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Family Genus Specific epithet Specific authority Infraspecific category
2C mean1(pg) 2C mean1(mbp) 2C range1 pg
Chromosome number (2n) Ploidy level
Number of 5S signals Range of 5S signals Position2 of 5S signals (5S P)
Number of 45S3 signals Range of 45S signals Position2 of 45S signals (45S P) Arrangement
Number of chromosomes with both 5S and 45S in the same arm (SA) Number of chromosomes with both 5S and 45S signals (SC)
Original reference Number of chromosomes with co-localized 5S and 45S signals (Coloc.)

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Chromosome number from: -   Ploidy level from: -

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1 source: Animal genome size database (
2 position refers to interstitial, pericentromeric, distal or occupying whole chromosome arm
3 refers to 45S rDNA (18S-5.8S-26S rRNA genes)

Welcome to the animal rDNA database (Release 1.1)!

Ribosomal DNA loci encoding ribosomal RNA genes (rDNA) are important components of chromosomes. They vary both in numbers and positions. These can be characteristic of a species or a genus and used for comparative purposes. For example, studies in evolutionary biology, systematics or animal breeding.

To make easily available this information we have constructed the animal rDNA database. The resource includes data for 1343 animal species from 264 families. It provides information on number, position and structure of rDNA loci. When available, it also offers data on ploidy level, chromosome number or genome size. It is parallel to the plant rDNA database, providing the same information for plants.

The data of this first release comes from 541 papers based on FISH* of 5S and 45S rDNA, published until the end of 2016.

(*) Fluorescent in situ hybridisation

NOTE: The database is not providing any rDNA sequence, only information about rDNA site number and position in chromosomes. If you are interested in sequence data, you can consult other databases listed here.

Animal rDNA Database