Cell culture-based karyotyping of orectolobiform sharks for chromosome-scale genome analysis

• DOI: 10.1038/s42003-020-01373-7
• Publication Date: 2020-11-06T11:02:46Z
• Authors: Yoshinobu Uno; Ryo Nozu; Itsuki Kiyatake; Nobuyuki Higashig...; Shuji Sodeyama; Kiyomi Murakumo; Keiichi Sato; Shigehiro Kuraku
• Keywords: Male; 0301 basic medicine; Comparative Genomic Hybridization; Cell Culture Techniques; Fibroblasts; Article; Chromosomes; 03 medical and health sciences; Karyotyping; Sharks; Animals; Female; Lymphocytes; 14. Life underwater; Cells, Cultured; In Situ Hybridization, Fluorescence

Karyotyping, traditionally performed using cytogenetic techniques, is indispensable for validating genome assemblies whose sequence lengths can be scaled up to chromosome sizes modern methods. Karyotype reports of chondrichthyans are scarce because the difficulty in cell culture. Here, we focused on carpet shark species and culture conditions fibroblasts lymphocytes. The utility cultured cells enabled high-fidelity characterization their karyotypes, namely 2n = 102 whale (Rhincodon typus) zebra (Stegostoma fasciatum), 106 brownbanded bamboo (Chiloscyllium punctatum) whitespotted (C. plagiosum). We identified heteromorphic XX/XY sex chromosomes two latter demonstrated first-ever fluorescence situ hybridization prepared from cells. Our protocols applicable diverse chondrichthyan will deepen understanding early vertebrate evolution at molecular level.