Ultrastructure of Endotrypanum

In my previous articles my main focus was on Leishmania equatorensis and the genus Leishmania.  The last article I looked at suggested that Leishmania equatorensis was more related to the Genus Endotrypanum.  I decided to focus on the Genus Endotrypanum for this third article to see what I could find out.

             In this study, Soares et. al. (1991) looked at the structures within species of the genus Endotrypanum.  The main focus of the researchers was the mitochondria, glycosomes, lipid inclusions, and membrane bound vacuoles.  Measurements were taken of each organelle so that the dimensions and volumes could be compared among species.  Only two species of Endotrypanum have been described, Endotrypanum monterogeii and Endotrypanum schaudinni.  Four strains of these parasites were looked at under an electron microscope, and electron micrographs were taken to get measurements of the organelles.  The results of this study showed that the four strains had the same morphological structures, and it was also stated that all the structures looked at are common among all trypanosomatids, which includes the genus Leishmania.  The study showed that there were no differences between the two species of Endotrypanum that could be used to tell them apart.  The glycosomes and lipid inclusions were larger in E. monterogeii than in E. schaudinni, however researchers suggested that the small differences could be due to physiological conditions.  However there was a strain, in this study labeled as IM201 (Endotrypanum sp.), that could be differentiated from the others due to the size of the kinetoplastid, and from the larger volume that its mitochondria and glycosome took up in the cell.  The data are more in agreement with data collected from individuals of the species Leptomonas samueli and Leishmania donovani.  As a result of differences seen in strain IM201, researchers suggest that this strain may not be of the genus Endotrypanum. 

As stated before, all members of the family trypanosomatidae have the morphological structures that were looked at in this study, and as mentioned before this family includes the genus Leishmania.  Knowing all of this, can these structures be looked at in what is now known as Leishmania equatorensis and be compared to the two species of Endotrypanum to determine if there are any differences between the two genera?  The papers I have found on L. equatorensis only focus on the molecular make up of the parasite, and not on the size and volume of its morphological features.  The sizes of the internal organelles are in no way going to definitively tell us what L. equatorensis is more closely related to but in conjunction with what is known about its molecular make up it may help give us a better idea of where it belongs.  One question I have after reading this paper is, are there any morphological structures that are specific to the genus Leishmania or to the genus Endotrypanum that could be used to help in identification of new species?  Going along with this question, I’m curious as to how Leishmania and Endotrypanum have been divided into two different genera.  Is it based only on molecular differences?    There is so little known about Endotrypanum and of L. equatorensis that there are so many unanswered questions. 

Soares, M. J.,  A. Lopes, and W. De Souza.  1991.  Ultrastructural and Stereological Analysis of Trypanosomatids of the Genus Endotrypanum.  Mem. Inst. Oswaldo Cruz. 86(2):  175-180.