Cavia Aperea Research Articles

Herbivory and dropping effects by small mammals on salt‐marsh vegetation vary across microhabitats

AbstractQuestionDoes the effect of droppings and herbivory by wild guinea pigs on salt‐marsh vegetation vary across microhabitats?LocationUpper salt marsh in the Mar Chiquita coastal lagoon (37°44′52″ S, 57°26′6″ W, Argentina).MethodsDuring autumn 2014, we performed a micro‐scale experiment manipulating droppings of wild guinea pigs (Cavia aperea). After 15 days, we compared the content of nutrients (i.e., NH4+, NO3−, and PO43−) in soil. Then, we started two factorial experiments in the high marsh, specifically one in marsh matrix (i.e., tall vegetation) and the other in open patches (i.e., short vegetation). Units were randomly assigned to different treatments (with and without herbivores and droppings). In early summer, we compared total plant cover, maximum height, above‐ground biomass, plant species richness and the composition of plant assemblages between treatments.ResultsDroppings increased the content of PO43− in soil by five times, but decreased the content of NO3−. Herbivory reduced total cover, plant height, and above‐ground biomass in the marsh matrix and the open patches. In the marsh matrix, droppings increased the total cover, whereas herbivory reduced the abundance of Spartina densiflora (cover and above‐ground biomass) and subordinate species (cover). Additionally, the cover of subordinate species was negatively associated with the cover of Spartina densiflora. Therefore, in the marsh matrix, by increasing light availability at the ground level, herbivory increased plant species richness, but with low cover of subordinate species. In contrast, in open patches, herbivory and droppings interacted to reduce plant species richness.ConclusionHerbivory by small mammals can control the above‐ground biomass, structure, and plant community composition of the high marsh, but non‐trophic mechanisms (droppings) can also affect community composition. Nonetheless, ecological impacts of small mammals depend on the context, because the magnitude and direction of trophic (herbivory) and non‐trophic (droppings) effects change across microhabitats.

Comparative trophic ecology of two sympatric canids in the Brazilian Pampa

AbstractStudies on resource utilization by carnivores are essential to assess the role of the species in the ecosystem. These studies help us to understand the mechanisms that influence vertebrate community structure and the relationships between predators and prey. The aims of this study were to compare and describe the food habits of the sympatric Pampas fox (Lycalopex gymnocercus) and crab‐eating fox (Cerdocyon thous) in the Brazilian Pampa, and to evaluate the food niche overlap between them, and infer aspects of habitat preferences on the basis of their prey. For the diet analyses, 25 stomach contents of Pampas foxes and 33 of crab‐eating foxes were collected. We identified 80 prey items (49 for the Pampas fox and 63 for the crab‐eating fox) and grouped them into eight main categories. Mammals and invertebrates were the most frequent items in the diets of both canids, followed by fruits. The trophic niche breadth of the Pampas fox (Bsta = 0.56) was larger than that of the crab‐eating fox (Bsta = 0.47). The diet overlap between them was Ojk = 0.58. However, a PERMANOVA test showed that diets did not differ between species or season. Our results showed that both L. gymnocercus and C. thous had generalist diets, with a great diversity of prey, but based on similar main food items. Items that contributed the most to the diet of the Pampas fox were insects (Gryllotalpidae and Scarabaeidae) and cavies (Cavia aperea) and those that contributed the most to the diet of the crab‐eating fox were fruits of Syagrus romanzoffiana, beetles (Scarabaeidae), amphibians (Leptodactylus spp.) and cavies. This is the first study to describe and compare the food habits of these two species, occurring in sympatry in the Brazilian Pampa.

Trophic ecology of sympatric small cats in the Brazilian Pampa.

Information about resource partitioning among small cat species that live in sympatry in South America is fairly incomplete. Knowledge about feeding habits is essential for understanding the role of these predators in the environment, the impact on prey populations, and potential competition among themselves and with other carnivores. This study aimed to describe and compare the diet of four sympatric small cats in the grasslands of southern Brazil. We analysed the stomach contents of 37 Geoffroy’s cats (Leopardus geoffroyi), 27 margays (Leopardus wiedii), 14 pampas cats (Leopardus colocola), and 20 jaguarundis (Herpailurus yagouaroundi) obtained as road kill in the Brazilian Pampa in southern Brazil. Small mammals were the most representative class consumed by all cats, followed by Aves, Reptilia, and Amphibia. Some items, such as rodents Cavia aperea, Akodon sp., Oligoryzomys sp. and Passeriformes were consumed by all cat species. Niche overlap varied widely, from 10% (margay x jaguarundi) to 92% (jaguarundi x pampas cat). Niche breadth indicated that jaguarundi were the most specialized of the cats (Bsta = 0.24) in this region, with a diet closely associated to C. aperea. Margay consumed more items associated with arboreal behaviour than other cat species, but consumed more terrestrial items than arboreal ones. The pampas cat consumed mostly terrestrial species associated with open fields. Geoffroy’s cat consumed mammals found in a diversity of habitats, indicating high ecological flexibility. Species with more similarity in diet such as jaguarundi and pampas cat probably present temporal segregation in activity. In conclusion, despite their habitat and diet similarities, these four species explore distinct microhabitats by foraging different prey groups, what favor them to live in sympatry.

Cortisol during adolescence organises personality traits and behavioural syndromes

Despite the growing evidence for the importance of developmental experiences shaping consistent individual differences in behaviour and physiology, the role of endocrine factors underlying the development and maintenance of such differences across multiple traits, remains poorly understood. Here, we investigated how an experimental manipulation of circulating glucocorticoids during early adolescence affects behavioural and physiological variation and covariation later in life in the precocial cavy (Cavia aperea). Plasma cortisol concentrations were experimentally elevated by administering cortisol via food for 3 weeks. Struggle docility, escape latency, boldness, exploration and social behaviour were then tested three times after individuals attained sexual maturity. In addition, blood samples were taken repeatedly to monitor circulating cortisol concentrations. Exogenous cortisol affected mean trait expression of plasma cortisol levels, struggle docility and escape latency. Repeatability of cortisol and escape latency was increased and repeatability of struggle docility tended to be higher (approaching significance) in treated individuals. Increased repeatability was mainly caused by an increase of among-individual variance. Correlations among docility, escape latency and cortisol were stronger in treated animals compared to control animals. These results suggest that exposure to elevated levels of cortisol during adolescence can alter animal personality traits as well as behavioural syndromes. Social and risk-taking traits showed no correlation with cortisol levels and were unaffected by the experimental manipulation, indicating behavioural modularity. Taken together, our data highlight that cortisol can have organising effects during adolescence on the development of personality traits and behavioural syndromes, adding to the increasing evidence that not only early life but also adolescence is an important sensitive period for behavioural development.

Seasonal effects on behavior and immunity in a precocial rodent

Environmental variation strongly influences individual life histories, behavior, and immunity. For many animals living in non-tropical regions, environmental variation due to season is very important and can be reliably predicted by photoperiod. By manipulating the pre- and post-natal photoperiod for cavies (Cavia aperea), we simulated different birth seasons that go along with predictable differences in life history. Offspring born into simulated spring conditions mature earlier, indicating a fast pace of life compared to offspring born into simulated fall. We investigated the development of two innate (titers of natural antibodies and complement) and one adaptive (immunoglobulin G) immune effectors across multiple life stages. In addition, we tested if three behaviors, indicating risk-taking and stress-coping, differed between seasons. Finally, we tested if behaviors and immune traits correlate with each other as predicted by the pace-of-life syndrome hypothesis. The season of birth influenced average trait expression of both immunity and behavior. Boldness, indicating risk-taking behavior, correlated positively with the titers of natural antibodies, fitting the predictions of the pace-of-life syndrome (POLS). However, fearlessness, indicating how an individual copes with a stressful situation, correlated positively with immunoglobulin G concentrations, against the predictions of the POLS. Together, our results show that behaviors and immune traits react to differences in expected life histories, but do not show the predicted covariation. We conclude that proximate mechanisms and different functions of traits need to be considered to predict the nature of behavior-immune associations. Individual life histories, behavior, and immunity are strongly influenced by the environment individual’s experience during early life. Recent theory predicts correlations between behavior and immunity to arise as a consequence of different life histories. By simulating different birth seasons, we induced different life history expectations as well as a season-dependent development of immunity and behavior. However, correlations between behavior and immunity do not fit theoretical predictions, highlighting the need for more detailed theory.

Effect of season on reproductive behaviors and fertilization success in cavies (Cavia aperea)

Finding the optimal timing for breeding is crucial for small mammals to ensure survival and maximize lifetime reproductive success. Species living in temperate regions therefore often restrict breeding to seasons with favorable food and weather conditions. Although caviomorph rodents such as guinea pigs are described as non-seasonal breeders, a series of recent publications has shown seasonal adaptations in litter size, offspring birth mass and maternal investment. Here, we aim to test if seasonal patterns of litter size variation found in earlier studies, are mediated by seasonal differences in female estrus length, fertilization rate and mating behavior. The female estrus period was longer in fall compared to all other seasons (p < 0.001), frequently lasting 7–9 days while estrus in spring usually lasted less than 2 days. In fall, females mated later during estrus (p < 0.001), resulting in reduced fertilization rates (p < 0.001). Fertilization rate was well above 95% in summer while it dropped to less than 85% in fall and winter. While none of the male mating characteristics such as number and duration of copulations differed across seasons, the number of mating bouts was reduced in fall (p = 0.04). Finally, the developmental stages of flushed embryos were more diverse in spring and summer compared to fall and winter. These results suggest that seasonal differences in fertilization rate and quality of implanted embryos are mediated by female estrus length and timing and intensity of mating behavior. Together, these effects contribute to the observed differences in litter size across seasons.

Life-history trade-offs: are they linked to personality in a precocial mammal ( Cavia aperea )?

Life-history trade-offs are predicted to contribute to the maintenance of personality variation. Individuals with 'fast' lifestyles should develop faster, reproduce earlier and exhibit more risky behaviours. Evidence for such predicted links, however, remains equivocal. Here, I test how growth rate, timing of maturation, litter size and maternal effort correlate with exploration, boldness, fearlessness, docility and escape latency. I found several links that were predicted by recent theory while others were against theoretical predictions, e.g. fast-growing individuals were more fearful. Thus, while I found personality to be integrated with life history, I cannot fully support recent hypotheses aiming to explain such behaviour-life-history associations.

First report on Leptospira interrogans in the sigmodontine rodent Scapteromys aquaticusPrimeiro relato da presença de Leptospira interrogans em roedores sigmodontíneos Scapteromys aquaticus

RESUMENLa leptospirosis es una enfermedad zoonótica de distribución mundial que puede transmitirse por contacto directo o indirecto con orina o tejidos de animales infectados. En Argentina, la leptospirosis es endémica en la provincia de Santa Fe y presenta brotes epidémicos durante las inundaciones. Sin embargo, se sabe muy poco sobre el papel que cumplen los roedores silvestres en la diseminación de la enfermedad en el país. El objetivo de este estudio fue identificar las especies hospederas de leptospiras patógenas entre los roedores presentes en un asentamiento ribereño de la provincia de Santa Fe.Se realizó un muestreo de roedores durante octubre de 2015. Los riñones de los animales capturados se analizaron por real-time PCR para el gen LipL32 de leptospiras patógenas. En los animales que resultaron positivos, se realizó test de microaglutinación (MAT) y tipificación molecular por amplificación del gen 16S rRNA y dos esquemas de MLST.Se capturaron 37 roedores de las especies Akodon azarae, Cavia aperea, Oligoryzomys flavescens, Rattus rattus y Scapteromys aquaticus. En el análisis por real-time PCR resultó positivo un macho de Scapteromys aquaticus. El suero de este individuo y del resto de los S. aquaticus capturados (n = 18) se analizaron por test de microaglutinación (MAT), y fueron no reactivos para los 10 serovares probados. La amplificación del gen 16S rRNA identificó la especie infectante como Leptospira interrogans, mientras que no se obtuvo amplificación para los dos esquemas de MLST.El hallazgo de este estudio aporta nueva información acerca de presencia de leptospiras patógenas en roedores silvestres, que es relevante para la zona por tratarse de una especie ampliamente distribuida en ambientes pantanosos e inundables de América del Sur.

Ixodes spp. (Acari: Ixodidae) ticks in Rio Grande do Sul state, Brazil

Among the 251 described species of ticks from the genus Ixodes, only eight were previously reported in Brazil, Ixodes amarali, Ixodes aragaoi, Ixodes auritulus, Ixodes fuscipes, Ixodes loricatus, Ixodes luciae, Ixodes paranaensis and Ixodes schulzei. Of those species, I. loricatus is considered commonly found, whereas I. auritulus and I. aragaoi were registered just one time in Rio Grande do Sul (RS) state, Southern Brazil. This paper aims to update the Ixodes species occurring in RS through the investigation of the ixodofauna of small rodents. Data from 314 wild rodents were analyzed from nine municipalities of Pampa biome and five from the Atlantic Rainforest in RS. Rodents belonging to the following species were infested by Ixodes spp. ticks: Akodon azarae, Akodon montensis, Akodon paranaensis, Akodon reigi, Calomys laucha, Delomys dorsalis, Deltamys kempi, Holochilus brasiliensis, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus nasutus, Scapteromys tumidus (Cricetidae) and Cavia aperea (Caviidae). The tick identification was performed based on morphological dichotomous keys, their updates and by molecular techniques. Considering the ticks from the rodents and those collected directly from the environment, 34 specimens of Ixodes spp. were collected. Our results improved to five the list of Ixodes species that occur in RS: I. loricatus, I. auritulus, I. aragaoi, I. fuscipes and I. longiscutatus. Moreover, the finding of I. longiscutatus increases to nine the number of Ixodes species in Brazil. The occurrence of two species of the Ixodes ricinus complex (I. aragaoi and I. fuscipes) highlights the potential impact of Ixodes spp. ticks on public health.

Cryptosporidium homai n. sp. (Apicomplexa: Cryptosporidiiae) from the guinea pig (Cavia porcellus)

The morphological, biological, and molecular characterisation of a new Cryptosporidium species from the guinea pig (Cavia porcellus) are described, and the species name Cryptosporidium homai n. sp. is proposed. Histological analysis conducted on a post-mortem sample from a guinea pig euthanised due to respiratory distress, identified developmental stages of C. homai n. sp. (trophozoites and meronts) along the intestinal epithelium. Molecular analysis at 18S rRNA (18S), actin and hsp70 loci was then conducted on faeces from an additional 7 guinea pigs positive for C. homai n. sp. At the 18S, actin and hsp70 loci, C. homai n. sp. exhibited genetic distances ranging from 3.1% to 14.3%, 14.4% to 24.5%, and 6.6% to 20.9% from other Cryptosporidium spp., respectively. At the 18S locus, C. homai n. sp. shared 99.1% similarity with a previously described Cryptosporidium genotype in guinea pigs from Brazil and it is likely that they are the same species, however this cannot be confirmed as actin and hsp70 sequences from the Brazilian guinea pig genotype are not available. Phylogenetic analysis of concatenated 18S, actin and hsp70 sequences showed that C. homai n. sp. exhibited 9.1% to 17.3% genetic distance from all other Cryptosporidium spp. This clearly supports the validity of C. homai n. sp. as a separate species.

Individual consistency in multiple cognitive performance: behavioural versus cognitive syndromes

Individuals within species differ consistently in their behaviour. Such individual differences may represent adaptations. Recently, researchers have started to implement the same adaptive framework to individual differences in cognition, leading to the suggestion that personality and cognition should covary. To determine the contextual consistency of cognitive traits and their covariation with several personality traits, 24 guinea pigs, Cavia aperea f. porcellus, were tested using a battery of 12 cognitive tests. Four tests each were conducted to test for problem solving, association learning and social learning. We assessed consistency within each of these three domains and tested for cognitive and behavioural syndromes between domains. Problem solving and social learning were consistent across contexts and positively correlated with each other. In addition, both correlated positively with boldness, and problem solving showed a negative correlation with aggressiveness and sociopositive behaviour. Association learning was neither consistent nor correlated with personality or performance in the other cognition tasks. We showed contextual consistency of two cognitive traits and found multiple links to personality traits that were predicted by recent theory. Surprisingly, associative learning was not consistent, demonstrating the importance of testing the relation between personality and multiple cognitive traits to increase our understanding of individual variation in cognition and personality.

The acoustic repertoire of Cavia intermedia as a contribution to the understanding of the Caviidae communication system

Wild cavies from the taxon Cavia aperea–Cavia porcellus are known for their extensive use of acoustic signals for communication including a courtship call that is a rarity in Mammalia. The genus Cavia includes an insular species (Cavia intermedia) derived from a continental “asocial” Cavia magna. We hypothesized that the courtship call and all the other 12 acoustic signals previously described for C. aperea–C. porcellus were synapomorphies of the genus and took the opportunity of recording the critically endangered C. intermedia. Four field trips lasting 10 days were conducted in 2008 and 2009. After collecting and analysing nearly 350 sound files of 38 individuals, we found all the 12 calls of wild and domestic cavies previously described, including the courtship call, and a new call, a peep. Despite the presence of the peep, our description of C. intermedia acoustic repertoire showed the evolutionary stability of the acoustic repertoire of this rodent genus of 6 species, even after domestication of C. porcellus and 8000 years under insular selective forces in C. intermedia. We present a discussion about the communicative function of Cavia calls in a comparative context and its repertoire size in accordance with the complexity level of sociality of this caviomorph rodent.

Nest and chicks of Pseudoscops clamator (Aves: Strigidae) in the highland plateau of the Sabana de Bogotá, Colombia

The Striped Owl (Pseudoscops clamator) has a wide geographic distribution despite that there is scarce information on its reproductive biology. In this study, we present the first published nesting records of P. clamator for Colombia. We provide data on its nesting habits and reproductive biology from observations between April and May 2013 of a nest found in a plantation of Eucalyptus globulus in Cajica, Cundinamarca, Colombia. The ground nest is similar to those described from Argentina, Brazil, and Suriname; with a clutch of two where only one chick survived and left the nest after 25-30 days. We found in the owl diet, Brazilian guinea pig (Cavia aperea) and Eared Dove (Zenaida auriculata). Little is known about other species predated by the Striped Owl or whether this species has more than one reproductive cycle in the Bogota highland plateau. Future studies should further examine these aspects to assess the possibilities for expansion of P. clamator in the Bogota highland plateau.

Trends in Marine Foraging in Precontact and Historic Leeward Kohala, Hawai‘i Island

Traditional Hawaiian fishing and marine exploitation have been studied using both ethnographic and archaeological approaches, but few studies have attempted to investigate intensity of marine foraging over time at a regional scale. In this paper we examine Hawaiian exploitation of the marine ecosystem of the leeward coast of Kohala, located on the northern tip of Hawai‘i Island. Over 158,000 specimens of fish, mollusks, arthropods, and echinoderms were recovered during archaeological excavation of 57 precontact (i.e., pre–AD 1778) residential features. These residences span a period of roughly 500 yr and are located both along the coast and in the interior. For these sites, we analyzed taxonomic abundance (NISP), number of taxa (NTAXA), taxonomic evenness, prey indices, and body-size changes over time. Results indicate that intensity of marine foraging increased over time, mirroring trends in increased numbers of residences (and inferred increases in human population size). There were no apparent declines in abundance of particular marine taxa. There were some differences in movement of marine resources into the upland Leeward Kohala Field System (LKFS), with larger-sized fish, mollusks, and echinoderms transported in increasing numbers. Examination of changes in body size suggest significant harvest pressure on fish and mollusks during the first 400 yr of human occupation and population rebound following human abandonment of the region in the postcontact period.

Effectiveness of a Nursing Capstone Project Course in Enhancing Nursing Student Creativity

Aims: The purpose of this study was to explore the effectiveness of a nursing capstone project course in enhancing nursing student creativity. Design: This study involved a pre–post-test design. Methods: Samples were tested through a questionnaire on factors influencing creativity during the first and final weeks of the course. The questionnaire included questions on nursing student characteristics, abilities, barriers, and motivations. This study was conducted from September 2014 to January 2015. A total of 300 nursing students were recruited, and 150 completed the pretest and posttest, indicating a 50% return rate. Of the 150 enrolled students, more than 90% had not participated in nursing project training or conferences or conducted nursing projects. Results: The nursing students exhibited significant differences in characteristics and abilities before and after the nursing capstone project course and showed enhanced positive characteristics and creative abilities by the end of the training course. However, the factors of barriers and motivations in creativity were not significantly different. The students also failed to enhance their creative motivations. Furthermore, the results of a multiple regression analysis revealed that before the nursing capstone project course, the students perceived the strongest predictors of their creativity to be abilities and barriers; by contrast, they perceived characteristics and motivations as the strongest predictors after the course. Conclusions: The nursing capstone project course affected the influencing factors of nursing student creativity. This study thus validates the effectiveness of the 18-week nursing capstone project course in enhancing the creativity of the nursing students, as indicated by the significantly increased creativity scores after the training course compared with those before the course.

Instituting Dark-Colored Cover to Improve Central Space Use Within Guinea Pig Enclosure

Domestic guinea pigs (Cavia aperea f. porcellus) in laboratories have been shown to actively avoid the centers of their cages. This experiment tested a novel, dark-colored “shader” placed over the central portion of a cage. Based on the observed behavior of wild guinea pig species, it was hypothesized that utilization of the central portion of the cage would increase when the shader was present. Eleven male and 11 female albino, 3-week-old Hartley guinea pigs (Crl:HA) experienced the control and treatment conditions in a crossover study design. They spent more time in central cage sections when the shader was present and spent more time in and around the food hopper when the shader was absent (p < .001). Differences between sexes included increased inactivity in males versus females (p < .05) and a difference in time spent in a corner section of the cage (p < .001), likely associated with location in the room. We concluded that the presence of a shader increased utilization of cage space, which appeared to provide a similar increase in space utilization as structural enrichments.

Blastocyst recovery and multifactorial gene expression analysis in the wild guinea pig (Cavia aperea)

The expression of specific developmentally important genes in preimplantation embryos is an accepted marker for unraveling the influence of single factors in studies that are mostly related to artificial reproduction techniques. Such studies, however, often reveal high levels of heterogeneity between single embryos, independently of the influence of factors of interest. A possible explanation for this variation could be the large variety of physiological and environmental factors to which early embryos are exposed and their ability to react to them. Here, we investigated several potentially important parameters of development at the same time, in blastocysts of the wild guinea pig (Cavia aperea) generated in vivo after natural mating. The optimal time for flushing fully developed blastocysts was between 123 and 126 hours after mating. The abundance of POU5F1 (P = 0.042), BAX (P < 0.001), SLC2A1 (P = 0.017), and DNMT3A (P < 0.001) mRNA changed significantly over time after mating. The number of sibling embryos present influenced STAT3 levels significantly (P = 0.02). Levels of BAX and POU5F1 were significantly affected by season (P = 0.03 and 0.04). The temporal pattern of SLC2A1 levels was significantly altered both after feeding a protein-deficient diet (P = 0.04) and temperature treatment (P = 0.04) of the sire. In addition, the identity of the father had a significant influence on POU5F1 (P = 0.049) and STAT3 (P < 0.001) mRNA abundances. These data report that the expression of specific genes in early embryos reflects the entire heterogeneity of their surroundings and that it is a plastic reaction toward a multifactorial environment.

Draft genome of the Leptospira interrogans strains, Acegua, RCA, Prea, and Capivara, obtained from wildlife maintenance hosts and infected domestic animals.

In the present paper, we announce new draft genomes of four Leptospira interrogans strains named Acegua, RCA, Prea, and Capivara. These strains were isolated in the state of Rio Grande do Sul, Brazil, from cattle, dog, Brazilian guinea pig, and capybara, respectively.

Hábitos alimentarios del gato montés (Leopardus geoffroyi) en agroecosistemas de Buenos Aires, Argentina

Geoffroy's cat ( Leopardus geoffroyi ), a small wild cat of South America, showed in the last years a decline in population abundance mainly related to both habitat destruction and hunting. The increasing human population densities and the consequent demand for food and natural resources will rapidly erode and fragment its remaining habitats. In Argentina most studies about Geoffroy's cat diet have been conducted in protected areas or in their surroundings, while there are no studies conducted in purely agricultural systems. We described the diet composition of Leopardus geoffroyi and its seasonal variations in an agricultural ecosystem to contribute knowledge of its ecology and natural history. The study was carried out from spring 2008 to spring 2011. A total of 494 scats were analyzed and at least 695 prey-items were identified. The diet included 81.58% of mammal prey, representing 93.32% of the potential biomass ingested. Within mammals, the principal prey were rodents, representing 79.57% of the total prey items and 59.39% of the total potential biomass consumed. Small rodents account for a great proportion of prey items, while larger species, as the caviid Cavia aperea , contributed more biomass. The diet plasticity may enhance the persistence of Geoffroy's cat populations in variable and anthropized ecosystems.

Paternal heat exposure causes DNA methylation and gene expression changes of Stat3 in Wild guinea pig sons

Epigenetic mechanisms convey environmental information through generations and can regulate gene expression. Epigenetic studies in wild mammals are rare, but enable understanding adaptation processes as they may occur in nature. In most wild mammal species, males are the dispersing sex and thus often have to cope with differing habitats and thermal changes more rapidly than the often philopatric females. As temperature is a major environmental selection factor, we investigated whether genetically heterogeneous Wild guinea pig (Cavia aperea) males adapt epigenetically to an increase in temperature, whether that response will be transmitted to the next generation(s), and whether it regulates mRNA expression. Five (F0) adult male guinea pigs were exposed to an increased ambient temperature for 2 months, corresponding to the duration of the species' spermatogenesis. To study the effect of heat, we focused on the main thermoregulatory organ, the liver. We analyzed CpG‐methylation changes of male offspring (F1) sired before and after the fathers' heat treatment (as has recently been described in Weyrich et al. [Mol. Ecol., 2015]). Transcription analysis was performed for the three genes with the highest number of differentially methylated changes detected: the thermoregulation gene Signal Transducer and Activator of Transcription 3 (Stat3), the proteolytic peptidase gene Cathepsin Z (Ctsz), and Sirtuin 6 (Sirt6) with function in epigenetic regulation. Stat3 gene expression was significantly reduced (P < 0.05), which indicated a close link between CpG‐methylation and expression levels for this gene. The two other genes did not show gene expression changes. Our results indicate the presence of a paternal transgenerational epigenetic effect. Quick adaptation to climatic changes may become increasingly relevant for the survival of wildlife species as global temperatures are rising.