Supernumerary chromosomes and their possible origin in the karyotype of Indian bush rat, Golunda ellioti gujerati.

The incidence of supernumerary chromosomes has been frequently observed in one of the subspecies of Indian bush rat, Golunda ellioti gujerati Thomas 1923. Their number varied from 1 to 4 with consistent number of supernumeraries in each individual specimen. A possible explanation is given towards the origin of supernumerary chromosomes in Golunda ellioti gujerati. Two acrocentric chromosomes can give rise to a single large acrocentric and a supernumerary chromosome. This can happen by separation of centromere from one of the acrocentrics and translocation of the centric arms to the telomeric region of the second chromosomes, thus to form large acrocentric leaving the centromeric fragment as supernumerary chromosome.