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C M Croce

Publications and source records attributed to C M Croce.

At least 469 records · Page 26Linked to original sources
PubMed1976

Linkage relationship between the genes for thymidine kinase and galactokinase in different primates.

In this study we investigated the expression of primate galactokinase in somatic cell hybrids between a thymidine kinase-deficient mouse cell line and two different primate cell lines, one of which was derived from African green monkey kidney cells and the other from chimpanzee fibroblasts. All the African green monkey-mouse hybrid clones, selected in HAT medium, expressed monkey galactokinase activity and contained a monkey chromosome similar to a human E-group chromosome. When these clones were backselected in medium containing 5-bromodeoxyuridine, both this chromosome and the monkey galactokinase activity were lost. All the hybrid clones between mouse and chimpanzee cells, which were selected in HAT medium, contained the chimpanzee chromosome 17 and expressed chimpanzee galactokinase activity. These results indicate that the linkage relationship between galactokinase and thymidine kinase has been maintained in 3 divergent primate species--man, chimpanzee, and Old World monkey.

Animals↗
PubMed1976

Assignment of the gene for cytoplasmic glutamic-oxaloacetic transaminase to the region q-24-qter of human chromosome 10.

Somatic cell hybrids between thymidine kinase-deficient mouse cells and human fibroblasts carrying a translocation of the distal third of the long arm of chromosome 10 to chromosome 17 were studied for the expression of cytoplasmic glutamic-oxaloacetic transaminase. A positive correlation between the expression of human cytoplasmic glutamic-oxaloacetic transaminase and the presence of the distal third of the long arm of chromosome 10 was established.

Aspartate Aminotransferases↗
PubMed1976

Characterization of heteropolymeric hexosaminidase A in human X mouse hybrid cells.

Expression of heteropolymeric hexosaminidase A activity is reported in a human X mouse hybrid cell line that contains an X/15 translocation chromosome but lacks human chromosome 5 and has no detectable human hexosaminidase B activity. (Hexosaminidase is beta-N-acetylglucosaminidase; EC 3.2.1.30; 2-acetamido-2-deoxy-beta-D-glucoside acetamidodeoxyglucohydrolase.) That the "hexosaminidase A" enzyme of these cells contains the human hexosaminidase-alpha subunit and not the human hexosaminidase-beta subunit is indicated by the cells' reactions to specific antisera prepared against the alpha subunit and against the beta subunit. Our results indicate that the "hexosaminidase A" activity in this hybrid cell line is the expression of a hybrid molecule composed of human hexosaminidase-alpha subunit and a mouse hexosaminidase subunit. These results are consistent with the hypothesis that the human hexosaminidase A enzyme is formed from alpha and beta subunits coded for by genes on chromosomes 15 and 5, respectively.

Animals↗
PubMed1976

Expression of human and suppression of mouse nucleolus organizer activity in mouse-human somatic cell hybrids.

Most mouse-human somatic cell hybrids show preferential loss of human chromosomes, absence of human 28S ribosomal RNA, and suppression of human nucleolus organizer activity, as visualized by the Ag-AS silver histochemical stain. In contrast, the mouse-human hybrids studied here show preferential loss of mouse chromosomes. The hybrids were made by fusion of HT-1080-6TG human fibrosarcoma cells with BALB/c mouse peritoneal macrophages or strain 129 mouse teratocarcinoma cells. The Ag-AS staining method shows nucleolus organizer activity of chromosomes 13, 14, 15, 21 (rarely), and 22 in the human parent and chromosomes 12, 15, 16 (rarely), and 18 in the BALB/c mouse parent. In the hybrid cells the human nucleolus organizer regions are active, as shown by Ag-AS staining and involvement in "satellite association." The mouse nucleolus organizer regions are not stained by the Ag-AS method even though mouse chromosomes 12, 15, and 18 are present in the BALB/c hybrids and at least one copy of each mouse chromosome is present in the teratocarcinoma-derived hybrids. Thus, in these mouse-human hybrids, unlike those that lose human chromosomes, only human nucleolus organizer activity is expressed, and mouse nucleolus organizer activity is suppressed.

Animals↗
PubMed1976

Loss of mouse chromosomes in somatic cell hybrids between HT-1080 human fibrosarcoma cells and mouse peritioneal macrophages.

Somatic cell hybrids between mouse peritioneal macrophages and HT-1080 human fibrosarcoma cells lose mouse chromosomes and retain the entire complement of human chromosomes. In contrast, somatic cell hybrids between cells derived from two different mouse continuous cell lines and HT-1080 human cells were found to lose human chromosomes preferentially. Loss of mouse chromosomes is not a general property of hybrids between mouse macrophages and transformed human cells; the hybridization of mouse macrophages with cells derived from five different human fibroblast lines transformed by simian virus 40 resulted in the production of hybrid clones that preferentially lost human chromosomes.

Animals↗
PubMed1976

Production of B-tropic murine leukemia virus by somatic cell hybrids between mouse peritoneal macrophages and simian virus 40-transformed human cells.

Simian virus 40 (SV40)-transformed human cells (LN-SV) were fused with BALB/c peritoneal macrophages (BALB/c X LN-SV) and with C57BL peritoneal macrophages (C57BL X LN-SV) and hybrid clones, all of which had segregated human chromosomes and contained the entire complement of mouse chromosomes, were isolated. All 15 BALB/c X LN-SV hybrid clones were producing varying titers (10 to 10(6) plaque-forming units/ml) of B-tropic murine leukemia virus, whereas none of the nine C57BL X LN-SV hybrid clones was producing detectable ecotropic murine leukemia virus.

Animals↗