A karyological study of the spirurid nematode Mastophorus muris (Nematoda : Spirocercidae)

The karyotype of Mastophorus muris (Gmelin, 1790) comprises four pairs of s mall autosomal chromosomes and two larger sex X chromosomes in females or o ne X chromosome in males (2n = 8 + XX/XO). All pairs of chromosomes possess rather uniform morphology without distinct primary or secondary constricti ons. No heterochromatin bands were found by C-bonding analysis. The absolut e chromosome length ranges from 4.02 to 2.24 mu m. The mean total length of the haploid complement is 14.34 mu m The course of gametogenesis represent s a typical pattern common in the order. Spirurida. The recently available karyotypes of spirurid nematodes have been reviewed.