Biomedical subjects
Publications and source records attributed to R S Sparkes.
We have used the cDNA probes for human aldehyde dehydrogenase-1 (ALDH1) and aldehyde dehydrogenase-2 (ALDH2) to determine regional chromosomal locations of these two genes by in situ hybridization. Results presented here allow localization of ALDH1 to band q21 on chromosome 9 and ALDH2 to band q24 on chromosome 12.
The authors studied a four-generation family with autosomal dominant congenital cataracts (ADCCs) using linkage analysis with 23 polymorphic phenotypic markers and DNA restriction fragment length polymorphisms (RFLPs) detected by lens-specific DNA probes. A total of 19 family members were studied and the ten affected members had embryonal lens opacities. Close linkage was rejected with DNA probes encoding beta-crystallin, gamma-crystallin, and the major intrinsic protein of the lens fiber membrane (MIP) excluding defects of these genes as the cause of the cataract in this family. No statistically significant lod scores were produced with the polymorphic phenotypic markers. These results support the genetic heterogeneity of ADCCs.
We have identified a family affected with X-linked recessive Norrie disease, in which a recombinational event occurred between the disease locus and the DXS7 locus identified by the probe L1.28. The addition of our family brings the total of published informative families to seven, with a maximum lod score of 7.58 at a recombination frequency of 0.038 +/- 0.036. This finding indicates that the L1.28 probe is useful but may not be completely reliable for prenatal diagnosis and that the gene for Norrie disease is not within the DNA sequence identified by the L1.28 probe.
D1S2 was one of the first restriction fragment length polymorphisms (RFLPs) assigned to chromosome 1, but its regional location was unknown. In this paper we present data that place this RFLP into both the genetic map and the physical-cytogenetic map. Linkage data maps D1S2 7 cM from PGM1, which is localized to the middle of the short arm at 1p22.1. Southern blot analysis of DNA samples from somatic cell hybrids containing parts of chromosome 1 maps D1S2 proximal to 1p32 and distal to PGM1.
The relationship between chronic myelogenous leukemia (CML) with and without the Ph1 chromosome is controversial. Although some suggest that these disorders are identical, other reports suggest that Ph1 chromosome negative CML is a distinct entity. To resolve this issue, we studied 11 patients with Ph1 chromosome negative CML for the translocation of the Abelson proto-oncogene (c-abl) to the breakpoint cluster region gene (bcr), internal genomic rearrangement of bcr, and transcription of a chimeric bcr/abl mRNA. Our data indicate that c-abl is translocated to chromosome 22 where it is inserted after exon "2" or "3" of the bcr gene. This results in transcription of a chimeric bcr/abl mRNA in which the splice is between bcr exon "2" or "3" and c-abl exon 2. These data suggest that CML with and without the Ph1 chromosome are molecularly identical disorders with regard to bcr and abl.
Intestinal fatty acid binding protein (I-FABP) is believed to participate in the uptake, intracellular metabolism, and/or transport of long chain fatty acids within enterocytes. The 15.1-kDA rodent proteins is a member of a family of low Mr cytoplasmic proteins that have evolved to bind different ligands. We have now determined the nucleotide sequence of the gene encoding human I-FABP and defined the primary structure of its protein product. The human I-FABP gene spans 3382 nucleotides and contains 4 exons (103 or 128, 173, 108, and 312 base pairs). interrupted by 3 introns (1194, 1023, and 444 base pairs). The 132-residue rat and human I-FABPs have 82% amino acid sequence identity. Blot hybridization studies of RNAs prepared from a variety of adult rhesus monkey tissues as well as human intestine and liver indicate that I-FABP mRNA is confined to the intestine. I-FABP mRNA was not detectable in a number of cultured human enterocyte-like cell lines, suggesting it may be a sensitive marker for differentiated, villus-associated, small intestinal lining cells. Given the similar patterns of tissue-specific expression exhibited by the rat and human genes, we compared their 5' nontranscribed regions. Optimal alignments of the two sequences disclosed 64% identity among the 260 nucleotides immediately 5' to the start site of transcription. Matrix plots revealed a 14-nucleotide long repeated sequence (5'-TGAACTTTGAACTT-3') in the 5' nontranscribed region of both genes as well as in a comparable region of another family member that is expressed in enterocytes, cellular retinol binding protein II. The linkage relationships between I-FABP and the homologous liver FABP (L-FABP) gene were defined in mice and humans. The mouse genes were mapped using restriction fragment length polymorphisms and recombinant inbred strains. The I-FABP gene is located on mouse chromosome 3 between the amylase 1,2 (Amy 1,2) and alcohol dehydrogenase 3 (Adh-3) loci while the L-FABP gene is on mouse chromosome 6 within 3 centimorgans of the lymphocyte antigen-2 (Ly-2) locus. Mouse L-FABP may be identical to the major liver protein-1 (Lvp-1) which is encoded by a gene situated within a centimorgan of Ly-2. Human gene mapping studies were carried out using a panel of mouse-human somatic cell hybrid clones as well as in situ hybridization to metaphase chromosomes.(ABSTRACT TRUNCATED AT 400 WORDS)
Sixteen retinoblastomas were examined with chromosome 13 polymorphic probes to determine the frequency of homozygosity for the chromosome in the tumors. Each of the tumors had two cytogenetically normal appearing No. 13 chromosomes. Nontumorous cells from the same patients were heterozygous for the various polymorphic chromosome 13 probes used. At least partial homozygosity for a single chromosome 13 was observed in 75% of the tumors. These studies confirm and extend previous studies which suggest that homozygosity or hemizygosity at RBI occurs in the majority of retinoblastomas. We also demonstrate in an additional tumor that rapid clonal evolution from hemizygosity to homozygosity can occur in the tumor.
A human lung carcinoma cell line, UCP3, was carried as subcutaneous xenotransplants in athymic mice. Autopsies of these animals showed rare foci of microscopically visible metastases to any of the other organs. A metastatic variant, 522, was established serendipitously in vitro as a continuous cell line by blind isolation of the pulmonary metastatic foci, at the time of autopsy, from the lungs of the animals that carried subcutaneous xenotransplants of the parental cell line. The parental UCP3 and the metastatic variant 522 were examined by karyotypic and isoenzyme analysis and shown to be human and related. The metastatic variant, 522, metastasizes spontaneously from subcutaneous sites (like the parental UCP3). However, it forms larger subcutaneous xenotransplants and forms more metastatic foci in the lungs of the animals than does the parental cell line. Comparisons of the cell surface glycolipids show many similarities and a few differences. This model system may now be used for further investigations into the processes of metastasis of this human neoplasm.
Oncogene abnormalities are thought to have a central role in some human malignant disorders, particularly Burkitt leukaemia/lymphoma and chronic myeloid leukaemia (CML). However, the extent to which specific oncogene changes determine the clinical features of these disorders is unknown. This question was studied in two groups of patients with CML negative for the Philadelphia (Ph) chromosome; one group showed clinical features typical of Ph-positive CML and the other group lacked such features. Molecular findings were compared with those of Ph-positive CML. In all ten patients there was evidence for rearrangement of the bcr (breakpoint cluster region) gene. In the four cases studied the c-abl proto-oncogene was translocated to chromosome 22 and in five cases there was transcription of a chimeric bcr-abl mRNA. Thus, the molecular abnormality is the same in both groups of Ph-negative CML and identical to that in Ph-positive CML. Factors other than the bcr/c-abl rearrangement must underlie the clinical heterogeneity of CML.
Cellular retinol binding protein II (CRBP II) is an abundant, 134-residue protein present in the small intestinal epithelium. It is thought to participate in the uptake and/or intracellular metabolism of vitamin A. We have isolated and sequenced the rat CRBP II gene. Its four exons span 0.65 kilobases and are interrupted by three introns with an aggregate length of 19.5 kilobases. Southern blot hybridization analysis indicated that this gene is highly conserved in rats, mice, and humans. CRBP II belongs to a protein family that contains eight known members. Computer-assisted comparative sequence analyses indicated that a region of internal homology spans its first two exons and that oligopeptide domains specified by these first two exons exhibit significant homology to all other family members as well as to a portion of the all-trans-retinol binding domain that has previously been defined in serum retinol binding protein. The CRBP II gene was mapped in mice using recombinant inbred strains and restriction fragment length polymorphisms. It is located on chromosome 9 within 5.3 centimorgans of the phosphoglucomutase-3 locus and is closely linked (within 3.0 centimorgans) to the gene specifying a highly homologous intracellular retinol binding protein known as CRBP. Mouse-human somatic cell hybrids were used to determine that both the CRBP and CRBP II genes are located on human chromosome 3.
A 5-yr-old girl with unilateral retinoblastoma was found to have del(13)(q14.1q14.3). Her 16-month-old sister and 35-year-old mother, with retinal colobomata but without retinoblastoma, have the same deletion. Esterase D studies indicate reduced gene dose at this locus in the 3 females, consistent with a deletion of band 13q14. These patients are of apparently normal intelligence but have a mildly "coarse" facial appearance, a broad nasal bridge, upturned nares, and a long upper lip with thin upper lip vermillion similar to the phenotype suggested by Motegi et al [1983a] for patients with this deletion. Review of the literature documents 2 other patients with deletions of band 13q14 but without retinoblastoma, indicating that retinoblastoma is not a necessary consequence of this deletion. Of the 12 reported patients with deletions limited to band 13q14, seven had normal intelligence and five were macrocephalic. Insufficient clinical information is provided to draw conclusions about phenotype. The family which we describe and those reviewed by Motegi et al suggest that there may be a characteristic appearance in patients with this deletion.
A dispersed middle repetitive DNA sequence isolated originally from human chromosome 12 did not show homology with rodent DNA under standard conditions of Southern DNA blot analysis. The evolutionary relationship of this human repetitive DNA to that of other primates was investigated using three hybridization methods: DNA dot blot, Southern DNA blot analysis, and chromosome in situ hybridization. Homology with the human repetitive DNA was found throughout the suborder Anthropoidea, in fourteen ape and New and Old World monkey species. In addition, the human pattern of hybridization to noncentromeric regions of all chromosomes was seen. No hybridization by any of the three techniques was found in five species of the suborder Prosimii. The phenomenon of marked differences in sequence homology and copy number of dispersed repetitive DNA from closely related species has been observed in protozoans (Plasmodia), Drosophila, sea urchins, mice and the great apes (Hominoidea). We report here a similar phenomenon that may have occurred at an early stage in primate evolution.
The assignment of the human myelin basic protein gene to 18q22-qter has been made using a mouse cDNA probe in the study of human-mouse somatic cell hybrids and by in situ hybridization. These results confirm the earlier assignment using in situ studies alone by Saxe et al. (1985).
The assignment of the human prealbumin (PALB) gene to chromosome region 18q11-q12.1 has been achieved using a human genomic probe in the study of human-mouse somatic cell hybrids and by in situ hybridization. Because familial amyloidotic polyneuropathy was reported previously to be due to a mutation in prealbumin, it can be inferred that the gene for this disorder also maps to 18q11.2-q12.1.
Cytogenetic abnormalities have been reported in lymphoproliferative disorders, the most common of which is the t(8;14) translocation in Burkitt and Burkitt-like lymphomas. We report a 30-year-old homosexual male with Burkitt-like lymphoma and trisomy 12. This patient presented with persistent generalized lymphadenopathy and subsequently developed advanced lymphoma. Cell surface markers revealed a monoclonal pattern containing mu heavy chain and kappa light chain immunoglobulins. Cytogenetic analysis of bone marrow involved with lymphoma revealed an additional chromosome #12. Mitogen-stimulated cultures of peripheral blood showed a normal 46,XY karyotype. Trisomy 12 has been found in chronic lymphocytic leukemia and in other low-grade B-cell lymphoproliferative disorders, but not in Burkitt-like lymphoma.
We have used cDNA probes for lipoprotein lipase and hepatic lipase to determine the chromosomal and subchromosomal locations of the human genes for these lipolytic enzymes. Southern blot analysis of genomic DNA from 17 independent mouse-human somatic cell hybrids demonstrated the presence of the gene for human lipoprotein lipase on chromosome 8, whereas the gene for hepatic lipase was on chromosome 15. Regional mapping of the genes by in situ hybridization to human chromosomes indicated that the lipoprotein lipase gene (LPL) resides in the p22 region of chromosome 8, while hepatic lipase gene (HL) resides in the q21 region of chromosome 15. We previously reported, on the basis of nucleotide and amino acid homologies, that these genes are members of a gene family of lipases, and, thus, the present findings indicate that the members of this family are dispersed. The results are also of significance with respect to disorders involving deficiencies of the enzymes. In particular, they suggest that certain rare combined deficiencies of both enzymes do not involve mutations of the structural loci.
We have used a cDNA probe for human cholesteryl ester transfer protein (CETP) to determine the chromosomal location for the human gene. Southern blot analysis of DNA from 17 independent mouse-human somatic cell hybrids demonstrated the presence of the gene for human CETP on chromosome 16. Regional mapping of the gene by in situ hybridization was consistent with these results and indicated that the gene resides in the 16q12-21 region of the chromosome. These findings provide an additional polymorphic marker for chromosome 16, as several relatively common restriction fragment length polymorphisms of the gene have previously been reported, and they have significance for studies directed at the identification of genetic factors affecting plasma lipoprotein metabolism and atherosclerosis.
The Ph1 chromosome is present in 95% of patients with chronic myelogenous leukaemia (CML). The Ph1 chromosome also occurs in 5-25% of children and adults with acute lymphoblastic leukaemia (ALL). This observation raises questions as to whether these diseases are similar or identical. In patients with CML the c-abl and bcr genes are translocated and abnormally expressed. We studied molecular events related to bcr and c-abl in five patients with ALL to determine its relationship to CML. Four had the Ph1 chromosome; the fifth a probable Ph1 chromosome. c-abl and bcr abnormalities identical to CML were detected in four suggesting a common molecular basis. One patient with the Ph1 chromosome and c-abl translocation lacked these molecular changes but had abnormal c-abl gene transcription apparently unrelated to bcr. These data suggest that Ph1 chromosome positive ALL is heterogeneous; in some patients the molecular abnormality is identical to CML; in others c-abl is likewise involved but via a different mechanism.