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Biomedical subjects

D Weil

Publications and source records attributed to D Weil.

At least 145 records · Page 8Linked to original sources
PubMed1977

[Regional localization of the genes for human IDHs, MDHs PGK, alphaGAL, G6PD by interspecific hybridization (author's transl)].

22 independent man-hamster (HGPRT-) hybrids using male human cells with balanced reciprocal translocation t(X;2)(p22;q32) were analysed for human genes localized on chromosome 2 (IDHs, MDHs), on chromosome X (PGK, alphaGAL, G6PD) and for the different chromosomes in relation with the balanced reciprocal translocation (chr.2, chr.2q-, chr.Xp+). The following results were obtained: The chromosomes 2 and 2q- are absent in the 22 hybrids. In 9 hybrids, the absence of MDHs in spite of the presence of the chromosome Xp+ indicates that the gene for MDHs is not localized on this chromosome (or that the gene for MDHs is not on the segment 2q32--2qter translocated on X). In 14hybrids, the three markers of X (PGK, alphaGAL, G6PD) and IDHs are expressed in the presence of the chromosome Xp+. This result indicates that the genes for these markers are on Xp+ or that the genes PGK, alphaGAL, G6PD are on X without the Xp22--Xter segment, translocated on the chr.2, and that the gene for IDHs is on the 2q32--2qter segment translocated on X. In 8 hybrids, in the absence of the intack chromosome Xp+, the higher percentage of the presence of G6PD (7 hybrids) and the lower percentage of the presence of IDHs (3 hybrids) are explained by the fact that these hybrids selected in HAT medium had to retain a segment of Xp+ bearing the human gene HGPRT. G6PD appeared very close to HGPRT and IDHs very distant from HGPRT. The study of the different correlations between the presence and the absence of these four markers on Xp+ in the different hybrids indicates the following order on the chromosome Xp+ from p to q: IDHs -- PGK --alphaGAL -- G6PD.

Animals↗
PubMed1977

The expression and relation of HLA, beta2-microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells.

The expression of HLA, human and mouse beta2-microglobulin (beta2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human beta2m and where redistribution experiments demonstrate that HLA is associated with mouse beta2m. Synteny between HLA and the receptor for MaRBC can be a useful tool to select HLA-positive hybrid clones.

Animals↗
PubMed1977

[Localization of enolases 1 and 2 on chromosomes 1 and 12 respectively by the analysis of human-mouse hybrids].

The study of enolase in man-mouse somatic hybrids confirms synteny between ENO1 and the markers on human chromosome 1 (AK2, PGM1, Pep-C) and synteny between ENO2 and the markers on human chromosome 12 (LDHB, Pep-B). The study also shows that the different enolase bands observed in mouse cell strains (Cl1D, R4, A9, 3T3), in hamster cell strains (CH, V79/4, A3), and in 3 of the different bands observed in human fibroblasts have a dimeric structure. The formation of these enolase bands depends on genes at two different loci alpha and beta. The hamster cell line CH (HGPRT) showed a rare enolase phenotype with a two-banded pattern in the intermediate region, a triple-banded pattern in the slow region, and one single isozyme in the fast region. This hamster strain is heterozygous for the first locus and homozygous for the second one. The relationship between these different enolase bands is as follow: in the slow "a" zone, alpha1alpha1,alpha1 alpha2,alpha2alpha2; in the intermediate "i" zone, alpha1beta1, alpha2beta1; and, in the fast "b" zone, beta1beta1. It appears that the frequency of heterozygotes for the alpha or beta loci in man is very low. Of 32 unrelated fibroblast strains investigated, none was found to be heterozygous for the alpha or beta locus.

Animals↗
PubMed1975

A study of hexosaminadases in interspecific hybrids and in GM2 gangliosidosis with a discussion on their genetic control.

1. Hexosaminidases were studied by electrophoresis with different human fibroblast extracts. We found in the same conditions of detection and culture three bands from the cathode to the anode, namely Hex B, Hex A, Hex C for the normal fibroblast, Hex B for the two different Tay-Sachs and Hex C for the two unrelated Sandhoff patients. 2. The analysis of man-rodent hybrids (hamster and mouse with normal and Sandhoff human fibroblasts) indicates a probable synteny between MPI, Hex C, "Hex A fast", and "Hex A-like". "Hex A fast" is probably a man-hamster hybrid enzyme, "Hex A-like" a man-mouse enzyme. Our data agree with the model of Ropers and Schwantes (Hex C = (alphaalpha)n; Hex A = (alphabeta)n; Hex B = (betabeta)n). Probably Hex A-fast = (alphabeta')n with hamster Hex B' = (beta'beta')n; and Hex A-like = (alphabeta1)n with mouse Hex B1 = (beta1beta1)n; and probably n = 2 according to the tetrameric structure model of Tallman et al. (1974). 3. As an explanation of the results given by Poenaru et al. (anti Hex A reacts with Hex A and Hex B but not with Hex C) we propose the existence of a compound antigen (alphabeta) for Hex A. Anti Hex A specific = anti (alphabeta); anti Hex A non-specific = anti Hex B = anti B, anti alpha being absent or negligible. 4. In our opinion, the Tay-Sachs mutation opposes the alphaB association while the alphaalpha association is possible at a low rate or unstable; it is thus possible to observe Hex C in certain conditions, e.g. in foetal brain. 5. We present a discussion about the genetic control of hexosaminidases, GM2 gangliosidosis, and the possible localization of the different mutations in the variants.

Animals↗
PubMed1975

[Genetic study of GM2 gangliosidosis (Tay-Sachs and Sandhoff) by the study of the hexosaminidases of the Sandhoff-rodents hybrids (mouse and hamster)].

The electrophoretic pattern of human fibroblast extracts displays three bands (cathode to anode) of hexosaminidase: Hex B, Hex A, Hex C in normal strains, only one B band in Tay-Sachs strains, and only one C band in Sandhoff strains. The author's observations on rodent-Sandhoff cellular hybrids agree with the hypothesis made by others: Hex B = (beta beta)n; Hex A = (alpha beta)n; and Hex B = (alpha alpha) n. The mutation occurred in the alpha chain in Tay-Sachs disease and in the beta chain in Sandhoff disease. When mannose phosphate isomerase (MPI) is present, and therefore Hex C because of the well known MPI - Hex C synteny, a new hexosaminidase band called "Hex A fast" is seen in Sandhoff-hamster hybrids, while a "Hex A like" band is seen in Sandhoff-mouse hybrids. Both bands are absent from parental cells. It is suggested that "Hex A fast" and "Hex A like" are human-rodent hybrid hexosaminidases: "Hex A fast" = (alpha beta')n; "Hex A like" = (alpha beta's)n with the assumption that hamster HB' = (beta' beta')n and mouse Hex B'S = (beta's beta's)n. The specific anti Hex A = anti (alpha beta); the non-specific anti Hex A = anti Hex B = anti (beta); the anti (alpha) would be absent or weak. This explains the reactivity of the anti-Hex A against Hex A and Hex B, but not against Hex C.

Animals↗