Rodentia

The agouti (Dasyprocta leporina) and paca (Agouti paca) are among the largest extant rodent species. Although these species have considerable economic potential, there are few reports in the literature concerning male reproductive biology in sexually mature agoutis and pacas. The objectives of the present study were to perform detailed stereologic and histologic analyses of the testis and estimate spermatogenic cycle length in these 2 Neotropical rodent species as well as to compare the data with those from other well-studied rodent members of the Hystricomorpha and Myomorpha suborders. Eight adult agoutis and 6 adult pacas were used. The spermatogenic cycle in agoutis and pacas lasted 9.5 6 0.03 and 11.5 6 0.16 days, respectively, whereas the total duration of spermatogenesis for these 2 species was 42.8 6 0.16 and 51.6 6 0.7 days, respectively. Most of the parameters investigated were similar to those obtained for the other members of the Hystricomorpha suborder. As a result of the combination of high values of seminiferous tubule volume density, number of Sertoli cells per gram of testis, Sertoli cell efficiency, and a relatively short duration of spermatogenesis, the spermatogenic efficiency found in agoutis (52 6 2 6 10 6 ) and pacas (39 6 2 6 10 6 ) was particularly high when compared with that of previously investigated mammalian species. The data presented in this investigation would be useful for studies related to animal production as well as improvement and conservation programs involving these 2 large Neotropical rodent species.

Approximately 3% of infants born have at least one serious congenital malformation. In the U.S., an average of 10 infants per thousand die before 1 y of life; about half of these deaths can be attributed to birth defects, low birth weight or prematurity. Although the causes of developmental abnormalities are clearly multifactorial in nature, we suggest that a common factor contributing to the occurrence of developmental abnormalities is suboptimal mineral nutrition during embryonic and fetal development. Using zinc and copper as examples, evidence is presented that nutritional deficiencies can rapidly affect the developing conceptus and result in gross structural abnormalities. Deficits of zinc or copper can result in rapid changes in cellular redox balance, tissue oxidative stress, inappropriate patterns of cell death, alterations in the migration of neural crest cells and changes in the expression of key patterning genes. In addition to well-recognized malformations, mineral deficiencies during perinatal development can result in behavioral, immunological and biochemical abnormalities that persist into adulthood. Although these persistent defects can in part be attributed to subtle morphological abnormalities, in other cases they may be secondary to epigenetic or developmental changes in DNA methylation patterns. Epigenetic defects combined with subtle morphological abnormalities can influence an individual's risk for certain chronic diseases and thus influence his or her risk for morbidity and mortality later in life.

Attention deficit hyperactivity disorder (ADHD) presents special challenges for drug development. Current treatment with psychostimulants and nonstimulants is effective, but their mechanism of action beyond the cellular level is incompletely understood. We review evidence suggesting that altered reinforcement mechanisms are a fundamental characteristic of ADHD. We show that a deficit in the transfer of dopamine signals from established positive reinforcers to cues that predict such reinforcers may underlie these altered reinforcement mechanisms, and in turn explain key symptoms of ADHD. We argue that the neural substrates controlling the excitation and inhibition of dopamine neurons during the transfer process are a promising target for future drug development. There is a need to develop animal models and behavioral paradigms that can be used to experimentally investigate these mechanisms and their effects on sensitivity to reinforcement. More specific and selective targeting of dru...

The study investigated the role of odor cues from two nism requiring direct contact with the breeding female. naked mole-rat colonies, in conjunction with behavioral ᭧ 1997 Academic Press cues from nonbreeding colony members, in maintaining suppression of ovulation in subordinate female naked mole-rats isolated from the two parent colonies. Four high ranking nonbreeding female naked mole-rats were Cooperatively breeding, or eusocial, species vary in removed from their respective parent colonies and singly the extent of differential reproductive success among housed in separate burrow systems. For a 64-day period, members in a group ; Sherman, Lathe removed females were maintained in daily odor concey, . In some species, several tact with their parent colony by daily rotating soiled bedindividuals within a single social group breed, resulting ding material between the parent colony and the burrow systems of removed females. In addition, subsets of nonin minimal differences between the reproductive sucbreeding animals from the respective parent colony were cess of group-living individuals (e.g., black-tailed prairegularly moved into the burrow systems of removed rie dogs Cynomys ludovicianus; Hoogland, 1995). In confemales for 2-day periods during this 64-day period. Retrast to this, other species exhibit social systems in moved females were therefore in continual social conwhich reproduction is usually limited to a single inditact with subsets of parent colony animals except for vidual within a sex, resulting in extensive differential the breeding pair. All four removed females exhibited reproductive success between individuals (e.g., insects; raised levels of urinary progesterone (õ 2 ng/mg Cr) in- Wilson, 1971).

Effective small interfering RNA (siRNA)-mediated therapeutics require the siRNA to be delivered into the cellular RNA-induced silencing complex (RISC). Quantitative information of this essential delivery step is currently inferred from the efficacy of gene silencing and siRNA uptake in the tissue. Here we report an approach to directly quantify siRNA in the RISC in rodents and monkey. This is achieved by specific immunoprecipitation of the RISC from tissue lysates and quantification of small RNAs in the immunoprecipitates by stem-loop PCR. The method, expected to be independent of delivery vehicle and target, is label-free, and the throughput is acceptable for preclinical animal studies. We characterized a lipid-formulated siRNA by integrating these approaches and obtained a quantitative perspective on siRNA tissue accumulation, RISC loading, and gene silencing. The described methodologies have utility for the study of silencing mechanism, the development of siRNA therapeutics, and ...

Among rodents, the lineage from Progonomys hispanicus to Stephanomys documents a case of increasing size and dental specialization during an approximately 9 Myr time-interval. On the contrary, some contemporaneous generalist lineages like Apodemus show a limited morphological evolution. Dental shape can be related to diet and can be used to assess the ecological changes along the lineages. Consequently, size and shape of the first upper molar were measured in order to quantify the patterns of morphological evolution along both lineages and compare them to environmental trends. Climatic changes do not have a direct influence on evolution, but they open new ecological opportunities by changing vegetation and allow the evolution of a specialist like Stephanomys. On the other hand, environmental changes are not dramatic enough to destroy the habitat of a long-term generalist like Apodemus. Hence, our results exemplify a case of an influence of climate on the evolution of specialist species, although a generalist species may persist without change.

The structural organization of the spermatozoon from the Eurasian beaver, Castor fiber (Family: Castoridae), was determined and compared to that of other sciuromorph rodents. The beaver spermatozoon has a head, which is variable in form but usually paddle-shaped, with a small nucleus and very large acrosome, and a tail that is relatively short compared to that of most other rodents. Transmission electron microscopy indicates that in most testicular spermatozoa the acrosome projects apically, although in a few it becomes partly flexed. During the final stages of maturation, however, the acrosome becomes highly folded so that the apical segment comes to lie alongside part of the acrosome that occurs lateral to the nucleus, with, in some cases, fusion taking place between the outer acrosomal membranes. The sperm nucleus is wedge-shaped, being broader basally and narrowing apically with an occasional large nuclear vacuole occurring. This spermatozoon structure is markedly different from that found in the other species of Geomyoidea, which is the sister group of the Castoridae. The findings thus emphasize the highly divergent nature of the beaver spermatozoon and demonstrate that, within the proposed Infraorder Castorimorpha, very large differences in sperm structure have evolved. J. Morphol. 268:683-689, 2007Morphol. 268:683-689, . 2007 Wiley-Liss, Inc.

The pineal of viscacha (Lagostomus maximus maximus) is formed by two main cellular populations of pinealocytes and interstitial cells. A connective capsule surrounds the gland sending numerous septa containing blood vessels and nerves. In the specimens collected during summer the pinealocyte displays a defined contour and a clear cytoplasm with abundant ribosomes and numerous cisternae of endoplasmic reticulum. The pinealocytes observed during winter have cytological characteristics of active cells with dense and elongated mitocondria, dense bodies, and a developed Golgi complex. These seasonal glandular changes could be related to the environmental condition and mainly to the summer photoperiod. The presence of abundant nerve terminals in the perivascular spaces suggests a neural control on the blood vessels.

A meta-analysis approach was used to test for chromosomal speciation in rodents. Forty-one pairs of sister species, identified in the two most species-rich rodent families (Cricetidae and Muridae), were used as phylogenetically independent data points, each resulting from a speciation event. About 30% of sister species have an identical karyotype. There was a significant difference in the number of chromosomal differences between sympatric and allopatric sister species, compatible with a direct role of chromosomal rearrangements in speciation.

The objective was to compare the use of powdered coconut water (ACP-109c; ACP Biotecnologia, Fortaleza, CE, Brazil) and Tris extenders for recovery and cryopreservation of epididymal sperm from agouti. The caudae epididymus and proximal ductus deferens from 10 sexually mature agoutis were subjected to retrograde washing using ACP-109c (ACP Biotecnologia) or Tris. Epididymal sperm were evaluated for motility, vigor, sperm viability, membrane integrity, and morphology. Samples were centrifuged, and extended in the same diluents plus egg yolk (20%) and glycerol (6%), frozen in liquid nitrogen, and subsequently thawed at 37°C for 1 min, followed by re-evaluation of sperm characteristics. The two extenders were similarly efficient for epididymal recovery, with regard to the number and quality of sperm recovered. However, for both extenders, sperm quality decreased (P Ͻ 0.05) after centrifugation and dilution. After sperm cryopreservation and thawing, there were (mean Ϯ SEM) 26.5 Ϯ 2.6% motile sperm with 2.6 Ϯ 0.2 vigor in the ACP-109c (ACP Biotecnologia) group, which was significantly better than 9.7 Ϯ 2.6% motile sperm with 1.2 Ϯ 0.3 vigor in Tris. In conclusion, agouti epididymal sperm were successfully recovered using either ACP-109c (ACP Biotecnologia) or Tris extenders; however, ACP-109c (ACP Biotecnologia) was a significantly better extender for processing and cryopreserving these sperm.

Habitat fragmentation and diversity loss due to increased conversion of natural habitats to agricultural uses influence the distribution and abundance of wildlife species and thus may change the ecology of pathogen transmission. We used hantaviruses in Panama as a research model to determine whether anthropogenic environmental change is associated with changes in the dynamics of viral transmission. Specifically, we wanted to determine whether hantavirus infection was correlated with spatial attributes of the landscape at both large and small scales or whether these changes are mediated by changes in community composition. When analyzed at coarse spatial scales, hantavirus reservoirs were more commonly found in disturbed habitats and edge habitats than in forested areas. At local scales, reservoir species dominance was significantly correlated with the slope of the terrain. To evaluate the effect of small-mammal diversity loss on infection dynamics, we implemented an experiment with selective species removal at experimental sites. Seroprevalence of hantavirus was higher in the community of small mammals and increased through time in the experimental sites. The higher seroprevalence in experimental plots suggests that greater diversity likely reduces encounter rates between infected and susceptible hosts. Our studies suggest that habitat loss and fragmentation and species diversity loss are altering hantavirus infection dynamics in Panama. Our work represents a multidisciplinary approach toward disease research that includes biodiversity concerns such as environmental change and degradation, human settlement patterns, and the ecology of host and nonhost species, work that may be especially important in tropical countries.

Harmful non-indigenous species (NIS) impose great economic and environmental impacts globally, but little is known about their impacts in Southeast Asia. Lack of knowledge of the magnitude of the problem hinders the allocation of appropriate resources for NIS prevention and management. We used benefit-cost analysis embedded in a Monte-Carlo simulation model and analysed economic and environmental impacts of NIS in the region to estimate the total burden of NIS in Southeast Asia. The total annual loss caused by NIS to agriculture, human health and the environment in Southeast Asia is estimated to be US$33.5 billion (5 th and 95 th percentile US$25.8-39.8 billion). Losses and costs to the agricultural sector are estimated to be nearly 90% of the total (US$23.4-33.9 billion), while the annual costs associated with human health and the environment are US$1.85 billion (US$1.4-2.5 billion) and US$2.1 billion (US$0.9-3.3 billion), respectively, although these estimates are based on conservative assumptions. We demonstrate that the economic and environmental impacts of NIS in low and middle-income regions can be considerable and that further measures, such as the adoption of regional risk assessment protocols to inform decisions on prevention and control of NIS in Southeast Asia, could be beneficial.

The conditioned place preference procedure is widely used in rodents for assessing drug effects on motivational processes (Schechter and Calcagnetti, 1993). In this paradigm, the positive reinforcing properties of a test substance are demonstrated by showing that animals prefer environments previously associated with the substance. Animals are conditioned in a two-compartment box in which they are allowed to explore one compartment under the influence of the test substance, while the other compartment is always explored after administration of vehicle. An increase in the time spent in the drug-paired compartment after conditioning suggests the presence of positive reinforcing effects (drug-induced place preference). This procedure is less time consuming than more complex techniques used to detect drug abuse, such as self-administration (UNIT 10.5) or drug-discrimination paradigms, and is sensitive to the reinforcing effects of many substances abused by humans. Other advantages of the test are the absence of any instrumental learning and the possibility of evaluating reinforcing effects in the absence of the test substance. This procedure is used to measure the positive reinforcing properties of test compounds in rats (see Basic Protocol 1) and mice (see Basic Protocol 2) using a two-compartment box place-preference paradigm. During the conditioning period, animals are allowed to repeatedly explore the two compartments of the box (one compartment at a time). Test compounds are always administered before exploration of one of the compartments, while vehicle is administered before exploration of the other compartment. During the test period conducted after conditioning, the animals have free access to both compartments, and the time spent in each is measured. A preference for the drug-paired compartment (drug-induced place preference) is indicated if the animal spends significantly more time in that compartment. The number of crossings from one compartment to the other is also scored to assess general locomotor activity. NOTE: All protocols using live animals must first be reviewed and approved by an Institutional Animal Care and Use Committee (IACUC) or must conform to governmental regulations regarding the care and use of laboratory animals. BASIC PROTOCOL 1 PLACE PREFERENCE TEST IN RATS Materials Male Wistar rats (180 to 200 g at the beginning of the experiment) Test compound(s) dissolved in physiological saline or suspended in 0.2% hydroxypropylmethylcellulose in physiological saline (for parenteral administration) Vehicle Transparent plastic (e.g., macrolon) cages (41 × 25 × 25-cm) Video camera and videotape recorder Six two-compartment test apparatuses (Fig. 10.4.1): experimental boxes (35 × 35 × 70-cm) with two compartments of equal size (35 × 35 × 35-cm) separated by a guillotine door (12 × 12-cm); each compartment is tactually and visually distinct (black-and-white striped walls with corrugated floors versus gray walls with smooth floors) 60-W red lights Animal balance with accuracy of 1 g (e.g., Sartorius 1401.001.2

The use of plant protection products on agricultural crops can result in exposure of birds and mammals to toxic chemicals. In the European Union, the risks from such exposures are assessed under the current (2009) guidance document from the European Food Safety Authority (EFSA), designed to increase the realism of the theoretical risk assessments in comparison to its predecessor (SANCO/4145/2000). Since its adoption over 7 yr ago, many plant protection products have been evaluated successfully using the 2009 EFSA guidance document. However, there are still significant areas of improvement recommended for future revisions of this guidance. The present Focus article discusses experiences to date with the current scheme, including levels of conservatism in input parameters and interpretation by regulatory authorities together with proposals for how the guidance document could be improved when it is revised in the not too distant future. Several areas for which further guidance is recom...

Different host species harbour parasite faunas that are anywhere from very similar to very different in species composition. A priori, the similarity in the parasite faunas of any two host species should decrease with increases in either the phylogenetic distance, the distinctness of the environments occupied or the geographical distance between these hosts. We tested these predictions using extensive data on the faunas of fleas (Insecta: Siphonaptera) and gamasid mites (Acari: Parasitiformes) parasitic on rodents across the Palaearctic. For each pair of host species, we computed the similarity in parasite faunas based on both species composition as well as the phylogenetic and/or taxonomic distinctness of parasite species. Phylogenetic distances between hosts were based on patristic distances through a rodent phylogeny, geographic distances were computed from geographic range data, and environmental dissimilarity was measured from the average climatic and vegetation scores of each host range. Using multiple regressions on distance matrices to assess the separate explanatory power of each of the three dependent variables, environmental dissimilarity between the ranges of host species emerged as the best predictor of dissimilarity between parasite faunas, especially for fleas; in the case of mites, phylogenetic distance between host species was also important. A closer look at the data indicates that the flea and mite faunas of two hosts inhabiting different environments are always different, whilst hosts living in similar environments can have either very similar or dissimilar parasite faunas. Additional tests showed that dissimilarity in flea or mite faunas between host geographic ranges was best explained by dissimilarity in vegetation, followed by dissimilarity in climatic conditions. Thus, external environmental factors may play greater roles than commonly thought in the evolution of host-parasite associations.

Although researchers have examined many aspects of fire modification, the rate and pattern of decomposition in charred remains have not been studied previously. This study utilized 48 domestic pigs, divided into 24 charred (head, neck, and limbs burned to Crow-Glassman level 1 and torso to level 2) and 24 un-charred pig carcasses. Decomposition of control carcasses was scored at 50 accumulated degree days (ADD) intervals, and charred carcasses were also observed and photographed at this time. A Charred Body Scale was subsequently created, and charred carcasses were scored retrospectively for the same ADD intervals. Analysis using a mixed-effect repeated measures model indicated that, while decomposition rate was not statistically different between the two groups (p = 0.2692), the charred remains initially displayed an ostensibly more advanced pattern. Body regions displaying significant charring decomposed at a faster rate (p < 0.001), while areas with very light levels of charring decomposed at a significantly slower rate (p < 0.001).

Yersinia pestis invaded the continental United States in 1900 and subsequently became established in wild rodent populations in several western states, traversing 2,250 km in approximately 40 years. However, the specific path of the eastward expansion of plague into the United States is poorly understood. We directly calculated velocities of disease spread and performed trend-surface analyses on spatio-temporally unique plague cases to clarify the route and speed of the initial spread of plague eastward. Velocities of disease spread were then analyzed using multiple linear regression models to identify environmental features that significantly impacted the rate of spread. Between one and three introductions of plague along the Pacific coast were observed, after which plague traveled from 45 to 87 km/year. In all regression models, the coast ranges of California were associated with slower spread, and the Southern Rockies were associated with a significant increase in the rate of dis...

A major cost of social behavior is the increased risk of exposure to parasites and infection. Animals utilize social information, including chemical signals, to recognize and avoid conspecifics infected with either endoparasites or ectoparasites. Here, we briefly discuss the relations among odors, parasite recognition, and avoidance, and consider some of the associated hormonal, neural, and genomic mechanisms. In rodents, odor cues mediate sexual and competitive interactions and are of major importance in individual recognition and mate detection and choice. Female mice distinguish between infected and uninfected males by urinary odors, displaying aversive response to, and avoidance of, the odors of infected individuals. This reduces both the likelihood of the transmission of parasites to themselves and allows females to select for parasite-free males. This set of olfactory and mate choice responses can be further modulated by social factors such as previous experience and exposure to infected males and the mate choices of other females. Male mice, who also face the threat of infection, similarly distinguish and avoid parasitized individuals by odor, thus reducing their likelihood of infection. This recognition and avoidance of the odors of infected individuals involves genes for the neuropeptide, oxytocin (OT), and estrogenic mechanisms. Mice with deletions of the oxytocin gene [OT knockout mice (OTKO)] and mice whose genes for estrogen receptor (ER)-a or ER-h have been disrupted [ER knockout mice (ERKO), a-ERKO and h-ERKO] are specifically impaired in their recognition of, aversion to, and memory of the odors of infected individuals. These findings reveal some of the genes involved in the mediation of social recognition in the ecologically relevant context of parasite recognition and avoidance. D

Kyungpook National University School Background The tropical rat mite, Ornithonyssus bacoti (O. bacoti), is an ectoparasite on of Medicine, Taegu, and Department many rodents, but when the rodent is not available, humans may become the victim of the of Dermatology, Catholic University mite's bite. The bite induces a nonspecific dermatitis; therefore, it is not easy to diagnose Medical College, Seoul, South Korea rat mite dermatitis unless the parasites are found. Correspondence Materials and methods Ten cases of rat mite dermatitis were found in medical students Sang Lip Chung, MD who had studied in the same room of the library. Their nonspecific dermatitis consisted of Department of Dermatology small papules, and parasites were found in the skin or in the environment. The mites were Kyungpook National University School collected and identified as O. bacoti, female. Histopathologic studies showed moderate of Medicine perivascular lymphohistiocytic infiltrations intermingled with some eosinophils. The presence Samduck 2-Ka 50, Chung-gu Taegu 700-721

Hantaviruses are causative agents of some severe human illnesses, including hemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS). The viruses are maintained by rodent hosts, and humans acquire infection by inhaling virus-contaminated excreta from infected animals. To examine the epidemiology of hantavirus infections in Japan and Far East Russia, we conducted epidemiological surveys in these regions. In Japan, anti-hantavirus antibodies were found in four rodent species, Clethrionomys rufocanus, Rattus norvegicus, R. rattus, and Apodemus speciosus. Although no new HFRS cases have been officially reported over the past 20 years in Japan, one member of the Japan Ground Self-Defense Force did test positive for hantavirus antibody. Repeated surveys in Far East Russia have revealed that two distinct hantavirus types cause severe HFRS in this region. Hantavirus sequences identified from A. peninsulae, fetal HFRS cases in Vladivostok, and Amur virus are highl...

This article reviews the main events of embryo-implantation and decidualization in rodents. In common laboratory rodents the embryo attaches to the uterine epithelial lining, usually on days 4 to 6 of pregnancy. A progressive degree of proximity between trophoblast and epithelium occurs until the epithelial cells undergo apoptosis and detach from the basement membrane. During the attachment stage, the spindle-shaped connective tissue cells that underlie the epithelium next to the embryos transform into polyhedral and closely packed decidual cells. Following the epithelial detachment and the breaching of the basement membrane the embryo is thus in direct contact with decidual cells. These cells accumulate organelles associated with synthesis of macromolecules, intermediate filaments, and eventually lipid droplets and glycogen. Another remarkable feature of decidual cells is the establishment of gap and adherens intercellular junctions. Differentiation of fibroblasts into decidual cells advances antimesometrially and mesometrially, creating in the endometrium several regions of cells with different morphology. The whole phenomenon of decidualization which is normally triggered by the embryo can be artificially induced in pseudopregnant or hormonally-prepared animals with the use of diverse stimuli. The uterine epithelium is probably responsible for the transduction of the initial stimulus. Prostaglandins have been shown to be important in the induction of decidualization. More recently other substances such as leukotrienes, platelet-activating factor (PAF), and transforming growth factor (TGF) have been thought to play a role in induction. Much evidence points to prostaglandin production by the decidual cells. New proteins such as a luteotropic factor, desmin, and other molecules were shown to be produced after rat stromal cells undergo decidual transformation. The extracellular matrix of the mouse decidua contains very thick collagen fibrils. Mouse decidual cells are also very active in phagocytosing the thick fibrils, contributing to the remodeling and involution of the decidua that accompanies embryonic growth. Radioautographic data indicates that mouse decidual cells produce and secrete collagen and sulfated proteoglycans. © 1993 Wiley-Liss, Inc.

In the past decade, epidemiological findings and data from experimental studies in animals have shown that the structure and function of the organism can be programmed during critical periods of development which can lead to detrimental long-term consequences for the health of an individual. Low birth weight has been linked to many adult diseases in humans including type 2 diabetes. The full detrimental effects of early growth restriction are often accompanied by the presence of obesity, which itself might be a manifestation of programmed appetite regulation in fetal and neonatal life. The understanding of interactions between leptin and insulin and their roles in glucose and body weight regulation provides clues towards mechanisms underlying altered appetite regulation and increased risk of type 2 diabetes in low birth weight individuals. Molecular mechanisms involved might include epigenetic alteration of the fetal genome in response to maternal nutrition. D Early Human Development (2005) 81, 981 -988 www.elsevier.com/locate/earlhumdev

В учебное пособие входят практические рекомендации по проведению отловов, учетов, коллектированию и содержанию в не-воле мелких млекопитающих. Пособие включает подробные методики по изучению поведения, питания, гельминтов грызунов и землероек, оригинальный определитель позволяет установить не только видовую, но и половозрастную принадлежность изучаемых объектов. Учебное пособие предназначено для студентов и аспирантов биологических специальностей и может быть использовано для про-ведения самостоятельных исследований учителями биологии, молодыми учеными.

S 0 3 7 8 -4 3 2 0 ( 0 0 ) 0 0 2 2 3 -2 P.I. Rekwot et al. / Animal Reproduction Science 65 (2001) 157-170 to developing the concept of "control systems technologies", aimed at controlling reproductive performance. The knowledge acquired on the effectiveness of biostimulation; the factor which conditions it and the biological mechanism which produces it in livestock species, allows its use as a breeding management tool. The understanding of the role of pheromones could be of potential economic importance in addressing some of the problems associated with livestock production in the tropics. The biostimulation technique offers a potentially useful and practical way to improve reproductive efficiency in livestock species in the tropics. The exact nature of the cues and the role of biostimulation in livestock species especially swine, sheep, goats and cattle in developing countries require more attention.

Human encroachment on wildlife habitats has contributed to the emergence of several zoonoses. Pathogenic hantaviruses are hosted by rodents and cause severe diseases in the Americas and Eurasia. We reviewed several factors that potentially drive prevalence (the proportion of infected rodents) in host populations. These include demography, behavior, host density, small mammal diversity, predation, and habitat and landscape characteristics. This review is the first to include a quantitative summary of the literature investigating hantavirus prevalence in rodents. Demographic structure and density were investigated the most and predation the least. Reported effects of demographic structure and small mammal diversity were consistent, whereby reproductive males were most likely to be infected and prevalence decreased with small mammal diversity. The influences of habitat and landscape properties are often complex and indirect. The relationship between density and prevalence merits more investigation. Most hantavirus hosts are habitat generalists and their control is challenging. Incorporating all potential factors and their interactions is essential to understanding and controlling infection in host populations.

This paper presents circumstantial evidence that the mating system of the North American pocket gophers (Rodentia: Geomyidae) is a promiscuous one, with female choice at its base. A molecular marker (a length variant in the mitochondria1 Control region [D-loop]) is used to show mating asymmetry in a hybrid zone between the species Thomomys bottae and Thomomys townsendii in northeastern California. A11 hybrids result from a bottae mother x townsendii father cross. Because of significant differences in body size and resulting burrow diameter, bottae females must have actively sought their respective townsendii mates for the asymmetry in mating to have occurred, signalling female choice in these subterranean mammals that are otherwise characterized by exclusive-use territories, skewed adult sex ratio in favour of females, and high variance in male reproductive success.

Beavers (Castor spp.) tend not to be a commonly held species and little published material exists relating to their captive care. We review published material and discuss husbandry issues taking into account the requirements of wild beavers. As social mammals with complex chemical communication systems and with such an ability to modify their environments, studies of wild counterparts suggest the captive requirements of beavers may actually be more sophisticated than generally perceived. Common field techniques may have practical application in the captive setting. Their widespread utilisation in conservation, including reintroductions, translocations and habitat management, also requires components of captive care. As welfare science advances there is increasing pressure on captive collections to improve standards and justify the keeping of animals. Conservation science is increasingly challenged to address individual welfare standards. Further research focusing on the captive care of beavers is required. Zoo Biol. XX:XX-XX, 2015.

Recently, in an examination of the phylogenetic relationships among the mole-rats of the family Bathyergidae (Mammalia: Rodentia), documented molecular evidence for the recognition of the Cryptomys mechowii species group at the generic level and resurrected the name Coetomys Gray, 1864 for this group. Subsequent literature review revealed that Coetomys is not available to this species group, being a junior synonym of Cryptomys Gray, 1864. Here, we describe and diagnose Fukomys genus novum. In addition, we discuss the taxonomic history of this group in an attempt to reduce the nomenclatural confusion that has plagued studies of the Bathyergidae for over a century.

Patagonian cavies (Dolichotis patagonum) are large South American rodents well adapted for cursorial life (well adapted for running). They are monogamous but can live in groups of up to 70 individuals who maintain communal burrows. They are primarily herbivorous and may be maintained on commercially produced rodent or primate diets. Their long, thin legs and skittish nature make them difficult to restrain. Common medical problems include malocclusion of cheek teeth, gastrointestinal parasites, hypertrophic cardiomyopathy, and traumatic leg fractures.

Behavioural and trapping studies of the social organization of coypus have suggested the occurrence of kin groups and a polygynous mating system. We used 16 microsatellite markers to analyse parentage and relatedness relationships in two populations (Jáuregui and Villa Ruiz) in the Argentinean Pampas. At Jáuregui, a dominant male monopolized most paternities, leading to a high variance in reproductive success between males and a high level of polygyny. At Villa Ruiz, variance in reproductive success was low among resident males and males were the fathers of zero to four offspring each. For females, no significant differences were found. Two different social groups in each study site were used to assess genetic relatedness within and between groups. These groups were neighbouring at Jáuregui but not at Villa Ruiz. At Villa Ruiz, coypus were significantly more related within than between groups, suggesting that behavioural groups were also genetic ones, and adult females were more rel...

We study the micromammals from the sites of Valdocarros and HAT, located in the lithostratigraphic unit of Arganda II and IV respectively, within the Arganda Complex Terrace, in the Jarama Valley (Madrid, Spain). The micromammal associations of these sites consist of the following taxa: in Valdocarros: Erinaceomorpha: Erinaceus europaeus; Soricomorpha: Crocidura aff. russula; Rodentia: Eliomys quercinus, Castor fiber, Apodemus sp., Cricetulus (Allocricetus) bursae, Arvicola aff. sapidus and Microtus brecciensis; and Lagomorpha: Oryctolagus cuniculus; and in HAT: Soricomorpha: Soricidae indet.; Rodentia: Eliomys quercinus, Apodemus sp., Arvicola aff. sapidus and Microtus cf. cabrerae; and Lagomorpha: cf. Oryctolagus sp. The micromammal assemblage of the Valdocarros site can be placed in the advanced Middle Pleistocene, but not in its end, because of the faunal association and the evolved state of Microtus brecciensis. However, in HAT, the presence of Microtus cf. cabrerae suggests that this site belongs to the Late Pleistocene. Both micromammal assemblages indicate a temperate climate and a well developed vegetation cover, consisting of some forest and also open areas, with shrub-like vegetation and also meadow and riverside vegetation.

Pain is present with many diseases as well as in association with surgical and traumatic conditions. The demonstration of pain is not always obvious; therefore, an animal should be assumed to be experiencing pain in any condition expected to produce pain in human beings. The assessment and control of pain is an art as well as a science. Human beings and animals express three types of opioid receptors: m, k, and d [1-5]. The authors have used this information for the clinical use of opioids in small mammals. Clinicians should keep in mind that the art of pain management is a continual learning experience requiring assessment and therapeutic adjustment for individual animals, even when they are undergoing similar surgical procedures. Therefore, standard or rule-of-thumb analgesic and anesthetic protocols are not always appropriate.

Fullest available information about mammals in Bulgaria is synthesized in the representation of individual species, and generalizations concerning the entire fauna, including some traditional aspects of this type of monographs - historical development patterns and the formation of the fauna, modern species composition, zoogeographic characteristics, territorial differentiation in the light of spatial heterogeneity of environmental conditions topography, geography, climate, vegetation). An extensive summary in English contains original keys, separately for three groups of characters ( external, skull, lower jaws), and short faunal information for each species.