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PubMed1997

A novel source of highly specific chromosome painting probes for human karyotype analysis derived from primate homologues.

We have established a series of highly specific painting probes for human acrocentric chromosomes. These chromosomes are involved in the formation of the nucleolar organizer region (NOR) and show DNA sequence homologies within their pericentric heterochromatin. To date, these chromosomes have shown considerable cross hybridization in chromosome painting experiments. Our probe set has been established from primate homologues that are not involved in the NOR in that particular species or from species in which highly repetitive sequences have undergone rapid sequence divergence. The new painting probes should be of particular value for automated microscopy, for which highly specific signals are required as they are recorded at low magnification, e.g. when scoring chromosome 21 domains in interphase nuclei.

Animals↗
PubMed1981

Karyotype analysis and quantitation of viral transforming genes in Rous sarcoma virus transformed, revertant, and retransformed field vole cells.

Comparative studies of the number of cellular chromosomes and viral genes, including the gene required for malignant transformation, were performed on several clones of Rous sarcoma virus-transformed, revertant, and spontaneously retransformed field vole cells. The results of these studies indicate that no appreciable differences in either total viral gene equivalents or transforming gene sequences can be detected between transformed and revertant cell types, even though considerable differences in the number of certain chromosomes exist among the clones tested. Furthermore, no increase in the amount of total genes or transforming gene sequences accompanies retransformation of revertant clones, including clones that exhibited significant increases in chromosome number following retransformation.

Animals↗
PubMed2000

Karyotypic analysis of the cotton boll weevil, Anthonomus grandis Boheman.

The diploid chromosome number of the cotton boll weevil, Anthonomus grandis Boheman, is 44. Both C- and N-banding techniques of mitotic cells demonstrated constitutive heterochromatin in the p arm of the eight largest chromosomes, the p arm of the X chromosome, and the centromeric region of autosomal groups A-D. Neither the y nor the group E autosomes appeared to contain constitutive heterochromatin. Supernumerary chromosomes were not found in the boll weevil. Restriction endonuclease banding of primary spermatocytes revealed a rod-shaped Xy tetrad in which the X and y were terminally associated. The p arm of the large, submetacentric X was C-band positive. While two of the autosomal tetrads were typically ring-shaped in primary spermatocytes, the remaining 19 autosomal tetrads were rod-shaped.

Animals↗
PubMed1996

A karyotypic analysis of the lesser Malay chevrotain, Tragulus javanicus (Artiodactyla: Tragulidae).

Chevrotains are small forest-dwelling ruminants of the family Tragulidae. The chromosome number of the lesser Malay chevrotain was determined to be 2n = 32, NF = 64, G- and Q-banding allowed the identification of homologous chromosomes, and C-banding demonstrated the presence of pericentromeric, telomeric and interstitial constitutive heterochromatin. Q-band comparisons with domestic cattle revealed relatively few monobrachial chromosome band homologies. However, the smallest biarmed autosome of the chevrotain, chromosome 15, was determined to be cytogenetically homologus with the acrocentric chromosome 19 of cattle. A molecular cytogenetic analysis confirmed this putative chromosomal homology. In fact, molecular cytogenetic analyses indicate complete conservation of synteny among mouse deer chromosome 15, domestic cattle chromosome 19, domestic pig chromosome 12 and human chromosome 17. In the light of these molecular cytogenetic data and since mouse deer chromosome 15 is submetacentric and appears homologous in banding to submetacentric chromosome 12 of the domestic pig, these outgroup comparisons indicate that the acrocentric condition of cattle chromosome 19 has been derived by inversion. Since this derivative condition is present in the Antilocapridae, Bovidae, Cervidae and Giraffidae, it is a chromosomal synapomorphy that unites these advance ruminant families within the Artiodactyla.

Animals↗
PubMed1986

The synaptonemal complexes of Caenorhabditis elegans: the dominant him mutant mnT6 and pachytene karyotype analysis of the X-autosome translocation.

The dominant X-autosome heterozygous translocation mutant mnT6 of the nematode Caenorhabditis elegans has an X chromosome that has been reduced in size by 40%, yet the remainder of the bivalent pairs effectively at pachytene and has a synaptonemal complex (SC) that has a normal appearance. Six SCs are present in pachytene nuclei of this mutant which correspond to a haploid value of n = 6. Nondisjunction of the X chromosome occurs at a rate of 37% and there are no 'Disjunction Regulator Regions' (DRR) in this him (high incidence of males) mutant. This is consistent with the notion that DRRs either promote disjunction or inhibit nondisjunction of the X chromosome. Their occurrence in pachytene nuclei is independent of the mechanism responsible for nondisjunction, i.e. point mutations as in him-8 versus chromosomal aberrations as in mnT6. Although an SC is present along the entire length of the X chromosome, crossover suppression is observed in mnT6.

Animals↗
PubMed1981

Karyotypic analysis of human ovarian carcinoma cells cloned in short term agar culture.

We report detailed chromosome banding analysis of six cases of ovarian adenocarcinoma cultured 24--96 hr in a recently developed bioassay for clonogenic tumor cells. The results of G and C banding revealed a variety of chromosome changes including the observation of a simple deletion for a portion of the long arm of chromosome #6, del(6)(pter leads to q15--21:), in tumor cells from four of six patients. Our study indicates that short-term agar culture can provide a valuable tool in the study of tumor cell karyology. A comparison of our results with previously published studies suggests that in addition to alterations of chromosome #1, the deletion of 6q may represent a characteristic chromosomal aberration in ovarian carcinoma.

Adenocarcinoma↗
PubMed1996

The synaptonemal complexes of the meiotic parthenogenetic Antarctic nematode Panagrolaimus davidi: karyotype analysis and three-dimensional reconstruction of pachytene nuclei.

This study represents the first complete reconstruction of synaptonemal complexes (SCs) and analysis of the pachytene stage of meiosis prophase I in the genus Panagrolaimus. In the free-living meiotic parthenogenetic Antarctic nematode P. davidi, pachytene nuclei had an average nuclear volume of 40 microns 3. Seven synaptonemal complexes were present (n = 7) and the average total length was 65.1 microns. The SCs were attached to the NE at only one end. The nucleolar organizer region was restricted to a central position on the SC. The unstriated central element consisted of two linear components and lacked transverse filaments. Such a modification of the SC has been seen in only two other organisms; the amphimictic nematode Heterodera glycines and the meiotic parthenogenetic nematode Heterodera betulae. Recombination nodules were not evident in the pachytene nuclei. There was no apparent interlocking of bivalents. Morphologically distinct sex chromosomes were not observed.

Animals↗
PubMed1985

Mapping of amplified c-myb oncogene, sister chromatid exchanges, and karyotypic analysis of the COLO 205 colon carcinoma cell line.

We have studied molecular and chromosomal details of cytogenetic status in a human tumor cell line COLO 205 that shows a stable, approximately tenfold amplification of the c-myb oncogene. The amplified copies of c-myb reside in two marker chromosomes that may have evolved from chromosome #6 by complex chromosomal rearrangements. No homogeneously staining regions can be discerned at the site of c-myb amplification. We suggest that c-myb was amplified in situ in a chromosomal segment (6q22-24) that became a part of the marker chromosome, possibly through isochromosome formation followed by duplication, and without the extrachromosomal intermediate form of double minute chromosomes. There is an enhanced frequency of sister chromatid exchanges at the site of amplified c-myb. These results are discussed in the context of models for gene amplification and oncogene activation.

Adenocarcinoma↗
PubMed2000

Ovarian metastases from colorectal carcinoma. Clinicopathologic profile, immunophenotype, and karyotype analysis.

Ovarian metastases from colorectal carcinoma frequently mimic primary ovarian carcinomas. The present study was performed to identify possible criteria helpful in differential diagnosis. Twenty-three ovarian metastases from colorectal carcinomas and 23 primary ovarian carcinomas were evaluated clinicopathologically and immunostained with antigastric M1 antigen, cathepsin E, CA125, vimentin, estrogen and progesterone receptors, cytokeratins 7 and 20, and alpha-inhibin antibodies. We performed a conventional and molecular cytogenetic study on 5 ovarian metastases from colorectal carcinoma using direct preparation, Q banding techniques, and fluorescence in situ hybridization. Integration of clinicopathologic, immunohistochemical, and cytogenetic features is helpful for the differential diagnosis of metastases of colorectal carcinomas from primary ovarian carcinomas. Bilaterality, extrapelvic spreading, high mitotic index, and cytokeratin 20 immunoreactivity, and lack of M1, CA125, and cytokeratin 7 immunoreactivity favor the diagnosis of ovarian metastases from colon carcinomas. The identification of 13q gain as a peculiar, sensitive, and specific marker of colorectal carcinomas seems relevant.

Adult↗
PubMed1999

Genomic alterations in distal bile duct carcinoma by comparative genomic hybridization and karyotype analysis.

We report genomic abnormalities identified in 14 human primary common bile duct carcinomas analyzed by cytogenetics or comparative genomic hybridization, or both. Combining the results of the two methods of analysis, 11 chromosomal arms were observed to be gained in whole or in part, and 9 chromosomal arms were lost in whole or in part in at least four tumors each. The most frequently lost chromosomal regions were, in decreasing order: 18q (eight tumors); 6q and 10p (seven tumors each); 8p, 12q, and 17p (six tumors each); and 7q, 12p, and 22q (four tumors each). The most frequently gained regions were 8q and 20q (six tumors each); 12p, 17q, and Xp (five tumors each); and 2q, 6p, 7p, 11q, 13q, and 19q (four tumors each). These results are similar to those we have previously reported in pancreatic cancer and suggest that carcinomas of the common bile duct and pancreas share a number of genetic changes.

Adult↗
PubMed1992

Isolation, sequence and molecular karyotype analysis of the actin gene of Cryptosporidium parvum.

Actin is an ubiquitous and highly conserved microfilament protein which is hypothesized to play a mechanical, force-generating role in the unusual gliding motility of sporozoan zoites and in their active penetration of host cells. We have identified and isolated an actin gene from a Cryptosporidium parvum genomic DNA library using a chicken beta-actin cDNA as an hybridization probe. The nucleotide sequences of two overlapping recombinant clones were identical and the amino acid sequence deduced from the single open reading frame was 85 % identical to the P. falciparum actin I and human gamma-actin proteins. The predicted 42 106-Da Cryptosporidium actin contains 376 amino acids and is encoded by a single-copy gene which contains no introns. The nucleic acid coding sequence is 72% biased to the use of A or T in the third position of codons. Chromosome-sized DNA released from intact C. parvum oocysts was resolved by OFAGE into 5 discrete ethidium bromide-staining DNAs ranging in size from 900 to 1400 kb; the cloned C. parvum actin gene hybridized to a single chromosomal DNA of approximately 1200 kb.

Actins↗
PubMed2003

Karyotypic characterization of representatives from Melolonthinae (Coleoptera: Scarabaeidae): karyotypic analysis, banding and fluorescent in situ hybridization (FISH).

Meiotic chromosomes of Phyllophaga (Phytalus) vestita, Phyllophaga (Phyllophaga) aff capillata and Lyogenys fuscus (Melolonthinae) were analyzed by conventional staining, C-banding, fluorochromes, silver nitrate and FISH. The three species had a diploid number of 2n=20 and a sex mechanism of the (Xyp; XYp) parachute type. P. (Phytalus) vestita,P. (Phyllophaga) aff capillata and Lyogenys fuscus showed pericentromeric constitutive heterochromatin (CH) in all autosomal bivalents and on X chromosomes. Staining with CMA3 and DAPI fluorochromes showed that the CH of P. (Phytalus) vestita is not specifically rich in AT and GC-base pairs, whereas in P. (Phyllophaga) aff capillata the sex bivalent and one autosomal pair were found to be enriched in GC base pairs with CMA3, and in Lyogenys fuscus CH was positive for DAPI. Silver nitrate staining revealed nucleolar remnants in all three species. However, FISH obtained a precise identification of nucleolar organizing regions with an rDNA 18S and 25S probe. A signal of hybridization was seen in each species, being detected in the X chromosome of P. (Phytalus) vestita and Lyogenys fuscus, and in a small autosomal bivalent of P. (Phyllophaga) aff capillata.

Animals↗
PubMed1995

Pachytene karyotype analysis of the nematode Meloidogyne spartinae in relation to the genus Meloidogyne.

Seven synaptonemal complexes (SC) were present in the pachytene nuclei of Meloidogyne spartinae. The SC was bipartite and consisted of two lateral elements, while lacking a striated central element. This pattern was similar in all Meloidogyne species studied thus far with the exception of M. microtyla. Each SC was attached by only one end to the nuclear envelope while the other end remained unattached and was free in the nucleoplasm. A bouquet formation at pachytene was absent. An average of eight recombination nodules were present on the SC during all stages of pachytene, although the length of SC increased approximately 77%, from an average of 78 to 138 microm from early to mid-late pachytene. In M. spartinae, there was no apparent relationship between SC length and amount of recombination at pachytene. In addition, nuclear volume increased >60% during pachytene while nucleolar volume decreased by approximately 35%. Two nucleolar organizer regions (NOR) were present during mid-pachytene, whereas other stages had only one NOR. This is the first time that two nucleoli have been identified at pachytene in any nematode. They were both the same chromosome yet in reverse order relative to the telomere attached to the nuclear envelope, suggesting that each telomere was competent to interact with the nuclear envelope.

Animals↗
PubMed1984

The synaptonemal complexes of Caenorhabditis elegans: pachytene karyotype analysis of the rad-4 radiation-sensitive mutant.

In the rad-4 mutant of C. elegans there is a specific increase in the number of 'Disjunction Regulator Regions' (DDR) present on the synaptonemal complexes (SC) in pachytene nuclei. These DRRs either promote disjunction or inhibit nondisjunction of the X-chromosome as evidenced by the 10-fold decrease in the rate of X-chromosome nondisjunction as compared to the wild-type. The structure of the tripartite SC is normal, thus, the decrease in the rate of X-chromosome nondisjunction in the rad-4 mutant is not related to the structure of the SC but may be related to the number of DRRs. Other changes are also associated with the sensitivity to irradiation, i.e. the pachytene nuclear morphology is altered such that nuclei and nucleoli are 50% the size of wild-type. In addition, the autosomal: X-chromosome size ratio is reduced in the rad-4 mutant. That there are six SCs confirms n = 6 in this mutant and of these six SCs three can be identified: (1) the XX bivalent, SC No. 1, is the shortest and pairs synchronously with the autosomes; (2) the longest bivalent, SC No. 6, carries the nucleolar organizer region at one extreme end; and (3) SC No. 5 has two DRRs located approximately one micron apart from each other.

Animals↗
PubMed1995

Karyotypic analysis in the process of immortalization of human cells treated with 4-nitroquinoline 1-oxide.

The establishment of a model system of neoplastic transformation of normal human cells has been attempted with a chemical carcinogen, 4-nitroquinoline 1-oxide (4NQO). In the course of these experiments, it was noticed that immortalization of human cells is a multi-step process involving several mutational genetic events. Thus, chromosomal changes which occurred during the process of immortalization of human fibroblasts were examined. To accomplish immortalization, fibroblasts obtained from an embryo were repeatedly treated with 10(-6) M 4NQO from primary culture to passage 51 (59 treatments in total). Before immortalization, some chromosomes (especially, chromosomes 2, 6, 8, 10, 11, 12, 15, 19, and 20), were lost at a relatively high frequency. After immortalization, the chromosomes distributed so broadly in the triploid to hypotetraploid region without a distinct modal number or without marker chromosomes that it was difficult to identify the specific chromosomes related to the immortalization of human cells. No specific structural chromosomal changes were detected. Although the significance of such chromosome changes in relation to immortalization is not clear, the loss of some specific chromosomes suggests that genes which are involved in cellular aging and which suppress immortalization may have been lost in the immortalization process.

4-Nitroquinoline-1-oxide↗
PubMed1982

The synaptonemal complexes of caenorhabditis elegans: comparison of wild-type and mutant strains and pachytene karyotype analysis of wild-type.

Normal synaptonemal complexes (SCs), consisting of two lateral elements and a central element, are present in wild-type, him-4 and him-8 mutant strains in both hermaphrodites and males of caenorhabditis elegans. Thus, the increase in rate of nondisjunction in the him mutants is not related to aberrant SC morphology. The wild-type hermaphrodite has six SCs, as determined from 3-D reconstruction analysis of serial section from electron microscopy. Thus, n=6 and this confirms early reports based on cytological studies with the light microscope. Only one end of the SC is attached to the nuclear envelope while the other end is free in the nucleoplasm and there is no apparent bouquet formation. Either end of the SC can attach to the nuclear envelope. The pairing behavior of the XX bivalent is normal and occurs synchronously with the autosomes. Electron dense bodies, or knobs, are associated with the SC via the central element and displace the chromatin for a distance of 200 nm. Each pachytene nucleus of the wild-type hermaphrodite has six such structures that are randomly dispersed along the bivalents such that some SCs have one or two knobs while others have none. Their function is unknown.

Animals↗