Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens.

The immune and the detoxication systems of animals are characterized by allelic polymorphisms, which underlie individual differences in ability to combat assaults from pathogens and toxic compounds. Previous studies have shown that females may improve offspring survival by selecting mates on the basis of sexual ornaments and signals that honestly reveal health. In many cases the expression of these ornaments appears to be particularly sensitive to oxidative stress. Activated immune and detoxication systems often generate oxidative stress by an extensive production of reactive metabolites and free radicals. Given that tolerance or resistance to toxic compounds and pathogens can be inherited, female choice should promote the evolution of male ornaments that reliably reveal the status of the bearers' level of oxidative stress. Hence, oxidative stress may be one important agent linking the expression of sexual ornaments to genetic variation in fitness-related traits, thus promoting the evolution of female mate choice and male sexual ornamentation, a controversial issue in evolutionary biology ever since Darwin.

/pdf/good-genes-oxidative-stress-and-condition-dependent-sexual-3va7efohyd.pdf

Good genes, oxidative stress and condition-dependent sexual signals

Theories of animal signalling emphasize the importance of costliness-to be effective, signals must be dependable; to be dependable, signals must carry costs-and carotenoid-based signals are a favoured example. The traditional view that carotenoids are costly because they are scarce still carries weight. However, biomedical research has led to alternative views on costliness, mainly related to beneficial, but also to detrimental, effects of carotenoids. Recent improvements in our understanding of carotenoids suggest that the relative importance of these mechanisms will soon be determined, leading to a fresh outlook on cost-based signalling.

Costly sexual signals: Are carotenoids rare, risky or required?

Hypoxia is a characteristic feature of the tissue microenvironment during bacterial infection. Here we report on our use of conditional gene targeting to examine the contribution of hypoxia-inducible factor 1, alpha subunit (HIF-1alpha) to myeloid cell innate immune function. HIF-1alpha was induced by bacterial infection, even under normoxia, and regulated the production of key immune effector molecules, including granule proteases, antimicrobial peptides, nitric oxide, and TNF-alpha. Mice lacking HIF-1alpha in their myeloid cell lineage showed decreased bactericidal activity and failed to restrict systemic spread of infection from an initial tissue focus. Conversely, activation of the HIF-1alpha pathway through deletion of von Hippel-Lindau tumor-suppressor protein or pharmacologic inducers supported myeloid cell production of defense factors and improved bactericidal capacity. HIF-1alpha control of myeloid cell activity in infected tissues could represent a novel therapeutic target for enhancing host defense.

/pdf/hif-1a-expression-regulates-the-bactericidal-capacity-of-4rkvdojn3h.pdf

HIF-1α expression regulates the bactericidal capacity of phagocytes

In this chapter, we discuss the diseases and related pathologic alterations that may be encountered in the gastrointestinal tract and associated organs of various species of laboratory animals, birds, fish, reptiles, and amphibians. Diseases of various segments of the gastrointestinal tract, the salivary glands, liver, and pancreas are discussed and categorized as inflammatory, parasitic, neoplastic, or miscellaneous. The latter category includes developmental anomalies and metabolic lesions. Due to space limitations, this presentation is not an all-inclusive review, but it does provide a rather extensive review of these lesions. We have also included a rather comprehensive literature review, with a list of references for those readers who want more detailed information with respect to specific diseases.

Joyce Johnson

Papers

Anticoccidial drugs: lesion scoring techniques in battery and floor-pen experiments with chickens.

Lowered Blood Carotenoid Levels in Chickens Infected with Coccidia

Eimeria tenella: Clinical Effects in Partially Immune and Susceptible Chickens

Histomoniasis in gnotobiotic chickens and turkeys: Biological aspects of the role of bacteria in the etiology

Practical Immunization of Chickens against Coccidiosis Using an Attenuated Strain of Eimeria tenella