Chromosomal analysis and meiosis studies of Oxya chinensis (Orthoptera: Acrididae) from Thailand

Abstract

The standard karyotype and meiotic cell divisions of Oxya chinensis Thunberg, 1815 (Orthotera: Acrididae) from Khon Kaen, Thailand were studied by conventional and silver staining techniques. Chromosomal preparations were made from grasshopper testes. The results showed that the male O. chinensis had diploid chromosome number 2n = 23 (XO). Karyotype was presented with eight long (1–4 pairs), eight medium (5–8 pairs) and six short (9–11 pairs) acrocentric chromosomes with minute short arms in all autosomes. The acrocentric X chromosome was approximately same in size as found for medium autosomes. The nucleolar organizer regions (NORs) were found on telomeric regions of all minute short arm acrocentric chromosomes in metaphase, including X chromosome. In zygotene stage of meiotic cell division, NORs were detected in three regions per cell by silver staining while only one region was found by conventional staining. Meiotic cell divisions were also studied to confirm the diploid chromosome number and normal meiotic behaviour. The karyotype formula was found in O. chinensis: 2n = 23 (XO); La 4 + Ma 4 + Sa 3 + X-chromosome. © 2016, Archana Sharma Foundation of Calcutta.