Molecular Biology

Enumerating Choices

Science  01 Jul 2005:
Vol. 309, Issue 5731, pp. 23
DOI: 10.1126/science.309.5731.23a

Alternative splicing increases the complexity of the proteome of multicellular organisms by allowing for the generation of a large number of mRNA and protein isoforms from a relatively small number of genes. To identify alternative splicing events in the fruit fly Drosophila melanogaster, Blanchette et al.developed a microarray assay in which they examined the target pre-mRNAs of four splicing regulators. The largest number (319) of splicing events was affected by the regulator dASF/SF2, whereas the smallest number (43) was affected by PSI, suggesting that the former is a general splicing factor and the latter a more specialized one. Intermediate numbers of splicing events were affected by B52/SRp55 (107 events) and by hrp48 (90 events), and this fits well with the estimated range of 10,000 to 40,000 alternative splice junctions and roughly 200 splicing factors in Drosophila. In addition, cooperation was observed such that hrp48 partnered with PSI in alternative splicing events, and antagonistic regulation was also present, albeit rarely, between SR proteins (such as dASF/SF2) on the one hand and hrp48 and PSI on the other. — BAP

Genes Dev. 19, 1306 (2005).

Navigate This Article