Figure 1.

Protein and RNA analyses of 35S:atRSZ33 transgenic Arabidopsis plants. (A) Western blot analysis of total protein extracts from control and T3 homozygous 35S:atRSZ33 lines (lanes 1–8) and SR proteins preparation from wild-type plants (lane 9). Lanes 1 and 2, wild-type plants and plants containing pBI121, respectively; 35S: catRSZ33 lines, lanes 3–5; one weaker 35S:gatRSZ33 line, lane 6; and two 35S:gatRSZ33 lines with stronger phenotype, lanes 7 and 8. Asterisks indicate unspecific bands. Arrow indicates position of atRSZ33 protein. (B) RT-PCR analysis of atRSZ33 transcripts in T0 generation. Lane 1, control plants containing pBI121; plants transformed with cDNA (lanes 2 and 3) and with genomic construct (lanes 4 and 5). (C) RT-PCR analysis of atRSZ33 transcripts in T3 generation (top). Lanes 1–8, same plants as indicated in A. Asterisk indicates unspecific band. Schematic representation of atRSZ33 gene structure, its mRNA isoforms detected in transgenic 35S:gatRSZ33 plants, and deduced proteins (bottom). Exons are shown as black boxes, 5′ and 3′-UTRs are gray boxes. 3′alt ss-3′ alternative splice site in the second intron. Bold lines represent included sequences of the second and third introns. Stars indicate premature stop codons. Deduced protein structures are shown as black, RRM; gray, RS-rich region; white, two zinc knuckles; light gray, SP region; and striped boxes, sequences included due to alternative splicing. Positions of primers used for RT-PCR analyses are shown as arrows. Schematic drawings are not to scale.