Intact Tails Research Articles

Behavioural trait covaries with immune responsiveness in a wild passerine

Immune system is highly integrated with the nervous and endocrine systems, which is thought to result in covariation between behavioural syndromes and stress- and immune-associated diseases. Very little is known about the associations between behaviour and immune traits in wild animals. Here we describe such an association in passerine birds, the greenfinches (Carduelis chloris). When wild-caught greenfinches are brought into captivity, some individuals damage their tail feathers against cage walls due to excited behaviour, while others retain their feathers in intact condition. We show that damage to tail feathers was associated with flapping flight movements and the frequency of such flapping bouts was individually consistent over 57 days. Birds with intact tails, i.e., relatively 'calm' individuals mounted stronger antibody response to a novel Brucella abortus antigen and their circulating phagocytes were capable of producing stronger oxidative burst in response to stimulation with bacterial lipopolysaccharide in vitro. As the behavioural trait was assessed 13-25 days before measuring immune responsiveness, our results demonstrate that individuals' coping styles with captivity predicted how these individuals would respond to forthcoming immune challenges. This is a novel evidence about covariation between immune responsiveness and a behavioural trait in a wild-caught animal.

Characteristics and Use of the Tail in Signaling by the Zebra-Tailed Lizard (Callisaurus draconoides)

Abstract The zebra-tailed lizard (Callisaurus draconoides) is a diurnal territorial insectivore from arid areas of North America. The underside of its tail has a series of black bands on a white background; individuals raise the tail to expose the underside as a social signal and to deter pursuit by predators. We characterized variation in banding of the tail within a population of C. draconoides from Sonora, Mexico, and examined the relationship between characteristics and use of the tail. Number of bands on intact tails was 4–10; individuals who have experienced some natural reduction in their tail can lack bands all together. The proportion of the underside of the tail that was black was 0–0.46. For males, snout–vent length and mass were positively correlated with number of bands and mean length of bars on the tail; snout–vent length, mass, and width of head were positively correlated with the proportion of black on tails. Females in better condition (based on residuals from regression of snout–vent le...

P06: Gene expression profiling in toxicological studies using FFPE tissues

Large numbers of formalin-fixed paraffin-embedded (FFPE) tissues from toxicological studies have been accumulated over the years in the archives. Although RNA extracted from FFPE tissue is significantly degraded, new technologies are allowing their use for gene expression analysis. In this study, the cDNA-mediated annealing, selection, extension and ligation (DASL™) assay from Illumina Inc. and the WT-Ovation™ FFPE-System from NuGEN Inc. were used. Both methods, compared to standard technologies, do not need intact mRNA poly-A tails for cDNA synthesis. The impact of formalin fixation time and RNA extraction method on RNA quality and gene expression in both technologies was evaluated. Furthermore, the comparability of gene expression data from FFPE to fresh frozen (FF) tissue was determined. Technically, livers from 3 untreated rats were fixed for different times in formalin. Using RNA extracted with either High Pure RNA Paraffin (Roche) or RNeasy ® FFPE Kits (Qiagen), the DASL™ assay was performed, and samples hybridized onto a custom DASL-BeadChip (512 liver toxicity genes). A subset of samples was processed using the NuGEN system and hybridized onto Affymetrix Rat 230 2.0 GeneChips ® . Secondly, FFPE livers from rats treated with a former drug candidate, who was positive for hepatotoxicity, and control animals were analyzed using the DASL™ assay and compared to FF samples (Illumina whole genome rat chip). Gene expression from FFPE tissue with RNA extracted with the High Pure RNA Paraffin kit showed the best correlation to FF samples. Overall, correlation coefficients dropped with increased formalin fixation times in both expression platforms. Longer fixation times resulted in increased alterations of signal intensities, correlating to increased degradation of mRNA. For the second study with treated animals, a dose- and time-dependent clustering was observed from the gene expression data. Focusing on the high dose treated animals it was clearly shown that two animals behaved differently than others, confirming the fresh frozen data as well as the histopathological findings, where these two animals showed the most severe hepatocellular hypertrophy, bile duct hyperplasia and bile duct/hepatocyte necrosis. In conclusion, results of gene expression analysis are heavily dependent on RNA extraction and fixation times. These studies showed that ideally tissues should not be fixed for longer than 1 week to obtain good gene expression data. Nevertheless, both techniques are appropriate methods for gene expression analysis when working with degraded RNA.

Losing stability: tail loss and jumping in the arboreal lizardAnolis carolinensis

Voluntary loss of an appendage, or autotomy, is a remarkable behavior that is widespread among many arthropods and lower vertebrates. Its immediate benefit, generally escape from a predator, is balanced by various costs, including impaired locomotor performance, reproductive success and long-term survival. Among vertebrates, autotomy is most widespread in lizards, in which tail loss has been documented in close to 100 species. Despite numerous studies of the potential costs of tail autotomy in lizards, none have focused on the importance of the tail in jumping. Using high-speed video we recorded jumps from six lizards (Anolis carolinensis) both before and after removing 80% of the tail to test the hypothesis that tail loss has a significant effect on jumping kinematics. Several key performance metrics, including jump distance and takeoff velocity, were not affected by experimental tail removal, averaging 21 cm and 124 cm s(-1), respectively, in both tailed and tailless lizards. However, in-air stability during jumping was greatly compromised after tail removal. Lizards without tails rotated posteriorly more than 30 deg., on average, between takeoff and landing (and sometimes more than 90 deg.) compared with an average of 5 deg. of rotation in lizards with intact tails. Such exaggerated posterior rotation prevents coordinated landing, which is critical for animals that spend much of their time jumping to and from small branches. This work augments recent experiments demonstrating the importance of the tail as a mid-air stabilizer during falling in geckos, and emphasizes new and severe functional costs associated with tail autotomy in arboreal lizards.

Reconstitution of Yeast Silent Chromatin: Multiple Contact Sites and O-AADPR Binding Load SIR Complexes onto Nucleosomes In Vitro

At yeast telomeres and silent mating-type loci, chromatin assumes a higher-order structure that represses transcription by means of the histone deacetylase Sir2 and structural proteins Sir3 and Sir4. Here, we present a fully reconstituted system to analyze SIR holocomplex binding to nucleosomal arrays. Purified Sir2-3-4 heterotrimers bind chromatin, cooperatively yielding a stable complex of homogeneous molecular weight. Remarkably, Sir2-3-4 also binds naked DNA, reflecting the strong, albeit nonspecific, DNA-binding activity of Sir4. The binding of Sir3 to nucleosomes is sensitive to histone H4 N-terminal tail removal, while that of Sir2-4 is not. Dot1-mediated methylation of histone H3K79 reduces the binding of both Sir3 and Sir2-3-4. Additionally, a byproduct of Sir2-mediated NAD hydrolysis, O-acetyl-ADP-ribose, increases the efficiency with which Sir3 and Sir2-3-4 bind nucleosomes. Thus, in small cumulative steps, each Sir protein, unmodified histone domains, and contacts with DNA contribute to the stability of the silent chromatin complex.

Morphological traits affect escape behaviour of the Balearic lizards (Podarcis lilfordi)

AbstractEscape theory predicts that a prey should start escaping (flight initiation distance = FID) from a predator when the costs of fleeing and the cost staying are equal or until future fitness is maximized. Consequently, prey escape performances and current reproductive asset can affect FID. We tested effects of body condition, morphology, and whether the tail was regenerated or original on FID in the Balearic lizard (Podarcis lilfordi) by ourselves simulating predators. Lizards with better body condition had longer FID and lizards with longer intact tails had shorter FID. Lizards with regenerated tail presented shorter FID than lizards with intact tails. These results suggest that impaired escape performance is counterbalanced by fitness costs of tail regeneration or by alteration of escape behaviour. The weak association between morphology, body condition and FID suggest that escape performances and asset protection have relatively small effect on P. lilfordi escape decisions.

Many‐lined sun skinks (Mabuya multifasciata) do not compensate for the costs of tail loss by increasing feeding rate or digestive efficiency

We used the many-lined sun skink (Mabuya multifasciata) as a model system to evaluate the energetic and locomotor costs of tail loss, and to examine whether tailless skinks compensate for the costs of tail loss by increasing feeding rate or digestive efficiency. We successively removed three tail segments from each of the 20 experimental skinks initially having intact tails. Energy content in each removed tail segment was measured, and swimming performance was measured for each experimental skink before and after each tail-removing treatment. Another independent sample of 19 skinks with intact tails were measured for swimming performance to serve as controls for successive measurements taken for the experimental skinks. Tailless experimental skinks and control skinks were then measured for food intake and digestive efficiency. Tail loss affected swimming speed, but the adverse influence was not significant until more than 55% of the tail (in length) was lost. Our data show that partial tail loss may not severely affect energy stores or locomotor performance in M. multifasciata. However, as tail breaks occurred more frequently in the proximal portion of the tail in skinks collected from the field, we conclude that caudal autotomy occurring in nature often incurs substantial energetic and locomotor costs. As tailless and tailed skinks did not differ in food intake, apparent digestive coefficient and assimilation efficiency, we conclude that tailless individuals do not compensate for the costs of tail loss by increasing feeding rate or digestive efficiency in M. multifasciata.

Relationships between tail biting in pigs and disease lesions and condemnations at slaughter

Two matched case-control studies were performed at an abattoir with a capacity of 780 pigs per hour, each study using the approximately 7000 pigs slaughtered on one day. In the...

Male Reproductive Success and Intrasexual Selection in the Common Lizard Determined by DNA-microsatellites

The common lizard (Lacerta vivipara) is a small, nonterritorial, live-bearing lacertid that is sexually dimorphic in several morphological traits (e.g., tail length, snout–vent length, head size). Using microsatellites, we examined paternity in a wild population and investigated whether sexual dimorphism could be the result of intra- or intersexual selection. We found multiple paternity in 65.4% of 26 clutches. There was no evidence of assortative mating. Successfully reproducing males were larger and heavier and had longer tail regenerates or intact tails compared to those that did not reproduce. Tail length and body condition of males were related to the number of offspring sired. However, we found no evidence that head width was related to male reproductive success. We conclude that (1) males with higher body condition index might be more successful in male-male interactions or might be able to search more effectively for females, (2) sex divergence in relative tail length in common lizards reflects the action of sexual selection for male reproductive success, and (3) intersexual dietary divergence could be an alternative hypothesis for head size difference between sexes rather than intrasexual selection.

Energetic and locomotor costs of tail loss in the Chinese skink, Eumeces chinensis

Caudal autotomy is a defense mechanism used by numerous lizards to evade predators, but this entails costs. We collected 294 adult Chinese skinks ( Eumeces chinensis) from a population in Lishui (eastern China) to evaluate energetic and locomotor costs of tail loss. Of the 294 skinks, 214 (c. 73%) had previously experienced caudal autotomy. Neither the proportion of individuals with regenerated tails nor the frequency distribution of locations of the tail break differed between sexes. We successively removed four tail segments from each of the 20 experimental skinks (adult males) initially having intact tails. Lipid content in each removed tail segment was measured, and locomotor performance (sprint speed, the maximal length traveled without stopping and the number of stops in the racetrack) was measured for each skink before and after each tail-removing treatment. Another independent sample of 20 adult males with intact tails was measured for locomotor performance to serve as controls for successive measurements taken for the experimental lizards. Caudal lipids were disproportionately stored along the length of the tail, with most lipids being aggregated in its proximal portion. Tail loss significantly affected sprint speed, but not the maximal length of, or the number of stops during the sprint. However, the adverse influence of tail loss on sprint speed was not significant until more than 51% of the tail (in length) was lost. Our data show that partial tail loss due to predatory encounters or other factors may not severely affect energy stores or locomotor performance in E. chinensis. As tail breaks occurred more frequently in the proximal portion of the tail in skinks collected from the field, we conclude that caudal autotomy occurring in nature often incurs substantial energetic and locomotor costs in E. chinensis.

Viability and acrosome staining of stallion spermatozoa by Chicago sky blue and Giemsa

A simple trypan blue-neutral red-Giemsa staining procedure for simultaneous evaluation of acrosome, sperm head, and tail membrane integrity and morphology has been used to evaluate equine spermatozoa. Some special characteristics and problems have arisen in evaluating stallion semen. One problem was the differentiation of intact vs. damaged sperm tails primarily in frozen and thawed samples. After freezing and thawing, a high percentage of spermatozoa with an unstained head and stained tail were observed. These cells are considered immotile. Therefore, unambiguous differentiation of intact vs. damaged sperm tail membrane is very important for evaluating semen quality. The aim of our study was to develop a method especially for stallion sperm to distinguish more accurately the different cell types. We compared Chicago sky blue 6B (CSB) to trypan blue (TB) for viability staining. CSB/Giemsa staining showed good repeatability and agreement with TB/Giemsa measurements. For densitometry analysis, individual digital images were taken from smears stained by CSB/Giemsa and by TB/Giemsa. A red-green-blue (RGB) histogram for each area of spermatozoa was drawn. Differences of means of RGB values of live vs. dead tails and separate live vs. dead heads from each photo were used to compare the two staining procedures. CSB produced similar live/dead sperm head differentiation and better tail differentiation. TB can be replaced by CSB and this results in more reliable evaluation. After staining with 0.16% CSB and 4 min fixation, 2–4 h Giemsa staining at 25–40° C is recommended for stallion semen.

Partial tail loss has no severe effects on energy stores and locomotor performance in a lacertid lizard, Takydromus septentrionalis

Many species of lizards use caudal autotomy as a defense strategy to avoid predation, but tail loss entails costs. These topics were studied experimentally in the northern grass lizard, Takydromus septentrionalis. We measured lipids in the three-tail segments removed from each of the 20 experimental lizards (adult females) initially having intact tails to evaluate the effect of tail loss on energy stores; we obtained data on locomotor performance (sprint speed, the maximal length traveled without stopping and the number of stops in the racetrack) for these lizards before and after the tail-removing treatments to evaluate the effect of tail loss on locomotor performance. An independent sample of 20 adult females that retained intact tails was measured for locomotor performance to serve as controls for successive measurements taken for the experimental lizards. The lipids stored in the removed tail was positively correlated with tailbase width when holding the tail length constant, indicating that thicker tails contained more lipids than did thinner tails of the same overall length. Most of the lipids stored in the tail were concentrated in the proximal portion of the tail. Locomotor performance was almost unaffected by tail loss until at least more than 71% of the tail (in length) was lost. Our data show that partial tail loss due to predatory encounters or other factors may not severely affect energy stores and locomotor performance in T. septentrionalis.

The development of harmful social behaviour in pigs with intact tails and different enrichment backgrounds in two housing systems

AbstractThe present study compared the performance and development of adverse behaviours of pigs with intact tails, when housed in a straw-bedded system or a part-slatted system enriched with a commercial device. The pigs had previously received different enrichment treatments (rooting box, liquid dispenser, straw bedding or none), either in the farrowing crate or with their lactating dam or post weaning. The pigs were mixed in groups at 10 weeks of age and from then on, every 2 weeks, behavioural observations were performed, focusing mainly on harmful social behaviour and enrichment use. The study showed that pigs with undocked tails can be at high risk of tail biting in part-slatted systems, whereas the straw bedding prevented the development of tail biting. The immediate effects of the environment seemed to exert a greater influence on the development of adverse behaviour than early life enrichment and adding a simple enrichment device could not compensate for the deficiencies in the barren environment of the part-slatted system. In order to prevent vice, functional design of environmental enrichment is required.

Longitudinal study of adverse behaviour of undocked pigs in two different housing systems

AbstractThe development of adverse behaviour in group–housed growing/ finishing pigs with intact tails was studied in a straw–flow housing system and in a part–slatted system with a commercial enrichment object. Food intake, body weight and behaviour were monitored over the finishing period, with tail biting outbreaks defined as an occasion where three or more pigs within a group had freshly damaged tails and tail biting behaviour was ongoing. Data from the two systems were analysed to identify tail–biting outbreaks and behavioural changes over time. Levels of pig manipulation were higher in the part–slatted system. Over time, pigs in both systems showed reduced interest in the enrichment provided, but not in each other. Despite the presence of the enrichment device, tail biting occurred in all groups in the part–slatted system, but only 1/12 groups in the straw–flow system. The amount of time occupied by manipulation of the enrichment provided was very significantly higher for straw than for the commercial object. Better design of enrichment strategies is therefore needed and should be based on species–relevant requirements.

More injuries in left‐footed individual lizards and Sphenodon

In lizards and Sphenodon, often the fourth toes of individuals with intact tails have more subdigital lamellae on the right than on the left side, and the opposite situation frequently occurs in individuals with injured tails. The difference between intact and injured individuals in morphological directional asymmetry was statistically significant (P<0.05) in 11.4% among 193 species from various lizard families. Lizard families varied in extent and direction of association, but no phylogenetic constraints were detected within genera. Statistical significance was greater in samples from homogenous geographic origin than from heterogeneous ones. Among gekkonid species, the difference was stronger in those with cursorial (terrestrial) habits, than in those with scansorial (rupestral or arboreal) habits. In Scincidae, loss seems more often lethal in left‐footed than in right‐footed individuals. Statistically significant associations between morphological left‐side dominance and tail injury exist also in three independent lineages with reduced limbs (Anguidae, Scincidae and Teidae). Hence such association is probably not a result of limb function. Rather, left‐side dominance seems to be the symptom of an unknown, perhaps organism‐wide, detrimental trait. Polymorphism in morphological dominance existed in all species, suggesting advantages and disadvantages in different situations to both phenotypes. We propose the hypothesis that an inversion of side dominance may occur in a single trait without systematic inversion of side dominance in all traits of the body. Inversion in a single trait causes incompatibility in multiple‐trait functions. Such a mechanism, rather than cultural conventions, could increase accident proneness also in left‐handed Homo sapiens, and could explain increased proneness to accident and warfare mortality in left‐handed men, beyond the possible involvement of cultural factors.

Shifted balance of risk and cost after autotomy affects use of cover, escape, activity, and foraging in the keeled earless lizard (Holbrookia propinqua)

Autotomy of expendable body parts is often a successful last-chance antipredatory defense for a variety of invertebrates and vertebrates, especially lizards. However, loss of a body part imposes costs and risks, some of which may be reduced by modifying subsequent behavior. I studied effects of experimentally induced autotomy of the tail in the keeled earless lizard (Holbrookia propinqua) on use of cover, escape behavior, activity, and feeding. Autotomized lizards stayed closer to plant cover than sham-autotomized lizards (having intact tails) when approached by an investigator simulating a predator. Autotomized males, but not females, fled further than sham-autotomized lizards. Autotomy did not affect the distance from an approaching predator when the lizards began to flee. After autotomy, the number of days on which lizards were active differed between sexes and lizards made fewer attempts to catch prey per unit time than lizards with intact tails. Tail loss did not affect the percentage of time spent moving. Staying closer to refuge, fleeing further after autotomy, and decreasing surface activity may compensate for decreased maximum escape speed or agility, and may reflect use of a greater margin of safety when the tail is unavailable for autotomy. Decrease in surface activity may be comparable to use of safer microhabitats reported for other lizards and damselflies subsequent to autotomy. Several possible reasons for the lower rate of feeding attempts by autotomized lizards are discussed.

Phenotypic plasticity of anuran larvae: environmental variables influence body shape and oral morphology in Rana temporaria tadpoles

AbstractEnvironmental variables shaped the morphology of tadpoles of the common frog, Rana temporaria, in various ways at the Pyrenean locality Circo de Piedrafita. Examining only specimens in similar developmental stages, those from small ponds (with higher temperature and higher tadpole density) had lower growth rates, lower relative tail height, lower relative body width and fewer labial keratodonts and keratodont rows. The variation in keratodonts may have been caused by heterochrony related to the slower growth rate. The number of lingual papillae also differed between ponds but was not related to pond size. Higher predator densities caused a higher percentage of damaged tails and a lower relative tail length in specimens with apparently intact tails, probably as a result of incomplete regeneration after mutilations earlier in development.

WHY DOES TAIL LOSS INCREASE A LIZARD'S LATER VULNERABILITY TO SNAKE PREDATORS?

We examined how autotomy–induced shifts in behavior of a diurnal lizard (Lampropholis guichenoti) and two natural snake predators influence the outcome of predatory interactions. During staged encounters in seminatural enclosures, we estimated the consumption order of lizards with recently autotomised tails (“tailless”) and intact tails (“tailed”). Tail loss increased a lizard's chances of being consumed first by a diurnal snake (Demansia psammophis), but not by a nocturnal species (Rhinoplocephalus nigrescens). We presented snakes with an inert tailed lizard vs. tailless lizard, scoring which was consumed first. Neither predator actively selected tailless prey. We quantified variation in the behavior of tailed and tailless lizards that determines the outcome of predator–prey interactions. Tailless lizards were not easier to detect visually or via chemoreception than were tailed lizards. Instead, the higher consumption rate of tailless lizards by the diurnal snake probably reflects reduced locomotor perfo...

ATP-dependent chromatin remodeling by the Cockayne syndrome B DNA repair-transcription-coupling factor.

The Cockayne syndrome B protein (CSB) is required for coupling DNA excision repair to transcription in a process known as transcription-coupled repair (TCR). Cockayne syndrome patients show UV sensitivity and severe neurodevelopmental abnormalities. CSB is a DNA-dependent ATPase of the SWI2/SNF2 family. SWI2/SNF2-like proteins are implicated in chromatin remodeling during transcription. Since chromatin structure also affects DNA repair efficiency, chromatin remodeling activities within repair are expected. Here we used purified recombinant CSB protein to investigate whether it can remodel chromatin in vitro. We show that binding of CSB to DNA results in an alteration of the DNA double-helix conformation. In addition, we find that CSB is able to remodel chromatin structure at the expense of ATP hydrolysis. Specifically, CSB can alter DNase I accessibility to reconstituted mononucleosome cores and disarrange an array of nucleosomes regularly spaced on plasmid DNA. In addition, we show that CSB interacts not only with double-stranded DNA but also directly with core histones. Finally, intact histone tails play an important role in CSB remodeling. CSB is the first repair protein found to play a direct role in modulating nucleosome structure. The relevance of this finding to the interplay between transcription and repair is discussed.

The effects of tail loss on survival, growth, reproduction, and sex ratio of offspring in the lizard Uta stansburiana in the field.

Tail autotomy is a defense against predators used by many lizard species but is associated with various costs, most of which have been measured only in the laboratory. We conducted a field experiment in which we induced tail autotomy to approximately half (58%) of a marked sample (n=326) of Uta stansburiana from western Texas in the fall, and left the other half with intact tails. The following spring we determined survival, measured growth, and brought females to the laboratory to allow them to oviposit their eggs, which we incubated until hatching. Based on past studies, we anticipated inferior survival, growth, and reproduction following tail autotomy. We also predicted that females with tail loss would be energetically compromised and would alter the sex ratio of their offspring toward more daughters (as predicted by the Trivers-Willard hypothesis). Tailless lizards experienced significantly reduced survivorship, but those that survived grew the same as their tailed counterparts. Tailed and tailless females produced clutches equivalent in number of eggs and total mass. Whereas tailed females showed a significant positive relationship between average egg mass and snout-vent length, tailless females did not. Contrary to our expectations, tailless females produced heavier hatchlings than tailed ones, and sex ratios of hatchlings were equivalent for tailed and tailless females. In this population, tail loss in subadults leads to an increased risk of death, but apparently does not impose an energetic handicap such that later growth and reproduction suffer. We suggest that because tailless females are faced with decreased reproductive value, they respond by growing as much and laying as many eggs of the same mass as tailed females, despite the fact that they are also regenerating the tail. In addition, they somehow produce larger hatchlings than tailed females. Nevertheless, tailless females probably end up with lower overall lifetime fitness than tailed females, and tail loss thus induces the conditional reproductive strategy "make the best of a bad situation". Because tailless females produce larger, not smaller, hatchlings, they do not produce more daughters as predicted; i.e., we found no evidence for the Trivers-Willard effect following tail autotomy.