Abstract
The African grass rat, Arvicanthis sp., from Benin shows sex‐chromosome polymorphism for the presence in the karyotype of three X‐chromosome forms: subtelocentric (Xst), submetacentric (Xsm), and metacentric (Xm). Here we report statistically significant differences of diploid genome size (g.s.) among individuals, from 6.22 ± 0.06 pg to 6.80 ± 0.10 pg, depending on the X‐chromosome form. The evaluation of the total and X‐chromosome heterochromatin content alone (Xst: 2.16 ± 0.22%; Xsm: 5.02 ± 0.22%; Xm: 6.54 ± 0.28%), supports this suggestion. DNA base‐pair preferential staining revealed that heterochromatin of both autosome and sex chromosomes is AT‐rich. Digestion of genomic DNA with sixteen restriction enzymes produced DNA bands representing the repetitive fraction of the genome. When these were used as probes for fluorescence in situ hybridization (FISH), two hybridization patterns were found: a) FISH positive signals localized in the pericentromeric areas of every chromosome of the complement and b) chromosome specific signals co‐localizing with both the pericentromeric regions of every chromosome and the heterochromatic regions of Xsm and Xm, but not on the Xst chromosome. FISH performed with a (TTAGGG)n probe revealed a telomere‐only pattern.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
