Marine heterotardigrades, Echiniscoides cf. sigismundi, were collected from barnacles in the intertidal zone at Lynæs, Zealand, Denmark (see [57 ]). Specimens of a parthenogenetic population of the eutardigrade, Richtersius cf. coronifer, were sampled from moss growing on limestone in Øland, Sweden (see [76 (link)]). Total RNA was extracted from active stage pools of ∼550 E. cf. sigismundi and ∼200 R. cf. coronifer, respectively, using a RNeasy Plus Universal Mini Kit (Qiagen,Hilden, Germany). RNA quantitation and quality analyses were performed using a NanoDrop ND-1000 (Thermo Scientific, Waltham, Massachusetts, USA) and a Bioanalyzer 2100 (Agilent Technologies, Santa Clara).
Cryptic species complexes are common within Tardigrada and the genus Echiniscoides has an exceptionally large genetic variation [19 (link)]. We therefore analyzed both transcriptomes with respect to the often used barcoding sequence of cytochrome c oxidase subunit I (COXI) using BLASTN searches in the NCBI nucleotide non-redundant database. The transcriptome data revealed tardigrade COXI contigs (CL4672.Contig1_Echiniscoides and CL1502.Contig2_Richtersius), which support that the 550 Echiniscoides and 200 Richtersius specimens each constitute single species. BLASTN searches in GenBank returned a 99% identity to the isolate Echiniscoides cf. sigismundi (voucher ZMUC:TAR Esi1; GenBank Accession number: HM193403.1; [77 (link)]. Similarly, the Richtersius cf. coronifer BLASTN search in GenBank returned a 99% identity to the isolate Richtersius cf. coronifer (GenBank Accession number: EU244606.1).
Cryptic species complexes are common within Tardigrada and the genus Echiniscoides has an exceptionally large genetic variation [19 (link)]. We therefore analyzed both transcriptomes with respect to the often used barcoding sequence of cytochrome c oxidase subunit I (COXI) using BLASTN searches in the NCBI nucleotide non-redundant database. The transcriptome data revealed tardigrade COXI contigs (CL4672.Contig1_Echiniscoides and CL1502.Contig2_Richtersius), which support that the 550 Echiniscoides and 200 Richtersius specimens each constitute single species. BLASTN searches in GenBank returned a 99% identity to the isolate Echiniscoides cf. sigismundi (voucher ZMUC:TAR Esi1; GenBank Accession number: HM193403.1; [77 (link)]. Similarly, the Richtersius cf. coronifer BLASTN search in GenBank returned a 99% identity to the isolate Richtersius cf. coronifer (GenBank Accession number: EU244606.1).
Free full text: Click here
