Changes in hypothalamic-pituitary-adrenal axis function, immunity, and glucose during acute Plasmodium relictum infection in house sparrows (Passer domesticus).

Hosts of the same species vary in physiological responses to the same parasite, and some groups of individuals can disproportionately affect disease dynamics; however, the underlying pathophysiology of host-parasite interactions is poorly understood in wildlife. We tested the hypothesis that the hypothalamic-pituitary-adrenal (HPA) axis mediates host resistance and tolerance to avian malaria during the acute phase of infection by evaluating whether individual variation in circulating glucocorticoids predicted resistance to avian malaria in a songbird. We experimentally inoculated wild-caught house sparrows (Passer domesticus) with naturally sourced Plasmodium relictum and quantified baseline and restraint-induced circulating corticosterone, negative feedback ability, cellular and humoral immune function, and baseline and restraint-induced glycemia, prior to and during acute malaria infection. During peak parasitemia, we also evaluated the expression of several liver cytokines that are established pathological hallmarks of malaria in mammals: two pro-inflammatory (IFN-γ and TNF-α) and two anti-inflammatory (IL-10 and TGF-ß). Although most of the host metrics we evaluated were not correlated with host resistance or tolerance to avian malaria, this experiment revealed novel relationships between malarial parasites and the avian immune system that further our understanding of the pathology of malaria infection in birds. Specifically, we found that: (1) TNF-α liver expression was positively correlated with parasitemia; (2) sparrows exhibited an anti-inflammatory profile during malaria infection; and (3) IFN-γ and circulating glucose were associated with several immune parameters, but only in infected sparrows. We also found that, during the acute phase of infection, sparrows increased the strength of corticosterone negative feedback at the level of the pituitary. In the context of our results, we discuss future methodological considerations and aspects of host physiology that may confer resistance to avian malaria, which can help inform conservation and rehabilitation strategies for avifauna at risk.

Rising to the Challenge: Mounting an Acute Phase Immune Response Has No Long-Term Negative Effects on Captive Sparrow Migratory Body Composition or Migratory Restlessness.

Migratory animals may trade-off between investing energy in immune defense versus investing in energy reserves needed for seasonal migration. However, these trade-offs are often masked by other sources of variation and may not be detected through observational field studies of free-living animals. Moreover, observational studies can rarely distinguish the costs of pathogenic infection from those of mounting an immune response. To disentangle such effects, we conducted an immune challenge experiment. We captured song sparrows (Melospiza melodia) and white-throated sparrows (Zonotrichia albicollis) in autumn migratory condition, challenged the sparrows with non-infectious antigens that induce an acute-phase immune response, then monitored body composition and migratory restlessness behavior. For both species, body mass was higher the day after exposure to keyhole limpet hemocyanin (KLH) compared to controls. White-throated sparrows, but not song sparrows, increased lean mass 1 week after exposure to lipopolysaccharide (LPS), suggesting that effects of immune upregulation on body composition may be long-lasting and specific to certain combinations of hosts and antigens. White-throated sparrows exposed to KLH increased nocturnal migratory restlessness (Zugunruhe) for the week following exposure. These findings suggest that short-term activation of the acute immune response does not constrain migratory physiology in these songbirds.

Host response to successive challenges with lentogenic and velogenic Newcastle disease virus in local chickens of Ghana.

Newcastle disease (ND) is a highly contagious viral disease that constantly threatens poultry production. The velogenic (highly virulent) form of ND inflicts the most damage and can lead to 100% mortality in unvaccinated village chicken flocks. This study sought to characterize responses of local chickens in Ghana after challenging them with lentogenic and velogenic Newcastle disease virus (NDV) strains. At 4 wk of age, chicks were challenged with lentogenic NDV. Traits measured were pre- and post-lentogenic infection growth rates (GR), viral load at 2 and 6 d post-lentogenic infection (DPI), viral clearance rate and antibody levels at 10 DPI. Subsequently, the chickens were naturally exposed to velogenic NDV (vNDV) after anti-NDV antibody titers had waned to levels ≤1:1,700. Body weights and blood samples were again collected for analysis. Finally, chickens were euthanized and lesion scores (LS) across tissues were recorded. Post-velogenic exposure GR; antibody levels at 21 and 34 days post-velogenic exposure (DPE); LS for trachea, proventriculus, intestines, and cecal tonsils; and average LS across tissues were measured. Variance components and heritabilities were estimated for all traits using univariate animal models. Mean pre- and post-lentogenic NDV infection GRs were 6.26 g/day and 7.93 g/day, respectively, but mean post-velogenic NDV exposure GR was -1.96 g/day. Mean lesion scores ranged from 0.52 (trachea) to 1.33 (intestine), with males having significantly higher (P < 0.05) lesion scores compared to females. Heritability estimates for the lentogenic NDV trial traits ranged from moderate (0.23) to high (0.55) whereas those for the vNDV natural exposure trial were very low (≤ 0.08). Therefore, in contrast to the vNDV exposure trial, differences in the traits measured in the lentogenic challenge were more affected by genetics and thus selection for these traits may be more feasible compared to those following vNDV exposure. Our results can form the basis for identifying local chickens with improved resilience in the face of NDV infection for selective breeding to improve productivity.

No Guts About It: Captivity, But Not Neophobia Phenotype, Influences the Cloacal Microbiome of House Sparrows (Passer domesticus).

Behavioral traits such as anxiety and depression have been linked to diversity of the gut microbiome in humans, domesticated animals, and lab-bred model species, but the extent to which this link exists in wild animals, and thus its ecological relevance, is poorly understood. We examined the relationship between a behavioral trait (neophobia) and the cloacal microbiome in wild house sparrows (Passer domesticus, n = 22) to determine whether gut microbial diversity is related to personality in a wild animal. We swabbed the cloaca immediately upon capture, assessed neophobia phenotypes in the lab, and then swabbed the cloaca again after several weeks in captivity to additionally test whether the microbiome of different personality types is affected disparately by captivity, and characterized gut microbiomes using 16S rRNA gene amplicon sequencing. We did not detect differences in cloacal alpha or beta microbial diversity between neophobic and non-neophobic house sparrows, and diversity for both phenotypes was negatively impacted by captivity. Although our results suggest that the adult cloacal microbiome and neophobia are not strongly linked in wild sparrows, we did detect specific OTUs that appeared more frequently and at higher abundances in neophobic sparrows, suggesting that links between the gut microbiome and behavior may occur at the level of specific taxa. Further investigations of personality and the gut microbiome are needed in more wild species to reveal how the microbiome-gut-brain axis and behavior interact in an ecological context.

Infectious Bronchitis Virus Surveillance in Broilers in California (2012-20).

Infectious bronchitis virus (IBV) causes severe economic losses among chicken flocks worldwide. Although IBV molecular surveillance has been conducted in California broilers, seasonal and spatial-temporal trends in IBV prevalence are poorly defined. The goals of this study were to evaluate seasonal and spatial-temporal trends in IBV prevalence and to determine the predominant IBV genotypes obtained over the last 8 yr from a broiler company located in the California Central Valley. In total, 3439 broilers with a suspicion of IBV infection were submitted to the California Animal Health and Food Safety laboratories between January 2012 and February 2020. Swabs from tracheas, kidneys, and cecal tonsils from each submission were independently pooled and screened for IBV using reverse transcriptase quantitative PCR (RT-qPCR). Positive samples were submitted for virus isolation. Viral isolates were subject to a conventional RT-PCR targeting the S1 gene hypervariable region. Positive samples from this RT-PCR were sequenced, and phylogenetic analyses were performed. In total, 1243 pooled swab samples were positive for IBV. Positive results were more frequently detected in fall and winter months compared to spring. Spatial analyses revealed an IBV hot spot in the vicinity of Livingston, and two areas with a low prevalence (i.e., cold spots) around Riverdale. The IBV spatial-temporal distribution identified three significant clusters: one hot spot around Turlock from 2015 to 2016, a second hot spot around Merced from 2012 to 2016, and a cold spot around Fresno from 2017 to 2020. Predominant genotypes changed over time from IBV Cal 99, which was predominant between 2012 and 2014, to IBV 3099 in 2019. Vaccination efforts were initiated in 2018, and as a result, we detected an emerging variant with 92% similarity to CA 3099 in 2020. This work highlights the importance of ongoing surveillance in IBV prevention programs. Surveillance strategies are necessary to monitor trends in diseases such as infectious bronchitis, and the tools used for surveillance need to be sensitive enough to detect new variants and identify spatial-temporal trends.

Vigilancia del virus de la bronquitis infecciosa en pollos de engorde en California (2012­2020). El virus de la bronquitis infecciosa (IBV) causa graves pérdidas económicas entre las parvadas de pollos en todo el mundo. Aunque la vigilancia molecular del virus de la bronquitis infecciosa se ha realizado en pollos de engorde en el estado de California, las tendencias estacionales y espacio-temporales sobre la prevalencia de este virus están mal definidas. Los objetivos de este estudio fueron evaluar las tendencias estacionales y espacio-temporales sobre la prevalencia del virus de la bronquitis infecciosa y determinar los genotipos predominantes de este virus obtenidos durante los últimos ocho años de una empresa de pollos de engorde ubicada en el Valle Central de California. En total, 3439 pollos de engorde con sospecha de infección por el virus de la bronquitis infecciosa se enviaron a los laboratorios de Salud Animal y Seguridad Alimentaria del estado de California entre enero del 2012 y febrero del 2020. Los hisopos de tráqueas, riñones y tonsilas cecales de cada caso se combinaron de forma independiente y se examinaron para detectar al virus de la bronquitis utilizando transcripción reversa y un método cuantitativo de PCR (RT-qPCR). Se enviaron muestras positivas para aislamiento del virus. Los aislados virales se sometieron a un método convencional de RT-PCR dirigido a la región hipervariable del gene S1. Se secuenciaron muestras positivas mediante la prueba RT-PCR y se realizaron análisis filogenéticos. Un total de 1243 muestras combinadas de hisopos dieron positivo para el virus de la bronquitis infecciosa. Los resultados positivos se detectaron con mayor frecuencia en los meses de otoño e invierno en comparación con la primavera. Los análisis espaciales revelaron un punto activo para el virus de la bronquitis infecciosa en las cercanías de Livingston y dos áreas con una baja prevalencia (es decir, puntos fríos) alrededor de Riverdale. La distribución espacio-temporal del virus de la bronquitis identificó tres grupos importantes: un punto activo alrededor de Turlock entre los años 2015 a 2016, un segundo punto activo alrededor de Merced entre los años 2012 a 2016 y un punto frío alrededor de Fresno entre los años 2017 a 2020. Los genotipos predominantes cambiaron con el tiempo, consideraron el subtipo IBV Cal 99, que fue predominante entre 2012 y 2014, a el tipo IBV 3099 en 2019. Los esfuerzos de vacunación se iniciaron en el 2018, y como resultado, detectamos una variante emergente con un 92% de similitud con el virus CA 3099 en 2020. Este trabajo destaca la importancia de la vigilancia continua en los programas de prevención para la bronquitis infecciosa. Las estrategias de vigilancia son necesarias para monitorear las tendencias en enfermedades como la bronquitis infecciosa, y las herramientas utilizadas para la vigilancia deben ser lo suficientemente sensibles como para detectar nuevas variantes e identificar tendencias espacio-temporales.

No, you go first: phenotype and social context affect house sparrow neophobia.

Novel object trials are commonly used to assess aversion to novelty (neophobia), and previous work has shown neophobia can be influenced by the social environment, but whether the altered behaviour persists afterwards (social learning) is largely unknown in wild animals. We assessed house sparrow (Passer domesticus) novel object responses before, during and after being paired with a conspecific of either similar or different behavioural phenotype. During paired trials, animals housed with a similar or more neophobic partner demonstrated an increased aversion to novel objects. This change did not persist a week after unpairing, but neophobia decreased after unpairing in birds previously housed with a less neophobic partner. We also compared novel object responses to non-object control trials to validate our experimental procedure. Our results provide evidence of social learning in a highly successful invasive species, and an interesting asymmetry in the effects of social environment on neophobia behaviour depending on the animal's initial behavioural phenotype.

Experimental Malaria Infection Affects Songbirds' Nocturnal Migratory Activity.

Migratory animals encounter multiple parasite communities, raising concerns that migration may aid transport of infectious disease. How migration affects disease spread depends fundamentally on how disease affects migration, specifically whether infection alters individuals' migratory physiology and behavior. We inoculated white-throated sparrows (Zonotrichia albicollis) with avian malaria parasites (Plasmodium sp.), monitored parasite loads for 5 wk as the birds reached spring migratory condition, and compared nocturnal migratory restlessness (Zugunruhe), body composition (fat, lean, and whole-body mass), and hematocrit among experimentally infected birds, sham-inoculated birds, and birds that were exposed to parasites but resisted infection. Migratory restlessness increased over time in the study, but the rate of change varied between sham (control) birds, infected birds, and birds that resisted infection. We were unable to detect any effects of malaria exposure on body condition. Our findings suggest that encountering parasites affects migratory activity, regardless of whether infection occurs or is resisted.

Alternative reproductive strategies in white-throated sparrows are associated with differences in parasite load following experimental infection.

Immune defences often trade off with other life-history components. Within species, optimal allocation to immunity may differ between the sexes or between alternative life-history strategies. White-throated sparrows (Zonotrichia albicollis) are unusual in having two discrete plumage morphs, white-striped and tan-striped. Within each sex, white-striped individuals are more aggressive and provide less parental care than tan-striped individuals. We extended immunocompetence handicap models, which predict sex differences in immunity and parasitism, to hypothesize that infection susceptibility should be greater in white-striped than tan-striped birds. We inoculated birds of both morphs with malarial parasites. Contrary to our prediction, among birds that became infected, parasite loads were higher in tan-striped than white-striped individuals and did not differ between the sexes. Circulating androgen levels did not differ between morphs but were higher in males than females. Our findings are not consistent with androgen-mediated immunosuppression. Instead, morph differences in immunity could reflect social interactions or life-history-related differences in risk of injury, and/or genetic factors. Although plumage and behavioural morphs of white-throated sparrow may differ in disease resistance, these differences do not parallel sex differences that have been reported in animals, and do not appear to be mediated by differences in androgen levels.

Stable Transmission of Borrelia burgdorferi Sensu Stricto on the Outer Banks of North Carolina.

The spirochaete (Borrelia burgdorferi) associated with Lyme disease was detected in questing ticks and rodents during a period of 18 years, 1991-2009, at five locations on the Outer Banks of North Carolina. The black-legged tick (Ixodes scapularis) was collected at varied intervals between 1991 and 2009 and examined for B. burgdorferi. The white-footed mouse (Peromyscus leucopus), house mouse (Mus musculus) marsh rice rat (Oryzomys palustris), marsh rabbit (Sylvilagus palustris), eastern cottontail (Sylvilagus floridanus) and six-lined racerunner (Cnemidophorus sexlineatus) were live-trapped, and their tissues cultured to isolate spirochaetes. Borrelia burgdorferi isolates were obtained from questing adult I. scapularis and engorged I. scapularis removed from P. leucopus, O. palustris and S. floridanus. The prevalence of B. burgdorferi infection was variable at different times and sites ranging from 7 to 14% of examined questing I. scapularis. Mitochondrial (16S) rRNA gene phylogenetic analysis from 65 adult I. scapularis identified 12 haplotypes in two major clades. Nine haplotypes were associated with northern/Midwestern I. scapularis populations and three with southern I. scapularis populations. Sixteen isolates obtained from tick hosts in 2005 were confirmed to be B. burgdorferi by amplifying and sequencing of 16S rRNA and 5S-23S intergenic spacer fragments. The sequences had 98-99% identity to B. burgdorferi sensu stricto strains B31, JD1 and M11p. Taken together, these studies indicate that B. burgdorferi sensu stricto is endemic in questing I. scapularis and mammalian tick hosts on the Outer Banks of North Carolina.

Chemical composition of preen wax reflects major histocompatibility complex similarity in songbirds.

In jawed vertebrates, genes of the major histocompatibility complex (MHC) play a key role in immunity by encoding cell-surface proteins that recognize and bind non-self antigens. High variability at MHC suggests that these loci may also function in social signalling such as mate choice and kin recognition. This requires that MHC genotype covaries with some perceptible phenotypic trait. In mammals and fish, MHC is signalled chemically through volatile and non-volatile peptide odour cues, facilitating MHC-dependent mate choice and other behaviours. In birds, despite evidence for MHC-dependent mating, candidate mechanisms for MHC signalling remain largely unexplored. However, feather preen wax has recently been implicated as a potential source of odour cues. We examined whether the chemical composition of preen wax correlates with MHC class IIß genotypes of wild song sparrows (Melospiza melodia). Pairwise chemical distance reflected amino acid distance at MHC for male-female dyads, although not for same-sex dyads. Chemical diversity did not reflect MHC diversity. We used gas chromatography-mass spectrometry (GC-MS) to characterize preen wax compounds, and identified four wax esters that best reflect MHC similarity. Provided songbirds can detect variation in preen wax composition, this cue may allow individuals to assess MHC compatibility of potential mates.

Lead in ammunition: a persistent threat to health and conservation.

Many scavenging bird populations have experienced abrupt declines across the globe, and intensive recovery activities have been necessary to sustain several species, including the critically endangered California condor (Gymnogyps californianus). Exposure to lead from lead-based ammunition is widespread in condors and lead toxicosis presents an immediate threat to condor recovery, accounting for the highest proportion of adult mortality. Lead contamination of carcasses across the landscape remains a serious threat to the health and sustainability of scavenging birds, and here we summarize recent evidence for exposure to lead-based ammunition and health implications across many species. California condors and other scavenging species are sensitive indicators of the occurrence of lead contaminated carcasses in the environment. Transdisciplinary science-based approaches have been critical to managing lead exposure in California condors and paving the way for use of non-lead ammunition in California. Similar transdisciplinary approaches are now needed to translate the science informing on this issue and establish education and outreach efforts that focus on concerns brought forth by key stakeholders.

Phacoemulsification of bilateral cataracts in a loggerhead sea turtle (Caretta caretta).

An immature free-living loggerhead sea turtle (Caretta caretta) of unknown sex was found moribund off the coast of Wise Point, Virginia. It was suffering from cachexia and had bilateral hypermature cataracts which were treated by phacoemulsification under general anaesthesia. The surgery restored the turtle's vision and it was returned to the wild.

Facile metal-assisted hydrolysis of a urethane.

Kinetic studies demonstrate that it is possible to achieve large rate enhancements (2 x 10(4)) for the hydrolysis of a urethane group by using metal-bound water or hydroxide as the nucleophile. [reaction: see text]

Progress toward a rationally designed molecular motor.

A retrospective overview of the work in the author's laboratory leading to a prototype (43a) of a chemically powered molecular motor is provided. Beginning with a molecular brake (23) and then proceeding through a molecular "ratchet" (31), the development of a rationally designed molecular motor is described. The thermodynamic underpinnings of the concept are outlined, the synthetic routes to 23, 31, and 43a, are summarized, and the data documenting the function of 23, 31, and 43a are presented.

Synthesis of the potent antimalarials calothrixin A and B.

A concise synthesis of calothrixins A (1) and B (2) that confirms their assigned structures and affords straightforward synthetic access to them is reported.

Synthesis of an orange anthrathiophene pigment isolated from a Japanese bryozoan.

A short, regiospecific synthesis of the naturally occurring anthrathiophene 1 from naphthazarin (7) is described.

Unidirectional rotary motion in a molecular system.

The conversion of energy into controlled motion plays an important role in both man-made devices and biological systems. The principles of operation of conventional motors are well established, but the molecular processes used by 'biological motors' such as muscle fibres, flagella and cilia to convert chemical energy into co-ordinated movement remain poorly understood. Although 'brownian ratchets' are known to permit thermally activated motion in one direction only, the concept of channelling random thermal energy into controlled motion has not yet been extended to the molecular level. Here we describe a molecule that uses chemical energy to activate and bias a thermally induced isomerization reaction, and thereby achieve unidirectional intramolecular rotary motion. The motion consists of a 120 degrees rotation around a single bond connecting a three-bladed subunit to the bulky remainder of the molecule, and unidirectional motion is achieved by reversibly introducing a tether between the two units to energetically favour one of the two possible rotation directions. Although our system does not achieve continuous and fast rotation, the design principles that we have used may prove relevant for a better understanding of biological and synthetic molecular motors producing unidirectional rotary motion.

Ultrastructural aspects of human cystic duct epithelium as a result of cholelithiasis and cholesterolosis.

Although there is a large body of data on the gallbladder and the importance of the cystic duct in surgical procedures, there is insufficient data regarding the morphology of the human cystic duct. In the present study, transmission electron microscopic (TEM) and scanning electron microscopic (SEM) survey of several surgical and autopsy cystic ducts in cholelithiasis and cholesterolosis is reported. In cholelithiasis, similar to gallbladder epithelium, the cystic duct epithelial cells display minor-to-severe alterations of the epithelial surface accompanied by variable erosion of the epithelium. Areas of intact surface epithelium demonstrate microvilli-covered cells coated by a rich glycocalyx and mucous production. In other areas, apical excrescences are associated with mucus hyperproduction and secretory events. Lipoid bodies are also present in many cells and especially in many of the cells' subliminal apical areas. In cholesterolosis, mucous secretory granules appear dilated, fatty deposits are infrequent, and peculiar intracellular cholesterol deposits can be detected in the apical and subapical region of cells and around condensed mitochondria. Following elective cholecystectomies, predominantly in association with cholelithiasis, eroded areas were detected; therefore, it appears that the action of intraluminal calculi may be a principal causative factor in discrete epithelial erosions of the cystic duct. Intraluminal calculi/ debris, along with the alteration of mucus, cell sloughing, and a decreased pool of bile acids and motility may participate in the gallstone nucleation process. The peculiar cholesterol inclusions may also play a role in that nucleating process.

Ultrastructural aspects of human gallbladder epithelial cells in cholelithiasis: production of anionic mucus.

The surface epithelium of 28 gallbladders removed during elective cholecystectomies and pathology collection was studied ultrastructurally. Focusing on 10 of the 28 cases that were diagnosed as cholecystitis, we found that the epithelium displayed numerous apical mucous granules and bulging apical apices. Mucous granule changes included 1) hyperproduction of secretory granules of neutral type containing an electron-dense proteinaceous spherule, similar to that described in other mucus-producing glands of the digestive system, and 2) production of anionic, osmiophilic secretory mucus. Other alterations of the surface epithelial cells included the production of bizarre surface appendages resembling primitive cilia without axoneme and epithelial excrescences.