Primary Site of Coxsackievirus B Replication in the Small Intestines: No Proof of Peyer’s Patches Involvement

Background: Enterovirus (EV) infections are associated with a broad range of diseases. Since the first experimental infection of primates with poliovirus (PV), tonsils and the Peyer’s patches (PPs) have been believed to be the primary replication sites of EVs. Our aim was to localize different viral markers in the small intestines (SI) of coxsackievirus B (CVB) orally and intraperitoneally (i.p.) infected mice. Methods: Transverse sections of SIs of both infected and control male outbred mice were collected at different intervals post-infection (p.i) and analyzed for presence of interferon-alpha (IFN-α) and viral protein VP1 by immunohistochemistry and in situ hybridization (ISH). Fluorescent marker, eGFP, was identified in cryosections of mice infected with eGFP-CVB3. Results: In the infected SIs, we observed enlarged germinating centers (GCs) in the PPs; IFN-α was detected in the PPs and mucosal layer of the SIs. However, VP1, viral RNA and the eGFP were absent in the GCs of PPs at all stages of infection irrespective of the virus strains used. Conclusions: Virus was present in the epithelial cells but not in GCs of the PPs of the murine SIs. Our results do not support the hypothesis of EV replication in the PP especially in the GCs.

Results of clinical trials of a trivalent vaccine for horses

We have developed a trivalent vaccine made from the SV/69 strain of the Rhinopneumonia virus (RHIV), the bacteria strains of Salmonella abortus equi BN-12 - the causative agent of Salmonella abortion and Streptococcus equi N-34 - the causative agent of the horse strangles. Preclinical laboratory studies of the immunogenicity of the vaccine in linear and outbred mice showed that the preparation protects against experimental infection with the Rhinopneumonia virus by 88.8%, from the causative agents of Salmonella abortion and horse strangles by 100%. There were carried out clinical trials of a trivalent inactivated vaccine with a centrifuge strain Bacillus subtilis TNP-3 as an immunomodulator in order to specifically prevent salmonella abortion, rhinopneumonia and horse strangles. Clinical trials were carried out on horses in the Central regions of Yakutia. The business output of foals was 50.2% in the republic. The business yield in immunized mares was 76,0 % and in unvaccinated mares only 38,0 % in a controlled production trial at the "Uyruye" agricultural production complex. Consequently, immunization of mares with trivalent vaccine increased the reproduction rate by 38,0 %. Results of extensive production tests on 2,568 heads of herd horses confirmed the data of preclinical laboratory studies of immunogenicity in linear and outbred mice. The trivalent vaccine against rhinopneumonia, salmonella abortion and horse strangles stimulates immunobiological reactivity, induces the synthesis of specific antibodies in high titers and increases the business yield of foals from 18,0 to 38,0 %. The vaccine is highly effective and can provide recovery of disadvantaged settlements.

Variation in the response to malaria in Diversity Outbred mice

We infected Diversity Outbred mice with Plasmodium chabaudi to better understand how the host response to infection can vary and to try to identify genetic loci responsible for this variation. We identified two loci correlating with binary traits: one on chromosome two was linked to undetectable parasite loads and another on chromosome ten which was linked to death. Though we tested many variable traits, none of those reached statistical significance using the 489 mice we tested.

Intermittent fasting and caloric restriction interact with genetics to shape physiological health in mice

Dietary interventions can dramatically affect physiological health and organismal lifespan. The degree to which organismal health is improved depends upon genotype and the severity of dietary intervention, but neither the effects of these factors, nor their interaction, have been quantified in an outbred population. Moreover, it is not well understood what physiological changes occur shortly after dietary change and how these may affect the health of an adult population. In this article, we investigated the effect of six month exposure of either caloric restriction or intermittent fasting on a broad range of physiological traits in 960 one year old Diversity Outbred mice. We found caloric restriction and intermittent fasting affected distinct aspects of physiology and neither the magnitude nor the direction (beneficial or detrimental) of effects were concordant with the severity of the intervention. In addition to the effects of diet, genetic variation significantly affected 31 of 36 traits (heritabilties ranged from 0.04-0.65). We observed significant covariation between many traits that was due to both diet and genetics and quantified these effects with phenotypic and genetic correlations. We genetically mapped 16 diet-independent and 2 diet-dependent significant quantitative trait loci, both of which were associated with cardiac physiology. Collectively, these results demonstrate the degree to which diet and genetics interact to shape the physiological health of adult mice following six months of dietary intervention.

Morphological differences in the commissural connections of the forebrain in white outbred mice and BALB/C mice

BACKGROUND: The study of the mechanisms of interaction of paired structures of the mammalian brain is a fundamental problem of modern neuroscience, which is of great applied importance. Even mild underdevelopment of the corpus callosum in humans can lead to autism. It is known that the intensity of intraspecific interactions in BALB/c mice is lower than in white outbred ones, while some BALB/c substrains are characterized by underdevelopment of the corpus callosum. AIM: To compare the morphological parameters of the large brain commissures in white outbred mice and BALB/c mice grown in the Rappolovo nursery (Leningrad region). MATERIALS AND METHODS: The morphology of the corpus callosum was studied in 13 male white outbred mice and 7 male BALB/c mice at the age of 8 months. RESULTS: In mice of both subpopulations, the area of the anterior commissure of the left hemisphere was smaller than that of the right hemisphere (p 0.05). There were no differences between subpopulations in this parameter. The area of the left section of the corpus callosum trunkus in outbred mice was larger than the right one (p 0.001), while in BALB/c mice the areas of the left and right slices did not differ. Despite the absence of significant differences in the area of the anterior part (rostrum et genu) of the corpus callosum the density of the location of oligodendrocytes in this brain structure in the mice of the two subpopulations was different. The number of oligodendrocytes in 0.01 mm2 on the left section of the anterior part of the corpus callosum in BALB/c mice was greater than in white outbred mice (p 0.05). A similar trend was revealed when comparing slices of the right hemisphere (p = 0.065). CONCLUSIONS: The large area of the right parasagittal slice of the anterior commissure suggests that some of its constituent fibers do not cross the midline, but end within the same hemisphere, which may be the morphological basis for the functional dominance of the temporal cortex of the left hemisphere in mice of both subpopulations. The corpus callosum in BALB/c mice is developed symmetrically, and in white outbred ones asymmetrically. This feature may be the morphological basis for the functional dominance of the parietal cortex of the right hemisphere in outbred animals.

Identification of sample mix-ups and mixtures in microbiome data in Diversity Outbred mice

In a Diversity Outbred mouse project with genotype data on 500 mice, including 297 with microbiome data, we identified three sets of sample mix-ups (two pairs and one trio) as well as at least 15 microbiome samples that appear to be mixtures of pairs of mice. The microbiome data consisted of shotgun sequencing reads from fecal DNA, used to characterize the gut microbial communities present in these mice. These sequence reads included sufficient reads derived from the host mouse to identify the individual. A number of microbiome samples appeared to contain a mixture of DNA from two mice. We describe a method for identifying sample mix-ups in such microbiome data, as well as a method for evaluating sample mixtures in this context.

The Gut Microbiome and Substance Use Disorder

Substance use disorders (SUDs) remain a significant public health challenge, affecting tens of millions of individuals worldwide each year. Often comorbid with other psychiatric disorders, SUD can be poly-drug and involve several different substances including cocaine, opiates, nicotine, and alcohol. SUD has a strong genetic component. Much of SUD research has focused on the neurologic and genetic facets of consumption behavior. There is now interest in the role of the gut microbiome in the pathogenesis of SUD. In this review, we summarize current animal and clinical evidence that the gut microbiome is involved in SUD, then address the underlying mechanisms by which the gut microbiome interacts with SUD through metabolomic, immune, neurological, and epigenetic mechanisms. Lastly, we discuss methods using various inbred and outbred mice models to gain an integrative understanding of the microbiome and host genetic controls in SUD.

CD-1 Outbred Mice Produce Less Variable Ultrasonic Vocalizations Than FVB Inbred Mice, While Displaying a Similar Developmental Trajectory

The production of ultrasonic vocalizations (USVs) in neonatal mice is a critical means of communication that is used to elicit maternal care. Alterations in neonatal USV production is also an indicator of neurological deficits. However, USVs have been predominately assessed in inbred animals and are significantly understudied in outbred mice, even though outbred animals better represent the genetic diversity of humans and are used in several neurological disorder models. To determine the reproducibility of USVs across models, we compared male and female CD-1 (outbred) and FVB (inbred) mice on postnatal days (PD) 4, 8, 12, 16, and 20. We found that CD-1 and FVB mice displayed a similar developmental trajectory of USVs. However, CD1 mice emitted more USVs on PD 12 than FVB mice. In addition, FVB mice emitted a longer duration of calls on PD 4 and 8 and a higher overall maximum and minimum frequency of USVs than CD-1 mice. No differences in mean amplitude were found between groups. We also detected numerous significant differences between outbred and inbred mice when comparing each group's call composition. We next assessed the relative variability of mouse vocalizations between groups, finding that outbred mice were less variable than inbred mice. For the spectral and temporal characteristics of the USVs, variability was similar between groups. Altogether, we found that CD-1 outbred mice display a similar, if not lower, degree of variability than FVB inbred mice when assessing neonatal USVs.