Angelo Gazzano

Discrimination of alarm pheromone (E)-β-farnesene by aphid odorant-binding proteins.

OBPs have been recently demonstrated to be required for odour perception in insects and directly involved in odour discrimination. In aphids they might represent new interesting targets for the control of their population in agriculture. Based on sequence information available in the EST database, we have cloned four genes encoding odorant-binding proteins (OBP) in Acyrthosiphon pisum and homologous genes in other aphid species. Unlike OBPs from other orders of insects, that are greatly divergent, in aphids these proteins have been found to be highly conserved, with differences between species limited to only few amino acid substitutions. On the contrary, similarities between OBP sequences of the same species are poor with 31% or less of identical amino acids. Three selected OBPs (OBP1, OBP3 and OBP8) have been expressed in bacteria and purified. Ligand-binding experiments have shown similar behaviour of the three proteins towards several organic compounds, but also some significant selectivities. In particular, (E)-beta-farnesene, the alarm pheromone and its related compound farnesol exhibited good affinity to OBP3, but did not bind the other two proteins. We suggest that OBP3 could mediate response of aphids to the alarm pheromone.

Post-conflict friendly reunion in a permanent group of horses (Equus caballus).

Gregarious animals living in permanent social groups experience intra-group competition. Conflicts over resources can escalate into costly aggression and, in some conditions, non-dispersive forms of conflict resolution may be favoured. Post-conflict friendly reunions, hence reconciliation, have been described in a variety of species. The aim of this study was to explore, for the first time, the occurrence of reconciliation in a group of domestic horses (Equus caballus) and learn more about strategies used to maintain group cohesion. The behaviour of seven horses living as permanent group in an enclosure for at least 2 years was observed by video for 108h from June to August 2007. We used a Post-Conflict/Matched Control method to assess the existence of reconciliation and third-party affiliation. Behaviours recorded Post-Conflict, or during Matched Control periods, were classified as affiliative based on previous descriptions of visual communication patterns in horses. The proportion of attracted pairs over total post-conflict situations was significantly greater than the proportion of dispersed pairs, both during dyadic interactions (p<0.001) and during triadic interactions (p=0.002). The results of the present study show that both dyadic reconciliation and third-party post-conflict affiliative interactions form important social mechanisms for managing post-conflict situations in horses.

Membrane integrity evaluation in rabbit spermatozoa

OBJECTIVES The behaviour of head and tail sperm membrane subjected to different vitality tests was evaluated, searching for possible correlations with sperm motility. STUDY DESIGN On fresh semen from seven rabbits we performed: the Eosin Exclusion Test (EET) and, with different incubation times (T(0), T(5), T(30)), a Hypoosmotic Swelling Test (HOS-test) and a combined Hypoosmotic and Eosin Test (HE-test). Kinetic parameters were determined by using the CASA system CELL-TRAK. Statistical analysis was performed by one way ANOVA and Pearsons correlation coefficient. RESULTS The HOS-test revealed significant differences between percentages of curled spermatozoa at T(0) (67.86+/-4.28) versus T(5) (72.86+/-3.28) and versus T(30) (75.14+/-6.5). Among four types of spermatozoa obtained with the HE-test, percentage of Type 1 sperm (HOS+/Eosine) at T(0) (32.3%+/-6.65), was lower than motile sperm (66.86%+/-9.72) but positively correlated. CONCLUSIONS The HE-test is a rapid instrument for predicting sperm motility, selecting spermatozoa with a high degree of membrane resistance both in the tail and the head compartment.

Owners as a secure base for their dogs

A modified version of the Ainsworth Strange Situation Test was used to analyse 40 dog–owner pairs in order to assess whether owners can represent a secure base for their dogs. The Wilcoxon test revealed significant differences between owner and stranger for protest at separation (whining), contact maintenance effect (proximity, attention seeking and physical contact) and secure base effect (exploration, individual play and social play). The results suggest that dogs behave similarly to children towards the mothers and to chimpanzees towards human caretakers in the Ainsworth Strange Situation Test: owners are the preferred recipient of affiliative behaviours and, in their absence, dogs show behaviours indicative of distress. After reunion with the owner, dogs show an increase in social behaviours towards him/her. Dogs did not show fear of the stranger, and it was regarded as a normal behaviour for adult well-socialized dogs. Until now whether owners represented a secure base for their dogs was debated, due to controversial results. This study found that dogs play and explore more when owners were present, suggesting that owners can represent a secure base for their dogs. Therefore, according to Bowlby’s definition, dogs are linked to their owners by an attachment bond.

An Odorant-Binding Protein Is Abundantly Expressed in the Nose and in the Seminal Fluid of the Rabbit

We have purified an abundant lipocalin from the seminal fluid of the rabbit, which shows significant similarity with the sub-class of pheromone carriers “urinary” and “salivary” and presents an N-terminal sequence identical with that of an odorant-binding protein (rabOBP3) expressed in the nasal tissue of the same species. This protein is synthesised in the prostate and found in the seminal fluid, but not in sperm cells. The same protein is also expressed in the nasal epithelium of both sexes, but is completely absent in female reproductive organs. It presents four cysteines, among which two are arranged to form a disulphide bridge, and is glycosylated. This is the first report of an OBP identified at the protein level in the seminal fluid of a vertebrate species. The protein purified from seminal fluid is bound to some organic chemicals whose structure is currently under investigation. We reasonably speculate that, like urinary and salivary proteins reported in other species of mammals, this lipocalin performs a dual role, as carrier of semiochemicals in the seminal fluid and as detector of chemical signals in the nose.

Scratching behaviour and its features: a questionnaire-based study in an Italian sample of domestic cats

Scratching behaviour in cats is described as a normal expression of the feline ethogram, having different possible purposes related to visual and chemical communication. During behavioural consultations owners often mention scratching as an additional problem. This preliminary study aimed to understand the characteristics of this complex behaviour by examining the variables displayed by a sample of the Italian feline population using multiple correspondence analysis. One hundred and twenty-eight cats were screened by means of a questionnaire to identify features of their scratching behaviour. Our data showed the importance of both the presence/absence of a scratching post in the cat’s living area and its relationship to marking. When a scratching post is present in a cat’s living area, the cat appears to use it. Some aspects related to sex, neutering, age and environmental characteristics may modify the expression of scratching as a marking behaviour. Research has led to increased knowledge of this behaviour and may help veterinarians in describing to owners why it is important for cats to express scratching behaviour in their environment. Such information could help veterinarians and owners to recognise normal and problematic scratching behaviours.

AFM characterization of rabbit spermatozoa

Atomic force microscopy (AFM) has been applied for determining the topological and structural features of rabbit spermatozoa. Fresh ejaculated spermatozoa were adsorbed passively onto a silicon slide or by motility from suspension onto a poly(L‐lysine)‐coated glass coverslip and then imaged in air and in buffer saline, respectively. AFM images clearly highlighted many details of spermatozoa head, neck, and tail. Distinct features were observed in the plasmatic membrane of spermatozoa. In particular, head topography easily recognized the acrosome, equatorial segment, equatorial subsegment, and postacrosome regions. Moreover, AFM images revealed the presence of double belt of invaginations around the spermatozoa head, at the boundary between equatorial subsegment and postacrosome regions. All together, the collected AFM images clearly defined a detailed map of spermatozoa morphology while giving some hints on the internal structure. Microsc. Res. Tech., 2008.

Analysis of the intraspecific visual communication in the domestic dog (Canis familiaris): A pilot study on the case of calming signals

ABSTRACT Studying the signaling of domestic dogs is crucial to have a better understanding of this species. The aim of this study was to scientifically assess if the behaviors called calming signals have a communicative and a calming function (i.e., de‐escalating the aggressive display in the other dog). Twenty‐four dogs, 12 females and 12 males, acted as senders; they were observed for the display of the behaviors considered by Rugaas (2006) as calming signals (CSs). The behavior of each sender dog was analyzed during four 5‐minute off‐leash encounters, in which the dog met 4 different recipients, respectively: a familiar and an unfamiliar dog of the same sex; a familiar and an unfamiliar dog of the other sex. The display and trend of aggressive behaviors in recipient dogs was also analyzed. In total, 2,130 CSs were observed. Some behaviors were displayed more often than others, especially, head turning, licking nose, freezing, and turning away. It was statistically more likely that the CSs were sent while the 2 dogs were interacting rather than when there was no interaction (χ2 = 836.155; P < 0.001), suggesting these signals have a communicative role. The statistical analysis revealed that a higher number of signals were observed during meetings between unfamiliar dogs (χ2 = 108.721; P < 0.001). Head turning, nose licking, freezing, making him/herself smaller, and paw lifting were displayed by the sender statistically more frequently while interacting with unfamiliar dogs. Licking the other dogs mouth was more commonly directed toward familiar dogs. In total, 109 episodes of aggressive behaviors were displayed by the recipient dogs. Aggressive episodes were never preceded by the display of a calming signal from the other dog. In 67.0% of cases (N = 73), at least 1 CS was displayed by the sender dog after having received an aggressive behavior from the recipient. When CSs were displayed after an aggressive interaction, in 79.4% of cases (N = 58), there was a de‐escalation in the aggressive display of the other dog. It was statistically less likely that the intensity of aggressive behaviors increased (5.5%/N = 4) or remained unvaried (15.1%/N = 11; χ2 = 13.17; P < 0.001). These findings suggest that these CSs indeed may have a role in social facilitation and preventing further aggressive behaviors.

Assessment of trans, trans-muconic acid in human seminal plasma.

Summary. Trans, trans‐muconic acid (tt‐MA) is one of the most important metabolites of benzene, a pollutant ubiquitously distributed in ambient air and classified in 1982 as a group I carcinogen. For its sensitivity and specificity, tt‐MA excreted in urine is considered a good biological marker of benzene exposure. In this study, seminal tt‐MA levels in occupationally nonexposed subjects (n = 32) have been determined. The seminal fluid of normozoospermic subjects contained an average tt‐MA concentration (170 ± 100 ng ml−1) significantly lower than that of teratozoospermic (310 ± 180 ng ml−1; P < 0.01), oligozoospermic (400 ± 180 ng ml−1; P < 0.001), and oligoasthenozoospermic (430 ± 230 ng ml−1; P < 0.01) subjects. A negative correlation existed between tt‐MA levels and sperm concentration (r = − 0.62; P < 0.001), percentage of normal spermatozoa (r = − 0.41; P < 0.05), and percentage of vital spermatozoa (r = − 0.89; P < 0.001). Average tt‐MA levels detected in seminal plasma were higher in smokers (350 ± 160 ng ml−1) than in nonsmokers (280 ± 210 ng ml−1). These results show that seminal plasma tt‐MA content could be an important biological indicator for evaluating the negative effects of benzene on spermatogenesis.

Electronic training devices: Discussion on the pros and cons of their use in dogs as a basis for the position statement of the European Society of Veterinary Clinical Ethology

ABSTRACT In recent years, the affirmation of a greater ethical sense and research generating a better knowledge of the mechanisms of animal learning, evidence of the existence of an animal mind, and studies on the dog‐human attachment bond have led to changes in the dog‐human relationship. These changes have caused a notable improvement in dog training techniques. Increased emphasis on dog welfare, overall, led to questioning of many training techniques and tools that used aversive means. Recent research on the use of aversive training devices has been performed and, on this basis, it has been possible to create guidelines to inform the public about utility and the possible detriments related to the use of these devices as a tool in dog training. The European Society of Clinical Animal Ethology has released a public position statement based on the current scientific information available on e‐collars, punitive training techniques, and canine welfare. This study elaborates and discusses the arguments “pro and contra the use of e‐collars and aversive training methods” leading to the statement in more detail. As a conclusion, European Society of Clinical Animal Ethology strongly opposes the use of e‐collars in dog training and urges all European countries to take an interest in and position on this welfare matter.