A chromosome-scale genome assembly and karyotype of the ctenophore Hormiphora californensis. Issue 11 (16th October 2021)

• Record Type: Journal Article
• Authors: Schultz, Darrin T; Francis, Warren R; McBroome, Jakob D; Christianson, Lynne M; Haddock, Steven H D; Green, Richard E
• Editors: Ross-Ibarra, J
• Is Part Of: G3. Volume 11:Issue 11(2021)
• Publication Date: 2021-10-16
• Subjects: ctenophore -- Ctenophora -- genomics -- comb jelly -- chromosome-scale -- heterozygosity -- Iso-Seq -- Hi-C -- PacBio -- inversion; Genetics -- Research -- Periodicals; Genomics -- Periodicals; Genetics; Genomics; Genes; Genetics -- Research; Genomics; Electronic journals; Periodical; Periodicals; Fulltext; Internet Resources; Periodicals; 572.8
• DOI: 10.1093/g3journal/jkab302
• Languages: English
• ISSNs: 2160-1836

Abstract

Abstract: Here, we present a karyotype, a chromosome-scale genome assembly, and a genome annotation from the ctenophore Hormiphora californensis (Ctenophora: Cydippida: Pleurobrachiidae). The assembly spans 110 Mb in 44 scaffolds and 99.47% of the bases are contained in 13 scaffolds. Chromosome micrographs and Hi-C heatmaps support a karyotype of 13 diploid chromosomes. Hi-C data reveal three large heterozygous inversions on chromosome 1, and one heterozygous inversion shares the same gene order found in the genome of the ctenophore Pleurobrachia bachei . We find evidence that H. californensis and P. bachei share thirteen homologous chromosomes, and the same karyotype of 1 n = 13. The manually curated PacBio Iso-Seq-based genome annotation reveals complex gene structures, including nested genes and trans-spliced leader sequences. This chromosome-scale assembly is a useful resource for ctenophore biology and will aid future studies of metazoan evolution and phylogenetics.