Biomaterial Database

Bloodstream and metacyclic variant surface glycoprotein gene expression sites of Trypanosoma brucei gambiense. 1990

D A Barnes, and J C Mottram, and N Agabian

Intercampus Program in Molecular Parasitology, School of Pharmacy, University of California, San Francisco 94143-1204.

Trypanosoma brucei gambiense is the causative agent of chronic human sleeping sickness. Previous studies have indicated that T. b. gambiense isolates expressed the antigens U1 or L2 in both the metacyclic and early bloodstream form of the parasite life cycle. These studies suggested that L2 and U1 were likely to be metacyclic variant surface glycoproteins (mVSG). The basic copies of the genes encoding the VSGs L2 and U1 are present in single copy in non-expressing isolates of T. b. gambiense. Furthermore, they have been found to be maintained stably in a large number of stocks isolated from a wide geographic area over a 30-year period. The genomic DNA comprising the upstream 5' flanking regions of the U1 and L2 putative mVSG gene expression sites have been cloned from bloodstream forms of T. b. gambiense. The L2 expression site clone, containing 12.5 kb of sequences 5' to the VSG gene, was found to lack the 72/76-bp repeat unit generally found in the 'barren' region upstream of bloodstream form expression sites. The U1 expression site clone, containing 13.5 kb of the 5' flanking region, appeared to have the repeats, which were localized to 2 kb of DNA immediately 5' to the U1 mVSG gene. Neither the U1 nor the L2 clone was found to have ESAG2 or ESAG3 gene sequences, but both were found to have ESAG1 genes. The ESAG1 genes from the putative metacyclic expression sites and from the U1 and L2 bloodstream form expression sites (in the form of cDNA clones) were sequenced and compared to all other published ESAG1 sequences.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D003850	Deoxyribonuclease I	An enzyme capable of hydrolyzing highly polymerized DNA by splitting phosphodiester linkages, preferentially adjacent to a pyrimidine nucleotide. This catalyzes endonucleolytic cleavage of DNA yielding 5'-phosphodi- and oligonucleotide end-products. The enzyme has a preference for double-stranded DNA.	DNase I,Streptodornase,DNA Endonuclease,DNA Nicking Enzyme,DNAase I,Dornavac,Endonuclease I,Nickase,Pancreatic DNase,T4-Endonuclease II,T7-Endonuclease I,Thymonuclease,DNase, Pancreatic,Endonuclease, DNA,T4 Endonuclease II,T7 Endonuclease I
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D005796	Genes	A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.	Cistron,Gene,Genetic Materials,Cistrons,Genetic Material,Material, Genetic,Materials, Genetic
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012689	Sequence Homology, Nucleic Acid	The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.	Base Sequence Homology,Homologous Sequences, Nucleic Acid,Homologs, Nucleic Acid Sequence,Homology, Base Sequence,Homology, Nucleic Acid Sequence,Nucleic Acid Sequence Homologs,Nucleic Acid Sequence Homology,Sequence Homology, Base,Base Sequence Homologies,Homologies, Base Sequence,Sequence Homologies, Base
D014347	Trypanosoma brucei gambiense	A hemoflagellate subspecies of parasitic protozoa that causes Gambian or West African sleeping sickness in humans. The vector host is usually the tsetse fly (Glossina).	Trypanosoma gambiense,Trypanosoma brucei gambienses,Trypanosoma gambienses,brucei gambiense, Trypanosoma,brucei gambienses, Trypanosoma,gambiense, Trypanosoma brucei,gambienses, Trypanosoma