International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)

Plenary Presentations * Oral Presentations *
Poster Presentations: Complex Genetics and Disease Modifiers * Developmental Genetics * Functional Genomics * Gene Discovery * Genetic Manipulations to Alter Gene Function * Mouse Models: Human Disease and Pharmacogenetics * Sequence Annotation and Comparative Analysis of Genomes *
Attendees * Sponsors * Table of Contents * Photographs * Awards

POSTER 157 - TRYPANOSOME RESISTANCE IN MICE IS ASSOCIATED WITH A BETTER CAPACITY TO CONTROL PARASITEMIA, BUT NOT ANEMIA

J. Naessens
ILRI

Nakamura Y, Iraqi F
ILRI

We used a mouse model, comparing susceptible A/J and more resistant C57BL/6 mice to identify genes that confer resistance to trypanosomosis. In previous studies three major QTL were identified in A/J x C57BL/6 crosses based on the longer survival time of C57BL/6 mice.To find out whether survival time depends on control of parasitemia or control of anemia, a series of infections with Trypanosoma congolense (a ruminant parasite) and T. brucei rhodesiense (a human parasite) were compared between A/J and C57BL/6. Parasitemias were much higher in A./J mice than in C57BL/6, although this was less considerable for T. b. rhodesiense. The first wave of parasitemia coincided with a first peak of mortality amongst the A/J, suggesting that they died as a consequence of high trypanosome numbers.  A second phase of mortality occurred during the later parasitemic waves. In contrast, anemia was more severe in the resistant C57BL/6.  The resistant mice were able to control trypanosome numbers, but not the associated anemia.  It is possible that they died as a result of severe anemia or other harmful side effects associated with infection.  These data suggest that the capacity to control parasitemia and the capacity to control anemia are two unrelated traits.  As survival time was used as the criterion to identify resistance-QTLs, it seems likely that the QTL will be linked to the mechanism that controls parasitemia. Indeed, the first peak of parasitemia occurs before the development of serious anemia.