Submit Manuscript

International Journal of Zoological Research

Year: 2006 | Volume: 2 | Issue: 4 | Page No.: 301-311
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Article Trend

Total views 427

Search

Authors

Adel A.B. Shahin

Abdel Tawab M. Ata

Mahmoud I. Shoulkamy

Keywords

Research Article

Chromosomal and C-heterochromatin Characterization of Arvicanthis niloticus (Rodentia: Murinae) in Egypt

Adel A.B. Shahin, Abdel Tawab M. Ata and Mahmoud I. Shoulkamy
The karyotype and C-banding pattern of the unstriped grass rat Arvicanthis niloticus from four localities in Egypt are presented. All individuals karyotyped, as a rule, have the same diploid number of 2n = 62 and autosomal Fundamental Number of aFN = 62. In addition, all chromosomes have a large centromeric block of fairly uniform size. However, an additional interstitial or telomeric small C-band is scored in some chromosomes. Nevertheless, frequent heteromorphism in the morphology and heterochromatin content of both the homologous chromosomes of the pair No. 1 and the X chromosome are scored in some individuals from the four localities and led to an aFN = 63. Accordingly, four forms or cytotypes, namely ANI-1a, ANI-1b, ANI-1c and ANI-1d, are recognized based on this variation, which is mostly attributed either to addition or deletion of a heterochromatic segment as a result of pericentric inversions. Of these four forms, the ANI-1a is considered ancestral for A. niloticus in Egypt and is closely similar to that of the Ethiopian A. dembeensis, regardless the contradiction concerned with nomenclature of the X chromosome, while the karyotypes of the other forms are synapomorphy of the form ANI-1a and showed as well a relative resemblance to those of the Ethiopian A. abyssinicus and A. blicki. Therefore, it is concluded that the genus Arvicanthis would be represented by an Egyptian-Ethiopian radiation (A. niloticus, A. dembeensis, A. abyssinicus and A. blicki) and by a Central-Western African one, including the karyotypes described as A. centralis and A. solatus. Moreover, A. niloticus should be regarded no longer as a single species but as a cluster of several proper species.
PDF Fulltext XML References Citation

Leave a Comment

Your email address will not be published. Required fields are marked *