We have collected over half a million splice sites from five species-Homo sapiens, Mus musculus, Drosophila melanogaster, Caenorhabditis elegans and Arabidopsis thaliana-and classified them into four subtypes: U2-type GT-AG and GC-AG and U12-type GT-AG and AT-AC. We have also found new examples of rare splice-site categories, such as U12-type introns without canonical borders, and U2-dependent ...

Simian virus 40 (SV40) early pre-mRNA is spliced using either of two alternative 5' splice sites and a common 3' splice site to produce two mRNAs that encode the T and t antigens. We have studied alternative splicing of SV40 early pre-mRNA in vitro using a HeLa cell nuclear extract. Synthetic SV40 early transcripts are processed to T and t antigen mRNAs in vitro. As in SV40-infected cells in vi...

Many disease-causing mutations affecting donor splice site recognition are reported in the literature. One of the more frequently observed nucleotide changes causing aberrant splicing are due to mutations in the donor splice site which lower the strength of base pairing with U1 snRNA (small nuclear RNA). However, recent data have highlighted the possibility of a recognition mechanism for weak d...

A system for utilizing an artificial neural network to predict splice sites in genes has been studied. The neural network uses a sliding window of nucleotides over a gene and predicts possible splice sites. Based on the neural network output, the exact location of the splice site is found using a curve fitting of a parabolic function. The splice site location is predicted without prior knowledg...

Intergenic regions of polycistronic pre-mRNAs of trypanosomatid protozoans are the sites of two processing reactions: polyadenylation of the upstream gene and trans-splicing of the capped miniexon to the downstream gene. Their close proximity and the lack of consensus motifs at poly(A) sites led us to test whether poly(A) site selection is governed by the location of the downstream splice accep...

Spliceosomes are assembled in stages. The first stage forms complex E, which is characterized by the presence of U1 snRNPs base-paired to the 5' splice site, components recognizing the 3' splice site and proteins thought to connect them. The splice sites are held in close proximity and the pre-mRNA is committed to splicing. Despite this, the sites for splicing appear not to be fixed until the n...

Individual olfactory receptor neurons (ORNs) selectively express one or a small number of odor receptors from among a large receptor repertoire. The expression of an odor receptor dictates the odor response spectrum of the ORN. The process of receptor gene choice relies in part on a combinatorial code of transcription factors. In Drosophila, the POU domain transcription factor Acj6 is one eleme...

This paper describes a technique to superconductively splice multifilament wires. To date the technique has achieved joints capable of carrying a superconducting current of 200 A at 10 K in self field. Joints details, as well as testing methods and results are presented here.