Trypanosma (Megatrypanum) melophagium: modes of attachment of parasites to mid-gut, hindgut and rectum of the sheep ked, Melophagus ovinus.

Observations on the mode of attachment of Trypanosoma melophagium to the different regions of the gut wall of Melophagus ovinus (L.) are described. The presence of hemidesmosomal attachment mechanism was noted in the hind-gut and rectum, but hemidesmosomes were not seen to mediate attachment to the microvilli of the mid-gut epithelian cells, attachment of the epimastigotes here being by interdigitation of the anterior end of the epimastigotes and the flagella amongst the microvilli and mycoplasma-like organisms lining the mid-gut cells. From these results and those of other workers on other parasites, it is concluded that hemidesmosomes seem to be a widespread attachment mechanism in Trypanosomatids.<new para>ADDITIONAL ABSTRACT:<new para>Melophagus ovinus was infected with Trypanosoma melophagium. The flagella of the epimastigotes in the mid-gut of M. ovinus interdigitate between the microvilli which form the lining brush border of the epithelial cells. Between the microvilli, large masses of mycoplasma-like organisms were seen. In the hind-gut triangle and hind-gut, the whole of the cuticular surface is lined with expanded flagella of epimastigotes and metacyclic trypomastigotes, and hemidesmosomal plaques are applied to the cuticle. In the rectum only a few epimastigotes and metacyclic trypomastigotes are attached to the folded cuticular epithelium, by a mechanism similar to that seen in the hind gut.