Molecular Cytogenetic Analysis and Isolation of a 5S rRNA-Related Marker in the Scleractinian Coral <i>Platygyra contorta</i> Veron 1990 (Hexacorallia, Anthozoa, Cnidaria)

Abstract

A molecular cytogenetic analysis was conducted on the scleractinian coral Platygyra contorta, which is commonly found along temperate coasts in Japan. P. contorta was karyotyped (2n=28) by conventional G-and C-bandings, and the karyogram revealed that about 50% of the metaphase spreads had a homogenously staining region (hsr) in the terminal portion of the long arm of chromosome 12. Fluorescence in situ hybridization (FISH) showed that this hsr consisted of rRNA genes (rDNA) stained by C-banding. The presence of an hsr, which is a highly amplified rDNA, may explain the molecular diversity of coral rDNA. FISH visualized and demonstrated the presence of a telomere motif (TTA GGG) n in this coral using a human telomere probe. Furthermore, we isolated a specific FISH marker (312 bp) designated PC-T1, which was located near the centromere of chromosome 11. A sequence analysis revealed that the terminal part of PC-T1 (51 bp from the 3′ end) was 90% homologous with a Montipora capitate microsatellite and the Actinia equine 5S rRNA gene. Isolating FISH markers will assist the classification of scleractinian corals with the progression on describing their genome. The data obtained in this study will be valuable for discriminating species among scleractinian corals and understanding their genetics, including chromosomal evolution.

Cytogenetic evidence and dmrt linkage indicate male heterogamety in a non-bilaterian animal

“…A karyotypic analysis which offers direct observation of the chromosome structures and organization, as well as the loci of specific genes, might serve as important in-situ reference to explore its sex determination system. Although several cytogenetic data from non-bilaterians have been reported, all the species investigated are hermaphroditic, in which their karyotypes may provide no information on their sex chromosomes and thus to their GSD system [ 18 – 21 ]. Chromosome information from gonochoric non-bilaterian species would provide the evidence for identifying the GSD system for these animals.…”

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

“…These banding patterns and chromosomal lengths are features that are conventionally used in pairing homologous chromosomes to construct the karyotype. Karyotyping of corals has recently been improved with the use of uorescence in situ hybridization (FISH), which provides a higher resolution that aids the observation of chromosomes by targeting gene loci as chromosomal markers [8][9][10][11] . This improvement revealed a chromosome number (2n) of 28 for most of the species of scleractinian corals and suggested slight variations in the number even within the species 9 .…”

FISH with Padlock Probes Can Efficiently Reveal the Genomic Position of Low or Single-Copy DNA Sequences

“…Fluorescence in situ hybridization (FISH) can analyze the genomic position and distribution of DNA sequences in nuclei and on chromosomes (Ebadi-Almas et al 2012, Shirakawa et al 2012, Ikeda et al 2013, Kuroki et al 2013, Ruan et al 2013, Yokomi et al 2013, Suto et al 2013, Lombello et al 2014, Abozeid et al 2015, Kantek et al 2015, Matsunaga 2016, Monkheang et al 2016, Shibata et al 2016, Tantivit et al 2016, Jantarat et al 2017, Taguchi et al 2017. Labeling of DNA probes for FISH has been generally performed through enzymatic incorporation of labeled dNTPs by PCR or nick translation (Shibata and Hizume 2015).…”