Chromosome-level genome of Poropuntius huangchuchieni provides a diploid progenitor-like reference genome for the allotetraploid Cyprinus carpio.

Abstract

The diploid Poropuntius huangchuchieni in the cyprinid family, which is widely distributed in the Mekong and Red River basins, is one of the most closely related diploid progenitor-like species of allotetraploid common carp, which was generated by merging of two diploid genomes during evolution. Therefore, the P. huangchuchieni genome is essential for polyploid evolution studies in Cyprinidae. Here, we report a high-quality chromosome-level genome assembly of P. huangchuchieni by integrating Oxford Nanopore and Hi-C technologies. The assembled genome size was 1,021.38Mb, 895.66Mb of which was anchored onto 25 chromosomes with a N50 of 32.93Mb. The genome contained 486.28Mb repetitive elements and 24,099 protein-coding genes. Approximately 95.9% of the complete BUSCOs were detected, suggesting a high completeness of the genome. Evolutionary analysis revealed that P. huangchuchieni diverged from Cyprinus carpio at approximately 12 Mya. Genome comparison between P. huangchuchieni and the B subgenome of C. carpio provided insights into chromosomal rearrangements during the allotetraploid speciation. With the complete gene set, 17,474 orthologous genes were identified between P. huangchuchieni and C. carpio, providing a broad view of the gene component in the allotetraploid genome, which is critical for future genetic analyses. The high-quality genomic data set created for P. huangchuchieni provides a diploid progenitor-like reference for the evolution and adaptation of allotetraploid carps.