In man, the specific chromosome that carries each of about 210 gene loci is known. These loci include at least one assigned to each chromosome (including the Y), about 110 assigned to specific autosomes, and about 100 to the X chromosome. For many loci, information on regional chromosomal localization is also available. The information comes mainly from studies in families and somatic cell hybrids, as well as an intgratsight of results from the two methods. Knowledge of the chromosome map gives insight into evolution, chromosomal organization in relation to genetic control mechanisms, and the pathogenesis of neoplasms and malformations. Furthermore, it is useful in prenatal or premorbid diagnosis of hereditary diseases.

https://science.sciencemag.org/content/sci/196/4288/390.full.pdf

The status of the gene map of the human chromosomes

https://oaji.net/articles/2014/109-1393667101.pdf

Human Bone Marrow Mesenchymal Stem Cell Behaviors on PCL/Gelatin Nanofibrous Scaffolds Modified with A Collagen IV-Derived RGD-Containing Peptide

The human genes for thymidine kinase, galactokinase and procollagen type I, located on chromosome 17, have been transferred to cultured mouse cells. In unstable cell lines the transferred genetic material is shown to exist independently, whereas in stable cell lines the transferred material has become associated with chromosomes of the recipient cell. The size of the transferred genetic material exceeds 1% of the human haploid genome in some of the transformed cell lines. In addition, the data indicate a gene order of: centromere–galactokinase–(thymidine kinase, procollagen type I), on the long arm of human chromosome 17.

Phenotype stabilisation and integration of transferred material in chromosome-mediated gene transfer

For mass isolation of plant metaphase chromosomes, cultured cells of wheat (Triticum monococcum) and parsley (Petroselinum hortense) were synchronized by hydroxyurea and colchicine treatment. This synchronization procedure resulted in high mitotic synchrony, especially in suspension cultures of parsley in which 80% of the cells were found to be at the metaphase stage. Mitotic protoplasts isolated from these synchronized cell cultures served as a source for isolation of chromosomes. The described isolation and purification method yielded relatively pure chromosome suspension. The uptake of the isolated plant chromosomes into recipient wheat, parsley, and maize protoplasts was induced by polyethylene-glycol treatment. Cytological studies provided evidences for uptake of plant chromosomes into plant protoplasts.

Uptake of isolated plant chromosomes by plant protoplasts.

Transformation frequencies of 4 × 10-5 were obtained in chromosome-mediated gene transfer experiments using human cell line HeLa S3 as donor and mouse cell line A9 as recipient. This high frequency of interspecific transformation was achieved by treating the recipient cells with dimethylsulfoxide in addition to other facilitators. The high frequency of transformation correlated positively with transgenome size on the basis of both co-transfer of linked markers and chromosome analysis. The syntenic human markers glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP+ 1-oxidoreductase, EC 1.1.1.49) and phosphoglycerate kinase (ATP:3-phospho-D-glycerate 1-phosphotransferase, EC 2.7.2.3) were sometimes transferred together with the selected X-linked prototrophic marker hypoxanthine phosphoribosyltransferase (IMP: pyrophosphate phosphoribosyltransferase, EC 2.4.2.8) into murine somatic cells. Donor human chromosome material could be demonstrated cytologically in some of the transformed cell lines. Transformants exhibited various rates of loss of the human hypoxanthine phosphoribosyltransferase marker when grown under nonselective conditions. These results reveal a broader range of possible interspecific transgenome sizes than has been recognized in the past. The largest transgenomes consist of cytologically detectable donor fragments and contain syntenic markers that are not closely linked to the selected marker.

Co-transfer of human X-linked markers into murine somatic cells via isolated metaphase chromosomes.

Evidence is presented for the uptake of radioactive-labeled isolated Chinese hamster chromosomes following incubation with Chinese hamster cells. Metaphases were found which contained radioactive labeled chromosomes in a very low frequency, and in some of the labeled chromosomes only one chromatid was labeled. Incubation of hypoxanthine phosphoribosyltransferase (HPRT)-deficient Chinese hamster cells with chromosomes isolated from HPRT+ Chinese hamster or human cells resulted in the appearance of HPRT+ cells. Clones derived from these cells were isolated in HA T medium. Cells in mitosis during incubation with the chromosomes yielded three times more HPRT+ clones than did cells in interphase. The intraspecies combination involving recipient cells and chromosomes from Chinese hamster origin yielded significantly higher numbers of HPRT+ clones than did the interspecies system using human chromosomes and Chinese hamster recipient cells (5×10−5 and 6×10−6 respectively). Electrophoresis of HPRT from Chinese hamster cells treated with human chromosomes revealed the pattern of the human enzyme.

Incorporation of isolated chromosomes and induction of hypoxanthine phosphoribosyltransferase in Chinese hamster cells.

Evidence is presented for the uptake of the human X chromosome by human-Chinese hamster cell hybrids which lack HPRT activity, following incubation with isolated human HeLa S3 chromosomes. Sixteen independent clonal cell lines were isolated in HAT medium, all of which contained a human X chromosome as determined by trypsin-Giemsa staining. The frequency of HAT-resistant clones was 32 × 10−6 when 107 cells were incubated with 108 HeLa chromosomes. Potential reversion of the hybrid cells in HAT medium was less than 5 × 10−7 The 16 isolated cell lines all contained activity of the human X-linked marker enzymes HPRT, PGK, α-Gal A, and G6PD, as determined by electrophoresis. The phenotype of G6PD was G6PD A, corresponding to G6PD A in HeLa cells. The human parental cells used in the fusion to form the hybrids had the G6PD B phenotype. The recipient cells gave no evidence of containing human X chromosomes. These results indicate that incorporation and expression of HeLa X chromosomes is accomplished in human-Chinese hamster hybrids which lack a human X chromosome.

Transfer of the human X chromosome to human--Chinese hamster cell hybrids via isolated HeLa metaphase chromosomes.

Chinese hamster cells deficient for the enzyme hypoxanthine phosphoribosyl transferase (HPRT) were incubated with isolated human metaphase chromosomes and 21 colonies were isolated in HAT medium. Three different types of cell lines were established from these clones. First, 4 cell lines had 10-30% of normal Chinese hamster HPRT activity with the same electrophoretic mobility as human HPRT. This HPRT activity remains detectable during at least 8 weeks of growth of the cells in nonselective medium. Second, 3 cell lines also had human-like HPRT with the same activity as the first type. This HPRT persists only if the cells are grown in HAT medium and disappears during 8 weeks of growth in nonselective medium. Third, other clones survived in HAT medium as well as in medium with 8-azaguanine. These cells had no detectable HPRT activity. Using differential chromosome staining techniques no recognizable human chromosome fragments were found in any of the cell lines.

D. Bootsma

Papers

Incorporation of isolated chromosomes and induction of hypoxanthine phosphoribosyltransferase in Chinese hamster cells.

Transfer of the human X chromosome to human--Chinese hamster cell hybrids via isolated HeLa metaphase chromosomes.

Expression of human hypoxanthine phosphoribosyl transferase in Chinese hamster cells treated with isolated human chromosomes.