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Biomedical subjects

A Reynaerts

Publications and source records attributed to A Reynaerts.

5 recordsLinked to original sources

cry IA(b) transcript formation in tobacco is inefficient.

Chimaeric PCaMV35Scry genes direct in tobacco mesophyll protoplasts mRNA levels of less than one transcript per cell. We provide evidence that this low cytoplasmic cry IA(b) mRNA level is not due to a rapid turnover but rather results from a marginal import flow of cry messenger into the cytoplasm. Run-on assays indicate that the frequency of transcription initiation is not limiting. However, the cry precursor mRNA carries at least three regions that are recognized as introns. The absence of high cytoplasmic levels of spliced cry mRNAs suggests that these mRNAs are unstable and/or not efficiently made. Point mutations in the 5' splice site of the most distal intron allows high accumulation levels of the full-length mRNA. This implies that the inefficient formation of full-size mRNA is a major cause of the low expression level of chimaeric cry IA(b) genes in tobacco.

Bacillus thuringiensis Toxins↗

Computer-assisted karyotyping with human interaction.

A system for machine assisted karyotyping and chromosome analysis has been developed. The system uses a drum- or TV-scanner as input device, runs provisionally in 32 K memory, and also allows human interaction on several stages. The accuracy with which banded chromosomes are karyotyped depends strongly on the type of classifier and varies from 40 up to 80%. The accuracy of the human assisted classifier (98%) comes close to that of a skilled technician (99.5%) using manual chromosomal analysis. Due to technical and memory limitations, the time necessary for the karyotyping of one cell is too long and depends on the interaction time; however karyotyping within 5 min, including human interaction, will be possible in the near future.

Chromosomes↗