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Biomedical subjects

C R Merril

Publications and source records attributed to C R Merril.

At least 73 records · Page 4Linked to original sources

Complementary DNA sequencing: expressed sequence tags and human genome project.

Automated partial DNA sequencing was conducted on more than 600 randomly selected human brain complementary DNA (cDNA) clones to generate expressed sequence tags (ESTs). ESTs have applications in the discovery of new human genes, mapping of the human genome, and identification of coding regions in genomic sequences. Of the sequences generated, 337 represent new genes, including 48 with significant similarity to genes from other organisms, such as a yeast RNA polymerase II subunit; Drosophila kinesin, Notch, and Enhancer of split; and a murine tyrosine kinase receptor. Forty-six ESTs were mapped to chromosomes after amplification by the polymerase chain reaction. This fast approach to cDNA characterization will facilitate the tagging of most human genes in a few years at a fraction of the cost of complete genomic sequencing, provide new genetic markers, and serve as a resource in diverse biological research fields.

Amino Acid Sequence↗

Increased biosynthesis of Alzheimer amyloid precursor protein in the cerebral cortex of rats with lesions of the nucleus basalis of Meynert.

The nucleus basalis of Meynert was lesioned by infusion of N-methyl-D-aspartate (NMDA) unilaterally in adult rat brain. Seven days post lesion we observed that polysomes isolated from the cerebral cortex affected by the lesion synthesized 2.6-fold greater amounts of the Alzheimer amyloid precursor protein (AAPP) compared to the nonlesioned side of the same rat brain. This increase exhibited specificity to AAPP in that overall protein synthesis was not altered by the lesion. The increase of AAPP did not alter the ratio of AAPP isotypes in rat brain (in which AAPP 695, which is lacking the protease inhibitor insert remains the predominant form). The increased synthesis did not result in the apparent accumulation of mature AAPP. These results indicate that a cholinergic lesion which models many of the neurochemical changes observed in Alzheimer's disease induces the expression of AAPP in a major projection region, the cerebral cortex.

Acetylcholinesterase↗