Understanding the evolution and maintenance of sexual reproduction is one of the central challenges of evolutionary biology, yet we know very little about how sex influences molecular evolution. The New Zealand freshwater snail Potamopyrgus antipodarum is ideally suited to address this knowledge gap because obligately sexual individuals often coexist with multiple independently derived obligately asexual lineages. This unusual situation allows direct comparisons both between sexual and asexual P. antipodarum and across populations that differ in the relative frequency of sexual individuals. As such, P. antipodarum has received a great deal of attention as a model system for the maintenance of sex in nature and is also used as a model for environmental toxicology and biological invasions. Molecular genetic resources for P. antipodarum will thus be useful to investigators in a variety of biological fields. We used 454 sequencing of cDNA libraries to generate transcriptomes from two sexual and two asexual P. antipodarum lineages. A de novo assembly of 116.7 Mb of sequence reads produced 41 396 contigs, and sequence similarity-based Gene Ontology annotations were obtained for 3740 contigs. We detected 408 315 SNP loci and 7315 microsatellite loci, which together represent the first genome-scale resource available for P. antipodarum.
P. antipodarum 454 read sequences
Read sequences from 454 sequencing of two sexual and two asexual lineages of the New Zealand snail Potamopyrgus antipodarum. RNA was extracted from four independently-isolated P. antipodarum lineages descended from wild-caught females originally sampled from three New Zealand South Island lakes: Lake Alexandrina (one sexual diploid lineage and one asexual triploid lineage), Lady Lake (sexual diploid), and Lake Mapourika (asexual triploid). Each lineage was represented by four arbitrarily selected adult females. For details on extraction and sequencing efforts, see the associated publication.
P_antipodarum_454_reads_FASTA.tar.gz
P. antipodarum contig annotations
BLAST results and Gene Ontology annotations of contig sequences from transcriptome sequencing of two sexual and two asexual lineages of New Zealand snail Potamopyrgus antipodarum. BLAST annotations were made using the Tera-BLASTX implementation of the BLASTX algorithm. GO annotations were made using the software BLAST2GO; BLAST2GO was provided with BLASTX results of a search against the NCBI ns database, and default values were used for all cutoff parameters.
P_antipodarum_annotations.tar.gz
P. antipodarum contig assemblies
Assemblies of reads from the transcriptome sequencing of two sexual and two asexual lineages of New Zealand snail Potamopyrgus antipodarum. Read assembly was carried out using the sotware MIRA3. The assemblies are in .ace format.
P_antipodarum_contig_assemblies.tar.gz
P. antipodarum contig sequences
Assembled contig sequences from the 454 transcriptome sequencing of two sexual and two asexual lineages of New Zealand snail Potamopyrgus antipodarum. Contig sequences were produced by the software MIRA3.
P_antipodarum_contig_sequences.fasta
P. antipodarum microsatellite loci
These files describe the locations (flanking sequence) of putative microsatellite loci in the New Zealand snail Potamopyrgus antipodarum. The loci were identified by scanning contig sequences from a 454 transcriptome sequencing experiment with the software MSATCOMMANDER.
P_antipodarum_microsatellites.tar.gz
P. antipodarum SNP loci
Locations of SNP loci from 454 transcriptome sequencing of two sexual and two asexual lineages the New Zealand snail Potamopyrgus antipodarum. Positions of SNPs are relative to contig sequences assembled in this sequencing experiment. The software MIRA3 was used for both read alignment (i.e., contig generation) and SNP discovery. Both padded and unpadded positions are given.
P_antipodarum_SNPs.tar.gz