Biomedical subjects

M Boyce-Jacino

Publications and source records attributed to M Boyce-Jacino.

3 recordsLinked to original sources

PubMed1999

Mining SNPs from EST databases.

There is considerable interest in the discovery and characterization of single nucleotide polymorphisms (SNPs) to enable the analysis of the potential relationships between human genotype and phenotype. Here we present a strategy that permits the rapid discovery of SNPs from publicly available expressed sequence tag (EST) databases. From a set of ESTs derived from 19 different cDNA libraries, we assembled 300,000 distinct sequences and identified 850 mismatches from contiguous EST data sets (candidate SNP sites), without de novo sequencing. Through a polymerase-mediated, single-base, primer extension technique, Genetic Bit Analysis (GBA), we confirmed the presence of a subset of these candidate SNP sites and have estimated the allele frequencies in three human populations with different ethnic origins. Altogether, our approach provides a basis for rapid and efficient regional and genome-wide SNP discovery using data assembled from sequences from different libraries of cDNAs.

DNA, Complementary↗

PubMed1990

Multiple, spatially distinct T cell epitopes within a pathogenic 123 residue cyanogen bromide peptide of bovine retinal s-antigen.

We have examined the T cell specificity of a Lewis rat T cell line (R208) specific for a pathogenic, 123 residue cyanogen bromide produced peptide of bovine S-antigen by using two independent sets of overlapping synthetic peptides representing the entire length of the 123 residue fragment. S-antigen, a 48 kDa immunopathogenic photoreceptor cell autoantigen induces T cell mediated experimental autoimmune uveoretinitis (EAU) in experimental animals. Extensive analyses revealed a heterogenous response by the R208 line to the panel of synthetic peptides, proliferating weakly to 4 distinct sites. Unexpectedly, peptides representing sequences (residues 286-297 and 303-320 of bovine S-antigen) known to actively induce the autoimmune pathology were unable to significantly stimulate the R208 line as assessed by proliferation assays. Similarly, attempts to isolate T cells specific for these sequences from the R208 line have proven unsuccessful. However, two sequences, residues 253-269 and 273-289, sufficiently stimulated R208 cells to allow isolation of sub-lines, R208:26 and R208:28, respectively. Neither of these peptides actively induce an autoimmune response. R208:26 does not transfer EAU and R208:28 transfers moderate EAU. As a control, we are able to isolate a pathogenic T cell line (R502) specific for the actively pathogenic sequence, residues 303-320, when this peptide is used as the immunogen. However, the R502 line proliferates to peptides (e.g. 305-322) which do not contain residues 303 and 304 which are critical for the active induction of disease. These results show a multiplicity of distinct T cell epitopes within a relatively small region of S-antigen.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1986

Molecular cloning and characterization of gag-, pol-, and env-related gene sequences in the ev- chicken.

Using less stringent hybridization conditions and cloned viral DNA probes representing the avian sarcoma virus gag, pol, env, and long terminal repeat (LTR) gene sequences, we detected related sequences in two avian species purportedly lacking all endogenous avian leukosis viruses, the ev- chicken and the Japanese quail. The blot hybridization patterns obtained with the various probes suggest the presence of between 40 and 100 copies of retrovirus-related sequences in the genomes of these two species. An ev- chicken genomic DNA library was prepared and screened with gag-specific and pol-specific DNA probes. Several different clones were obtained from this library and characterized. Analysis of these clones revealed that the retrovirus-related gene sequences are linked in the order LTR-gag-pol-env-LTR, a structure indicative of a complete provirus. These data indicate the presence of previously unidentified endogenous retrovirus species in avian cells, suggesting that under the appropriate conditions of hybridization additional, more distantly evolved families of endogenous retrovirus genes may be identified in vertebrate species.

Animals↗