Figure 3.

The SpTransformer (SpTrf) gene family is diverse, but the gene structure is simple. (A) Digests of genomic DNA from three sea urchins (1–3) with PstI are shown as duplicate Southern blots that are evaluated with ³²P-labeled riboprobes spanning elements 1–7 (5′ end) and from elements 7–25 (3′ end) (see Figure 2 for elements). Both probes hybridize to bands of less than 2 kB (arrows) (see Terwilliger et al. (6) for methods). This figure is reprinted from Ref. (16). (B) The SpTrf genes are small with two exons. Although the genes show significant sequence diversity, their overall structure is generally the same with two exons. This figure is modified from Ref. (2). (C) Amplified, cloned, and sequenced genes (171 total) from three sea urchins are represented as red, blue, and green circles in this Venn diagram. Comparisons among nucleotide sequences of the full-length genes within and among sea urchins identified no identical matches (left). However, shared element sequences are present in genes within and among sea urchins (right). Shared sequences are indicated by intersections of the circles. This figure is reprinted from Ref. (16).