Lines Of Biological Evidence Research Articles

A network of synaptic genes associated with schizophrenia and bipolar disorder

Identification of novel candidate genes for schizophrenia (SZ) and bipolar disorder (BP), two psychiatric disorders with large epidemiological impacts, is a key research area in neurosciences and psychiatric genetics. Previous evidence from genome-wide studies suggests an important role for genes involved in synaptic plasticity in the risk for SZ and BP. We used a convergent genomics approach, combining different lines of biological evidence, to identify genes involved in the cAMP/PKA/CREB functional pathway that could be novel candidates for BP and SZ: CREB1, CREM, GRIN2C, NPY2R, NF1, PPP3CB and PRKAR1A. These 7 genes were analyzed in a HapMap based association study comprising 48 common SNPs in 486 SZ, 351 BP patients and 514 control individuals recruited from an isolated population in Northern Sweden. Genetic analysis showed significant allelic associations of SNPs in PRKAR1A with SZ and of PPP3CB and PRKAR1A with BP. Our results highlight the feasibility and the importance of convergent genomic data analysis for the identification of candidate genes and our data provide support for the role of common inherited variants in synaptic genes and their involvement in the etiology of BP and SZ.

The Influence of Female Hormones on Malignant Melanoma

Several lines of biological evidence have suggested a relationship between the behaviour of melanocytes and cutaneous malignant melanoma (CMM) and the action of female hormones. The present overview, however, indicates that the effect of reproductive, menstrual and hormonal factors, including oral contraceptives, on onset and outcome of CMM must be very weak, if any. The only consistent findings which may suggest a role of female hormones on CMM seem to be: 1) a different distribution by anatomic site in men and women, and 2) a more favorable outcome of CMM in women as compared to men. Neither of them, however, necessarily implies a direct effect of female hormones on CMM.

Atypical Transfer RNA's And Their Origin In Neoplastic Cells

Publisher Summary This chapter focuses on the structure and synthesis of transfer RNA (tRNA) and discusses the biochemistry of tRNA methylases. Translation is the most complex molecular mechanism known in the living cell. It requires messenger RNA, which is the simplest of the structures involved, even though it is laden with information. The ribosomes are complex structures composed of RNA and at least a score of different proteins. Transfer RNA is the most complex biomacromolecule known. In addition to these major components, there are ancillary ones— enzymes that transfer amino acids to the transfer RNA. Moreover, there are at least 8 soluble protein factors needed for the completion of the synthesis of a protein. Any or all of these numerous components could be a regulatory factor in protein synthesis. There are three different lines of biological evidence that point to transfer RNA as a regulatory factor. Transfer RNA is a pivotal molecule in protein synthesis. It is the link between the amino acids and the message-bearing nucleic acids. The tRNA methylases are a complex family of enzymes that modify the structure of preformed tRNA by the insertion of methyl groups into specific positions in the four main bases of tRNA. The enzymes are species-specific, organ-specific, base-specific, and even site-specific for particular bases.

The General Nature of the Gene Concept

THE conception of the gene has resulted from two lines of biological evidence: (1) The amazing stability of the germ plasm, as expressed in the facts of heredity; (2) its occasional instability, as shown by the occurrence of mutations. That external forces, such as X-rays, impinging upon the germinal material should produce changes, is not surprising but inevitable. That the resulting effects are inherited, however, shows that the organism is incapable of regulating against changes in this particular part of its cell structure.