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

2019 ◽  
Vol 158 (4) ◽  
pp. 213-224 ◽  
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.

scholarly journals An exploration of the relationship between recruitment communication and foraging in stingless bees

2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter
Keyword(s):  
Stingless Bees ◽  
Sugar Content ◽  
Social Information ◽  
Food Resources ◽  
Food Sources ◽  
Foraging Strategies ◽  
High Quality ◽  
Recruitment Communication ◽  
Eusocial Bees ◽  
The Relationship

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.

scholarly journals Differential response to heat stress among evolutionary lineages of an aquatic invertebrate species complex

2018 ◽  
Vol 14 (11) ◽  
pp. 20180498 ◽  
Author(s):  
Sofia Paraskevopoulou ◽  
Ralph Tiedemann ◽  
Guntram Weithoff
Keyword(s):  
Heat Stress ◽  
Cryptic Species ◽  
Heat Tolerance ◽  
Species Complex ◽  
Environmental Changes ◽  
Integrative Taxonomy ◽  
Sensu Stricto ◽  
Apparent Temperature ◽  
Phenotypic Trait ◽  
Evolutionary Lineages

Under global warming scenarios, rising temperatures can constitute heat stress to which species may respond differentially. Within a described species, knowledge on cryptic diversity is of further relevance, as different lineages/cryptic species may respond differentially to environmental change. The Brachionus calyciflorus species complex (Rotifera), which was recently described using integrative taxonomy, is an essential component of aquatic ecosystems. Here, we tested the hypothesis that these (formerly cryptic) species differ in their heat tolerance. We assigned 47 clones with nuclear ITS1 (nuITS1) and mitochondrial COI (mtCOI) markers to evolutionary lineages, now named B. calyciflorus sensu stricto (s.s.) and B. fernandoi . We selected 15 representative clones and assessed their heat tolerance as a bi-dimensional phenotypic trait affected by both the intensity and duration of heat stress. We found two distinct groups, with B. calyciflorus s.s. clones having higher heat tolerance than the novel species B. fernandoi . This apparent temperature specialization among former cryptic species underscores the necessity of a sound species delimitation and assignment, when organismal responses to environmental changes are investigated.

scholarly journals Comparative molecular cytogenetics in Melipona Illiger species (Hymenoptera, Apidae)

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 696 ◽  
Author(s):  
Vanderly Andrade-Souza ◽  
Olivia Maria Pereira Duarte ◽  
Cinthia Caroline Cardoso Martins ◽  
Igor Silva Santos ◽  
Márcio Gilberto Cardoso Costa ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Number ◽  
Fluorescent In Situ Hybridization ◽  
Molecular Cytogenetics ◽  
Fluorochrome Staining ◽  
Rdna Sites ◽  
Cytogenetic Studies ◽  
Melipona Species ◽  
Almost All

Cytogenetic studies in Melipona are scarce with only 24 species analyzed cytogenetically. Of these, six species had the rDNA sites physically mapped and characterized by Fluorescent in situ Hybridization (fish). The aim of this study was to perform karyotype analyzes on Melipona species from different regions of Brazil, with a greater sampling representative of the Amazonian fauna and using conventional, fluorochrome staining and FISH with heterologous rDNA probes. The predominant chromosome number was 2n = 18, however, the subspecies M. seminigra abunensis and M. s. pernigra showed 2n = 22 chromosomes. The karyotypes were symmetrical, however M. bicolor, M. quadrifasciata, M. flavolineata, M. fuscopilosa, M. nebulosa presented the first pair heteromorphic in length. CMA3+ blocks also exhibited heteromorphism of size and in almost all cases coincided with rDNA sites, except for M. crinita and M. nebulosa, which presented additional non-coincident CMA3+ blocks. The CMA/ rDNA sites were terminal and interstitial in species with high heterochromatic content, and pericentromeric in those species with low heterochromatic content. In addition to pointing out cytogenetic features of cytotaxonomic importance, the reorganization of the genome in Melipona is discussed.

scholarly journals Chromosome Evolution in Connection with Repetitive Sequences and Epigenetics in Plants

Genes ◽  
2017 ◽  
Vol 8 (10) ◽  
pp. 290 ◽  
Author(s):  
Shu-Fen Li ◽  
Ting Su ◽  
Guang-Qian Cheng ◽  
Bing-Xiao Wang ◽  
Xu Li ◽  
...  
Keyword(s):  
Chromosome Evolution ◽  
Repetitive Sequences

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

Genetica ◽  
2020 ◽  
Vol 148 (1) ◽  
pp. 25-32 ◽  
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

scholarly journals Evaluation of DNA Methylation Changes and Micronuclei in Workers Exposed to a Construction Environment

2019 ◽  
Vol 16 (6) ◽  
pp. 902 ◽  
Author(s):  
Isana Silva ◽  
Manoela Ramos ◽  
Lídia Arantes ◽  
André Lengert ◽  
Marco Oliveira ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Particulate Matter ◽  
Repetitive Sequences ◽  
Promoter Regions ◽  
Exposed Workers ◽  
Polycyclic Aromatic ◽  
Group 2 ◽  
Environmental Air ◽  
The Relationship ◽  
Group 1

Methylation levels in tumor-suppressor genes and repetitive sequences have previously been used to study the relationship between environmental air pollution and epigenetic changes related to cancer. In this study, we measured the methylation profiles of the promoter regions CDKN2A, MLH1 and APC and the repetitive sequence LINE-1 in 59 workers exposed to the construction environment and in 49 unexposed workers. We also evaluated the micronuclei frequency and levels of trace elements in the blood of all workers. We evaluated of levels of particulate matter and polycyclic aromatic hydrocarbons (PAHs) at the construction site to characterize the environmental exposure. Our findings demonstrated that exposed workers exhibited significantly higher average levels of promoter methylation of CDKN2A, APC, and MLH1 genes and increased hypomethylation of the LINE-1 in comparison to unexposed workers (all p < 0.05). A higher frequency of micronuclei was observed in the exposed group (2 ± 2) compared to the unexposed group (1 ± 1) with p < 0.001. High levels of particulate matter (51–841 μg/m3) and some PAHs were found in samples from the construction environment. In summary, we provide evidence of increased DNA damage and altered DNA methylation of exposed workers, suggesting that genomic approaches to biomonitoring may be an effective way of estimating future cancer risk for construction workers.

scholarly journals Monocentric chromosomes in Juncus (Juncaceae) and implications for the chromosome evolution of the family

2019 ◽  
Vol 191 (4) ◽  
pp. 475-483 ◽  
Author(s):  
Marcelo Guerra ◽  
Tiago Ribeiro ◽  
Leonardo P Felix
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Chromosome Evolution ◽  
Holocentric Chromosomes ◽  
Mitotic Chromosomes ◽  
Restricted Area ◽  
Rdna Sites ◽  
The Family ◽  
Meiotic Analyses

Abstract Holocentric chromosomes are rare among angiosperms, but have been suggested to be shared by all or most of the species of Cyperaceae and Juncaceae. However, no clear demonstration of the centromere type in Juncus, the largest genus of Juncaceae, has so far been published. Thus, we conducted a detailed chromosomal investigation of four Juncus spp. aiming to identify their centromere type. Mitotic chromosomes were analysed using the fluorochromes CMA and DAPI, fluorescent in situ hybridization (FISH) with rDNA probes and immunodetection of histones H3 phosphorylated at serine 10 (H3-S10ph) and H2A phosphorylated at threonine 133 (H2A-T133ph). DAPI-stained chromosomes of all species displayed typical primary constrictions, which were not related to AT-poor CMA+ heterochromatin or rDNA sites (usually negatively stained with DAPI). Immunodetection with H3-S10ph and H2A-T133ph revealed hyperphosphorylation of pericentromeric and centromeric regions, respectively, in a restricted area, as observed in monocentric chromosomes. Meiotic analyses in J. microcephalus showed no indication of inverted meiosis, commonly found in plants with holocentric chromosomes. Since the species investigated here belong to four different sections of Juncus and all of them display typical monocentric chromosomes, it seems that this kind of centromere is common in the genus and may represent the standard centromere organization for Juncus. If Juncus has monocentric chromosomes, there is no reason to hypothesize that other genera of Juncaceae for which centromeres have not been carefully investigated have holocentric chromosomes.

Notes on the genus Cactodera Krall & Krall, 1978 and proposal of Betulodera betulae gen. nov., comb. nov. (Nematoda: Heteroderidae)

Nematology ◽  
2002 ◽  
Vol 4 (7) ◽  
pp. 875-882 ◽  
Author(s):  
Dieter Sturhan
Keyword(s):  
Adaptive Radiation ◽  
New Genus ◽  
Morphological Characteristics ◽  
Sensu Stricto ◽  
Lateral Field ◽  
Second Stage ◽  
Species Inquirenda ◽  
Definition Of ◽  
Relationship Of ◽  
The Relationship

AbstractBased mainly on an analysis of the host ranges of the species presently placed in Cactodera, sensu lato, and of selected morphological characteristics, an attempt is made to improve the definition of the genus which, after exclusion of C. betulae and C. johanseni, is considered to be monophyletic. The host range of Cactodera, sensu stricto, appears to be restricted to the subclass Caryophyllidae with the ten known species showing an adaptive radiation on host genera in five families of the orders Caryophyllales and Polygonales. This may be a result of co-evolution. Cactodera betulae cannot be assigned to any of the presently recognised genera of cyst-forming nematodes and therefore Betulodera gen. nov. is proposed with B. betulae comb. nov. as the type and only species. The relationship of Betulodera gen. nov. to other genera of Heteroderidae and to some undescribed heteroderid species has still to be evaluated. The new genus is characterised by circumfenestrate cysts with only a slightly protruding vulval cone, three incisures in the lateral field of the second-stage juveniles and presence of phasmids in the males. The hosts are in unrelated plant orders and subclasses. Cactodera aquatica, a species inquirenda, is returned to the genus Heterodera and Heterodera johanseni (Sharma et al. , 2001) comb. nov. is proposed for C. johanseni.

scholarly journals Lateral Moraines of Glacier De Tsidjiore Nouve: Form, Development, and Implications

1983 ◽  
Vol 29 (102) ◽  
pp. 250-259 ◽  
Author(s):  
R. J. Small
Keyword(s):  
Complex Form ◽  
Current Mode ◽  
Sensu Stricto ◽  
Kinematic Wave ◽  
Glacial Erosion ◽  
Accumulation Zone ◽  
Mode Of Development ◽  
Form Development ◽  
The Relationship

AbstractThe relationship between supraglacial lateral moraines and lateral dump moraines at Arolla. Switzerland, is discussed. A detailed study of the lateral moraines of glacier de Tsidjiore Nouve reveals their complex form (as superimposed and nested ridges) and the current mode of development (possibly related to the passage of a kinematic wave). Sedimentological analysis indicates that much of the constituent debris is of supraglacial origin; it is transported either directly from the base of slopes flanking the Pigne d’Arolla ice-fall or via englacial septa comprising marginal sediment incorporated in the accumulation zone. A calculation of the volume of debris in the lateral moraines suggests that glacier de Tsidjiore Nouve has recently been more active in transporting and depositing supraglacial debris than in glacial erosionsensu stricto.

Evolution of Bird Sex Chromosomes Narrated by Repetitive Sequences: Unusual W Chromosome Enlargement in Gallinula melanops (Aves: Gruiformes: Rallidae)

2019 ◽  
Vol 158 (3) ◽  
pp. 152-159 ◽  
Author(s):  
Ricardo J. Gunski ◽  
Rafael Kretschmer ◽  
Marcelo Santos de Souza ◽  
Ivanete de Oliveira Furo ◽  
Suziane A. Barcellos ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
18S Rdna ◽  
Organizer Region ◽  
Repetitive Sequences ◽  
Nucleolar Organizer Region ◽  
Molecular Cytogenetics ◽  
5S Rdna ◽  
Nucleolar Organizer ◽  
W Chromosome ◽  
Rdna Sites

Among birds, species with the ZZ/ZW sex determination system generally show significant differences in morphology and size between the Z and W chromosomes (with the W usually being smaller than the Z). In the present study, we report for the first time the karyotype of the spot-flanked gallinule (Gallinula melanops) by means of classical and molecular cytogenetics. The spot-flanked gallinule has 2n = 80 (11 pairs of macrochromosomes and 29 pairs of microchromosomes) with an unusual W chromosome that is larger than the Z. Besides being totally heterochromatic, it has a secondary constriction in its long arm corresponding to the nucleolar organizer region, as confirmed by both silver staining and mapping of 18S rDNA probes. This is an unprecedented fact among birds. Additionally, 18S rDNA sites were also observed in 6 microchromosomes, while 5S rDNA was found in just 1 microchromosomal pair. Seven out of the 11 used microsatellite sequences were found to be accumulated in microchromosomes, and 6 microsatellite sequences were found in the W chromosome. In addition to the involvement of heterochromatin and repetitive DNAs in the differentiation of the large W chromosome, the results also show an alternative scenario that highlights the plasticity that shapes the evolutionary history of bird sex chromosomes.

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