CHROMOREP: A REPTILES CHROMOSOMES DATABASE
The “Reptiles chromosomes database” is a catalogue of the karyological data of reptiles available so far and includes more than 2000 records.
For each species the following data are reported:
1) Scientific name (names of genera or species in brackets are those originally reported by the authors) 2) Diploid chromosome number: number of macrochromosomes (number of biarmed macrochromosomes, number of uniarmed macrochromosomes) number of microchromosomes.
(e.g. Cuora trifasciata 52: 28 (18,10) 24) 3) an = arm number (fundamental number). i.e. total number of chromosomes arm in the karyotype
4) Localisation of the nucleolar organiser region based on: the presence of a secondary constriction (scNOR), on the silver staining method (AgNOR), on the in situ hybridisation of ribosomal DNA probes (rDNA)
5) Sex chromosomes = presence and type of sex chromosomes: XY, ZW or similar
6) Several types of banding: a) C banding b) G banding c) Q banding d) R = reverse banding e) RBG = Replication banding f) Restrictase banding = banding obtained after the treatment with restriction enzymes g) DAPI (A-T rich DNA specific stain) banding h) Chromomycine (G-C rich DNA specific stain) banding i) FISH (Fluorescent in situ hybridisation of specific DNA probes, like centromeric,
telomeric or highly repetitive sequences) j) Hoechst = Hoechst fluorescent stain which can cause decondensation of the centromeric chromatin 7) References
The identification of the chromosome morphology is sometimes difficult, mainly as regard the distinction between macrochromosomes and microchromosomes. Therefore all the data are reported as originally indicated by each author.
The classification is based on the EMBL reptile database by Peter Uetz (2003 version).
Some specific shortening:
Satellite DNA or Sat DNA = Highly repetitive DNA sequences Bkm = Banded krite (Bungarus) minor satellite DNA found on the W sex chromosomes of several snakes Macro = macrochromosomes Micro = microchromosomes Meta = metacentric chromosomes Submeta = submetacentric chromosomes Acro = acrocentric or telocentric chromosomes 3n = triplod chromosomes set 4n = tetraploid chromosomes set W heterochromatin = Interfase heterochromatic blocks corresponding to the metaphase W sex chromosome
Nucleolar organiser region bearing chromosomes of Lacertidae:
a. L = Large sized chromosomes (from 5th to 7th)
b. M = medium sized chromosomes (from 10th to 12th )
c. S = small sized chromosomes (from 17th to 18th)
d. MS = medium small sized chromosomes (from 14th to 16th )
e. m = microchromosomes. Numbers in brackets indicate the chromosomes presumably corresponding to each category
New data, corrections, comments or any suggestions are welcome and must be sent (preferably by E-mail) to: Prof. Ettore Olmo. Istituto di Biologia e Genetica. Università Politecnica delle Marche. Via Brecce Bianche, I-60131, Ancona (Italy). Fax ++39-071-2204609. E-mail:
The authors of this database are: Prof. Ettore Olmo and Mr. Giorgio Gelo Signorino