Comparative Cytogenetic Analysis Research Articles

Cytogenetic Approach to Estimation of Developmental Stability of the Natural Populations of Coregonid Fish

A comparative cytogenetic analysis of coregonid fish was carried out in the river and lake ecosystems of the northern Tyumen' District. The occurrence of chromosomal aberrations in embryonic cells of fish steadily increased during the period from 1989 until 2001. Possible causes of this dynamic are discussed.

Comparative cytogenetic and DNA flow cytometric analysis of 242 primary breast carcinomas

The cytogenetic and DNA flow cytometric findings in 242 breast carcinomas were compared. The combined use of both techniques improved the detection of abnormal cell populations from 65% by cytogenetic analysis alone and 59% by DNA flow cytometric analysis alone to 84%. Informative and comparable cytogenetic and flow cytometric data were obtained for 155 tumors. Among these 155 tumors, there was good concordance (64%) between the estimates of genomic changes by the two methods. Most discrepancies were among the DNA-diploid cases, where cytogenetic analysis detected small genomic changes. There were, however, also some exceptions in which large genomic changes detected by one method were missed by the other. Of the specific breast cancer–associated cytogenetic aberrations subjected to separate correlation analysis, polysomy for chromosome 20 was significantly associated with a high S-phase fraction, whereas loss of the long arm of chromosome 16 and/or the presence of a der(1;16) were significantly associated with a low S-phase fraction. Our data show that cytogenetic and DNA flow cytometric analyses of breast carcinomas give largely comparable results, and that combining data from both methods significantly improves the information obtained by either technique used alone on the genetic abnormalities in these tumors.

Comparative cytogenetic analysis on four tree frog species (Anura, Hylidae, Hylinae) from Brazil

A comparative cytogenetic analysis was carried out on four Hylinae tree frogs from Brazil (Aparasphenodon brunoi, Corythomantis greeningi, Osteocephalus langsdorffii, and Scinax fuscovarius) using Giemsa staining, BrdU replication banding, Ag-NOR staining, C-banding, DAPI and CMA₃ fluorochrome staining, and fluorescence in situ hybridization (FISH) with an rDNA probe. All the species share closely similar 2n = 24 karyotypes, almost indistinguishable by standard staining. The technique of BrdU incorporation allowed the identification of each pair of homologs and the establishment of extensive homeology for the great majority of the chromosomes, mainly of A. brunoi, C. greeningi, and O. langsdorffii. Despite highly conserved replication banding patterns, the use of the other banding techniques disclosed some minor differences, which reinforces the importance of extensive cytogenetic analyses for the karyotypic characterization of Anuran species. The present cytogenetic data confirm the closer proximity of A. brunoi, C. greeningi, and O. langsdorffii, whereas S. fuscovarius is phylogenetically more distant.

Karyotype, constitutive heterochromatin and nucleolus organizer regions in two species of Liolaemus (Squamata, Tropiduridae)

Abstract A comparative cytogenetic analysis, based on chromosome morphology, Ag- NOR staining and CBG- banding was undertaken on two species of Liolaemus: L. chacoensis and Liolaemus azarai, a new undescribed species. The intestines, bone marrow and testes were sampled. Both species showed a karyotype with 12 biarmed macrochromosomes and 22 microchromomes. No sexual chromosomal heteromorphism was found. The patterns of C and NOR bands were similar. Constitutive heterochromatin was located in the pericentromeric regions of macrochromosomes and nucleolar organizer regions were detected on the long arm of the pair 2.

Comparative cytogenetic analysis of the South American alligators Caiman latirostris and Caiman yacare (Reptilia, Alligatoridae) from Argentina

Abstract One of the most important cytogenetic characteristics among the crocodilians is the diploid number, that ranges from 30 to 42 chromosomes and the fundamental number (FN) from 56 to 62, without sex chromosomes heteromorphisms. The purpose of this study was to characterise the chromosome complement of Caiman yacare and C. latirostris from Argentina through conventional Giemsa staining and simple banding techniques (CBC and NOR). The chromosome preparations were made from peripherical blood culture, and C- and NOR- banding were applied following routinary methods. The data obtained point out that both species share a similar chromosome number (2n = 42) and morphology with the complements composed by 12 pairs of telocentric chromosomes, 7 pairs of biarmed chromosomes and 2 pairs which could be considered microchromosomes. No conspicuous differences were revealed in the C-banding patterns and in both species the NOR’s was found on one of the small chromosome pairs.

Chromosomal evolution in Mugilidae: karyotype characterization of Liza saliens and comparative localization of major and minor ribosomal genes in the six Mediterranean mullets

This study continues a comparative cytogenetic analysis of the fish family Mugilidae, reporting the karyotype characterization of the leaping mullet, Liza saliens, by C-banding, Ag- and fluorochrome-staining, and completing the fluorescence in situ hybridization (FISH)-mapping of the 18S and 5S rRNA genes (rDNA) to the chromosomes of the six Mediterranean mullets, namely L. saliens, L. ramada, L. aurata, Mugil cephalus, Chelon labrosus and Oedalechilus labeo. In all species, except M. cephalus, the 5S rDNA sites were localized on a medium-sized acrocentric chromosome pair, which was considered homeologous in all of them. In L. saliens, an additional 5S rDNA site was detected in a location close to the one shown by major ribosomal genes in M. cephalus, i.e. the subtelomeric region of chromosome pair 1. The 5S rDNA site in M. cephalus is located on the smallest chromosome pair of the complement, which, on the other hand, though on a different position, bears 18S rDNA in all the species of Liza and Chelon examined. The heterochromatin composition and the major and minor ribosomal gene locations suggest that the karyotype of L. saliens (subgenus Protomugil) can be considered intermediate between the karyotype of the more primitive M. cephalus and those of the other Liza (subgenus Liza) species and of the representatives of the more derived genera Chelon and Oedalechilus.

Comparative cytogenetics among sympatric species of Characidium (Pisces, Characiformes). Diversity analysis with the description of a ZW sex chromosome system and natural triploidy

Abstract A comparative cytogenetic analysis was carried out in two sympatric fish species of the genus Characidium, C. gomesi and C. cf. zebra, from the Parana basin, Sao Paulo State, Brazil. Although both species showed the same diploid number (2n = 50) and a similar karyotypic macrostructure, an interspecific diversity was detected concerning the distribution of the C-bands and the nucleolar organizing regions in the karyotypes, as well as the sex chromosomes. A ZZ/ZW sex chromosome system was detected in C. gomesi, where the W chromosome appears fully heterochromatic and with a small size than Z chromosome. This species also presented a triploid female specimen bearing one W and two Z chromosomes. In C. cf.zebra heteromorphic sex chromosomes were not found. These data are discussed concerning the characterization of the regional ictiofauna and its evolutionary aspects.

Comparative genomic in situ hybridization (cGISH) analysis on plant chromosomes revealed by labelled Arabidopsis DNA.

A new approach for comparative cytogenetic banding analysis of plant chromosomes has been established. The comparative GISH (cGISH) technique is universally applicable to various complex genomes of Monocotyledonae (Triticum aestivum, Agropyron elongatum, Secale cereale, Hordeum vulgare, Allium cepa, Muscari armenaticum and Lilium longiflorum) and Dicotyledonae (Vicia faba, Beta vulgaris, Arabidopsis thaliana). Labelled total genomic DNA of A. thaliana generates signals at conserved chromosome regions. The nucleolus organizing regions (NORs) containing the majority of tandemly repeated rDNA sequences, N-band regions containing satellite DNA, conserved homologous sequences at telomeres and additional chromosome-characteristic markers were detected in heterologous FISH experiments. Multicolour FISH analysis with repetitive DNA probes simultaneously revealed the chromosome assignment of 56 cGISH signals in rye and 61 cGISH signals in barley. Further advantages of this technique are: (1) the fast and straightforward preparation of the probe; (2) the generation of signals with high intensity and reproducibility even without signal amplification; and (3) no requirement of species-specific sequences suitable for molecular karyotype analysis. Hybridization can be performed without competitive DNA. Signal detection without significant background is possible under low stringency conditions. The universal application of this fast and simple one-step fluorescence banding technique for plant cytogenetic and plant genome evolution is discussed.

Peculiarity of the analysis of heterochromatic regions in small chromosomes of plants.

Visual analysis of small chromosomes of plants is difficult in most cases, because the chromosomes are similar in morphology and banding patterns. The computer software applied to chromosome analysis extended the capabilities of karyotypic analysis of small-chromosome species, because precise mathematical parameters of chromosomes and chromosome bands became available [1‐4]. This approach made it possible to completely identify chromosomes of some small-chromosome species and compare their karyotypes with the use of C-banding, which is commonly accepted in plant chromosome analysis [3‐7]. However, standard C-banding of chromosome preparations is often ineffective, and the banding pattern does not enable chromosome identification and measurements. To elongate small chromosomes, DNA intercalators are usually used [5, 6, 8], which enhances the resolution of C-banding patterns, and, hence, the possibility of chromosome identification. However, variation in C-banding patterns increases as the chromosome lengths increase after treatment with DNA intercalators. At the same time, there are no exact principles determining the range of chromosome length enabling stable C-banding and accurate morphometry to ensure not only chromosome identification and construction of idiograms, but also the possibility of comparative cytogenetic analysis. In this study, we aimed to develop these criteria. We demonstrated that, in principle, genomic polymorphism of the small-chromosome plant species can be studied by means of morphometric chromosome analysis, and the basic rules of the latter were formulated. We studied changes in the sizes of heterochromatic regions in both large and small mitotic chromosomes during their shortening. Chromosome selection for further measurements was based on the following criteria: the average size in the karyotype, the presence of intercalary heterochromatic bands, the absence of the secondary constriction, and the simplest identification. We finally selected chromosomes of the fourth groups in the karyotypes of the Djau-Kabutac cultivar of barley ( Hordeum vulgare L.) [9] and large-flower flax ( Linum grandiflorum Desf.) [6]. We examined all chromosomes identifiable from C-banding patterns that did not overlap in the same preparation meristem from a single plant to exclude the possibility of individual C-banding polymorphism. Barley chromosome preparations were obtained using the standard technique described previously [9]. To obtain flax preparations, the intercalator 9-aminoacridine was used [6]. On every barley or flax metaphase plate, one of a pair of homologous chromosomes was analyzed morphometrically. Numerous preliminary measurements (at least 30) of the same barley or flax chromosome were made to determine the limits of error for the morphometry. Similar results were obtained with both types of chromosomes (0.056 μ m).

Comparative Genomic Hybridization and Conventional Cytogenetic Analyses in Childhood Acute Myeloid Leukemia

Comparative genornic hybridization (CGH) analysis was performed on bone marrow specimens from 19 children with acute myeloid leukemia (AML) at diagnosis. The results of CGH were compared to those of conventional cytogenetic analysis. The most common CGH aberrations were gains of whole chromosomes 6 and 8, both of which appeared three times. Two losses were seen twice; losses of whole chromosomes 7 and X. The CGH findings were concordant with the results of conventional karyotyping. CGH did not add new information to the karyotypes. Since no high-level amplification was found among the samples and standard karyotyping was highly successful, we do not advocate routine use of CGH in the diagnostic evaluation of childhood AML.

Cytogenetic study of buffalo under pollution of environmental conditions

Thirty-four buffalos were used in the present study. Animals were kept in three experimental groups, two groups of which were reared in polluted areas, and the third group in an agricultural area (control group). the first and second groups were exposed to industrial and automobile exhaust emissions of genotoxic agents. Comparative cytogenetic analysis was made between the three groups. The cytogenetic studies of peripheral blood lymphocytes included chromosomal aberration and sister chromatide exchange (SCE). Significant differences ( P<0.05) were observed in the percentage of cells with total chromosomal aberrations and gaps between buffalo from polluted and agricultural areas (31±1.4% and 21.1±6.7% and 7.6±1.6% and 6.8±1%, respectively). The differences of frequencies of the total gaps between the first and second groups were significant, while it was non-significant in the total chromosomal aberrations. The frequency of sister chromatide exchange of buffalo from polluted areas was 11.8±1.4% compared to 8.3±1.2% from the agricultural area, the difference was statistically significant ( P<0.05). These results indicated that cytogenetic analysis of chromosomes in peripheral lymphocytes of buffalo exposed to environmental pollution allows to direct detection of mutation in somatic cell, which can be prevented.

Étude caryologique de trois espèces d’Hypochoeris originaires d'Argentine : H. chillensis, H. microcephala var. albiflora et H. megapotamica

Three Hypochoeris species from Argentina with the same chromosome number (x = 4) and similar karyotypes (typically bimodal) show significant ecological and morphological differences. Comparative cytogenetic analysis was done for these taxa, producing karyotypes with correlated idiograms. The number of secondary constrictions and nucleolar organizers varied. The results from this study are discussed in terms of the mechanisms of microevolution within this group of closely related species, and in terms of the evolutionary trend in the genus and in the tribe Cichorieae. Key words: Hypochoeris, Cichorieae, bimodal karyotype, secondary constriction, nucleolar organizer, asymmetry index.

Comparative cytogenetic and dna flow cytometric analysis of 150 bone and soft‐tissue tumors

Samples from 48 benign and 102 malignant bone and soft-tissue tumors were analyzed cytogenetically and by DNA flow cytometry. Clonal chromosome abnormalities were found in 82 tumors and normal karyotypes in 68; 61 tumors were DNA-non-diploid and 89 were diploid. The cytogenetically abnormal tumors were used for comparison between the 2 types of investigation; 45 of these tumors were DNA-diploid and 37 were DNA-non-diploid. There was, with few exceptions, good correspondence between the quantitative estimates of genomic changes by the 2 methods, indicating that the cells cytogenetically analyzed from short-term cultures are representative of the in vivo cell populations. Discrepancies were primarily found in cases with indexes above 1.5, in which the DNA index was higher than the chromosome index. The chromosome analysis suggested that skewed stemline (G0/G1) peaks in the diploid region in DNA histograms indicate the presence of cell populations with small net quantitative genomic changes, although not all such populations were detected by DNA flow cytometric analysis. The view that one of the peaks in bimodal stemline DNA histograms with narrow peaks represents a non-diploid cell population was also corroborated. On average, the cell populations giving rise to double stemlines in DNA histograms showed quantitatively larger genomic changes than those that gave rise to broad or skewed diploid G0/G1 peaks. The findings indicate that these histogram profiles are not artifactual but reflect chromosomal changes in the tumor parenchyma.

Chromosomal characterization and comparative cytogenetic analysis of two species ofProechimys(Echimyidae, Rodentia) from the Caatinga domain of the State of Bahia, Brazil

SUMMARYG-, C-, and R-banding and silver staining techniques were used to analyze the chromosomes of twelve specimens of Proechimys sp. n. (2n = 54; FN = 104) that will be described as a new species by one of us (P.L.B. Rocha) and four of Proechimys albispinus (2n = 60; FN = 116), collected in two localities of the State of Bahia, Brazil. The meiotic studies after silver staining in pachytene cells allowed the visualization of the sex vesicle and the synaptonemal complexes of all autosomal bivalents. Other meiotic phases are studied after conventional staining. A comparative analysis of G-banding patterns among Proechimys sp. n., Proechimys albispinus and Proechimys iheringi iheringi, previously described (YONENAGA-YASSUDA et al. 1985) is presented. These three species are included in the subgenus Trinomys.

Comparative cytogenetic analysis between cyclophosphamide‐sensitive and ‐resistant lines of acute myeloid leukemia in the lewis brown norway hybrid rat

An animal model of acute myeloid leukemia (AML) has been developed in the Brown Norway (BN) rat and has successfully been introduced into the Lewis x BN F1 hybrid (LBN) and designated LBN AML. The original LBN AML is sensitive to the chemotherapeutic agent cyclophosphamide (CY). Recently, a CY-resistant cell line of LBN AML has been established. To characterize this animal model of human leukemia better, we analyzed and compared the chromosomal makeup of both the CY-sensitive and CY-resistant LBN AML lines. The CY-sensitive LBN AML cultures contained two cell lines--line I (88%): 41,XX,-1,-2,-9,del(12)(q16), + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11); and line II (12%): 41,XX,-1,-2,-9,del(12),del(20)(q13) + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11). The recently developed CY-resistant AML cells contained two cell lines--line I (88%): 41,XX,-1,-2,-9,del(3)(q36q42.1),del(4) (q42.2),?t(5;?)(q35;?),?t(8;?)(q24;?),del(12)(q16), + der(1)t(1;?8)(p13;q31), + der(2)t(2;9)(p11;q11); and line II (12%): 42,XX (probably represents host contamination). The new chromosomal aberrations in the CY-resistant line I [del(3)(q36q42.1),del(4)(q42.2),?t(5;?)(q35;?), and ?t(8;?)(q24;?)] suggest a possible interrelationship between these secondary karyotypic abnormalities and acquisition of resistance to the chemotherapeutic agent.

Sister-chromatid exchanges induced by triethylenemelamine: in vivo and in vivo/in vitro studies in mouse and Chinese hamster bone marrow and spleen cells

This study was designed to obtain sister-chromatid exchange (SCE) frequencies in bone marrow and spleen cells of mice and Chinese hamsters under in vivo and in vivo/in vitro systems following treatment of animals with varying doses (15–405 μg/kg) of triethylenemelamine (TEM). A dose-related SCE response was found in both species, tissues, and systems analyzed following TEM treatment. In vivo, similar responses were noted for both tissues in both species. However, in vivo/in vitro, the response was lower than in vivo and it varied with the tissue. The spleen cells were more sensitive and gave higher numbers of SCEs than bone marrow of both species at the two highest doses tested (135 and 405 μg/kg). These differences may be attributed to cell-culturing effects, type of cells analyzed, species and tissue specificities, and pharmacokinetic properties of the chemical. This study lends support to recently established in vivo/in vitro cell culture methodologies employing mice and Chinese hamsters for comparative cytogenetic analysis.

Karyological Study in Some Yugoslavian Populations ofHypochoeris(Compositae)

SUMMARYA comparative cytogenetic analysis is done in two taxa of the genus Hypochoeris: H. maculata L. and H. illyrica K. Maly. The first is largely distributed in Eurasia, while the second is endemic in the yugoslavian flora. Further investigations were wanted in this last taxon because of its often reconsidered systematic position. Several yugoslavian populations are karyologically studied. Hypochoeris illyrica K. Maly is found at diploid level only (2n = 2x = 10), while Hypochoeris maculata L. is sometimes found at polyploid level (2n = 4x = 20). At diploid level the two taxa are very similar. Karyological characteristics of each of them are pointed out.

Comparative cytogenetic analysis of bone marrow damage induced in male B6C3F1 mice by multiple exposures to gaseous 1,3-butadiene.

Groups of male B6C3F1 mice (N = 12) were exposed to ambient air or to gaseous 1,3-butadiene (BD) at 6.25, 62.5, and 625 ppm for 10 exposure days (6 hr + T90/day). Exposure to BD induced in bone marrow: 1) a significant increase in the frequency of chromosomal aberrations (CA); 2) a significant elevation in the frequency of sister chromatid exchanges (SCE); 3) a significant lengthening of the average generation time (AGT); 4) a significant depression in the mitotic index (MI); and, as measured in the peripheral blood, 5) a significant increase in the proportion of circulating polychromatic erythrocytes (%PCE), and 6) a significant increase in the level of micronucleated PCE (MN-PCE) and micronucleated normochromatic erythrocytes (MN-NCE). The most sensitive indicator of genotoxic damage was the frequency of SCE (significant at 6.25 ppm), followed by MN-PCE levels (significant at 62.5 ppm), and then by CA and MN-NCE frequencies (significant at 625 ppm). The most sensitive measure of cytotoxic damage was AGT (significant at 62.5 ppm), followed by %PCE (significant at 625 ppm), and then by MI (significant by trend test only). Because each cytogenetic endpoint was evaluated in every animal, a correlation analysis was conducted to evaluate the degree of concordance among the various indicators of genotoxic and cytotoxic damage. The extent of concordance ranged from a very good correlation between the induction of MN-PCE and the induction of SCE (correlation coefficient r = 0.9562) to the lack of a significant correlation between the depression in the MI and any other endpoint (r less than 0.37).

Comparative cytogenetic analysis in mice chronically treated with arsenic alone and with arsenic in combination with ethyl methanesulfonate

Comparative cytogenetic analysis in mice chronically treated with arsenic alone and with arsenic in combination with ethyl methanesulfonate

Mutant Lines of Guinea Pig L 2 C Leukemia. II. Comparative Cytogenetic Studies and Banding Analyses of Normal and Leukemic Karyotypes

Chromosomes of normal guinea pig (strain 2) cells and of cell lines dervied from a spontaneously arising leukemia were analyzed in detail. All cell lines studied, LG-L2C, GH-L2-C, BZ-LC, and EN-L2C, contained one M1 marker and two X chromosomes, in addition to other chromosome abnormalities specific for each cell line. The presence of the M1 marker and the two X chromosomes confirmed that all of these leukemic cell lines are derived from one ancestral line. Comparison of the chromosome markers and immunologic characteristics of these lines revealed that possibly the gene involved in the determination of C3 receptor sites is located on the terminal portion of the long arm of chromosome No. 2, but no other correlations could be made.