Databases containing information about NUCLEIC ACIDS such as BASE SEQUENCE; SNPS; NUCLEIC ACID CONFORMATION; and other properties. Information about the DNA fragments kept in a GENE LIBRARY or GENOMIC LIBRARY is often maintained in DNA databases.
Adaptive antiviral defense mechanisms, in archaea and bacteria, based on DNA repeat arrays called CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR elements) that function in conjunction with CRISPR-ASSOCIATED PROTEINS (Cas proteins). Several types have been distinguished, including Type I, Type II, and Type III, based on signature motifs of CRISPR-ASSOCIATED PROTEINS.
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.
Family of RNA viruses that infects birds and mammals and encodes the enzyme reverse transcriptase. The family contains seven genera: DELTARETROVIRUS; LENTIVIRUS; RETROVIRUSES TYPE B, MAMMALIAN; ALPHARETROVIRUS; GAMMARETROVIRUS; RETROVIRUSES TYPE D; and SPUMAVIRUS. A key feature of retrovirus biology is the synthesis of a DNA copy of the genome which is integrated into cellular DNA. After integration it is sometimes not expressed but maintained in a latent state (PROVIRUSES).
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (From DeVita Jr et al., Cancer: Principles & Practice of Oncology, 3d ed, p1471)
Examination of any part of the body for diagnostic purposes by means of X-RAYS or GAMMA RAYS, recording the image on a sensitized surface (such as photographic film).
A nondirective psychotherapy approach originated by Carl Rogers. The goals of therapy are to promote the client's congruence, self awareness, and self acceptance. This approach views the client as naturally directed toward self actualization, and only needing facilitative conditions in order to promote this tendency.
The subdivisions used under Catholic Church may also be used under Catholic Church--Ambrosian rite; Catholic Church--Byzantine rite, etc. --subdivision Catholic Church under subjects, e.g. Asceticism--Catholic Church
A historical and cultural entity dispersed across a wide geographical area under the political domination and influence of ancient Rome, bringing to the conquered people the Roman civilization and culture from 753 B.C. to the beginning of the imperial rule under Augustus in 27 B.C. The early city built on seven hills grew to conquer Sicily, Sardinia, Carthage, Gaul, Spain, Britain, Greece, Asia Minor, etc., and extended ultimately from Mesopotamia to the Atlantic. Roman medicine was almost entirely in Greek hands, but Rome, with its superior water system, remains a model of sanitation and hygiene. (From A. Castiglioni, A History of Medicine, 2d ed pp196-99; from F. H. Garrison, An Introduction to the History of Medicine, 4th ed, pp107-120)
