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We investigate the acoustic structure of alarm calls in a highly social rodent, the Harting's vole (Microtus hartingi) and describe the phenomenon of collective shouting of bursts of alarm calls which could be produced in synchronized series. The alarm calls of Harting's voles were recorded using an automatic device from 10 different family groups, containing from 4 to 15 potential callers, released to outdoor enclosures. Natural predators and humans served as call-eliciting stimuli. We reveal acoustic differences between urgent alarm calls, evoked by close-vicinity predators and identified from recordings by their calls and by rustle noise from the caller's escape to burrow, and other alarm calls. We also reveal acoustic parameters between alarm calls produced in bursts and other alarm calls (produced in individual series or by a few non-synchronized callers). We discuss why the alarm calls of Harting's voles are unusually high-frequency (about 17 kHz on average in the maximum fundamental frequency) among other vole species producing high-frequency alarms. Adaptive significance of producing the collective synchronized bursts of alarm calls by Harting's voles remains unclear without direct observations of vocal vigilance in this species under natural conditions. [ABSTRACT FROM AUTHOR]

Background: Recent studies showed that a single injection of human monoclonal allergen‐specific IgG antibodies significantly reduced allergic symptoms in birch pollen‐allergic patients. Since the production of full monoclonal antibodies in sufficient amounts is laborious and expensive, we sought to investigate if smaller recombinant allergen‐specific antibody fragments, that is, nanobodies, have similar protective potential. For this purpose, nanobodies specific for Bet v 1, the major birch pollen allergen, were generated to evaluate their efficacy to inhibit IgE‐mediated responses. Methods: A cDNA‐VHH library was constructed from a camel immunized with Bet v 1 and screened for Bet v 1 binders encoding sequences by phage display. Selected nanobodies were expressed, purified, and analyzed in regards of epitope‐specificity and affinity to Bet v 1. Furthermore, cross‐reactivity to Bet v 1‐homologues from alder, hazel and apple, and their usefulness to inhibit IgE binding and allergen‐induced basophil activation were investigated. Results: We isolated three nanobodies that recognize Bet v 1 with high affinity and cross‐react with Aln g 1 (alder) and Cor a 1 (hazel). Their epitopes were mapped to the alpha‐helix at the C‐terminus of Bet v 1. All nanobodies inhibited allergic patients' polyclonal IgE binding to Bet v 1, Aln g 1, and Cor a 1 and partially suppressed Bet v 1‐induced basophil activation. Conclusion: We identified high‐affinity Bet v 1‐specific nanobodies that recognize an important IgE epitope and reduce allergen‐induced basophil activation revealing the first proof that allergen‐specific nanobodies are useful tools for future treatment of pollen allergy. [ABSTRACT FROM AUTHOR]

Secondary contact zones between related species are key to understanding speciation mechanisms. The Central European sympatry zone of West European (Erinaceus europaeus) and northern white-breasted (Erinaceus roumanicus) hedgehogs is well studied, whereas data on the Eastern European sympatry zone are scarce. We examined the genetic variation in Russian populations using the mitochondrial Cytb gene, TTR intron 1 and 11 microsatellites to assess genetic variability and distribution patterns. In contrast to the Central European sympatry zone, we found evidence of ongoing hybridization between the two species in the sympatry zone of European Russia, where the proportion of individuals with mixed ancestry was c. 20%. Our data indicate bi-directional mtDNA introgression, but with a higher frequency of E. europaeus haplotypes in hybrids. The proportion of pure specimens with introgressed mitotypes is higher in E. roumanicus than in E. europaeus. Nuclear data showed the prevalence of the genetic contribution from E. roumanicus in admixed individuals. Demographic analyses indicated recent population growth in E. europaeus and little change in E. roumanicus , suggesting that E. europaeus colonized East Europe later than E. roumanicus. [ABSTRACT FROM AUTHOR]

Among ruminants, some species of cervids, bovids and camelids are capable of producing very high-frequency (HF) calls potentially produced by the aerodynamic whistle mechanism. We analysed the HF calls of six individual adult captive camels: three male and one female two-humped Camelus bactrianus and one male and one female one-humped C. dromedarius. Context of emission differed between sexes and individuals. Males of both species vocalised when guarding females during the rut. Females of both species vocalised towards their mates, postpartum (female C. bactrianus) or when protesting against preventing locomotion over enclosure (female C. dromedarius). In either species or sex, the HF calls were faint tonal vocalisations slightly modulated in fundamental frequency (f0). Between species, the calls were significantly lower-frequency (1.7 ± 0.16 kHz) and longer (0.23 ± 0.08 s) in C. bactrianus than in C. dromedarius (3.12 ± 0.11 kHz; 0.16 ± 0.05 s). Nonlinear vocal phenomena (subharmonics and sidebands) occurred in both species but not in all individuals. We discuss the relationship of the f0 of the HF calls with body size and vocal fold length in ruminants. We conclude that the 'whistling' HF calls of C. dromedarius are the highest-frequency vocalisations in Artiodactyla. [ABSTRACT FROM AUTHOR]

Studying pup isolation calls of wild rodents provides background for developing new early-life animal models for biomedical research and drug testing. This study discovered a highly complex acoustic phenotype of pup isolation calls in 4-5-day-old Mongolian hamsters Allocricetulus curtatus . We analyzed the acoustic structure of 5,010 isolation calls emitted in the broad range of frequencies (sonic, below 20 kHz, and ultrasonic, from 20 to 128 kHz) by 23 pups during 2-min isolation test trials, 1 trial per pup. In addition, we measured 5 body size parameters and the body weight of each pup. The calls could contain up to 3 independent fundamental frequencies in their spectra, the low (f0), the medium (g0), and the high (h0), or purely consisted of chaos in which the fundamental frequency could not be tracked. By presence/absence of the 3 fundamental frequencies or their combinations and chaos, we classified calls into 6 distinctive categories (low-frequency [LF]-f0, LF-chaos, high-frequency [HF]-g0, HF-h0, HF-g0 + h0, and HF-chaos) and estimated the relative abundance of calls in each category. Between categories, we compared acoustic parameters and estimated their relationship with pup body size index. We discuss the results of this study with data on the acoustics of pup isolation calls reported for other species of rodents. We conclude that such high complexity of Mongolian hamster pup isolation calls is unusual for rodents. Decreased acoustic complexity serves as a good indicator of autism spectrum disorders in knockout mouse models, which makes knockout hamster models prospective new wild animal model of neurodevelopmental disorders., Competing Interests: The authors declare no conflict of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of Editorial Office, Current Zoology.)