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R. Cremonini - One of the best experts on this subject based on the ideXlab platform.

  • Cytological and molecular characterization of Vicia barbazitae Ten. & Guss.
    Protoplasma, 2011
    Co-Authors: M. Ruffini Castiglione, M. Frediani, M. T. Gelati, Gianfranco Venora, Lucia Giorgetti, Paolo Caputo, R. Cremonini
    Abstract:

    Vicia barbazitae, a taxon belonging to section Vicia of subgenus Vicia, was recovered and analysed by cytological, karyological and molecular methods with the aim of both proposing a general characterisation of this species and studying the relationships among the species of section Vicia . Phylogenetic relationships among the species of the section Vicia and those of the sections Microcarinae, Wiggersia and Atossa were also analysed. Automated karyotype analysis has been determined after Feulgen’s reaction; chromosome banding was performed by sequence-specific Fluorochrome Staining. Fluorescent chromosome banding showed CMA+/DAPI- NOR-associated heterochromatin in the satellite pair. Karyomorphological parameters, based on symmetry indices, the dendrogram of linkage distance constructed on 37 chromosome parameters, as well as the molecular data based on internal transcribed spacer sequences provided information about phylogenetic position of this species inside the section Vicia and among the species belonging to the sections Microcarinae, Wiggersia, Atossa and Vicia. From our karyological and molecular results, it emerges that V. barbazitae can be considered a natural member of section Vicia.

  • Cytological characterization of Vicia oroboides Wulfen in Jacq
    Protoplasma, 2009
    Co-Authors: Monica Ruffini Castiglione, M. Frediani, Gianfranco Venora, C. Ravalli, R. Cremonini
    Abstract:

    Vicia oroboides , a rare taxon belonging to section Atossa of subgenus Vicia , was recovered and analysed by means of cytological and karyological methods with the aim of both characterising this species and integrating our knowledge on phylogeny of subgenus Vicia . Automated karyotype analysis and nuclear DNA content have been determined after Feulgen’s reaction; chromosome banding was performed by Fluorochrome Staining to evidence heterochromatic blocks along the chromosome complement. The chromosome number is in line with the values of the species of section Atossa ; the GC- and AT-rich sites were identified by CMA and DAPI Staining. Karyomorphological parameters, based on symmetry indices, provide information about the phylogenetic position of this species inside the subgenus Vicia . DNA content is reported for the first time.

Marco Antonio Costa - One of the best experts on this subject based on the ideXlab platform.

  • Cytogenetic Analysis in Trigona spinipes Fabricius (Hymenoptera, Meliponina) Reveals Intraspecific Variation
    Neotropical Entomology, 2021
    Co-Authors: Vilmara Pereira Barboza, Marco Antonio Costa
    Abstract:

    Trigona spinipes Fabricius is a stingless bee with wide geographical distribution. Although being sometimes considered an agricultural pest, in fact, it has great pollinating potential, and therefore economic interest. Conventional and molecular cytogenetic techniques have been little used to verify genetic diversity in this species, despite its potential to reveal information about the reorganization of the genome having been demonstrated in other species. Conventional cytogenetic techniques, Fluorochrome Staining, and fluorescent in situ hybridization with 18S rDNA, telomeric, and microsatellite probes (GA)_15 were used in this study to characterize and compare T . spinipes from different locations. The karyotypes showed a conserved chromosome number 2n = 34; however, geographic variations were verified in the different features and cytogenetic techniques analyzed, such as karyotype formulas, fluorocrome Staining, and FISH. Although the 18S rDNA probe revealed the same number of markings in five rDNA clusters, the chromosomal pairs containing these markers varied between studied locations. The probe for microsatellite (GA)_15 also showed polymorphisms within this species. The results reveal that T. spinipes has many intraspecific differences, revealing a higher chromosomal variation than expected.

  • A cytogenetic study of three parasitic wasp species (Hymenoptera, Chalcidoidea, Eulophidae, Trichogrammatidae) from Brazil using chromosome morphometrics and base-specific Fluorochrome Staining
    Pensoft Publishers, 2017
    Co-Authors: Vladimir E. Gokhman, Fabricio Fagundes Pereira, Marco Antonio Costa
    Abstract:

    Chromosomes of three chalcid wasp species from Brazil, Palmistichus elaeisis Delvare et LaSalle, 1993, Trichospilus diatraeae Cherian et Margabandhu, 1942 (both belonging to the family Eulophidae) and Trichogramma pretiosum Riley, 1879 (Trichogrammatidae), were studied using chromosome morphometrics and base-specific Fluorochrome Staining. The present study confirmed that these species respectively have 2n = 12, 14 and 10. Chromomycin A3 / 4’, 6-diamidino-2-phenylindole (CMA3/DAPI) Staining revealed a single CMA3-positive and DAPI-negative band within haploid karyotypes of both P. elaeisis and T. pretiosum. This CG-rich band clearly corresponds to the nucleolus organizing region (NOR). Moreover, analogous multiple telomeric bands found on all chromosomes of T. diatraeae may also represent NORs. Certain features of karyotype evolution of the phylogenetic lineage comprising both Eulophidae and Trichogrammatidae are discussed. The results obtained during the present study demonstrate the importance of chromosome research on tropical parasitoids that remain poorly known in this respect

  • molecular cytogenetics and phylogenetic analysis of brazilian leaf frog species of the genera phyllomedusa and phasmahyla hylidae phyllomedusinae
    Canadian Journal of Zoology, 2014
    Co-Authors: Adriane Barth, Mirco Sole, Miguel Vences, Marco Antonio Costa
    Abstract:

    In this study we describe the karyotypes and molecular phylogenetic relationships of the leaf frogs Phyllomedusa bahiana Lutz, 1925, Phyllomedusa burmeisteri Boulenger, 1882, Phyllomedusa nordestina Caramaschi, 2006, Phyllomedusa rohdei Mertens, 1926, Phyllomedusa hypochondrialis (Daudin, 1800), and Phasmahyla spectabilis Cruz, Feio and Nascimento, 2008. We analyzed the karyotypes using C-banding, Fluorochrome Staining, and fluorescence in situ hybridization of telomeric probe, and inferred phylogeny using nuclear tyrosinase and mitochondrial 16S rDNA sequences. Heterochromatin distribution in P. nordestina diverged from the other species, and P. bahiana and P. rohdei showed evident interstitial telomere sequences. Molecular analyzes confirmed the current taxonomic classification, grouping mitochondrial DNA sequences of each species, and usually without haplotype sharing in the nuclear gene. We also extended the distribution of P. burmeisteri to northern Bahia state and restricted P. bahiana to southern B...

  • Karyotype characterization of Trigona fulviventris Guérin, 1835 (Hymenoptera, Meliponini) by C banding and Fluorochrome Staining: report of a new chromosome number in the genus
    Genetics and Molecular Biology, 2005
    Co-Authors: Alayne Magalhães Trindade Domingues, Ana Maria Waldschmidt, Sintia Emmanuelle Andrade, Vanderly Andrade-souza, Rogério Marco De Oliveira Alves, Juvenal Cordeiro Silva Junior, Marco Antonio Costa
    Abstract:

    Although many species of the genus Trigona have been taxonomically described, cytogenetic studies of these species are still rare. The aim of the present study was to obtain cytogenetic data by conventional Staining, C banding and Fluorochrome Staining for the karyotype characterization of the species Trigona fulviventris. Cytogenetic analysis revealed that this species possesses a diploid chromosome number of 2n = 32, different from most other species of this genus studied so far. This variation was probably due to the centric fusion in a higher numbered ancestral karyotype, this fusion producing the large metacentric chromosome pair and the lower chromosome number observed in Trigona fulviventris. Heterochromatin was detected in the pericentromeric region of the first chromosome pair and in one of the arms of the remaining pairs. Base-specific Fluorochrome Staining with 4'-6-diamidino-2-phenylindole (DAPI) showed that the heterochromatin was rich in AT base pairs (DAPI+) except for pair 13, which was chromomycin A3 (CMA3) positive indicating an excess of GC base pairs. Our data also suggests that there was variation in heterochromatin base composition.

Denny Sakkas - One of the best experts on this subject based on the ideXlab platform.

  • Effect of deoxyribonucleic acid protamination on Fluorochrome Staining and in situ nick-translation of murine and human mature spermatozoa.
    Biology of reproduction, 1993
    Co-Authors: Pg Bianchi, Gian Carlo Manicardi, Davide Bizzaro, U. Bianchi, Denny Sakkas
    Abstract:

    A major event in enhancing sperm chromatin stability is the replacement of the histones by protamines during spermiogenesis. In this study, we present results indicating that chromomycin A3 (CMA3 ) can be used to show protamine deficiency in sperm chromatin. Fixed chromatin of mature mouse spermatozoa showed high fluorescence after treatment with ethidium bromide (EB), but was completely unstained after treatment with CMA3. The same chromatin was found to be highly resistant to in situ nick-translation. In contrast, a substantial fraction of human spermatozoa were positive for CMA3. The accessibility of CMA to the DNA of human sperm was eliminated if the slides were previously treated with protamine in situ. This treatment did not affect the accessibility of EB to the chromatin. Individual human sperm samples revealed a substantial frequency of spermatozoa with endogenous nicks, which was found to be the same as the frequency of spermatozoa responding positively to CMA3 Staining. Treatment of preparations with protamines prevented the identification of the endogenous nicks. These data as a whole suggest that CMA3 could represent a useful tool for the detection of protamine deficiency in sperm chromatin. Furthermore, confirmation of experiments relating sensitivity to nick translation and positivity to CMA3 may allow an indirect in situ visualization of nicked and partially denatured DNA, which could correlate with certain forms of male factor infertility.

M. Omura - One of the best experts on this subject based on the ideXlab platform.

  • Chromosome markers and alterations in mitotic cells from interspecific Citrus somatic hybrids analysed by Fluorochrome Staining.
    Plant cell reports, 1997
    Co-Authors: M. Miranda, T. Endo, T. Moriguchi, Fukio Ikeda, M. Omura
    Abstract:

    Mitotic cells from Rough lemon (Citrus jambhiri Lush.), Ohta ponkan (C. reticulata Blanco) and two somatic hybrid plants obtained from protoplast fusion were analysed by double Staining with chromomycin A3 (CMA) and 4′-6-diamidino-2-phenylindole. Only CMA-positive bands were observed in metaphasic chromosomes. The two parental karyotypes (2n=2x=18) were heteromorphic, yielding some marker chromosomes that could be identified in the somatic hybrids. One of the somatic hybrids had 2n=37 chromosomes, and the possible extra chromosome was distinguishable. The second somatic hybrid was tetraploid (2n=4x=36), with one of the chromosomes bearing a putative structural alteration. Furthermore, aneusomaty and some mitotic abnormalities were also observed in this latter plant. Such irregularities are reported for the first time for citrus somatic hybrids, and their possible causes and implications are discussed.

  • Comparative analysis on the distribution of heterochromatin in Citrus, Poncirus and Fortunella chromosomes
    Chromosome Research, 1997
    Co-Authors: M. Miranda, F. Ikeda, T. Endo, T. Moriguchi, M. Omura
    Abstract:

    Double Fluorochrome Staining with chromomycin A_3 (CMA) and 4′-6-diamidino-2-phenylindole (DAPI) was used to characterize and compare the distribution of constitutive heterochromatin along chromosomes of Citrus, Poncirus and Fortunella species. Only CMA-positive bands were distinguishable in metaphase chromosomes. Preferential distribution of heterochromatin in terminal regions, mainly of the long arm, and centromeric regions of a few long chromosomes was a common feature of these genera. Heteromorphism between possible homologous chromosomes was present in the majority of species. Citrus and Poncirus revealed some remarkably uniform chromosomes without any intensively fluorescing region, whereas Fortunella cultivars were differentiated by the presence of CMA bands in all chromosomes. Through measurements assisted by a computer, amounts of CMA-positive regions were shown to be highest in Fortunella . Similarities between Citrus and Poncirus suggest little heterochromatin diversification among karyotypes of these genera, whereas Fortunella , with higher amounts and more homogenous distribution of heterochromatin, is more divergent.

Gian Carlo Manicardi - One of the best experts on this subject based on the ideXlab platform.

  • X-linked heterochromatin distribution in the holocentric chromosomes of the green apple aphid Aphis pomi
    Genetica, 2005
    Co-Authors: A. Criniti, Davide Bizzaro, G. Simonazzi, S. Cassanelli, M. Ferrari, Gian Carlo Manicardi
    Abstract:

    Chromatin organization in the holocentric chromosomes of the green apple aphid Aphis pomi has been investigated at a cytological level after C-banding, NOR, Giemsa, Fluorochrome Staining and fluorescent in situ hybridization (FISH). C-banding technique showed that heterochromatic bands are exclusively located on X chromosomes. This data represents a peculiar feature that clearly contradicts the equilocal distribution of heterochromatin typical of monocentric chromosomes. Moreover, silver Staining and FISH carried out with a 28S rDNA probe localized rDNA genes on one telomere of each X chromosome; CMA_3 Staining reveals that these silver positive telomeres are the only GC-rich regions among A. pomi heterochromatin, whereas all other C-positive bands are DAPI positive thus containing AT-rich DNA.

  • Silver Staining as a new banding technique to identify aphid chromosomes
    Chromosome Research, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Mauro Mandrioli, Umberto Bianchi
    Abstract:

    The karyotype of the aphid Aphis sambuci has been studied by means of C-banding, Fluorochrome Staining and AgNO3 Staining. Heterochromatic areas are confined exclusively to the X chromosomes. Interestingly, silver Staining produces a clear-cut longitudinal differentiation of all chromosomes, which allows reliable identification of homologues.

  • Effect of deoxyribonucleic acid protamination on Fluorochrome Staining and in situ nick-translation of murine and human mature spermatozoa.
    Biology of reproduction, 1993
    Co-Authors: Pg Bianchi, Gian Carlo Manicardi, Davide Bizzaro, U. Bianchi, Denny Sakkas
    Abstract:

    A major event in enhancing sperm chromatin stability is the replacement of the histones by protamines during spermiogenesis. In this study, we present results indicating that chromomycin A3 (CMA3 ) can be used to show protamine deficiency in sperm chromatin. Fixed chromatin of mature mouse spermatozoa showed high fluorescence after treatment with ethidium bromide (EB), but was completely unstained after treatment with CMA3. The same chromatin was found to be highly resistant to in situ nick-translation. In contrast, a substantial fraction of human spermatozoa were positive for CMA3. The accessibility of CMA to the DNA of human sperm was eliminated if the slides were previously treated with protamine in situ. This treatment did not affect the accessibility of EB to the chromatin. Individual human sperm samples revealed a substantial frequency of spermatozoa with endogenous nicks, which was found to be the same as the frequency of spermatozoa responding positively to CMA3 Staining. Treatment of preparations with protamines prevented the identification of the endogenous nicks. These data as a whole suggest that CMA3 could represent a useful tool for the detection of protamine deficiency in sperm chromatin. Furthermore, confirmation of experiments relating sensitivity to nick translation and positivity to CMA3 may allow an indirect in situ visualization of nicked and partially denatured DNA, which could correlate with certain forms of male factor infertility.