FMRFamide-like peptides expand the behavioral repertoire of a densely connected nervous system

Animals, including humans, can adapt to environmental stress through phenotypic plasticity. The free-living nematode Caenorhabditis elegans can adapt to harsh environments by undergoing a whole-animal change, involving exiting reproductive development and entering the stress-resistant dauer larval stage. The dauer is a dispersal stage with dauer-specific behaviors for finding and stowing onto carrier animals, but how dauers acquire these behaviors, despite having a physically limited nervous system of 302 neurons, is poorly understood. We compared dauer and reproductive development using whole-animal RNA sequencing at fine time points and at sufficient depth to measure transcriptional changes within single cells. We detected 8,042 genes differentially expressed during dauer and reproductive development and observed striking up-regulation of neuropeptide genes during dauer entry. We knocked down neuropeptide processing using sbt-1 mutants and demonstrate that neuropeptide signaling promotes the decision to enter dauer rather than reproductive development. We also demonstrate that during dauer neuropeptides modulate the dauer-specific nictation behavior (carrier animal-hitchhiking) and are necessary for switching from repulsion to CO2 (a carrier animal cue) in nondauers to CO2 attraction in dauers. We tested individual neuropeptides using CRISPR knockouts and existing strains and demonstrate that the combined effects of flp-10 and flp-17 mimic the effects of sbt-1 on nictation and CO2 attraction. Through meta-analysis, we discovered similar up-regulation of neuropeptides in the dauer-like infective juveniles of diverse parasitic nematodes, suggesting the antiparasitic target potential of SBT-1. Our findings reveal that, under stress, increased neuropeptide signaling in C. elegans enhances their decision-making accuracy and expands their behavioral repertoire.

Restor(y)ing the ‘fierce green fire’: animal agency, wolf conservation and environmental memory in Yellowstone National Park

This paper tracks human–animal entanglements through one particular species, Canis lupus, the wolf, with a view to exploring how this contested predator might be used to unpack normative assumptions about wildlife science, conservation practice and storytelling. The focus of attention here is on Yellowstone National Park and the century-long struggle to eradicate and then restore the wolf based on the shifting rubrics of science and environmental ethics. The ‘wild heart’ of North America and a centre of scientific and popular environmental mythology, Yellowstone presents a useful terrain (both material and contextual) in which to theorize the wolf as an environmental agent and explore its special provenance within an evolving narrative of ecological science. More specifically, the landmark story of restor(y)ation that played out in the national park serves to illuminate the complex web of temporality, narrative and memory that frames our configurations of animal agency. Wiped out in the late nineteenth and early twentieth centuries and ruminated on in the interwar period, the wolf was returned to ancestral haunts in the 1990s (to great fanfare) as a charismatic poster animal for environmental consciousness and a vital ‘missing link’ in the psychological and biotic fabric of the landscape. Ornamented with what conservationist Aldo Leopold famously called a ‘fierce green fire’, the wolf became a carrier animal for Yellowstone's environmental memory, transporting with it the fates of other threatened species and the promise of an enlightened Ecological Age. Beneath this teleological tale of expanding biological knowledge and ethical awakening lies a convoluted (and interesting) story that reveals the sinuous connections between the material and the imagined animal as well as the challenges and the complexities of reading non-human traces.

The detection of toxigenicCorynebacterium ulceransfrom cats with nasal inflammation in Japan

SUMMARYCorynebacterium ulcerans(toxigenicC. ulcerans) produces the diphtheria toxin, which causes pharyngeal and cutaneous diphtheria-like disease in people, and this bacterium is commonly detected in dogs and cats that are reared at home. It is considered dangerous when a carrier animal becomes the source of infection in people. To investigate the carrier situation of toxigenicC. ulceransof cats bred in Japan, bacteria were isolated from 37 cats with a primary complaint of rhinitis in 16 veterinary hospitals in Osaka. ToxigenicC. ulceranswas detected in two of the cats. By drug sensitivity testing, the detected bacterium was sensitive to all investigated drugs, except clindamycin. It appears necessary to create awareness regarding toxigenicC. ulceransinfection in pet owners because this bacterium is believed to be the causative organism for rhinitis in cats.

Infection cycle of Salmonella enterica serovar Enteritidis in latent carrier mice 1The work was carried out at the Microbial Biotechnology Laboratory of Universidade Estadual de Santa Cruz, Ilhéus, Bahia State, Brazil.

This work reports the distribution of an oral dose of Salmonella enterica serovar Enteritidis (SE) in C57Bl/6-Bcgr mice, to study its pathogenesis in a latent carrier animal. Mice orally inoculated with a high dose of SE developed a latent infection characterized by the absence of clinical symptoms in which the cecum is functioning as a “strategic site” of SE proliferation, releasing bacteria into feces intermittently over the 4-week study. A sequence of disruptions occurred in the small intestine at 1 day postinculation (PI). The microvilli exhibited different degrees of degeneration, which were reversible as the cells became vacuolated. From 2 days PI, SE was detected in the mononuclear phagocytic system, and an exponential growth of the remaining bacteria in tissues was observed until 4 days PI. The production of interferon gamma from 3 days PI is restricting the SE growth, and a plateau phase was observed from 4 to 15 days PI. A recurrence of the bacterial growth in tissue occurred from 15 to 28 days PI, especially in the cecum. Increasing our knowledge about the host–pathogen interaction of adapted pathogens with the ability to develop latency is essential for the development of an efficient strategy for Salmonella control.

Factor XI mutation in normally fertile and repeat breeding Holstein cows in the Middle Anatolian region of Turkey: a financial approach

The aim of this study was to compare the prevalence of factor XI deficiency (FXID) carriers and potential financial losses depending on ‘extended calving interval’ and ‘extra service’ in normally fertile and repeat breeder cows in Turkey. For this purpose, a total of 161 Holstein cows were genotyped for the FXI gene mutation originating from various herds located in the Middle Anatolian region of Turkey. In the study, animals were divided into two groups – normally fertile (n = 118) and repeat breeding (n = 43) cows. In each group, one FXID carrier animal was identified and the prevalence of the FXID carrier was found to be 0.85 and 2.33% in normally fertile and repeat breeder cows, respectively. In a financial analysis, it was determined that extended calving interval in a normally fertile cow caused $246 losses and $546 losses in a repeat breeder cow. Additionally, financial losses due to extra service per conception were calculated as $12 and $36 per cow in normally fertile and repeat breeder cows, respectively. In normally fertile and repeat breeder cows, the sum of losses due to extended calving interval and extra service was calculated as $258 (246 + 12) and $582 (546 + 36). This study found that a repeat breeder cow causes an extra $324 ($582 – $258) financial loss compared with a normally fertile cow. Consequently, unlike other genetic disorders like BLAD and DUMPS, which do not decrease the performance of carrier animals, the mutant FXI allele could lead to repeat breeder syndrome in FXID carrier cows and cause important financial losses in dairy farms.

Detection of a carrier state in Theileria parva-infected cattle by the polymerase chain reaction

SUMMARYTwo sets of oligonucleotide primers, one derived from a repetitive sequence and the other from the gene encoding a 67 kDa sporozoite antigen of Theileria parva, were used to amplify parasite DNA from the blood of T. parva-infected carrier cattle using the polymerase chain reaction (PCR). PCR amplification products were obtained from 15 carrier cattle infected with one of 4 different T. parva stocks. Successful amplifications were performed using DNA from 2 cattle infected with T. p. parva Pemba Mnarani, 10 cattle infected with T. p. parva Marikebuni, 2 cattle infected with T. p. bovis Boleni and 1 animal infected with T. p. lawrencei 7014. No amplification products were obtained from any of 7 cattle which had been infected with the T. p. parva Muguga stock. A synthetic oligonucleotide, which hybridized specifically to T. p. parva Marikebuni DNA among 6 T. parva stocks tested, was designed using sequence data from within the region of the T. parva genome amplified by the repetitive sequence primers. The oligonucleotide was used to probe PCR products and to increase the sensitivity and specificity of carrier animal detection. Southern blot analysis using a T. parva repetitive sequence probe demonstrated the existence of restriction fragment length polymorphisms between parasites isolated from T. p. parva Marikebuni-infected carrier cattle. The use of the PCR and other methods of carrier animal detection are discussed.

Time Required to Achieve Homogeneity of Test Substances Added to Dog Feed

The homogeneity of test substances in a carrier (animal feed) is a critical factor In conducting long-term feeding studies in laboratory animals. A method for determining the adequate amount of mixing to achieve homogeneity by a mixer of the type described has been determined when 2 distinctly different compounds are added to ground dog feed. Nicotinic acid and butylated hydroxyanlsole at a concentration of 1% were separately mixed with the dog feed for 15,30,45,60, and 120 min to determine optimum mixing time. Test portions were taken from 4 different sampling sites at each time period and analyzed in duplicate for the added substance. Four batches were prepared and the results were aggregated. Very little interbatch variability was observed. The variance of the average values from the 4 sampling sites at each time period was calculated and used as a simple, crude, but effective numerical quantity to monitor the approach to homogeneity of the mixture.

Observations on the carrier state and related antibody titres during an outbreak of foot-and-mouth disease

SummaryAn outbreak of foot-and-mouth disease in a partially immune population of cattle in Botswana is described. The results show that when cattle immunized by vaccination were presented with natural field challenge of FMD, many animals with immunity sufficient to protect them against clinical disease were, however, susceptible to pharyngeal infection and subsequently became virus carriers. The proportion of animals becoming carriers appeared to vary with the degree of severity of the challenge.Vaccination before exposure to virus appeared to have little effect on the duration of the carrier state. No evidence was obtained of the spread of carrier virus to immune herds following the outbreak.Antibody titres during the outbreak were higher in the clinically infected animals than in the carrier animals and the uninfected animals. Evidence suggested that natural challenge boosted the titres of immune animals. After the outbreak, however, it was not possible to distinguish by their antibody titres between the carrier animal and the virus-negative animal.Antigenic studies on the strains of virus isolated are described.