Biomaterial Database

Molecular cytogenetic analysis of heterochromatin in the chromosomes of tilapia, Oreochromis niloticus (Teleostei: Cichlidae). 1998

C Oliveira, and J M Wright

Departamento de Morfologia, Instituto de Biociências, UNESP, Botucatu, São Paulo, Brazil.

The structure of the heterochromatic bands in mitotic chromosomes of the important tropical aquaculture species of tilapia, Oreochromis niloticus, was investigated by the combination of the C-banding technique, chromosomal digestion with two restriction endonucleases and fluorescence in situ hybridization (FISH) of two satellite DNAs (SATA and SATB). The tilapia chromosomes presented heterochromatic bands in the centromeres and in the short arms of almost all chromosomes that were differentially digested by the restriction endonucleases HaeIII and EcoRI. FISH of SATA showed that this satellite sequence is distributed in the centromeric region of all chromosomes of tilapia. FISH also revealed an intense hybridization signal for SATB in only one chromosome pair, but less intense signals were also present in several other pairs. The digestion of tilapia chromosomes by HaeIII and EcoRI was positively correlated with the position of SATA and SATB in chromosomes as revealed by FISH. The results obtained may be useful in future molecular and genetic studies of tilapias.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D002871	Chromosome Banding	Staining of bands, or chromosome segments, allowing the precise identification of individual chromosomes or parts of chromosomes. Applications include the determination of chromosome rearrangements in malformation syndromes and cancer, the chemistry of chromosome segments, chromosome changes during evolution, and, in conjunction with cell hybridization studies, chromosome mapping.	Banding, Chromosome,Bandings, Chromosome,Chromosome Bandings
D002875	Chromosomes	In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Chromosome
D004276	DNA, Satellite	Highly repetitive DNA sequences found in HETEROCHROMATIN, mainly near centromeres. They are composed of simple sequences (very short) (see MINISATELLITE REPEATS) repeated in tandem many times to form large blocks of sequence. Additionally, following the accumulation of mutations, these blocks of repeats have been repeated in tandem themselves. The degree of repetition is on the order of 1000 to 10 million at each locus. Loci are few, usually one or two per chromosome. They were called satellites since in density gradients, they often sediment as distinct, satellite bands separate from the bulk of genomic DNA owing to a distinct BASE COMPOSITION.	Satellite DNA,Satellite I DNA,DNA, Satellite I,DNAs, Satellite,DNAs, Satellite I,I DNA, Satellite,I DNAs, Satellite,Satellite DNAs,Satellite I DNAs
D005260	Female		Females
D006570	Heterochromatin	The portion of chromosome material that remains condensed and is transcriptionally inactive during INTERPHASE.	Heterochromatins
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D015183	Restriction Mapping	Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.	Endonuclease Mapping, Restriction,Enzyme Mapping, Restriction,Site Mapping, Restriction,Analysis, Restriction Enzyme,Enzyme Analysis, Restriction,Restriction Enzyme Analysis,Analyses, Restriction Enzyme,Endonuclease Mappings, Restriction,Enzyme Analyses, Restriction,Enzyme Mappings, Restriction,Mapping, Restriction,Mapping, Restriction Endonuclease,Mapping, Restriction Enzyme,Mapping, Restriction Site,Mappings, Restriction,Mappings, Restriction Endonuclease,Mappings, Restriction Enzyme,Mappings, Restriction Site,Restriction Endonuclease Mapping,Restriction Endonuclease Mappings,Restriction Enzyme Analyses,Restriction Enzyme Mapping,Restriction Enzyme Mappings,Restriction Mappings,Restriction Site Mapping,Restriction Site Mappings,Site Mappings, Restriction
D016045	Human Genome Project	A coordinated effort of researchers to map (CHROMOSOME MAPPING) and sequence (SEQUENCE ANALYSIS, DNA) the human GENOME.	Genome Project, Human,Human Genome Diversity Project,Human Genome Mapping Project,Genome Projects, Human,Human Genome Projects,Project, Human Genome,Projects, Human Genome
D017210	Tilapia	A freshwater fish used as an experimental organism and for food. This genus of the family Cichlidae (CICHLIDS) inhabits Central and South America (one species extends north into Texas), West Indies, Africa, Madagascar, Syria, and coastal India.	Oreochromis mossambicus,Tilapia mossambica,Mozambique Tilapia,Mozambique Tilapias,Tilapia, Mozambique,Tilapias, Mozambique