1,308 research outputs found
Phylogenetic inferences of Atelinae (Platyrrhini) based on multi-directional chromosome painting in Brachyteles arachnoides, Ateles paniscus paniscus and Ateles b. marginatus
We performed multi-directional chromosome painting in a comparative cytogenetic study of the three Atelinae species Brachyteles arachnoides, Ateles paniscus paniscus and Ateles belzebuth marginatus, in order to reconstruct phylogenetic relationships within this Platyrrhini subfamily. Comparative chromosome maps between these species were established by multi-color fluorescence in situ hybridization ( FISH) employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. The three species included in this study and four previously analyzed species from all four Atelinae genera were subjected to a phylogenetic analysis on the basis of a data matrix comprised of 82 discrete chromosome characters. The results confirmed that Atelinae represent a monophyletic clade with a putative ancestral karyotype of 2n = 62 chromosomes. Phylogenetic analysis revealed an evolutionary branching sequence \{Alouatta \{Brachyteles \{Lagothrix and Ateles\}\}\} in Atelinae and \{Ateles belzebuth marginatus \{Ateles paniscus paniscus \{Ateles belzebuth hybridus and Ateles geoffroyi\}\}\} in genus Ateles. The chromosomal data support a re-evaluation of the taxonomic status of Ateles b. hybridus. Copyright (C) 2005 S. Karger AG, Basel
Molecular cytotaxonomy of primates by chromosomal in situ suppression hybridization
A new strategy for analyzing chromosomal evolution in primates is presented using chromosomal in situ suppression (CISS) hybridization. Biotin-labeled DNA libraries from flow-sorted human chromosomes are hybridized to chromosome preparations of catarrhines, platyrrhines, and prosimians. By this approach rearrangements of chromosomes that occurred during hominoid evolution are visualized directly at the level of DNA sequences, even in primate species with pronounced chromosomal shuffles
Comparative chromosome band mapping in primates byin situ suppression hybridization of band specific DNA microlibraries
A DNA-library established from microdissected bands 8q23 to 8q24.1 of normal human chromosomes 8 (Lüdecke et al., 1989) was used as a probe for chromosomal in situ suppression (CISS-) hybridization to metaphase chromosomes of man and primates including Hylobates lar and Macaca fuscata. Comparative band mapping as first applied in this study shows the specific visualization of a single subchromosomal region in all three species and thus demonstrates that synteny of the bulk sequences of a specific human chromosome subregion has been conserved for more than 20 million years
The Chromosomes of Lepturinae (Coleoptera: Cerambycidae) II. A study of 8 more species, with focus on Desmocerus palliatus
International audienc
A strategy for the characterization of minute chromosome rearrangements using multiple color fluorescence in situ hybridization with chromosome-specific DNA libraries and YAC clones
The identification of marker chromosomes in clinical and tumor cytogenetics by chromosome banding analysis can create problems. In this study, we present a strategy to define minute chromosomal rearrangements by multicolor fluorescence in situ hybridization (FISH) with whole chromosome painting probes derived from chromosome-specific DNA libraries and Alu-polymerase chain reaction (PCR) products of various region-specific yeast artificial chromosome (YAC) clones. To demonstrate the usefulness of this strategy for the characterization of chromosome rearrangements unidentifiable by banding techniques, an 8p+ marker chromosome with two extra bands present in the karyotype of a child with multiple anomalies, malformations, and severe mental retardation was investigated. A series of seven-color FISH experiments with sets of fluorochrome-labeled DNA library probes from flow-sorted chromosomes demonstrated that the additional segment on 8p+ was derived from chromosome 6. For a more detailed characterization of the marker chromosome, three-color FISH experiments with library probes specific to chromosomes 6 and 8 were performed in combination with newly established telomeric and subtelomeric YAC clones from 6q25, 6p23, and 8p23. These experiments demonstrated a trisomy 6pter6p22 and a monosomy 8pter8p23 in the patient. The present limitations for a broad application of this strategy and its possible improvements are discusse
The origin of human chromosome 2 analyzed by comparative chromosome mapping with a DNA microlibrary
Fluorescencein situ hybridization (FISH) of microlibraries established from distinct chromosome subregions can test the evolutionary conservation of chromosome bands as well as chromosomal rearrangements that occurred during primate evolution and will help to clarify phylogenetic relationships. We used a DNA library established by microdissection and microcloning from the entire long arm of human chromosome 2 for fluorescencein situ hybridization and comparative mapping of the chromosomes of human, great apes (Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus) and Old World monkeys (Macaca fuscata andCercopithecus aethiops). Inversions were found in the pericentric region of the primate chromosome 2p homologs in great apes, and the hybridization pattern demonstrates the known phylogenetically derived telomere fusion in the line that leads to human chromosome 2. The hybridization of the 2q microlibrary to chromosomes of Old World monkeys gave a different pattern from that in the gorilla and the orang-utan, but a pattern similar to that of chimpanzees. This suggests convergence of chromosomal rearrangements in different phylogenetic lines
Unscheduled DNA synthesis after partial UV irradiation of the cell nucleus
Cells of an euploid strain of the Chinese hamster synchronized in the G1 phase were microirradiated in the nucleus with a laser UV microbeam (λ = 257 nm) and pulse-labelled with [3H]thymidine. In autoradiographs of cells fixed immediately after the pulse unscheduled DNA synthesis (UDS) was found restricted to the microirradiated part of the nucleus. The rate of UDS varied with the UV energy applied and the post-irradiation incubation time. In other experiments chromosome preparations were established after an additional chase and a subsequent growth period. In 28 mitotic cells autoradiographic label was found concentrated on a few chromosomes which lay adjacent to each other in one part of the metaphase plate. The distribution of label on the chromosomes could clearly be distinguished from patterns which originate from semi-conservative DNA synthesis within S phase. The label on chromosomes of microirradiated cells thus represents UDS. Our findings support the following ideas on the arrangement of interphase chromosomes: (1) Decondensed interphase chromosomes may occupy rather compact territories. (2) Chromosomes do not necessarily exhibit a close and permanent association with their respective homologues
Analysis of chromosome positions in the interphase nucleus of Chinese hamster cells by laser-UV-microirradiation experiments
Unsynchronized cells of an essentially diploid strain of female Chinese hamster cells derived from lung tissue (CHL) were laser-UV-microirradiated (=257 nm) in the nucleus either at its central part or at its periphery. After 7–9 h postincubation with 0.5 mM caffeine, chromosome preparations were made in situ. Twenty-one and 29 metaphase spreads, respectively, with partial chromosome shattering (PCS) obtained after micro-irradiation at these two nuclear sites, were Q-banded and analyzed in detail. A positive correlation was observed between the frequency of damage of chromosomes and both their DNA content and length at metaphase. No significant difference was observed between the frequencies of damage obtained for individual chromosomes at either site of microirradiation. The frequency of joint damage of homologous chromosomes was low as compared to nonhomologous ones. Considerable variation was noted in different cells in the combinations of jointly shattered chromosomes. Evidence which justifies an interpretation of these data in terms of an interphase arrangement of chromosome territories is discussed. Our data strongly argue against somatic pairing as a regular event, and suggest a considerable variability of chromosome positions in different nuclei. However, present data do not exclude the possibility of certain non-random chromosomal arrangements in CHL-nuclei. The interphase chromosome distribution revealed by these experiments is compared with centromere-centromere, centromere-center and angle analyses of metaphase spreads and the relationship between interphase and metaphase arrangements of chromosomes is discussed
Differences in the localization and morphology of chromosomes in the human nucleus
Using fluorescence in situ hybridization
we show striking differences in nuclear position,
chromosome morphology, and interactions with nuclear
substructure for human chromosomes 18 and
19. Human chromosome 19 is shown to adopt a
more internal position in the nucleus than chromosome
18 and to be more extensively associated with
the nuclear matrix. The more peripheral localization
of chromosome 18 is established early in the cell cycle
and is maintained thereafter. We show that the
preferential localization of chromosomes 18 and 19
in the nucleus is reflected in the orientation of translocation
chromosomes in the nucleus. Lastly, we
show that the inhibition of transcription can have
gross, but reversible, effects on chromosome architecture.
Our data demonstrate that the distribution of
genomic sequences between chromosomes has implications
for nuclear structure and we discuss our
findings in relation to a model of the human nucleus
that is functionally compartmentalized
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