Modification of Fecal Bacteria Counts and Blood Immune Cells in the Offspring of BALB/c and C57BL/6 Mice Obtained through Interstrain Mouse Embryo Transfer.

The reproducibility of results obtained with rodent models depends on the genetic purity of the strain and the stability of the environment. However, another potential factor is changes in the gut microbiota due to the transmission of mother's bacteria during embryo transfer. In this study, we demonstrate the transmission of the microbiota and immune cell blood phenotype to the offspring of 2 strains, C57BL/6JNskrc and BALB/cJNskrc, from surrogate dams of different genotypes. Interstrain embryo transfer resulted in a change in the number of Enterococcus spp. organisms, as shown by quantitative PCR analysis. The number of blood leukocytes was also affected, as estimated by flow cytometry. The number of blood leukocytes, including B cells and helper T cells, and the number of Enterococcus spp. organisms in male C57BL/6JNskrc offspring bornto BALB/cJNskrc surrogate dams became similar to those of male BALB/cJNskrc mice born to BALB/cJNskrc dams. Likewise, the same parameters of male BALB/cJNskrc mice born to C57BL/6JNskrc dams became similar to those of male C57BL/6JNskrc offspring. Researchers should be aware of the possible transmission of the dam's microbiota and immune cell phenotypes to the experimental strains when planning embryo transfer experiments, because these factors could affect the experimental outcomes or the reproducibility of experimental results.

Phenotypic variations in transferred progeny due to genotype of surrogate mother.

STUDY QUESTION: Does the genotype of the surrogate mother modulate the body composition and immunity of her offspring? SUMMARY ANSWER: C57BL/6J (B6) progenies carried by immunodeficient NOD SCID (NS) mothers had increased adaptive but decreased innate, immune responsiveness in comparison with the same genotype offspring carried by immunocompetent mothers, B6 and BALB/c (C); the B6 progenies carried by the same genotype mothers also showed higher body fat than the others. WHAT IS KNOWN ALREADY: Differences in the major histocompatibility complex (MHC) genes between mother and foetus is considered as an important factor in prenatal embryo development, whereas the impact of such dissimilarity on the phenotype of the mature progeny is unclear. STUDY DESIGN, SIZE, DURATION: Transplantation of two-cell mouse embryos into recipient females of the different MHC (H2) genotypes was used as an approach to simulate three variants of the immunogenic mother-foetus interaction: (i) bidirectional immunogenic dialogue between B6 (H2b haplotype) embryos and C (H2d haplotype) surrogate mother; (ii) one-way immunogenic interaction between B6 embryos and immunodeficient NS (H2g7 haplotype) surrogate mother and (iii) reduced immunogenetic dialogue between embryos and surrogate mother of the same H2b haplotype resulting in only a maternal response to HY antigens of male foetuses. Delivered by Caesarean section, pups were fostered by lactating B6 females and weighed after weaning (n = 171). Body mass and composition and innate and adaptive immunity were assessed in selected progeny groups at 9-11 weeks of age. PARTICIPANTS/MATERIALS, SETTING, METHODS: The study was performed on the specific pathogen-free mouse, inbred strains C57BL/6J, NOD SCID and BALB/c. Plasma progesterone in pregnant females was measured by enzyme-linked immunosorbent assay (ELISA). Body composition was determined by magnetic resonance spectroscopy using a low-field NMR spectrometer (EchoMRI, USA). To assess peritoneal macrophage responses (innate immunity) to anthrax, lactate dehydrogenase (LDH) and interleukin-1 (IL-1ß) were measured in a culture medium 24 h after the addition of both anthrax-lethal factor and anthrax-protective antigen. To assess adaptive immunity, 9-10 males in experimental groups were infected with Helicobacter hepaticus. Faeces collected 2 and 4 weeks after infection was used for quantitative assessment of the H. hepaticus DNA by real-time polymerase chain reaction. IgA, interferon (IFN-γ), tumour necrosis factor (TNFα), interleukin-17 (IL-17) and interleukin-10 (IL-10) in colon tissue and IgG in serum were determined in samples collected 4 weeks after gavage with H. hepaticus using ELISA. For statistical analyses, ANCOVA, post hoc least significant difference (LSD) test, Student's t-test, Spearman rank correlations and χ2 test were performed. P-value <0.05 was considered as a statistically significant difference. MAIN RESULTS AND THE ROLE OF CHANCE: ANCOVA with litter size and age as covariates revealed significant effects of the surrogate mother genotype on body mass and percent of fat in their adult progeny (F2149 = 15.60, P < 0.001 and F2149 = 5.02, P = 0.007, respectively). Adult B6 mice carried by B6 surrogate mothers were characterized by a higher percentage of body fat in comparison with offspring that were carried by NS and C females. In comparison with the male offspring carried by the B6 and C mothers, male B6 progenies carried by immunodeficient NS mothers had a higher humoral immune response (serum IgG) against oral infection with H. hepaticus, but lower in vitro macrophage IL-1ß reaction to the anthrax. Four weeks after the infection of offspring, concentrations of serum IgG and colon IL-10 correlated positively with maternal progesterone on Day 4 after embryo transfer and negatively with DNA of H. hepaticus. One-way ANOVA confirmed a statistically significant impact of surrogate mother genotype on adaptive (IgG) and innate (IL-1ß) immunity (F2.26 = 26.39, P < 0.001 and F2.27 = 5.89, P = 0.008, respectively). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The main limitation of our study is the number of combinations of mother and foetus interactions, in particular, transfer of only one embryo genotype was used. Also, it is a descriptive study, which requires further analysis of the epigenetic mechanisms of the observed phenotypic effects of surrogate mother genotype. WIDER IMPLICATIONS OF THE FINDINGS: Our experimental data demonstrate that the transfer of inbred embryos to surrogate mothers of the different genotypes is a prospective experimental model for the study of epigenetic effects of the immunogenetic interactions between mother and foetus. The experimental approach tested in our study will be in demand for the development of criteria for choosing surrogate mothers. In particular, immunocompetence of the surrogate mother along with genetic distance of her MHC alleles to the transferred embryos have a significant impact on offspring development. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the Russian FPI (6/099/2017), budget projects (0324-2016-0002 and 0324-2018-0016) and implemented using the equipment of the Centre for Genetic Resources of Laboratory Animals at ICG SB RAS, supported by the Ministry of Education and Science of Russia (Unique project identifier RFMEFI62117X0015). The authors report no conflicts of interest.

Unexpected phenotypic effects of a transgene integration causing a knockout of the endogenous Contactin-5 gene in mice.

Contactins (Cntn1-6) are a family of neuronal membrane proteins expressed in the brain. They are required for establishing cell-to-cell contacts between neurons and for the growth and maturation of the axons. In humans, structural genomic variations in the Contactin genes are implicated in neurodevelopmental disorders. In addition, population genetic studies associate Contactins loci with obesity and hypertension. Cntn5 knockout mice were first described in 2003, but showed no gross physiological or behavioral abnormalities (just minor auditory defects). We report a novel Cntn5 knockout mouse line generated by a random transgene integration as an outcome of pronuclear microinjection. Investigation of the transgene integration site revealed that the 6Kbp transgene construct coding for the human granulocyte-macrophage colony-stimulating factor (hGMCSF) replaced 170 Kbp of the Cntn5 gene, including four exons. Reverse transcription PCR analysis of the Cntn5 transcripts in the wild-type and transgenic mouse lines showed that splicing of the transgene leads to a set of chimeric hGMCSF-Cntn5 transcript variants, none of which encode functional Cntn5 protein due to introduction of stop codons. Although Cntn5 knockout animals displayed no abnormalities in behavior, we noted that they were leaner, with less body mass and fat percentage than wild-type animals. Their cardiovascular parameters (heart rate, blood pressure and blood flow speed) were elevated compared to controls. These findings link Cntn5 deficiency to obesity and hypertension.

Modulation of embryonic development due to mating with immunised males.

The modification of pre- and postnatal development conferred by immunogenic stimulation of mothers provides a population-level adaptation mechanism for non-genetic transfer of maternal experiences to progeny. However little is known about the transmission of paternal immune experiences to offspring. Here, we show that immune priming of males 3-9 days before mating affects the growth and humoral environment of developing embryos of outbred (ICR) and inbred (C57BL and BALB/c) mice. Antigenic stimulation of fathers caused a significant increase in embryonic bodyweight as measured on Day 16 of pregnancy and altered other gestation parameters, such as feto-placental ratio. Pregnant females mated with immunised males were also characterised by changes in humoral conditions as shown by measurements of blood and amniotic progesterone, testosterone and granulocyte-macrophage colony-stimulating factor (GM-CSF) cytokine concentrations. These results emphasise the role of paternal effects of immune priming on the in utero environment and fetal growth.

Eradication of Helicobacter spp. in mucin2-deficient mice.

Infections with Helicobacter spp. are known to have serious effects on rodent health, especially in immunocompromised animals. In this study three approaches were used to eradicate Helicobacter spp. infection in mice with a deficiency in intestinal proteoglycan (mucin2), namely triple oral antibiotic therapy (amoxicillin, clarithromycin and metronidazole), cross-fostering of neonatal pups by surrogate mothers negative for Helicobacter spp., and in vitro fertilization (IVF) with embryo transfer into Helicobacter-free mothers. However, triple antibiotic therapy in mice with mucin2 deficiency was not effective and had negative effects on reproductive performance, and high susceptibility of mucin2-deficient mice to Helicobacter spp. during the first 12 h after birth rendered cross-fostering impossible. Only IVF with embryo transfer was effective in eradicating Helicobacter infection from transgenic mice with mucin2 deficiency.

Neurometabolic Effect of Altaian Fungus Ganoderma lucidum (Reishi Mushroom) in Rats Under Moderate Alcohol Consumption.

BACKGROUND: The medications produced from natural products are widely used as prophylactics for sickness induced by alcohol consumption. One such prophylactic is produced from the Reishi mushroom, Ganoderma lucidum. Because of the antioxidant properties of these preparations, we expect neuroprotective prophylactic effects of Reishi-based medications in alcohol-treated animals. METHODS: The Reishi (R) suspension was produced as water extract from Altaian mushrooms. Sprague-Dawley male rats were separated into the following 3 experimental groups: Group A + R received R (6 days per week) starting 1 week before alcohol exposure, and during the next 3 weeks, they received both R and alcohol; group A received alcohol; and group C received water. At the end of experiment, we determined the metabolic profile using proton magnetic resonance spectroscopy ((1) H MRS) of the brain cortex and phosphorus magnetic resonance spectroscopy of the liver. Additionally, the blood cells were collected, and the serum biochemistry and liver histology were performed after euthanasia. RESULTS: Partial least squares discriminant analysis processing of the brain (1) H MRS gave 2 axes, the Y1 axis positively correlated with the level of taurine and negatively correlated with the level of lactate, and the Y2 axis positively correlated with the content of GABA and glycine and negatively correlated with the sum of the excitatory neurotransmitters, glutamate and glutamine. The Y1 values reflecting the brain energetics for the A + R group exceeded the corresponding values for groups C and A. The maximal level of Y2 reflecting the prevalence of inhibitory metabolites in the brain was observed in the rats exposed to alcohol. Moderate alcohol consumption did not cause significant pathological changes in the livers of the experimental animals. However, 20 days of alcohol consumption significantly increased the number of binuclear hepatocytes compared to the control. This effect was mitigated in the rats that received the Reishi extract. CONCLUSIONS: Regular administration of the Reishi suspension improved the energy supply to the brain cortex and decreased the prevalence of inhibitory neurotransmitters that are characteristic of alcohol consumption. The alcohol-induced increase in liver proliferation was significantly suppressed by regular administration of the G. lucidum water suspension.

IL-1ß-independent activation of lung immunity in male mice by female odor.

In previous studies, we showed that long-term perception of female odor increases flu virus resistance in male mice. To expand on this finding, we examined the ability of female chemical cues to rapidly induce leukocyte mobilization into male lung tissue as a critical condition of signal-derived respiratory infection risk reduction, which is usually associated with sniffing scent marks. Here, we compared the immune and endocrine effects of female chemical cues and lipopolysaccharide (LPS) as common triggers of innate immunity. The number of leukocytes in the lung tissue, concentrations of IL-1ß in lung and hypothalamus, and plasma corticosterone and testosterone levels were assessed in ICR male mice 2h after the intranasal application of female urine, LPS or urine and LPS. Both stimuli induced leukocyte mobilization but, in contrast to LPS, female urine alone did not stimulate increased IL-1ß levels in lung and hypothalamus. Plasma corticosterone increased and plasma testosterone decreased in response to LPS, whereas the concentrations of these hormones did not change in response to female chemical cues. Thus, the present study gives additional evidence for an anticipatory adaptation of male mice to potential breeding risks. Appreciable mobilization of leukocytes to the lungs requires less than 2h and develops through an IL-1ß-independent pathway.