Single-sequence probes reveal chromosomal locations of tandemly repetitive genes in scleractinian coral Acropora pruinosa: a potential tool for karyotyping [post]

Joshua Vacarizas, Takahiro Taguchi, Takuma Mezaki, Masatoshi Okumura, Rei Kawakami, Masumi Ito, Satoshi Kubota
2021 unpublished
The short and similar sized chromosomes of Acropora pose a challenge for karyotyping. Conventional methods, such as staining of heterochromatic regions, provide unclear banding patterns that hamper identification of such chromosomes. In this study, we used short single-sequence probes for tandemly repetitive 5S ribosomal RNA (rRNA) and core histone genes to identify specific chromosomes of Acropora pruinosa. Both the probes produced intense signals in fluorescence in situ hybridization, which
more » ... ridization, which distinguished chromosome pairs. The locus of the core histone gene was on chromosome 8, whereas that of 5S rRNA gene was on chromosome 5. The sequence of the 5S rRNA probe was composed largely of U1 and U2 spliceosomal small nuclear RNA (snRNA) genes and their interspacers, flanked by short sequences of the 5S rRNA gene. This is the first report of a tandemly repetitive linkage of snRNA and 5S rRNA genes in Cnidaria. Based on the constructed tentative karyogram and whole genome hybridization, the longest chromosome pair (chromosome 1) was heteromorphic. The probes also hybridized effectively with chromosomes of other Acropora species and population, revealing an additional core histone gene locus. We demonstrated the applicability of short-sequence probes as chromosomal markers with potential for use across populations and species of Acropora.
doi:10.21203/rs.3.rs-272521/v1 fatcat:lgmvbae62vempp3dgois6wukwy