ABSTRACT
Biological systems by default involve complex components with complex relationships. To decipher how biological systems work, we assume that one needs to integrate information over multiple levels of complexity. The songbird vocal communication system is ideal for such integration due to many years of ethological investigation and a discreet dedicated brain network. Here we announce the beginnings of a songbird brain integrative project that involves high-throughput, molecular, anatomical, electrophysiological and behavioral levels of analysis. We first formed a rationale for inclusion of specific biological levels of analysis, then developed high-throughput molecular technologies on songbird brains, developed technologies for combined analysis of electrophysiological activity and gene regulation in awake behaving animals, and developed bioinformatic tools that predict causal interactions within and between biological levels of organization. This integrative brain project is fitting for the interdisciplinary approaches taken in the current songbird issue of the Journal of Comparative Physiology A and is expected to be conducive to deciphering how brains generate and perceive complex behaviors.
Subject(s)
Brain/physiology , Songbirds/physiology , Animals , Auditory Pathways , Bayes Theorem , Brain/anatomy & histology , Brain Mapping , Computational Biology , Computer Simulation , DNA-Binding Proteins/metabolism , Electrophysiology , Gene Expression Profiling , Gene Expression Regulation, Developmental , Gene Library , Learning , Models, Neurological , Motor Activity/physiology , Nerve Net , Neural Networks, Computer , Transcription Factors/metabolism , Vocalization, Animal/physiologyABSTRACT
It is hypothesized that psoriasis may be caused by aberrant gene expression. In an effort to identify and clone psoriasis-specific genes, we compared gene expression in normal, tape-stripped (wounded), and psoriatic skin using the cDNA differential display technique. Four genes not previously described in psoriasis--connexin 26, a gap junction protein; squamous cell carcinoma antigen-1 (SCCA1), a serine protease inhibitor; and mitochondrial NAD subunits 5 and 6--were identified as having very high expression levels in psoriatic skin. In situ hybridizations showed that connexin 26 mRNA was expressed 10-fold higher in psoriatic and 4-fold higher in tape-stripped epidermis than in controls. SCCA1 showed a 40-fold increase in mRNA expression, whereas mitochondrial NAD5 and NAD6 expression was increased 10- and 20-fold, respectively, in psoriatic skin. Northern blots confirmed the increased expression of connexin 26, SCCA1, and NAD6 genes in psoriatic skin. Immunohistochemistry showed that connexin 26 protein was strongly expressed in spinous keratinocytes from psoriatic skin and chronic wounds, but was absent in normal epidermis. These studies demonstrate the usefulness of this approach for identifying genes that are conditionally expressed in growth-activated human skin.
Subject(s)
Antigens, Neoplasm/genetics , Connexins/genetics , DNA, Complementary/isolation & purification , Psoriasis/genetics , Serpins , Skin/chemistry , Connexin 26 , Gene Expression Regulation , Humans , In Situ Hybridization , Mitochondria/enzymology , NAD , Sequence Analysis , Wounds and Injuries/geneticsABSTRACT
The nucleotide (nt) sequences of the Bacillus pumilus trpE, trpD and 5' portions of trpC genes have been determined. Genetic analysis suggested the presence of an internal promoter upstream from the trpC gene, yet no typical consensus sequences were found. The nt and amino acid sequence homologies between the B. pumilus, Bacillus subtilis and Escherichia coli trp genes are presented.
