摘要:

A panel of 25 microsatellite loci known to map to human chromosome 18 was screened for length polymorphisms in a multigenerational pedigree of baboons (Papio hαmadryas). Eight of these loci were polymorphic in the baboon pedigrees, with observed heterozygosity values ranging from 0.16 to 0.88. All eight loci show strong evidence of linkage. The most likely map order among the microsatellite loci for Pαpio is completely compatible with the locus order found in the human genome, and sex differences in recombination rates are also similar in the two species. We conclude that the organization of the chromosomal region defined by these loci is largely conserved between baboons and human

ISSN:1424-8581    

DOI:10.1159/000134484

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Hydronephrosis caused by pelvi-ureteric junction obstruction (PUJO) is a frequent urological malformation assumed to result from a deficient development of the ureteric bud. The exact etiology of pelvi-ureteric junction stenosis is unknown, but there is convincing evidence for a genetic cause, with linkage analysis predicting a hereditary hydronephrosis locus on chromosome 6p. We encountered a patient with a de novo autosomal t(6;19)(p21;q13.1) and attendant bilateral multicystic renal dysplasia (MRD), bilateral PUJO resulting in massive hydronephrosis, and an associated von Mayer-Rokitansky-Küster disorder. On the basis of the presumption that in this patient the putative hydronephrosis gene might be disrupted by the translocation, we sought to isolate DNA from the breakpoint regions as the initial step in a strategy to identify genes affected by the t(6;19). Using sequential rounds of fiuorescence in situ hybridization (FISH) with cosmids selected from a detailed integrated map of the long arm of chromosome 19, we have identified a cosmid clone that spans the breakpoint. The position of the breakpoint was further localized by Southern blot analysis. Using a vectorette PCR approach, rearranged DNA fragments were isolated and, by comparative nucleotide sequence analysis, these were shown to contain ectopic sequences. A cosmid clone containing these ectopic sequences was isolated and shown by CASH (chromosome assignment using somatic cell hybrids) and FISH (fluorescence in situ hybridization) analysis to map to the short arm of chromosome 6 and to span the breakpoint found in the MRD patient. The isolated cosmid clones are useful reagents for analysis of other MRD patients and for the search for genes at or flanking the breakpoints

ISSN:1424-8581    

DOI:10.1159/000134485

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Loss of the wild-type allele of a tumor suppressor gene, or loss of heterozygosity (LOH), is one of the most important mechanisms of carcinogenesis. Adenine phosphoribosyl-transferase (APRT) has been used as a surrogate marker for tumor suppressor genes. We have previously shown that APRT deficiency in an APRT heterozygous human cell line, MR12-1, was predominantly caused by the loss of the remaining wild-type allele. Here we report the characterization of the chromosomal pathways leading to LOH in four clones derived from this heteroploid cell line. We performed karyotype analysis, chromosome 16-specifïc painting, and fluorescence in situ hybridization with an APRT-containing cosmid on these clones and their heteroploid parental cells. Our findings suggest that LOH occurs in tetraploid as well as diploid cells, and that diploid cells with LOH may undergo endoreduplication to attain tetraploidy. Our results also suggest that, in addition to LOH being caused by a single event (such as mitotic recombination or deletion), LOH may be caused by a combination of sequential events, such as mitotic recombination or translocation followed by chromosome loss. The instability of the genomes of the parental cells may have provided a greater diversity of options for genetic evolution. Similar karyotypic evolution may occur at late stages of carcinogenesis in vivo

ISSN:1424-8581    

DOI:10.1159/000134486

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134487

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The ribosomal protein genes are members of multigene families, most of which are processed pseudogenes. Here we report that an intronless pseudogene for the L5 ribosomal protein maps within an intron of the SNRPN transcription unit on human chromosome 15. The pseudogene (RPL5P1) shares 95% sequence homology with the L5 mRNA, has a poly (A) stretch and is flanked by direct repeats.

ISSN:1424-8581    

DOI:10.1159/000134488

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The human PCSK5 gene, which encodes a subtilisin-like proprotein processing enzyme, has been mapped by analysis of somatic cell hybrids and YAC clones as well as fluorescence in situ hybridization to chromosome 9q21.3 near markers D9S175 and D9S276.

ISSN:1424-8581    

DOI:10.1159/000134489

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Zinc finger genes represent a large multigene family present in mammalian and other genomes. A subgroup of these genes contain a conserved motif, the KRAB domain, at the NH2-terminal region, which was recently shown to posses a potent transcriptional repression activity. For one such gene, ZNF45, we determined the complete coding sequence, along with the exon/intron arrangement and the splice junctions. Exon 2 codes exclusively for the KRAB-A element of 42 amino acids, and exon 4 contains the 19 zinc finger repeats. In addition, we generated an EST (expressed sequence tag) from the 3’-end of ZNF45 that we used for polymerase chain reaction screening of a Pl-derived genomic library. We isolated a 65-kb clone that was used for localizing this gene on chromosome 19ql 3.2 by fluorescence in situ hybridizatio

ISSN:1424-8581    

DOI:10.1159/000134490

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

We have analyzed by Ag- and CMA3-staining, and rDNA fluorescent in situ hybridization an unusual NOR site polymorphism in a population of Salmo trutta from Miño basin (Northwestern Spain). A multichromosomal Ag-NOR distribution largely different from standard individuals both in the number and position of Ag-NORs, as well as in the pattern of activity, was revealed. Atypical Ag-NORs consist of rDNA genes, as evidenced by rDNA FISH, and are capable of constituting their own nucleolus. In spite of the large number of available NORs per individual, the mean number of Ag-NOR per cell was less than 3 in most individuals, which suggests a regulation mechanism to adjust the ribosomal production. The new rDNA clusters detected seem to be stably integrated, however, some characteristics of the NOR pattern observed suggest that this polymorphism is an unstable phenomenon

ISSN:1424-8581    

DOI:10.1159/000134491

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Six phage clones containing gene members of the family of antimicrobial peptides named cathelicidins, were mapped to bovine chromosome 22q24, by means of fluorescence in situ hybridization. The mapping data suggest the clustering of cathelicidins into a CATHL@ locus, in a similar manner as for β-defensins, another family of antimicrobial peptides, defining the locus DEFB@ mapped to 27q13→q

ISSN:1424-8581    

DOI:10.1159/000134492

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The search for the SMA defect has culminated in the identification of two candidate 5q13.1 SMA genes, NAIP and SMN both of which are deleted in individuals with SMA. It was postulated that the intact and degenerate versions of NAIP are present in variable and frequently high copy numbers in this region while SMN was proposed to be present in only two copies. In order to assess the copy number of NAIP and SMN we have conducted interphase FISH analysis using NAIP and SMN gene-containing cosmid and plasmid probes. Our results confirm the variability in the number of NAIP signals in non-SMA chromosomes (2–6) and show that SMN is present on average twice per chromosome although in one chromosome 4–5 signals for the SMN-containing cosmid probe were detected. Our analysis reveals that one of four and three of six type I SMA chromosomes had a lower than normal number of NAIP and SMN signals, respectively. In two of six SMA type I chromosomes, complete loss of hybridization signal was observed on one chromosome 5 with our SMN cosmid probe possibly reflecting a large scale deletion. Large scale deletions were not detectable when metaphase chromosomes of an SMA type II and III patient were analy

ISSN:1424-8581    

DOI:10.1159/000134493

出版商:S. Karger AG    

年代:1996

数据来源: Karger