Adam Friedmann

The UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase gene is mutated in recessive hereditary inclusion body myopathy

Hereditary inclusion body myopathy (HIBM; OMIM 600737) is a unique group of neuromuscular disorders characterized by adult onset, slowly progressive distal and proximal weakness and a typical muscle pathology including rimmed vacuoles and filamentous inclusions. The autosomal recessive form described in Jews of Persian descent is the HIBM prototype. This myopathy affects mainly leg muscles, but with an unusual distribution that spares the quadriceps. This particular pattern of weakness distribution, termed quadriceps-sparing myopathy (QSM), was later found in Jews originating from other Middle Eastern countries as well as in non-Jews. We previously localized the gene causing HIBM in Middle Eastern Jews on chromosome 9p12–13 (ref. 5) within a genomic interval of about 700 kb (ref. 6). Haplotype analysis around the HIBM gene region of 104 affected people from 47 Middle Eastern families indicates one unique ancestral founder chromosome in this community. By contrast, single non-Jewish families from India, Georgia (USA) and the Bahamas, with QSM and linkage to the same 9p12–13 region, show three distinct haplotypes. After excluding other potential candidate genes, we eventually identified mutations in the UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase (GNE) gene in the HIBM families: all patients from Middle Eastern descent shared a single homozygous missense mutation, whereas distinct compound heterozygotes were identified in affected individuals of families of other ethnic origins. Our findings indicate that GNE is the gene responsible for recessive HIBM.

Molecular analysis of HLA class II genes in primary sjögren's syndrome. A study of Israeli Jewish and Greek Non-Jewish patients

In an attempt to define the role of HLA class II genes in predisposition to primary Sjögrens syndrome, patients of two different ethnic groups (Israeli Jews and Greeks of non-Jewish origin) suffering from this disorder were studied. Oligonucleotide genotyping revealed the majority in both groups to carry either DRB1*1101 or DRB1*1104, alleles that are in linkage disequilibrium with DQB1*0301 and DQA1*0501. The high frequency of the two alleles in these SS patients is in contrast with the accepted association of primary SS with HLA-DR3 in Italian and American individuals. Molecular analysis of DQB1 and DQA1 alleles found in American Caucasian and American black SS (or SLE) patients demonstrated high frequencies of DQB1*0201 and DQA1*0501. The fact that the majority of SS patients, across racial and ethnic boundaries, carry a common allele, DQA1*0501, implies its involvement in the predisposition to primary SS. Based on sequence analysis and the computer imaging of the HLA class II molecule structure, a hypothetical model for the role of the DQ molecule in promoting primary SS is proposed.

Extraction of cell-associated varicella-zoster virus DNA with Triton X-100-NaCl

Varicella-zoster virus (VZV) DNA was extracted from infected cells with 0.25% Triton X-100-0.2 M NaCl and purified by isopycnic centrifugation in CsCl. In each of eight experiments, 1.8-9.8 micrograms VZV DNA was obtained from 107 infected cells. The VZV DNA obtained by this procedure had a molecular weight of 88-100 x 106 as determined by sucrose gradient sedimentation and electron microscopy, and cleavage patterns after digestion with four restriction enzymes that corresponded to patterns previously described with six strains of VZV; the pattern of BamHI-cleaved Triton-NaCl-extracted VZV DNA was identical to the pattern seen after DNA extraction from virions. These studies expand the usefulness of Triton X-100-NaCl for extraction of large molecular weight viral DNA from a system where considerable cell-free virus is produced (Pignatti et al., 1979, Virology 93, 260) to a system known for its marked cell association.

Narcolepsy-cataplexy in Israeli Jews is associated exclusively with the HLA DR2 haplotype A study at the serological and genomic level

Narcolepsy is a very rare disease among Israeli Jews with a frequency of 7/3 X 10(6). An investigation of the association of narcolepsy with the human leukocyte antigen system was conducted in Israeli Jews at the serologic and genomic levels. The human leukocyte antigen class I and class II antigen typing of 7 clinically diagnosed narcoleptics, 3 individuals suffering from sleep disorders other than narcolepsy, and 11 healthy matched controls revealed that all narcoleptic patients (100%) investigated in the present study carried the HLA-DR2 haplotype, whereas patients with other sleep disorders did not. The HLA-B7 and DR2 occurred jointly in 57% (4/7) of the narcoleptic patients, as compared to 2% in randomly selected Israeli healthy controls. Restriction fragment length polymorphism analysis was performed with several restriction enzymes and three cDNA probes for DQ alpha, DQ beta, and DR beta genes on genomic DNAs obtained from narcoleptics and patients with other sleep disorders, matched controls, and 3 homozygous typing cells representing the DR2 subtypes Dw2, Dw12, and DwAZH. The restriction fragment length polymorphism analysis showed that all narcoleptics (7 of 7) shared virtually identical restriction fragment length polymorphisms with one of the homozygous typing cells (GSO), which defines DR2,Dw2. The frequency of the DR2,Dw2 haplotype in the healthy Israeli population is 3.2%. Other non-narcoleptic patients did not share these restriction fragment length polymorphisms. These findings indicate that narcolepsy is associated worldwide with the HLA-DR2,Dw2 haplotype.

Do specific pockets of HLA-C molecules predispose Jewish patients to psoriasis vulgaris?

BACKGROUND Psoriasis vulgaris was reported to be associated with a specific alanine residue at position 73 of HLA-C alleles in Japanese patients. OBJECTIVE Our purpose was to determine the role of HLA genes in susceptibility to psoriasis vulgaris in the Israeli Jewish population. METHODS Twenty-eight Israeli patients were analyzed for their HLA class I and II specificities by means of serologic and molecular methods. RESULTS All patients possessed in their HLA-C antigens an alanine residue at position 73 (p < 0.002). A significantly increased frequency of HLA-Cw6 and of Cw7 was also observed among the patients (p < 0.02). CONCLUSION Our study clearly shows that alanine in position 73 is significantly associated with psoriasis vulgaris in Jewish patients. Cw6 and Cw7 have a unique antigen-binding pocket containing both alanine at position 73 and a negatively charged aspartic acid at position 9. These residues are most probably important in determining the conformation of the C pocket and in turn the nature of the peptide bound to it. We suggest that this combination confers the highest risk of the development of psoriasis vulgaris.

Electron microscopy of herpes simplex virus DNA molecules isolated from infected cells by centrifugation in CsCl density gradients.

Herpes simplex virus (HSV) DNA molecules were isolated from infected BSC 1 cells and centrifuged in CsCl-ethidium bromide density gradients. Both newly labelled and mature virus DNA molecules were found to have a linear conformation. The morphology of virus DNA molecules at different stages of the virus growth cycle in BSC 1 cells, was studied by electron microscopy after separation of virus DNA from cellular DNA by centrifugation in CsCl gradients. In each sample, about 200 virus DNA molecules were photographed and the different morphological forms were studied. Four classes of virus DNA molecules were observed: (a) mature linear DNA molecules, 52-4 +/- 3-3 micronm in length, (b) DNA intermediates, (c) virus DNA molecules having one or more single-stranded filaments attached to them and (d) molecules with collapsed regions or with branches. A few circular molecules as well as linear DNA molecules longer than unit length were also observed. The virus DNA molecules resembling replicative intermediates gradually increased in number and reached a maximal amount of about 5% of the virus DNA population at 12 h after infection. The other forms of virus DNA were found to persist after the number of replicating DNA molecules decreased.

Replicative intermediates of herpes simplex virus DNA

Abstract The DNA synthesized in herpes simplex virus (HSV)-infected nuclei in vivo was analyzed by chromatography on benzoylated naphthoylated DEAE-cellulose columns. Viral-DNA molecules that elute with caffeine contain single-stranded DNA sequences sensitive to a micrococcal endonuclease that cleaves single-stranded DNA only. These viral-DNA molecules behave kinetically as precursors to mature virion DNA, and their transition to the mature double-stranded form occurs within a period of 10 to 20 min. Electron microscopy revealed viral-DNA molecules at different stages of replication. The mechanism of HSV-DNA replication is discussed.

The change in genetic diversity down the core-edge gradient in the eastern spadefoot toad (Pelobates syriacus)

Several hypotheses are available to predict change in genetic diversity when approaching peripheral populations. We used the eastern spadefoot toad in Israel as a model system to examine these hypotheses using population genetics analyses and network theory. Our results contradicted most of the predictions from the ‘abundant centre’ model, that edge populations should have lower density and lower genetic diversity than core populations. Furthermore, dispersal rate between core and peripheral populations is expected to be asymmetric, mostly directed outwards from the core population, but we did not detect such a trend. Our data did not support the hypothesis of no change or a non‐linear change in genetic diversity towards the range edge. However, our results did fit the Fisher (The Genetical Theory of Natural Selection, Clarendon Press, Oxford, 1930) hypothesis, which predicts increase in genetic variability from core to edge of distribution. We attributed this finding to the much harsher climatic and abiotic conditions at the edge, which must be tolerated over generations by both tadpoles and post‐metamorphic individuals in this region. Finally, our results have significant conservation implications for the survival of this species in Israel, where it is critically endangered. We identified two distinct communities, which are genetically linked through two specific rain pools in the Upper Galilee. Details on the spatial subdivision of this species are cardinal for future management and restoration of temporary wetlands in Israel.

(TG)n uncovers a sex-specific hybridization pattern in cattle.

Screening of a bovine genomic library with the human minisatellite 33.6 probe uncovered a family of clones that, when used to probe Southern blots of bovine genomic DNA digested with the restriction enzyme HaeIII or MboI, revealed sexually dimorphic, but otherwise virtually monomorphic, patterns among the larger DNA fragments to which they hybridized. Characterization of one of these clones revealed that it contains different minisatellite sequences. The sexual dimorphism hybridization pattern observed with this clone was found to be due to multiple copies of two tandemly interspersed repeats: the simple sequence (TG)n and a previously undescribed 29-bp sequence. Both repeats appear to share many genomic loci including autosomal loci. In contrast, Southern analysis of AluI- or HinfI-digested bovine DNA with the (TG)n repeat used as a probe yielded substantial polymorphism. These results show that (i) different minisatellites can be found in a cluster, (ii) both simple and more complex repeated sequences other than the simple quaternary (GATA)n repeat can be sexually dimorphic, and (iii) simple repeats can reveal substantial polymorphism.

Replication of Theiler's murine encephalomyelitis viruses in BHK21 cells: An electron microscopic study

Abstract The replication of two different Theilers murine encephalomyelitis viruses (GDVII and DA) in BHK21 cells was studied by electron microscopy. During the early stages of infection, the changes observed in infected cells were identical for both viruses, and typical of those described in the literature for other picornaviruses. However, fundamental differences in the intracellular development of GDVII and DA viruses were observed late in the infection. Well-developed crystalline arrays of virions were observed in the cytoplasm of GDVII virus-infected cells, and virus was readily released upon cell lysis. In contrast, DA virus did not form similar crystals. Instead, in DA virus-infected cells unique membranous structures consisting of two membrane units enclosing a layer of virions one particle deep were regularly observed in the cytoplasm at late times in the infection. In addition, DA virus did not appear to be freely released upon cell lysis. Single cell growth kinetics of GDVII and DA viruses in BHK21 cells showed a close correlation with the electron microscopic observations. While GDVII virus was released from cells DA virus remained cell associated. The proliferation of similar membranous structures in parallel with maturation of virus particles has not been described previously in electron microscopic studies of other picornaviruses.