Chromosomal mapping of repetitive DNA in Melipona seminigra merrillae Cockerell, 1919 (Hymenoptera, Apidae, Meliponini)

Melipona Illiger, 1806 is represented by 74 known species of stingless bees, distributed throughout the Neotropical region. Cytogenetically it is the most studied stingless bee genus of the tribe Meliponini. Member species are divided in two groups based on the volume of heterochromatin. This study aim was to analyze the composition and organization of chromatin of the stingless bee subspecies Melipona seminigra merrillae Cockerell, 1919 using classical and molecular cytogenetic techniques, so contributing to a better understanding of the processes of chromosomal changes within the genus. We confirm that M. seminigra merrillae has a chromosome number of 2n = 22 and n = 11, results that differ from those reported for the genus in the absence of B chromosomes. The heterochromatic pattern revealed a karyotype composed of chromosomes with a high heterochromatin content, which makes it difficult to visualize the centromere. Silver nitrate impregnation (Ag-NOR) showed transcriptionally active sites on the second chromosomal pair. Staining of base-specific fluorophores DAPI-CMA3 indicated a homogeneous distribution of intensely DAPI-stained heterochromatin, while CMA3 markings appeared on those terminal portions of the chromosomes corresponding to euchromatin. Similar to Ag-NOR, fluorescence in situ hybridization (FISH) with 18S ribosomal DNA probe revealed distinct signals on the second pair of chromosomes. Microsatellite mapping (GA)15 showed markings distributed in euchromatic regions, while mapping with (CA)15 showed marking patterns in heterochromatic regions, together with a fully marked chromosome pair. Microsatellite hybridization, both in heterochromatic and euchromatic regions, may be related to the activity of transposable elements. These are capable of forming new microsatellites that can be dispersed and amplified in different regions of the genome, demonstrating that repetitive sequences can evolve rapidly, thus resulting in within-genus diversification.

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Chromosomal mapping of repetitive DNA in Melipona seminigra merrillae Cockerell, 1919 (Hymenoptera, Apidae, Meliponini)

Comparative Cytogenetics ◽

10.3897/compcytogen.v15.i1.56430 ◽

2021 ◽

Vol 15 (1) ◽

pp. 77-87

Author(s):

Ingrid Cândido de Oliveira Barbosa ◽

Carlos Henrique Schneider ◽

Leonardo Gusso Goll ◽

Eliana Feldberg ◽

Gislene Almeida Carvalho-Zilse

Keyword(s):

Active Sites ◽

Repetitive Sequences ◽

Neotropical Region ◽

Stingless Bee ◽

Chromosomal Mapping ◽

Homogeneous Distribution ◽

Marked Chromosome ◽

Chromosomal Changes ◽

Molecular Cytogenetic Techniques ◽

Microsatellite Mapping

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Cytogenetic Analysis and Chromosomal Mapping of Repetitive DNA in Melipona Species (Hymenoptera, Meliponini)

Cytogenetic and Genome Research ◽

10.1159/000501754 ◽

2019 ◽

Vol 158 (4) ◽

pp. 213-224 ◽

Cited By ~ 5

Author(s):

Natália M. Travenzoli ◽

Bárbara A. Lima ◽

Danon C. Cardoso ◽

Jorge A. Dergam ◽

Tânia M. Fernandes-Salomão ◽

...

Keyword(s):

Stingless Bees ◽

Chromosome Evolution ◽

Repetitive Sequences ◽

Sensu Stricto ◽

Chromosomal Mapping ◽

Evolutionary Constraints ◽

Rdna Sites ◽

Melipona Species ◽

The Relationship ◽

Evolutionary Lineages

Stingless bees of the genus Melipona are subdivided into 4 subgenera called Eomelipona, Melikerria, Melipona sensu stricto, and Michmelia according to species morphology. Cytogenetically, the species of the genus Melipona show variation in the amount and distribution of heterochromatin along their chromosomes and can be separated into 2 groups: the first with low content of heterochromatin and the second with high content of heterochromatin. These heterochromatin patterns and the number of chromosomes are characteristics exclusive to Melipona karyotypes that distinguish them from the other genera of the Meliponini. To better understand the karyotype organization in Melipona and the relationship among the subgenera, we mapped repetitive sequences and analyzed previously reported cytogenetic data with the aim to identify cytogenetic markers to be used for investigating the phylogenetic relationships and chromosome evolution in the genus. In general, Melipona species have 2n = 18 chromosomes, and the species of each subgenus share the same characteristics in relation to heterochromatin regions, DAPI/CMA3 fluorophores, and the number and distribution of 18S rDNA sites. Microsatellites were observed only in euchromatin regions, whereas the (TTAGG)6 repeats were found at telomeric sites in both groups. Our data indicate that in addition to the chromosome number, the karyotypes in Melipona could be separated into 2 groups that are characterized by conserved cytogenetic features and patterns that generally are shared by species within each subgenus, which may reflect evolutionary constraints. Our results agree with the morphological separation of the Melipona into 4 subgenera, suggesting that they must be independent evolutionary lineages.

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Influence of the precursor chemical composition on heavy metal adsorption properties of hemp (Cannabis Sativa) fibers based biocarbon

Journal of the Serbian Chemical Society ◽

10.2298/jsc170310080v ◽

2017 ◽

Vol 82 (12) ◽

pp. 1417-1431 ◽

Cited By ~ 2

Author(s):

Marija Vukcevic ◽

Biljana Pejic ◽

Ivana Pajic-Lijakovic ◽

Ana Kalijadis ◽

Mirjana Kostic ◽

...

Keyword(s):

Heavy Metal ◽

Chemical Composition ◽

Surface Area ◽

Active Sites ◽

Cannabis Sativa ◽

Lignin Content ◽

Area Measurement ◽

Bet Surface Area ◽

Homogeneous Distribution ◽

Hemp Fibers

Waste hemp (Cannabis sativa) fibers were used as sustainable and renewable raw materials for production of low-cost biocarbon sorbent for heavy metals removal. Carbon precursors of different chemical composition were obtained by oxidative and alkaline treatments of hemp fibers. Influence of lignocellulosic precursor chemical composition on hemp fibers-based biocarbon (HFB) characteristics was examined by BET surface area measurement, scanning electron microscopy and mass titration. It was found that lignin content and polymorphic transformation of cellulose increase the SBET of microporous HFBs, while hemicelluloses induce more homogeneous distribution of adsorption active sites. Heavy metal ions adsorption onto HFBs is primarily influenced by the amount of surface oxygen groups, while specific surface area plays a secondary role. Equilibrium data obtained for lead ions adsorption were analyzed by different nonlinear adsorption isotherms, and the best fitting model was chosen using standard deviation and Akaike information criterion (AICC). The maximum adsorption capacities of HFBs ranged from 103.1 to 116.3 mg Pb/g. Thermodynamic parameters showed that Pb2+ adsorption onto HFBs is a spontaneous and complex endothermic process, suggesting the coexistence of physisorption and chemisorption mechanisms.

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Catalytic Cracking of n-Hexadecane Using Carbon Nanostructures/Nano-Zeolite-Y Composite Catalyst

Catalysts ◽

10.3390/catal10121385 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1385

Author(s):

Botagoz Zhuman ◽

Shaheen Fatima Anis ◽

Saepurahman ◽

Gnanapragasam Singravel ◽

Raed Hashaikeh

Keyword(s):

Surface Area ◽

Catalytic Cracking ◽

Carbon Nanostructures ◽

Active Sites ◽

Zeolite Y ◽

High Surface ◽

High Surface Area ◽

Composite Catalyst ◽

Homogeneous Distribution ◽

Binding Material

Zeolite-based catalysts are usually utilized in the form of a composite with binders, such as alumina, silica, clay, and others. However, these binders are usually known to block the accessibility of the active sites in zeolites, leading to a decreased effective surface area and agglomeration of zeolite particles. The aim of this work is to utilize carbon nanostructures (CNS) as a binding material for nano-zeolite-Y particles. The unique properties of CNS, such as its high surface area, thermal stability, and flexibility of its fibrous structure, makes it a promising material to hold and bind the nano-zeolite particles, yet with a contemporaneous accessibility of the reactants to the porous zeolite structure. In the current study, a nano-zeolite-Y/CNS composite catalyst was fabricated through a ball milling approach. The catalyst possesses a high surface area of 834 m2/g, which is significantly higher than the conventional commercial cracking catalysts. Using CNS as a binding material provided homogeneous distribution of the zeolite nanoparticles with high accessibility to the active sites and good mechanical stability. In addition, CNS was found to be an effective binding material for nano-zeolite particles, solving their major drawback of agglomeration. The nano-zeolite-Y/CNS composite showed 80% conversion for hexadecane catalytic cracking into valuable olefins and hydrogen gas, which was 14% higher compared to that of pure nano-zeolite-Y particles.

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Chromosomal mapping of repetitive sequences in Hyphessobrycon eques (Characiformes, Characidae): a special case of the spreading of 5S rDNA clusters in a genome

Genetica ◽

10.1007/s10709-020-00086-3 ◽

2020 ◽

Vol 148 (1) ◽

pp. 25-32 ◽

Cited By ~ 1

Author(s):

Diovani Piscor ◽

Leonardo Marcel Paiz ◽

Lucas Baumgärtner ◽

Fiorindo José Cerqueira ◽

Carlos Alexandre Fernandes ◽

...

Keyword(s):

Repetitive Sequences ◽

5S Rdna ◽

Chromosomal Mapping ◽

A Genome ◽

Special Case

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Adsorption and recovery of nonylphenol ethoxylate on a crosslinked β-cyclodextrin-carboxymethylcellulose polymer

Water Science & Technology ◽

10.2166/wst.2010.152 ◽

2010 ◽

Vol 61 (9) ◽

pp. 2293-2301 ◽

Cited By ~ 10

Author(s):

Danielle Bonenfant ◽

Patrick Niquette ◽

Murielle Mimeault ◽

Robert Hausler

Keyword(s):

Adsorption Capacity ◽

Atmospheric Pressure ◽

Active Sites ◽

Adsorption Process ◽

Adsorption Equilibrium ◽

Physical Adsorption ◽

Polymer Network ◽

Homogeneous Distribution ◽

Nonylphenol Ethoxylate ◽

Monolayer Coverage

A study of adsorption/recovery of nonylphenol 9 mole ethoxylate (NP9EO) on a crosslinked β-cyclodextrin-carboxymethylcellulose (β-CD-CMC) polymer was carried out by ultraviolet-visible (UV-vis) and Fourier transform infrared (FTIR) spectroscopies. The adsorption was performed in mixtures containing 500 mg of the β-CD-CMC polymer and aqueous NP9EO solutions at concentrations 12–82 mg/L, whereas the recovery of NP9EO was effectuated by shaking the β-CD-CMC polymer loaded with methanol. The assays were made at 25°C and atmospheric pressure under agitation. The results have shown that the adsorption is a rapid process and the β-CD-CMC polymer exhibits a high NP9EO adsorption capacity of 83–92 w% (1.1–6.8 mg NP9EO/g β-CD-CMC polymer) dependent of the initial NP9EO concentration in liquid phase. This adsorption may involve the formation of an inclusion complex β-CD-NP9EO and a physical adsorption in the polymer network. The adsorption equilibrium measurements, which were analyzed using the Langmuir isotherm, have indicated a monolayer coverage and the homogeneous distribution of active sites at the surface of the β-CD-CMC polymer. Moreover, the negative value obtained for the free energy change (−13.2 kJ/mol) has indicated that the adsorption process is spontaneous. In parallel, the β-CD-CMC polymer exhibited a high NP9EO recovery efficiency of 97 w% that may occur through a decrease of binding strength between β-CD-CMC polymer and NP9EO. Together, these results suggest that the β-CD-CMC polymer could constitute a good adsorbent for removing nonylphenol ethoxylates from wastewater due to its high adsorption capacity and non-toxic character of β-CD and CMC to environment.

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Stingless bees of the genus Nannotrigona Cockerell (Hymenoptera: Apidae: Meliponini) in Colombia

Zootaxa ◽

10.11646/zootaxa.4706.2.8 ◽

2019 ◽

Vol 4706 (2) ◽

pp. 349-365

Author(s):

JOANNA JARAMILLO ◽

RODULFO OSPINA ◽

VICTOR H. GONZALEZ

Keyword(s):

Stingless Bees ◽

Neotropical Region ◽

Stingless Bee ◽

South American ◽

Museum Specimens ◽

Key To Species ◽

South American Country ◽

Number Of Species

Nannotrigona Cockerell is one of the few stingless bee genera widely distributed and commonly encountered throughout the Neotropical region. Some species are abundant and managed in meliponiculture. However, the identity and number of species occurring in some countries or areas is almost entirely unknown. Herein we reviewed the species of Nannotrigona in Colombia, a South American country with literature records indicating the presence of either one or five species of this genus. Appraisal of museum specimens revealed the existence of the following eight species, three of which we describe as new: N. camargoi Rasmussen & Gonzalez, N. gaboi n. sp., N. melanocera (Schwarz), N. mellaria (Smith), N. occidentalis n. sp., N. pilosa n. sp., N. schultzei (Friese), and N. tristella (Cockerell).We describe and figure the male of N. camargoi, N. gaboi, N. melanocera, and N. pilosa. In addition, we provide comparative diagnoses, a key to species, and new geographical records.

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Chromosomal Mapping of Repetitive DNAs in Characidium (Teleostei, Characiformes): Genomic Organization and Diversification of ZW Sex Chromosomes

Cytogenetic and Genome Research ◽

10.1159/000437165 ◽

2015 ◽

Vol 146 (2) ◽

pp. 136-143 ◽

Cited By ~ 10

Author(s):

Priscilla C. Scacchetti ◽

Ricardo Utsunomia ◽

José C. Pansonato-Alves ◽

Marcelo R. Vicari ◽

Roberto F. Artoni ◽

...

Keyword(s):

Sex Chromosomes ◽

Dna Sequences ◽

Sex Chromosome ◽

Repetitive Sequences ◽

5S Rdna ◽

Chromosome Mapping ◽

Chromosomal Mapping ◽

Specific Probe ◽

W Chromosome ◽

Sex Chromosome System

The speciose neotropical genus Characidium has proven to be a good model for cytogenetic exploration. Representatives of this genus often have a conserved diploid chromosome number; some species exhibit a highly differentiated ZZ/ZW sex chromosome system, while others do not show any sex-related chromosome heteromorphism. In this study, chromosome painting using a W-specific probe and comparative chromosome mapping of repetitive sequences, including ribosomal clusters and 4 microsatellite motifs - (CA)15, (GA)15, (CG)15, and (TTA)10 -, were performed in 6 Characidium species, 5 of which possessed a heteromorphic ZW sex chromosome system. The W-specific probe showed hybridization signals on the W chromosome of all analyzed species, indicating homology among the W chromosomes. Remarkably, a single major rDNA-bearing chromosome pair was found in all species. The 18S rDNA localized to the sex chromosomes in C. lanei, C. timbuiense and C. pterostictum, while the major rDNA localized to one autosome pair in C. vidali and C. gomesi. In contrast, the number of 5S rDNA-bearing chromosomes varied. Notably, minor ribosomal clusters were identified in the W chromosome of C. vidali. Microsatellites were widely distributed across almost all chromosomes of the karyotypes, with a greater accumulation in the subtelomeric regions. However, clear differences in the abundance of each motif were detected in each species. In addition, the Z and W chromosomes showed the differential accumulation of distinct motifs. Our results revealed variability in the distribution of repetitive DNA sequences and their possible association with sex chromosome diversification in Characidium species.

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Observations on the urban ecology of the Neotropical stingless bee Tetragonisca angustula (Hymenoptera: Apidae: Meliponini)

Journal of Melittology ◽

10.17161/jom.v0i15.4528 ◽

2013 ◽

pp. 1 ◽

Cited By ~ 8

Author(s):

Rita I. Velez-Ruiz ◽

Victor H. Gonzalez ◽

Michael S. Engel

Keyword(s):

Light Intensity ◽

Ambient Temperature ◽

Urban Ecology ◽

Natural Enemies ◽

Neotropical Region ◽

Urban Environments ◽

Stingless Bee ◽

Nest Entrance ◽

Foraging Activity ◽

Tetragonisca Angustula

Tetragonisca angustula (Latreille) is a small, docile, cavity-nestingstingless bee that is widely distributed in the Neotropical region. This speciesis particularly abundant in disturbed environments, including humansettlements. Between August 2005 and March 2006, we located and followed duringeight months 59 nests of this species in Medellín, the second most populatedcity in Colombia. Herein, we document their foraging behavior, mortality, andincidence of predators and natural enemies. Also, to determine if higherambient temperature and light intensity in urban environments affect the dailyforaging activity of T. angustula, wecompared the daily foraging activity of bees from nests found in open areas in thecity and bees from nests from a nearby covered, forested area. Likewise, todetermine if urban nests of T. angustulaare largely undetected and undisturbed by people, we experimentally made themvisible by adding a ring color (white, red, or black) around the nest entrance tube.Our observations indicate that higher ambient temperature and light intensity inurban environments do not significantly affect the daily foraging activity of T. angustula. Nearly half of the markednests disappeared, thus suggesting that nests of T. angustula are often undetected by people in Medellín. We discussbriefly some features of the biology of T.angustula that might contribute to its success in urban environments.

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