Testing the resource trade-off hypothesis for carotenoid-based signal honesty using genetic variants of the domestic canary.

Carotenoid-based coloration in birds is widely considered an honest signal of individual condition, but the mechanisms responsible for condition dependency in such ornaments remain debated. Currently, the most common explanation for how carotenoid coloration serves as a reliable signal of condition is the resource trade-off hypothesis, which proposes that use of carotenoids for ornaments reduces their availability for use by the immune system or for protection from oxidative damage. However, two main assumptions of the hypothesis remain in question: whether carotenoids boost the performance of internal processes such as immune and antioxidant defenses, and whether allocating carotenoids to ornaments imposes a trade-off with such benefits.

Rapid Antagonistic Coevolution in an Emerging Pathogen and Its Vertebrate Host.

Host-pathogen coevolution is assumed to play a key role in eco-evolutionary processes, including epidemiological dynamics and the evolution of sexual reproduction [1-4]. Despite this, direct evidence for host-pathogen coevolution is exceptional [5-7], particularly in vertebrate hosts. Indeed, although vertebrate hosts have been shown to evolve in response to pathogens or vice versa [8-12], there is little evidence for the necessary reciprocal changes in the success of both antagonists over time [13].

Linking stress and immunity: Immunoglobulin A as a non-invasive physiological biomarker in animal welfare studies.

As the animal welfare community strives to empirically assess how care and management practices can help maintain or even enhance welfare, the development of tools for non-invasively measuring physiological biomarkers is essential. Of the suite of physiological biomarkers, Immunoglobulin A (IgA), particularly the secretory form (Secretory IgA or SIgA), is at the forefront because of its crucial role in mucosal immunity and links to physical health, stress, and overall psychological well-being. While interpretation of changes in SIgA concentrations on short time scales is complex, long-term SIgA patterns are consistent: conditions that create chronic stress lead to suppression of SIgA.

Detection of Mycoplasma gallisepticum in House Finches ( Haemorhous mexicanus) from Arizona.

In 1994, an endemic poultry pathogen, Mycoplasma gallisepticum (MG), was identified as the causative agent of a novel disease in house finches ( Haemorhous mexicanus). After an initial outbreak in Maryland, MG spread rapidly throughout eastern North American populations of house finches. Subsequently, MG spread slowly through the northern interior of North America and then into the Pacific Northwest, finally reaching California in 2006.

Bacterial Pathogen Emergence Requires More than Direct Contact with a Novel Passerine Host.

While direct contact may sometimes be sufficient to allow a pathogen to jump into a new host species, in other cases, fortuitously adaptive mutations that arise in the original donor host are also necessary. Viruses have been the focus of most host shift studies, so less is known about the importance of ecological versus evolutionary processes to successful bacterial host shifts. Here we tested whether direct contact with the novel host was sufficient to enable the mid-1990s jump of the bacterium from domestic poultry to house finches ().

Ketocarotenoid circulation, but not retinal carotenoid accumulation, is linked to eye disease status in a wild songbird.

Pathogenic or parasitic infections pose numerous physiological challenges to organisms. Carotenoid pigments have often been used as biomarkers of disease state and impact because they integrate multiple aspects of an individual's condition and nutritional and health state. Some diseases are known to influence carotenoid uptake from food (e.

Identification of a novel subtype of South River virus (family Bunyaviridae).

We previously reported the isolation of South River virus (SORV) from a pool of mosquitoes collected in the Yucatan Peninsula of Mexico (Farfan-Ale et al. in Vector Borne Zoonotic Dis 10:777-783, 5). The isolate (designated SORV-252) was identified as SORV after a 197-nucleotide region of its small RNA genome segment was sequenced.

Universal primers for the amplification and sequence analysis of actin-1 from diverse mosquito species.

We report the development of universal primers for the reverse-transcription polymerase chain reaction (RT-PCR) amplification and nucleotide sequence analysis of actin cDNAs from taxonomically diverse mosquito species. Primers specific to conserved regions of the invertebrate actin-1 gene were designed after actin cDNA sequences of Anopheles gambiae, Bombyx mori, Drosophila melanogaster, and Caenorhabditis elegans. The efficacy of these primers was determined by RT-PCR with the use of total RNA from mosquitoes belonging to 30 species and 8 genera (Aedes, Anopheles, Culex, Deinocerites, Mansonia, Psorophora, Toxorhynchites, and Wyeomyia).

Detection of flaviviruses and orthobunyaviruses in mosquitoes in the Yucatan Peninsula of Mexico in 2008.

A total of 191,244 mosquitoes from 24 species were collected in the Yucatan Peninsula of Mexico from January to December 2008, and tested for the presence of cytopathic virus by virus isolation in Vero cells. Eighteen virus isolates were obtained, all of which were orthobunyaviruses. These were identified by reverse transcription-polymerase chain reaction (RT-PCR) and nucleotide sequencing as Cache Valley virus (n=17) and South River virus (n=1).

Genomic sequence and phylogenetic analysis of Culex flavivirus, an insect-specific flavivirus, isolated from Culex pipiens (Diptera: Culicidae) in Iowa.

Adult mosquitoes (Diptera: Culicidae) were collected in 2007 and tested for specific viruses, including West Nile virus, as part of the ongoing arbovirus surveillance efforts in the state of Iowa. A subset of these mosquitoes (6,061 individuals in 340 pools) was further tested by reverse transcription-polymerase chain reaction (RT-PCR) using flavivirus universal primers. Of the 211 pools of Culex pipiens (L.