Genomic organization and alternative transcripts of nb001 / minicollagen. (a) Mapping of nb001 EST-contigs (nb001-sv1 to nb001-sv5; black) and amplified PCR products (nb001-sv6 to nb001-sv9; blue) to the corresponding genomic locus (H. magnipapillata genomic scaffold NW_002161526). nb001 transcripts encode a protein with a signal peptide (sp; green), pro-peptide (pro; black) and a collagen-like domain (yellow) flanked by two praline repeats (Pn; magenta) and two cystein-rich-domains (CRD; red). (b) Alignment of the amino acid sequences of predicted splice variants. (c) Northern blot indicates the presence of nb001 transcripts corresponding to most of the predicted splice variants. Probe for hybridization corresponds to exon 2 and the first half of exon 3 (yellow line in (a)). Asterisks indicate stop codons.