PubMed Health⌕ Search

Biomedical subjects

B Fritsche

Publications and source records attributed to B Fritsche.

2 recordsLinked to original sources

Molecular analysis of a Phanerochaete chrysosporium lignin peroxidase gene.

The basidiomycete fungus Phanerochaete chrysosporium produces a number of extracellular peroxidases which appear to be important for lignin degradation. We present here the isolation and complete nucleotide (nt) sequence of a gene (lpo) coding for lignin peroxidase (LPO), the coding region of which is identical to a lpo cDNA sequence which had previously been described [M. Tien and C.-P.D. Tu, Nature 326 (1987) 520-523]. The deduced amino acid (aa) sequence corresponds to 372 aa residues and the coding region is interrupted by eight short introns that range in size from 50 to 62 nt. Southern blot experiments using the cloned lpo gene as hybridization probe revealed a complex restriction fragment pattern, indicating that there are a number of lpo-related nucleotide sequences present in P. chrysosporium DNA which cross-hybridize. We also present data on the in vivo expression of the lpo genes and show that they are regulated at the RNA level and that the structure of the transcripts as judged from S1 experiments is complex. These data are consistent with the idea that there are a number of related lpo genes in P. chrysosporium which constitute a gene family.

Base Sequence↗

Release from proactive interference by experimental amnesia: electroconvulsive shock improves radial-arm maze performance in rats.

Rats were trained in an eight-arm radial maze and tested using a proactive interference (PI) procedure. Each test trial consisted of forced choices of four randomly selected arms followed, after a 2-h delay, by free choices among all eight arms. Normally, rats chose correctly during the free choices by entering and retrieving food from the four arms not yet visited during the test trial. Occasionally, an interference trial preceded the test trial by 1.5 or 3 h; interference trials consisted of forced choices of another four arms and an immediate test. The presence of an interference trial lowered test-trial performance (PI). Electroconvulsive shock (ECS) administered immediately after the interference trial had no effect; i.e., PI was still observed. When ECS was administered at the midpoint of the 3-h intertrial interval, performance increased to control (no ECS, no PI) levels. Such release from PI, however, was not obtained, and test-trial performance remained inaccurate when ECS was delivered immediately after the forced choices of the test trial (either 1.5 or 3 h after the interference trial).

Amnesia↗