Assembly, Gene Annotation and Marker Development Using 454 Floral Transcriptome Sequences in Ziziphus Celata (Rhamnaceae), a Highly Endangered, Florida Endemic Plant

Large-scale DNA sequence data may enable development of genetic resources in endangered species, thereby facilitating conservation efforts. Ziziphus celata, a federally endangered, self-incompatible plant species occurring in Florida, USA, is one species for which genetic resources are necessary to facilitate new introductions and augmentations essential for recovery of the species. We used 454 pyrosequencing of a Z. celata normalized floral cDNA library to create a genomic resource for gene and marker discovery. A half-plate GS-FLX Titanium run yielded 655 337 reads averaging 250 bp. A total of 474 025 reads were assembled de novo into 84 645 contigs averaging 408 bp, while 181 312 reads remained unassembled. Forty-seven and 43% of contig consensus sequences had BLAST matches to known proteins in the Uniref50 and TAIR9 annotated protein databases, respectively; many contigs fully represented orthologous proteins in TAIR9. A total of 22 707 unique genes were sequenced, indicating substantial coverage of the Z. celata transcriptome. We detected single-nucleotide polymorphisms and simple sequence repeats (SSRs) and developed thousands of SSR primers for use in future genetic studies. As a first step towards understanding self-incompatibility in Z. celata, we identified sequences belonging to the gene family encoding self-incompatibility. This study demonstrates the efficacy of 454 transcriptome sequencing for rapid gene and marker discovery in an endangered plant

Prolonged morphological expansion of spiny-rayed fishes following the end-Cretaceous

Spiny-rayed fishes (Acanthomorpha) dominate modern marine habitats and account for more than a quarter of all living vertebrate species. Previous time-calibrated phylogenies and patterns from the fossil record explain this dominance by correlating the origin of major acanthomorph lineages with the Cretaceous–Palaeogene mass extinction. Here we infer a time-calibrated phylogeny using ultraconserved elements that samples 91.4% of all acanthomorph families and investigate patterns of body shape disparity. Our results show that acanthomorph lineages steadily accumulated throughout the Cenozoic and underwent a significant expansion of among-clade morphological disparity several million years after the end-Cretaceous. These acanthomorph lineages radiated into and diversified within distinct regions of morphospace that characterize iconic lineages, including fast-swimming open-ocean predators, laterally compressed reef fishes, bottom-dwelling flatfishes, seahorses and pufferfishes. The evolutionary success of spiny-rayed fishes is the culmination of multiple species-rich and phenotypically disparate lineages independently diversifying across the globe under a wide range of ecological conditions