Mus Musculus Domesticus (mu + musculus_domesticu)

Distribution by Scientific Domains

Selected Abstracts

Heterogeneity of the coumarin anticoagulant targeted vitamin K epoxide reduction system.

Study of kinetic parameters in susceptible, resistant mice (Mus musculus domesticus)
Abstract Vitamin K epoxide reductase (VKOR) activity in liver microsomes from a susceptible and a genetically warfarin-resistant strain of mice (Mus Musculus domesticus) was analyzed to determine the mechanism of resistance to this 4-hydroxycoumarin derivative. Kinetic parameters for VKOR were calculated for each strain by incubating liver microsomes with vitamin K epoxide ± warfarin. In susceptible mice, an Eadie,Hofstee plot of the data was not linear and suggested the involvement of at least two different components. Apparent kinetic parameters were obtained by nonlinear regression using a Michaelis--Menten model, which takes into account two enzymatic components. Component A presents a high Km and a high Vm, and as a consequence only an enzymatic efficiency Vm/Km was obtained (0.0024 mL/min/mg). Estimated warfarin Ki was 0.17 ,M. Component B presented an apparent Km of 12.73 ,M, an apparent Vm of 0.32 nmol/min/mg, and an apparent Ki for warfarin of 6.0 ,M. In resistant mice, the enzymatic efficiency corresponding to component A was highly decreased (0.0003,0.00066 mL/min/mg) while the Ki for warfarin was not modified. The apparent Vm of component B was poorly modified between susceptible and resistant mice. The apparent Km of component B observed in resistant mice was similar to the Km observed in susceptible mice. These modifications of the catalytic properties are associated with a single nucleotide polymorphism (T175G) in the VKOR-C1 gene, which corresponds to a Trp59Gly mutation in the protein. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:221,229, 2006; Published online in Wiley InterScience ( DOI 10.1002/jbt.20144 [source]

Wild mouse open field behavior is embedded within the multidimensional data space spanned by laboratory inbred strains

E. Fonio
The vast majority of studies on mouse behavior are performed on laboratory mouse strains (Mus laboratorius), while studies of wild-mouse behavior are relatively rare. An interesting question is the relationship between the phenotypes of M. laboratorius and the phenotypes of their wild ancestors. It is commonly believed, often in the absence of hard evidence, that the behavior of wild mice exceeds by far, in terms of repertoire richness, magnitude of variables and variability of behavioral measures, the behavior of the classical inbred strains. Having phenotyped the open field behavior (OF) of eight of the commonly used laboratory inbred strains, two wild-derived strains and a group of first-generation-in-captivity local wild mice (Mus musculus domesticus), we show that contrary to common belief, wild-mouse OF behavior is moderate, both in terms of end-point values and in terms of their variability, being embedded within the multidimensional data space spanned by laboratory inbred strains. The implication could be that whereas natural selection favors moderate locomotor behavior in wild mice, the inbreeding process tends to generate in mice, in some of the features, extreme and more variable behavior. [source]

Cross-strain protection reduces effectiveness of virally vectored fertility control: results from individual-based multistrain models

Summary 1Pest mammals have severe economic, environmental and social impacts throughout the world. Fertility control could reduce these impacts. Virally vectored immunocontraception (VVIC) has been proposed as an economic way to achieve this. However, the ability of an immunocontraceptive virus to control populations may be compromised if: (i) sufficient infected mice are not made infertile; (ii) the virus does not transmit at a sufficient rate; (iii) there is competition with field strains of virus; or (iv) its ability to induce infertility is altered by the presence of field strains. We tested this with stochastic, individual-based, disease,host models based on murine cytomegalovirus (MCMV) and house mice Mus musculus domesticus. 2Using field estimates of the MCMV transmission rate, immunocontraceptive MCMV (icMCMV) could prevent mouse populations from growing rapidly to damaging levels provided > 70% of mice infected with the virus became infertile. Successful control was possible even if engineering icMCMV reduced its transmission rate to c. 30% of the field-estimated value, but greater reductions in the transmission rate compromised successful control. 3Effective control was compromised if there was competition between icMCMV and field strains because of cross-immunity to infection or if previous infection with field strains blocked the development of infertility in mice subsequently infected with icMCMV. In these cases effectiveness was diminished, particularly if the transmission rate of icMCMV was reduced relative to field strains, or if close to 100% infertility of infected mice could not be achieved. If the blocking developed early after infection with field strains, doubling the transmission rate of icMCMV relative to field strains still could not produce successful control. 4Synthesis and applications. VVIC requires preliminary estimates of its efficacy to satisfy regulatory requirements before it can be released into the environment. Our models indicate that successful control of an outbreaking species using VVIC is possible if high levels of infertility can be achieved, but this is compromised by cross-strain protection and low transmission rates of engineered virus. Future research effort should focus on determining whether these compromising effects occur for specific engineered viruses and, if so, whether they can be overcome. [source]

Reproductive isolation between chromosomal races of the house mouse Mus musculus domesticus in a parapatric contact area revealed by an analysis of multiple unlinked loci

Abstract The house mouse, Mus musculus domesticus, exhibits a high level of chromosomal polymorphism because of the occurrence and fast fixation of Robertsonian fusions between telocentric chromosomes. For this reason, it has been considered a classical speciation model to analyse the role of the chromosomal changes in reproductive isolation. In this study, we analysed a parapatric contact area between two metacentric races in central Italy, the Cittaducale race (CD: 2n = 22) and the Ancarano race (ACR: 2n = 24), to estimate gene flow at the boundary. Hybrids between these two races show high levels of structural heterozygosity and are expected to be highly infertile. A sample of 88 mice from 14 sites was used. The mice were genotyped by means of eight microsatellite loci mapped in four different autosomal arms. The results show clear genetic differentiation between the CD and ACR races, as revealed by differences in allele frequencies, factorial correspondence analysis and indexes of genetic population (e.g. FST and RST) along the contact zone. The genetic differentiation between the races was further highlighted by assignation and clustering analyses, in which all the individuals were correctly assigned by their genotypes to the source chromosomal race. This result is particularly interesting in view of the absence of any geographical or ecological barrier in the parapatric contact zone, which occurs within a village. In these conditions, the observed genetic separation suggests an absence of gene flow between the races. The CD,ACR contact area is a rare example of a final stage of speciation between chromosomal races of rodents because of their chromosomal incompatibility. [source]

Estimating species' absence, colonization and local extinction in patchy landscapes: an application of occupancy models with rodents

A. Mortelliti
Abstract Making an inference on the absence of a species in a site is often problematic, due to detection probability being, in most cases, <1. Inference is more complicated if detection probability, together with distribution patterns, vary during the year, since the possibility of inferring a species absence, at reasonable costs, may be possible only in certain periods. Our aim here is to show how such challenging situations can be by tackled by applying some recently developed occupancy models combined with sample size (number of repeated surveys) estimation. We thus analysed the distribution of two rodents Myodes glareolus and Mus musculus domesticus in a fragmented landscape in central Italy pointing out how it is possible to identify true absences, non-detections, extinctions/colonizations and determine seasonal values of detection probability. [source]

Phylogeography and postglacial expansion of Mus musculus domesticus inferred from mitochondrial DNA coalescent, from Iran to Europe

Abstract Few genetic data document the postglacial history of the western house mouse, Mus musculus domesticus. We address this by studying a sample from the southeastern tip of the Fertile Crescent in the Iranian province of Ahvaz. Including other published and unpublished data from France, Germany, Italy, Bulgaria, Turkey and other places in Iran, altogether 321 mitochondrial D-loop sequences are simultaneously analysed. The patterns of coalescence obtained corroborate the classical proposal according to which the Fertile Crescent is where commensalism with humans has started in the Western Hemisphere, and from where the subspecies has expanded further west. Our data also clearly show that despite multiple colonisations and long-range transportation, there is still a rather high ,ST of 0.39. The original expansion signal is still recognisable, with two well-separated derived clades, allowing us to propose a hypothetical scenario in which expansion toward Europe and Asia Minor took at least two routes, tentatively termed the Mediterranean and the Bosphorus/Black Sea routes. This scenario resembles that of another domesticated species, the goat, and fits with the known progression of Neolithic culture. Given the concomitance of both phenomena around 12 000 years ago, we propose a recalibration of the D-loop mutation rate to a much faster tick of ~40% per site per million years (Myr). This value should be used for intrasubspecific polymorphism, while the interspecific rate in Mus is presently estimated at 6,10%/site/Myr. This is in keeping with the now well recognised fact that only a subfraction of segregating mutations go to fixation. [source]

Asymmetric size and shape variation in the Central European transect across the house mouse hybrid zone

We studied asymmetric variation of the mandible in the Central European portion of the hybrid zone between two house mouse subspecies, Mus musculus musculus and Mus musculus domesticus. Within introgression classes, defined by the share of diagnostic allozymes, we quantified the directional and fluctuating component of asymmetric variation, as well as skewness and kurtosis of individual asymmetry distributions. Furthermore, in the same manner we re-analysed asymmetric variation of the ventral side of the skull. According to the quadratic polynomial model, the mandible shape-fluctuating asymmetry, but not size-fluctuating asymmetry, was significantly decreased in the centre of the hybrid zone (with a minimum predicted for a hybrid index of 0.41). On the contrary, the skull shape-fluctuating asymmetry non-monotonically increased towards the musculus side of the hybrid zone (with a peak predicted for a hybrid index of 0.86). Thus, the impact of hybridization on fluctuating asymmetry is trait-specific in this portion of the house mouse hybrid zone. The only general feature of asymmetric variation we observed was the shift towards the platykurtosis of asymmetry distributions in the centre of the hybrid zone. Taken together, we suggest genetic variability for right,left asymmetries to be generally increased, but the developmental instability of mandible shape to be decreased, by hybridization. We hypothesize the decrease of developmental instability to be caused by overdominant effects on developmental dynamics rather than by increased heterozygosity. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101, 13,27. [source]

Morphological variation in house mice from the Robertsonian polymorphism area of Barcelona

Morphometric variation in the Robertsonian polymorphism zone of Barcelona of Mus musculus domesticus was studied by geometric morphometrics. This system is characterized by populations of reduced diploid number (2n = 27,39) surrounded by standard populations (2n = 40). We investigated the morphological variation in mice from this area, as well as the effect of geographical distance and karyotype on this variation. We also investigated the degree of co-variation between the two functional units of the mandible to explore the origin of this system (primary intergradation or secondary contact). The size and shape of the cranium, mandible and scapula were analysed for 226 specimens grouped by population, chromosome number and structural heterozygosity. Size was estimated as the centroid size, and shape was estimated after Procrustes superimposition. No significant differences in size between populations or chromosomal groups were detected. Diploid number, structural heterozygosity and local geographical isolation contributed to the differentiation in shape. Morphological differentiation between standard mice and Robertsonian specimens was observed, suggesting genetic isolation between these groups. Co-variation between the ascending ramus and alveolar region of the mandible was quantified by the trace correlation between landmark subsets of these modules. The trace values showed an ascending trend, correlated with the distance from the centre of the polymorphism area, a pattern consistent with a primary intergradation scenario. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 97, 555,570. [source]

Morphology, growth and reproduction in the Australian house mouse: differential effects of moderate temperatures

The house mouse (Mus musculus domesticus) was introduced into Australia two centuries ago and is now succeeding in a wide range of habitats and climatic regions. To explore how mice exploit such extreme environments, we compared growth rate, morphology and reproductive success of animals reared under differing thermal regimes (13 °C ,cool', 22 °C ,moderate' and 30 °C ,warm') in laboratory mice derived from wild stock. ,Warm' group young were smaller and grew more slowly than those from other groups. At 6 weeks of age, body mass was less in ,warm' than in ,cool' treatment individuals; and liver mass/body mass also was less in ,warm' than in ,cool' treatment individuals. Paired kidney mass/body mass and paired adrenal mass/body mass were less in ,warm' than in ,cool' and ,moderate' treatment mice. Low heritability values indicate that these effects were from the temperature treatments rather than genetic influences. Irrespective of temperature treatment, females were more likely to produce a litter from post-partum matings if they were experienced, rather than young or reproductively naďve, and also bore more young from post-partum matings. These observations contribute to understanding of the sudden plague activities of mice in some parts of Australia and also their sparse distribution in the interior of the continent. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 94, 21,30. [source]