The B chromosome in the meiotic process of the African pest grasshopper Taphronota thaelephora STAL. (Orthoptera: Pyrgomorphidae)

This paper presents the first record of B chromosomes in some adult male individuals of the African pest grasshopper Taphronota thaelephora collected from Balepa - Mbouda in the Western Province of Cameroon. Of the twenty individuals examined; thirteen had the characteristic Pyrgomorphidae karyotype of 2N= 19(18A+XO) while the remaining seven had a diploid chromosome number of 2N= 20(18A+XO+1B) indicating the presence of a single B chromosome. The B chromosome in this population was short; acrocentric in morphology and stained to the same intensity as the autosomes throughout meiosis. It did not associate with any chromosome in meiosis. In some cells it migrated to the same pole as the X-chromosome while in other cells it migrated to the pole opposite to that of the X-chromosome indicating irregular behaviour in meiosis. The presence of the B chromosome did not affect chiasma frequency in the species

Schistosomiasis research at the Blair Research Institute - Annual report - 1991

Genetic studies on some schistosome intermediate host snails in Zimbabwe were carried out. The variation in enzyme; electrophoresis patterns and chromosome numbers of snails from different geographical areas were examined. From the data collected and partial analysis of the electrophoresis data; there was no evidence suggesting the existence of more than one species (Balinus globosus) in the studied areas. The chromosome preparations observed did not show any variations in chromosome numbers (n = 18); although eliminating the existence of polyploidy it does not clarify which members of the B. tropicus/truncatus exists in Matabeleland (B. tropicus and/or B. tropicus) hence further research is needed; possibly using Biotechnological techniques