References

Anisimova, M. and Liberles, D.A. (2007) The quest for natural selection in the age of comparative genomics. Heredity 99, 567-579. Avila, A., Silverman, N., Diaz-Meco, M.T., and Moscat, J. (2002) The Drosophila atypical protein kinase C-ref(2)P complex constitutes a conserved module for signaling in the toll pathway. Molecular and Cellular Biology 22, 8787-8795. Bangham, J., Obbard, D.J., Kim, K.W. et al. (2007) The age and evolution of an antiviral resistance mutation in Drosophila...

Evolutionary patterns in the antiviral immune response

Early characterization of the immune response focused primarily on antimicrobial defence. Antiviral defence is at least partially distinct from that against microbes, and currently is only poorly understood. Both the Toll and Imd pathways are activated during the course of some viral infections however, only the Toll pathway seems to confer protection (Lemaitre and Hoffmann, 2007). RNAi provides an independent mechanism of defence that is specific against RNA viruses (Wang et al., 2006)....

Interaction between the local and systemic immune response

The local immune response in diverse epithelia and the systemic immune response of the fat body are independent immune mechanisms, as each can be selectively induced depending on the mode of infection. However, some infections may require coordination of both systems to fully control pathogens. Recently, a number of recent studies have identified potential mechanisms that facilitate communication between the different immune compartments of Drosophila (Figure 2.6). 2.4.1 Gut infection and fat...

The fibrinogen domain immunolectin FBN gene family

Members of the FBN gene family, also known as fibrinogen-related proteins (FREPs), share a fibrinogen-like domain (FBG) that is evolutionarily conserved and extends from invertebrates to mammals (Gokudan et al., 1999 Fujita, 2002 Wang et al., 2005). In mammals, fibrinogen participates in both the cellular and fluid phases of coagulation. This soluble plasma protein is composed of six polypep-tide chains, two each of the Aa, Bp, and y chains (Gorkun et al, 1997). The FBG domain consists of...

The puzzle of acute stressinduced immunosuppression in animals

When responding to danger, animals shift into a new physiological state the acute stress response. Most of the resulting alterations in physiological function optimize the animal's ability to perform flight-or-fight behaviours (Figure 11.1 insects, Roeder, 2005 mammals, Charmandari et al., 2005). However, the effects of acute stress on immune function seem maladaptive. Acute stress is immunosuppressive in animals from three different phyla (Chordata, Mollusca, and Arthropoda) (Adamo, 2008b). It...

Why does acute stressinduced immunosuppression exist

Increased susceptibility to disease during flight-or-fight should reduce survival. As Dhabhar (2002) has pointed out, during fighting or fleeing, animals run a real risk of injury and, therefore, exposure to pathogens. Although it might make good adaptive sense to delay copulation, digestion, and egg-laying until the predator has passed, the immune response may not be dispensable during flight-or-fight behaviours, because of the increased risk of injury (Dhabhar, 2002). Nevertheless, animals...

The systemic immune response AMPs

Center Dap Peptidoglycan

Among the various molecules produced by the fat body in response to infection, AMPs are the best characterized reviewed in Imler and Bulet, 2005 . Gene transcripts encoding AMPs are not detected in uninfected conditions, and molecular studies have revealed that their expression is induced upon infection. Over 20 AMPs, which comprise seven classes, have been identified. They are small lt 10 kDa with the exception of the 25 kDa Attacin , cationic, and exhibit a broad range of activities against...

From genotype to phenotype

All the patterns discussed thus far have pertained to the long-term evolution of the immune system. It is important to remember, however, that all adaptive evolution is based on phenotypic polymorphism that segregates in populations at some point in time. Indeed, extant natural populations harbour considerable genetic variation for immunocompe-tence. This segregating phenotypic variation is the substrate for short-term evolution. Understanding its genetic basis and the forces governing its...

Epithelial immunity the local immune response

The systemic immune response has been studied through the direct introduction of pathogens into the body cavity. This approach has limited the study of the immune response to the steps involved in recognition and antimicrobial response in the fat body. While these studies have revealed insights on the molecular basis of the Drosophila immune response, they may not reflect the most common mode of host interaction with potential pathogens. In metazoans, the epithelia of the digestive,...

Models of Drosophila virus infection

Insects are susceptible to highly diverse families of RNA and DNA viruses Friesen and Miller, 2001 . Interestingly, many members of these insect virus families have counterparts in vertebrates. This is the case for insect viruses that belong to the families Poxviridae, Reoviridae, Picornaviridae, or Parvoviridae, and this observation suggests that viruses of vertebrates and invertebrates have common origins. The unusual conservation of specific genes found in baculoviruses, entomopoxviruses,...