Histone H3 gene in the Pacific oyster, Crassostrea gigas Thunberg, 1793: molecular and cytogenetic characterisations

By

Bouilly, Karine
Chaves, Raquel, 1969-
Fernandes, Mariana Sofia Peixoto
Guedes-Pinto, Henrique

Type

Article

Date of Publication

2010

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

4

Series / Issue

Issue: 2

Pages

111-121

Subjects

ivalves, Crassostrea gigas, fluorescence in situ h

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/compcytogen.v4i2.32

 

Abstract

The Pacific oyster, Crassostrea gigas Thunberg, 1793 (2n = 20) is an economically important mollusc species cultured throughout the world. The most frequently used technique for molecular cytogenetic studies is fluorescence in situ hybridisation which offers new opportunities for the identification of oyster chromosomes. In oysters, it has been used to locate telomeric sequences, satellite DNA, simple sequence repeats, ribosomal RNA genes, and bacteriophage P1 clones. However, regarding chromosome identification, no study has been done with histone H3 gene. Histone H3 is among the most conserved eukaryotic proteins. Most histone H3 genes are repeatedly organised into clusters, which make them an ideal chromosomal marker. In bivalves, some data exist concerning sequence information but little knowledge is available concerning the physical mapping of histone genes. The histone H3 gene was sequenced in C. gigas and phylogenetic analysis revealed that C. gigas was more closely related to Ostrea edulis Linnaeus, 1758 and species of the genus Mytilus Linnaeus, 1758. In C. gigas, the histone H3 gene was mapped on two different pairs of chromosomes, one at an interstitial site on the long arm of chromosome pair 4, and the other on the telomeres of the smaller chromosome pair (pair 10). Polymorphism was detected on the telomeres of pair 10, once it was possible to observe single or double signals. Comparative chromosomal mapping should improve our understanding of bivalve genome organisation.