (CGG)10 along with diverse methylation patterns, especially on the sex chromosomes in both species. Our study provides a baseline for future cytogenetic analyses of other Australian freshwater fishes, especially species from the family Percichthyidae, to better understand their genome and sex chromosome evolution.


Assuntos
Água Doce , Cariótipo , Percas/genética , Perciformes/genética , Cromossomos Sexuais/genética , Animais , Bandeamento Cromossômico , Metilação de DNA/genética , Feminino , Geografia , Masculino , Metáfase , Repetições de Microssatélites/genética , Filogenia , Especificidade da Espécie , Telômero/genética
17.
Int J Mol Sci ; 20(17)2019 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-31480792

RESUMO

Arowanas (Osteoglossinae) are charismatic freshwater fishes with six species and two genera (Osteoglossum and Scleropages) distributed in South America, Asia, and Australia. In an attempt to provide a better assessment of the processes shaping their evolution, we employed a set of cytogenetic and genomic approaches, including i) molecular cytogenetic analyses using C- and CMA3/DAPI staining, repetitive DNA mapping, comparative genomic hybridization (CGH), and Zoo-FISH, along with ii) the genotypic analyses of single nucleotide polymorphisms (SNPs) generated by diversity array technology sequencing (DArTseq). We observed diploid chromosome numbers of 2n = 56 and 54 in O. bicirrhosum and O. ferreirai, respectively, and 2n = 50 in S. formosus, while S. jardinii and S. leichardti presented 2n = 48 and 44, respectively. A time-calibrated phylogenetic tree revealed that Osteoglossum and Scleropages divergence occurred approximately 50 million years ago (MYA), at the time of the final separation of Australia and South America (with Antarctica). Asian S. formosus and Australian Scleropages diverged about 35.5 MYA, substantially after the latest terrestrial connection between Australia and Southeast Asia through the Indian plate movement. Our combined data provided a comprehensive perspective of the cytogenomic diversity and evolution of arowana species on a timescale.


Assuntos
Evolução Biológica , Peixes/genética , Genômica , Animais , Bandeamento Cromossômico , Mapeamento Cromossômico , Variação Genética , Técnicas de Genotipagem , Geografia , Cariótipo , Análise de Componente Principal
18.
Parasitol Res ; 118(10): 2789-2800, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31485863

RESUMO

An original cytogenetic study combining classical karyotype analysis and modern fluorescence in situ hybridization using telomeric (TTAGGG)n and ribosomal sequences (18S rDNA) was performed in Khawia abbottinae (Cestoda, Caryophyllidea), a parasite of Chinese false gudgeon (Abbottina rivularis) from China. Analyses based on conventional Giemsa staining, DAPI, YOYO-1 dye, and silver (Ag) staining were also carried out. The karyotype is composed of eight pairs of metacentric and telocentric chromosomes (2n = 16, n=5m + 3t). Constitutive heterochromatin was mainly positioned at pericentromeric regions, and telomeric sequences (TTAGGG)n were restricted to the end of all chromosomes. In mitotic preparations stained with Giemsa, both homologues of chromosome pair 4 showed a distinct secondary constriction. FISH with rDNA probe confirmed that this secondary constriction contains a nucleolar organizer region (NOR). The process of spermatocyte meiosis and the dynamics of nucleolus degradation in dividing cell were scrutinized. The present study and its results enhance the limited knowledge on basic karyotype characteristics and 18S rDNA clusters location in caryophyllidean tapeworms.


Assuntos
Cestoides/genética , Cromossomos/genética , DNA Ribossômico/genética , Telômero/genética , Animais , Cestoides/classificação , Cestoides/isolamento & purificação , China , Cyprinidae/genética , DNA de Helmintos/genética , Proteínas de Helminto/genética , Heterocromatina/genética , Hibridização in Situ Fluorescente , Cariótipo , Cariotipagem , Ribossomos/genética
19.
Cytogenet Genome Res ; 158(3): 160-169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31394537

RESUMO

The discovery of sex chromosome systems in non-model organisms has elicited growing recognition that sex chromosomes evolved via diverse paths that are not fully elucidated. Lineages with labile sex determination, such as turtles, hold critical cues, yet data are skewed toward hide-neck turtles (suborder Cryptodira) and scant for side-neck turtles (suborder Pleurodira). Here, we used classic and molecular cytogenetics to investigate Emydura subglobosa (ESU), an unstudied side-neck turtle with genotypic sex determination from the family Chelidae, where extensive morphological divergence exists among XX/XY systems. Our data represent the first cytogenetic description for ESU. Similarities were found between ESU and E. macquarii (EMA), such as identical chromosome number (2n = 50), a single and dimorphic nucleolus organizer region (NOR) localized in a microchromosome pair (ESU14) of both sexes (detected via FISH of 18S rDNA). Only the larger NOR is active (detected by silver staining). As in EMA, comparative genome hybridization revealed putative macro XX/XY chromosomes in ESU (the 4th largest pair). Our comparative analyses and revaluation of previous data strongly support the hypothesis that Emydura's XX/XY system evolved via fusion of an ancestral micro-Y (retained by Chelodina longicollis) onto a macro-autosome. This evolutionary trajectory differs from the purported independent evolution of XX/XY from separate ancestral autosomes in Chelodina and Emydura that was previously reported. Our data permit dating this Y-autosome fusion to at least the split of Emydura around 45 Mya and add critical information about the evolution of the remarkable diversity of sex-determining mechanisms in turtles, reptiles, and vertebrates.


Assuntos
Evolução Molecular , Cromossomos Sexuais/genética , Tartarugas/genética , Animais , Hibridização Genômica Comparativa , Hibridização in Situ Fluorescente , Cariótipo , Masculino , Repetições de Microssatélites/genética , RNA Ribossômico 18S/genética , Coloração pela Prata , Tartarugas/classificação
20.
Nat Commun ; 10(1): 3466, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371715

RESUMO

Under the neutral theory, genetic diversity is expected to increase with population size. While comparative analyses have consistently failed to find strong relationships between census population size and genetic diversity, a recent study across animals identified a strong correlation between propagule size and genetic diversity, suggesting that r-strategists that produce many small offspring, have greater long-term population sizes. Here we compare genome-wide genetic diversity across 38 species of European butterflies (Papilionoidea), a group that shows little variation in reproductive strategy. We show that genetic diversity across butterflies varies over an order of magnitude and that this variation cannot be explained by differences in current abundance, propagule size, host or geographic range. Instead, neutral genetic diversity is negatively correlated with body size and positively with the length of the genetic map. This suggests that genetic diversity is determined both by differences in long-term population size and the effect of selection on linked sites.


Assuntos
Borboletas/classificação , Borboletas/genética , Variação Genética/genética , Seleção Genética , Animais , Biodiversidade , Tamanho Corporal , Cromossomos , Evolução Molecular , Deriva Genética , Genoma , Tamanho do Genoma , Cariótipo , Mitocôndrias/genética , Filogenia , Filogeografia , Densidade Demográfica , Recombinação Genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA