A familial deletion 4q syndrome: An outcome of a paracentric inversion

Chromosome inversions are intra-chromosomal rearrangements formed when the chromosome breaks occur at two places, and in the process of repair the intervening segments are joined in an inverted or opposite manner. Inversions themselves do not appear to cause clinical anomalies, if balanced. Abnormal phenotypes can occur due to gene disruption at the point of breakage and reunion or due to duplication/deficiency recombinants formed during crossover at meiosis. We report a case with familial deletion 4q syndrome in a 1-year-old female child with dysmorphism and congenital abnormalities. The deletion was an outcome of a paracentric inversion 4q31.2q35.2. The deletion was confirmed by fluorescence in situ hybridization using telomeric DNA probes for chromosome No. 4. An attempt was made to correlate the genotype with the phenotype. The father had the same rearrangement with a milder phenotype. The recurrence risk in such cases is high.     

Detection of fos protein during osteogenesis by monoclonal antibodies.

We have generated monoclonal antibodies by using a synthetic peptide corresponding to amino acid positions 4 to 17 of the human fos protein. The antibodies detected both v- and c-fos proteins by immunoprecipitation, immunoblotting, and indirect immunofluorescence. The monoclonal antibodies not only identified the fos protein complex with the cellular 39-kilodalton protein, but also recognized the modified forms of the mouse, rat, and human fos proteins. In day-17 rat embryos, nuclear-staining fos protein could be identified in the cartilage by immunohistochemical staining.     

Molecular recognition of a branched peptide with HIV-1 Rev Response Element (RRE) RNA

Interaction of HIV-1 rev response element (RRE) RNA with its cognate protein, Rev, is critical for HIV-1 replication. Understanding the mode of interaction between RRE RNA and ligands at the binding site can facilitate RNA molecular recognition as well as provide a strategy for developing anti-HIV therapeutics. Our approach utilizes branched peptides as a scaffold for multivalent binding to RRE IIB (high affinity rev binding site) with incorporation of unnatural amino acids to increase affinity via non-canonical interactions with the RNA. Previous high throughput screening of a 46,656-member library revealed several hits that bound RRE IIB RNA in the sub-micromolar range. In particular, the lead compound, 4B3, displayed a K_d value of 410?nM and demonstrated selectivity towards RRE. A ribonuclease protection assay revealed that 4B3 binds to the stem-loop structure of RRE IIB RNA, which was confirmed by SHAPE analysis with 234 nt long NL4-3 RRE RNA. Our studies further indicated interaction of 4B3 with both primary and secondary Rev binding sites.     

Restriction endonuclease resistant chromatin in human chromosomes

Summary The recent addition of restriction endonucleases in obtaining selective bands in the human genome has added a new dimension to molecular genetics. However, a considerable discrepancy exists in banding patterns produced by AluI in chromosomes 19 and 20, by MboI in chromosomes 4, 5, 8, 21 and 22 and by RsaI in chromosomes 12, 21 and 22. The principal causes of these differences are highlighted.     

Retroviral vector targeting to human immunodeficiency virus type 1-infected cells by receptor pseudotyping

We report the generation of retroviral vectors based on Moloney murine leukemia virus that specifically transduce cells infected with T-cell-tropic human immunodeficiency virus type 1 (HIV-1). This vector was pseudotyped with T-cell-tropic HIV-1 receptors CD4 and CXCR4. We demonstrate that transduction is contingent upon HIV-1 gp120 and gp41 expression.     

Influence of carbohydrates on quantitative aspects of growth and embryo formation in wild carrot suspension cultures

The rate of kaurene biosynthesis from mevalonate in a cell-free enzyme preparation from the endosperm of immature seeds of Marah macrocarpus is regulated by adenylate energy charge. The response curve is typical of a biosynthetic energy-utilizing sequence in which the rate of biosynthesis increases sharply as the energy charge is increased above 0.80. ADP proved to be an effective inhibitor of this process. AMP gave no inhibition at concentrations up to 2 mm and orthophosphate gave no inhibition up to 15 mm. Measurement of the pool sizes of intermediates in the sequence showed that the presence of ADP caused an increase in the levels of 5-phosphomevalonate and 5-pyrophosphomevalonate and a decrease in the levels of isopentenyl pyrophosphate and kaurene. These results indicate that pyrophosphomevalonate decarboxylase is the enzyme most subject to regulation by adenylate energy charge. The rate of conversion of isopentenyl pyrophosphate to kaurene and the rate of utilization of mevalonate by mevalonate kinase were not influenced by variations in the adenylate energy charge.     

Development of intron targeted amplified polymorphic markers of metal homeostasis genes for monitoring their introgression from <Emphasis Type="Italic">Aegilops</Emphasis> species to wheat

The identification of transfers of useful alien genes for metal homeostasis from non-progenitor Aegilops species using the widely available anchored wheat SSR markers is difficult due to their lower polymorphism with the distant related wild species and the lack of locus specificity further restricts their application. The present study deals with the development of intron targeted amplified polymorphic (ITAP) markers for the metal homeostasis genes present on chromosomes of groups 2 and 7 of Triticeae. The mRNA sequences of 27 metal homeostasis genes were retrieved from different plant species using NCBI database and their BLASTn was performed against the wheat draft genome sequences in Ensemblplants to get exonic and intronic sequences of the corresponding metal homeostasis genes in wheat. The ITAP primers were developed in such a way that they would anneal to the conserved flanking exonic regions of the genes and amplify across highly variable introns within the PCR limits. The primers led to the amplification of variable intronic sequences of genes with polymorphism between non-progenitor Aegilops species and the recipient wheat cultivars. Further, the polymorphic ITAP markers were used to characterize the transfers of metal homeostasis genes from the non-progenitor Aegilops species to the BC₂F₅ wheat-Aegilops derivatives, developed through induced homoeologous pairing. The derivatives with significant percent increase in grain Fe and Zn content over the elite cultivar PBW343 LrP showed the introgression of some of the useful Aegilops alleles of the metal homeostasis genes. The use of different metal homeostasis genes using this approach is the first report of the direct contribution of the genes for increasing the grain micronutrient content for developing biofortified wheat lines with reduced linkage drag.     

Telomeric repeat [TTAGGG]n sequences of human chromosomes are conserved in chimpanzee (Pan troglodytes)

Summary Using a series of genetic parameters, attempts have been made for more than two decades to establish the close kinship of human (Homo sapiens) with chimpanzee (Pan troglodytes). Molecular and cytogenetic data presently suggest that the two species are closely related. The recent isolation of a human telomeric probe (P5097-B.5) has prompted us to cross hybridize it to chimpanzee chromosomes in order to explore convergence and/or divergence of the telomeric repeat sequences (TTAGGG)_n. On hybridization, the human probe bound to both ends (telomeres) of chimpanzee chromosomes, suggesting a concerted evolution of tandemly repeated short simple sequences (TTAGGG)_n. Even the terminal heterochromatin of chimpanzee chromosomes was found to be endowed with telomeric repeats, suggesting that evolution of heterochromatin and capping with tandemly repeated short sequences are highly complex phenomena.     

Phosphorylation of the pro-apoptotic protein BIK: mapping of phosphorylation sites and effect on apoptosis

BIK is a pro-apoptotic BCL-2 family member and is the founding member of a subfamily of pro-apoptotic proteins known as "BH3-alone" proteins. Ectopic expression of BIK induces apoptosis in variety of mammalian cells. BIK complexes with various anti-apoptotic BCL-2 family proteins such as adenovirus E1B-19K and BCL-2 via the BH3 domain. However, the heterodimerization activity of BIK alone is insufficient for its apoptotic activity. Previous studies have shown that phosphorylation regulates the functional activity of both anti-apoptotic and pro-apoptotic members of the BCL-2 family. Here, we have examined phosphorylation of BIK and its effect on the apoptotic activity of BIK. We show that BIK exists as a phosphoprotein and is phosphorylated at residues 33 (threonine) and 35 (serine). Mutation of the phosphorylation sites, in which the Thr and Ser residues were changed to alanine residues, reduced the apoptotic activity of BIK without significantly affecting its ability to heterodimerize with BCL-2. Our results suggest that phosphorylation of BIK is required for eliciting efficient apoptotic activity. Partial purification of the protein kinase from HeLa cell cytoplasmic extracts suggest that BIK may be phosphorylated by a casein kinase II-related enzyme.     

Post-translational processing of 7S and 11S components of soybean storage proteins

The synthesis and processing of the major storage proteins in soybean cotyledons was studied both in vivo and in vitro. The and subunits of 7S as well as the 11S proteins are synthesized as higher molecular weight-precursors on membrane-bound polysomes. The initial translation products of the 7S are proteolytically cleaved during translation suggesting the removal of a signal peptide as evidenced by the presence of 2 and 2 peptides immunoreactive with 7S antibody in the in vitro chain completion products of the membrane-bound polysomes. This is followed or accompanied by cotranslational glycosylation, which increases their size equivalent to that of initially-synthesized precursors. In vivo pulse-labelled 7S and products are of slightly higher molecular weights than the immunoprecipitable chain-completion products, indicating further post-translational modifications. A slow post-translational processing during a period of 1.5 to 16 h yields the final 7S and glycoproteins.Acidic and basic subunits of the 11S protein appear to be synthesized from common large molecular weight (60K-59K) precursors. Antibodies to the 11S acidic component recognize both acidic and basic domains in the precursor while those raised against basic subunits appear to be specific for that region only. The processing of the 11S precursor is also very slow and occurs post-translationally. This slow rate of processing, coupled with a temporal difference in the synthesis of 7S and 11S components, suggests a highly coordinated mechanism for synthesis and packaging of these proteins into protein bodies during seed development.