Article Figures & Data
Figures
- Fig. 1.
Coulter size distributions of the responsive (thin line) and unresponsive (thick line) isolates used for sexual induction and a simplified schematic of the resulting life cycle features of the responsive (left side) and unresponsive (right side) cells. The mean cell diameter of the responsive culture was 10.8 μm, and the mean cell diameter of the unresponsive culture was 12.9 μm.
- Fig. 2.
Comparison of the steady-state levels of transcription of 10 differentially expressed cDNA clones. Spots of approximately 0.5 μg of the total cDNAs isolated from the unresponsive (U) and responsive (R) cultures 5 h after the dark-induced cultures were returned to continuous light are shown.
- Fig. 3.
Structure and expression of Sig1,Sig2, and Sig2. (A) Schematic of the genomic structures of the Sig1, Sig2, and Sig3transcription units. Rectangles, exons; lines, introns; solid rectangles, untranslated RNA. Arrows indicate approximate locations of the PCR primers used for RT-PCR. (B) Two hundred nanograms of poly (A)-selected RNA isolated from the responsive (R) and unresponsive (U) cultures 5 h after the dark-induced cultures were returned to continuous light were reverse transcribed. Total genomic DNA (G) or equal amounts of the first strand-cDNAs (R or U) were PCR amplified with the primers specific to Sig1, Sig2, andSig3 shown in panel A. Molecular weight markers (in kilobases) are shown on the left. PCR primers specific to carbonic anhydrase (Cal) were used to PCR amplify equal amounts of the first-strand cDNAs, and PCR products were analyzed on a second gel; molecular weight markers for this gel are shown on the right.
- Fig. 4.
Alignment and structure of the predicted amino acid sequences of SIG1, SIG2, and SIG3. (A) Alignment of the predicted amino acid sequences; amino acid numbering, beginning with the initiator methionine, is shown to the right of each line. Dashes, alignment gaps; solid diamond, potential cleavage site of the signal sequences; boldfaced N’s, potential N-linked glycosylation sites; areas highlighted in black, amino acid identity domains I through V. The location of RGD in SIG1 is indicated by asterisks. The EF hand in SIG1 and the ATP/GTP binding site in SIG2 are boxed. (B) Schematic of the structure and orientation of domains I through V within the SIG polypeptides. The five different patterns represent the five different domains, arranged from left to right with domain I leftmost. Only domain I of SIG2 and domain III in each polypeptide do not contain an EGF-like motif. Open rectangles, nonconserved regions. In SIG1, the asterisk above domain I indicates the location of the RGD motif. In SIG2, the asterisk indicates the location of the ATP/GTP binding motif. The short vertical lines above SIG1 and SIG2 indicate the locations of potential N-linked glycosylation sites.
- Fig. 5.
Alignments of composites of the predicted amino acid sequence from domains I through V for SIG1, SIG2, and SIG3 with the EGF-like domains of tenascin X from mice (GenBank accession no. 2564958), humans (4), or cows (13). Alignment gaps are indicated by dashes. Identical and similar amino acids (similarly charged acidic [D and E] or basic [R, K, and H] residues or uncharged [M, L, V and A] residues) are highlighted in black. Amino acids 19 to 206 of SIG3 are included. Amino acids 391 to 575 (Ms1), 298 to 451 (Ms2), 236 to 389 (Ms3), 484 to 637 (Ms4), 546 to 732 (Ms5), and 132 to 296 (Ms6) of the mouse sequence, amino acids 283 to 467 (Hu1), 407 to 591 (Hu2), 221 to 405 (Hu3), 500 to 681 (Hu4), 146 to 312 (Hu5), and 593 to 748 (Hu6) of the human sequence, and amino acids 403 to 619 (Bov1), 279 to 463 (Bov2), 558 to 744 (Bov3), and 142 to 308 (Bov4) of the bovine sequence are included.
