H3S28P Antibody Staining of Okinawan  Oikopleura dioica Suggests the Presence of Three Chromosomes [version 2; peer review: 2 approved]

• Published in: F1000 research Vol. 9; p. 780
• Main Authors: Liu, Andrew W, Tan, Yongkai, Masunaga, Aki, Bliznina, Aleksandra, West, Charlotte, Plessy, Charles, Luscombe, Nicholas M
• Format: Journal Article
• Language: English
• Published: England Faculty of 1000 Ltd 01-03-2021; F1000 Research Limited; F1000 Research Ltd
• Subjects: Animals; Antibodies; Antibodies, Monoclonal; Brief Report; Cell cycle; Centromere - immunology; Chromosomes; Chromosomes - genetics; Developmental biology; Diploids; Embryos; Female; Genomes; Genomics; Histone H3; Histones; Japan; Karyotyping; Life cycles; Localization; Male; Males; Marine ecosystems; Metaphase; Oikopleura dioica; Oocytes; Prophase; Sperm; Staining and Labeling; Telomeres; Urochordata - genetics; Zooplankton; Japan; histone H3; H3S28P; centromere; karyotype; oocyte; Oikopleura; chromosome; embryo
• DOI: 10.12688/f1000research.25019.2
• EISSN: 2046-1402

Oikopleura dioica is a ubiquitous marine zooplankton of biological interest owing to features that include dioecious reproduction, a short life cycle, conserved chordate body plan, and a compact genome. It is an important tunicate model for evolutionary and developmental research, as well as investigations into marine ecosystems. The genome of north Atlantic
O. dioica comprises three chromosomes. However, comparisons with the genomes of
O. dioica sampled from
mainland and southern Japan revealed extensive sequence differences. Moreover, historical studies have reported widely varying chromosome counts. We recently initiated a project to study the genomes of
O. dioica individuals collected from the coastline of the Ryukyu (Okinawa) Islands in southern Japan. Given the potentially large extent of genomic diversity, we employed karyological techniques to count individual animals' chromosomes
in situ using centromere-specific antibodies directed against H3S28P, a prophase-metaphase cell cycle-specific marker of histone H3. Epifluorescence and confocal images were obtained of embryos and oocytes stained with two commercial anti-H3S28P antibodies (Abcam ab10543 and Thermo Fisher 07-145). The data lead us to conclude that diploid cells from Okinawan
O. dioica contain three pairs of chromosomes, in line with the north Atlantic populations. The finding facilitates the telomere-to-telomere assembly of Okinawan
O. dioica genome sequences and gives insight into the genomic diversity of
O. dioica from different geographical locations. The data deposited in the EBI BioImage Archive provide representative images of the antibodies' staining properties for use in epifluorescent and confocal based fluorescent microscopy.