Study of Bovine Trypanotolerance by Whole Transcriptome Analysis

Abstract

African trypanosomiases are parasitic diseases transmitted by tse-tse flies, considered as the main sanitary obstacle to animal production development in sub-Saharan Africa. However, if trypanosomiases have dramatic consequences on zebu (Bos indicus) populations, they have a weaker impact on the western African taurine (Bos taurus), which is known to be naturally tolerant to trypanosome infection. Mechanisms governing this trypanotolerant trait are still poorly understood, but today, recent postgenomic biotechnologies, such as the SAGE technique (serial analysis of gene expression) allow us to explore the full transcriptome. Twelve SAGE libraries were constructed from two trypanotolerant animals (N'Dama and Baoulé) and one susceptible species of cattle (the Sudanese zebu) during an experimental Trypanosoma congolense infection; 43,458 different tags were obtained at several particular points during the infection (before infection, at the maximum of parasitemia, the maximum of anemia, and at the end of the experiment after value normalization). Bioinformatics analyses highlighted some interesting gene variations with respect to the trypanotolerance status of the animal.

Climate change and the characterization, breeding and conservation of animal genetic resources

“…2008) and study gene expression (e.g. Berthier et al. 2008) in relation to these diseases, but no reports verifying causal mutations have been produced.…”

African Trypanosomes Undermine Humoral Responses and Vaccine Development: Link with Inflammatory Responses?

“…Whether these latter approaches will lead to the development of an effective protective and antipathology vaccine will be challenging and possibly not achievable given that African trypanosomes undermine B-cell memory responses. In addition, also the whole genome transcriptome analysis (i.e., SAGE technique) that enables to (i) explore the full transcriptome of trypanosusceptible and trypanotolerant cattle might lead to the identification of interesting gene variations linked to the trypanotolerance status of the animal (151–153) and (ii) understand the molecular aspects of the trypanosome dialog with its tsetse and mammalian hosts (i.e., interaction with the salivary glands and LS versus SS differentiation, respectively) might pave the way to develop novel diagnostic/therapeutic intervention strategies (154, 155). Furthermore, although the loss of B-cell responses/memory during AT might rely on either a parasite-induced or a host-induced effect or a combination of both, understanding the molecular mechanisms used by the trypanosomes to dampen B cell responses might lead to the development of new therapeutics not only for AT but also for other diseases such as autoimmune diseases (i.e., CIA) or malaria, where B-cell dysfunction is contributing to the disease outcome (131, 156–158).…”

Untitled

“…12 Whole transcriptome analysis has revealed the gene variations related to the trypanotolerance trait in cattle. 16 Trypanotolerance was associated with increases, at the early phase, in transcripts for genes encoding proinflammatory cytokine mediators during infection of N'Dama cattle. 17 Temporal peripheral blood mononuclear cell gene expression in response to trypanosome infection was also recognised to be contributory to trypanotolerance in N'Dama cattle.…”