scholarly journals Decontamination of genetically modified mice strains by embryo transfer for obtaining SPF colonies in a Brazilian animal facility

2019 ◽  
Vol 56 (1) ◽  
pp. e143588
Author(s):  
Ana Tada Fonseca Brasil Antiorio ◽  
Sílvia Maria Gomes Massironi ◽  
Rosália Regina de Luca ◽  
Márcio Augusto Caldas Rocha Carvalho ◽  
Vanessa Yamamoto Tambellini ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Genetically Modified ◽  
Animal Health ◽  
Laboratory Mouse ◽  
Mouse Strains ◽  
Biomedical Sciences ◽  
Intestinal Protozoa ◽  
Cell Stage ◽  
Specific Pathogen ◽  
Aseptic Conditions

The introduction of new strains of mice in specific pathogen-free (SPF) animal facilities should be performed carefully to avoid breaking sanitary barriers. To meet this need, animals should be rederived to reduce infection risk and thus avoid research interference caused by loss of animal health status and welfare. The objective of this study was to implement mice embryo transfer in the laboratory mouse facility of the Department of Immunology at the Institute of Biomedical Sciences/University of São Paulo, Brazil. Embryo transfers were performed to rederive genetically modified mouse strains with undefined sanitary status, received from different research and educational institutions. Fertilized eggs at two-cell stage were obtained by natural means and transferred into the oviducts of SPF pseudo-pregnant female mice. All surgical procedures were performed under aseptic conditions. A total of 625 embryos were transferred into therecipients. 148 pups were born, of which 140 were reared. Viruses, bacteria and intestinal protozoa were eliminated using this technique. The improvement in the microbiological status of mice allowed their expansion in our SPF facility. With these results, we can stimulate the use of embryo transfer technique between rodent facilities in Brazil and thus encourage the distribution of better models to our scientific community.

Quantitating Aortic Atherosclerosis in Rabbits and Mice

1997 ◽  
Vol 3 (S2) ◽  
pp. 317-318
Author(s):  
David A. Sanan ◽  
Dale L. Newland
Keyword(s):  
Gene Knockout ◽  
Laboratory Mouse ◽  
Lipoprotein Metabolism ◽  
Wild Type Mouse ◽  
Mouse Strains ◽  
Chow Diet ◽  
Homologous Genes ◽  
Normal Chow ◽  
Metabolism Gene ◽  
Knockout Technology

Build-up of visible atherosclerotic plaque in the arteries is readily quantifiable. The mouse and the rabbit provide useful models for understanding the pathogenesis of atherosclerosis by investigating the effects of genetic and dietary perturbations.Although the wild type mouse does not develop atherosclerosis, atherosclerosis susceptibility genes have been identified in some laboratory mouse strains which do. Furthermore, transgenic technology and gene targeting have produced genetically modified mice that express various apolipoproteins, enzymes and cofactors involved in human lipoprotein metabolism. Gene “knockout” technology allows transgene expression without interference from homologous genes. One notable “knockout” mouse, deficient in apolipoprotein E, develops spontaneous atherosclerosis on a normal chow diet. Transgenic modulations of the atherosclerotic responses of these highly susceptible mice are more pronounced and easily measured. Small, cheap and fast breeding, mice are convenient animal models. But to make mice susceptible to atherosclerosis, their genetic background has to be so drastically altered that the resulting lipoprotein metabolism may not model the human metabolism accurately enough.

scholarly journals Optimization of the balance between effort and yield in unilateral surgical transfer of mouse embryos

2017 ◽  
Vol 51 (6) ◽  
pp. 622-628 ◽  
Author(s):  
Pablo González-Jara ◽  
Tomás Fontela ◽  
Esther López-Mimbela ◽  
Marta Cereceda ◽  
Daniel Del Olmo ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Mouse Embryos ◽  
Mouse Strains ◽  
Optimization Approach ◽  
Use Of Resources ◽  
Heterogeneous Nature ◽  
Laboratory Manuals ◽  
The Mean ◽  
Transfer Procedures

Surgical transfer of embryos is carried out daily in animal facilities worldwide for the rederivation of mouse strains/lines, among other purposes. Current protocols described in laboratory manuals recommend using a high number of embryos during transfer, typically in the range of 15 up to 25. To optimize the use of resources it is necessary to estimate and relate the effort required and the yield obtained. Here, we analyse the balance between the number of embryos transferred (the effort), and the yield as the number of born pups obtained from surgical embryo transfer. To accomplish this, we have analyzed data obtained during rederivation of nearly one hundred lines of mice to a new animal facility. Our results confirm that the use of increasing numbers of embryos per transfer increases the yields of born pups, as has been described previously in the literature, but they also highlight the disproportionate effort required, i.e. in the number of embryos that needed to be transferred. An estimate of the mean expected yields of surgical transfers and their comparison with the actual observed yields indicated that the balance between effort and yield is optimized when using lower numbers of embryos than in currently used protocols, in the range of 8 to 12. Given the heterogeneous nature of the data presented and analyzed here, which is from a population of mice that may be considered as representative of any animal facility, our optimization approach should help save resources in similar facilities and improve the yields of embryo transfer procedures.

scholarly journals MoG+: a database of genomic variations across three mouse subspecies for biomedical research

2021 ◽  
Author(s):  
Toyoyuki Takada ◽  
Kentaro Fukuta ◽  
Daiki Usuda ◽  
Tatsuya Kushida ◽  
Shinji Kondo ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Laboratory Mouse ◽  
Genomic Analysis ◽  
Inbred Strains ◽  
Genetic Distances ◽  
Mouse Strains ◽  
Comparative Genomic ◽  
Genome Database ◽  
Data Resource ◽  
Genomic Variations

AbstractLaboratory mouse strains have mosaic genomes derived from at least three major subspecies that are distributed in Eurasia. Here, we describe genomic variations in ten inbred strains: Mus musculus musculus-derived BLG2/Ms, NJL/Ms, CHD/Ms, SWN/Ms, and KJR/Ms; M. m. domesticus-derived PGN2/Ms and BFM/Ms; M. m. castaneus-derived HMI/Ms; and JF1/Ms and MSM/Ms, which were derived from a hybrid between M. m. musculus and M. m. castaneus. These strains were established by Prof. Moriwaki in the 1980s and are collectively named the “Mishima Battery”. These strains show large phenotypic variations in body size and in many physiological traits. We resequenced the genomes of the Mishima Battery strains and performed a comparative genomic analysis with dbSNP data. More than 81 million nucleotide coordinates were identified as variant sites due to the large genetic distances among the mouse subspecies; 8,062,070 new SNP sites were detected in this study, and these may underlie the large phenotypic diversity observed in the Mishima Battery. The new information was collected in a reconstructed genome database, termed MoG+ that includes new application software and viewers. MoG+ intuitively visualizes nucleotide variants in genes and intergenic regions, and amino acid substitutions across the three mouse subspecies. We report statistical data from the resequencing and comparative genomic analyses and newly collected phenotype data of the Mishima Battery, and provide a brief description of the functions of MoG+, which provides a searchable and unique data resource of the numerous genomic variations across the three mouse subspecies. The data in MoG+ will be invaluable for research into phenotype-genotype links in diverse mouse strains.

scholarly journals Three-Dimensional Live Imaging of Bovine Preimplantation Embryos: A New Method for IVF Embryo Evaluation

2021 ◽  
Vol 8 ◽  
Author(s):  
Yasumitsu Masuda ◽  
Ryo Hasebe ◽  
Yasushi Kuromi ◽  
Masayoshi Kobayashi ◽  
Kanako Urataki ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Three Dimensional ◽  
Preimplantation Embryos ◽  
Infrared Light ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Developmental Potential

Conception rates for transferred bovine embryos are lower than those for artificial insemination. Embryo transfer (ET) is widely used in cattle but many of the transferred embryos fail to develop, thus, a more effective method for selecting bovine embryos suitable for ET is required. To evaluate the developmental potential of bovine preimplantation embryos (2-cell stage embryos and blastocysts), we have used the non-invasive method of optical coherence tomography (OCT) to obtain live images. The images were used to evaluate 22 parameters of blastocysts, such as the volume of the inner cell mass and the thicknesses of the trophectoderm (TE). Bovine embryos were obtained by in vitro fertilization (IVF) of the cumulus-oocyte complexes aspirated by ovum pick-up from Japanese Black cattle. The quality of the blastocysts was examined under an inverted microscope and all were confirmed to be Code1 according to the International Embryo Transfer Society standards for embryo evaluation. The OCT images of embryos were taken at the 2-cell and blastocyst stages prior to the transfer. In OCT, the embryos were irradiated with near-infrared light for a few minutes to capture three-dimensional images. Nuclei of the 2-cell stage embryos were clearly observed by OCT, and polynuclear cells at the 2-cell stage were also clearly found. With OCT, we were able to observe embryos at the blastocyst stage and evaluate their parameters. The conception rate following OCT (15/30; 50%) is typical for ETs and no newborn calves showed neonatal overgrowth or died, indicating that the OCT did not adversely affect the ET. A principal components analysis was unable to identify the parameters associated with successful pregnancy, while by using hierarchical clustering analysis, TE volume has been suggested to be one of the parameters for the evaluation of bovine embryo. The present results show that OCT imaging can be used to investigate time-dependent changes of IVF embryos. With further improvements, it should be useful for selecting high-quality embryos for transfer.

Beyond Cost Minimisation: Farmers’ Perspectives on the Adoption of GM Fodder in Sweden

2021 ◽  
Vol 70 (2) ◽  
pp. 84-100
Author(s):  
Klara Fischer ◽  
Sebastian Hess
Keyword(s):  
Public Perception ◽  
Genetically Modified ◽  
Animal Health ◽  
Farm Management ◽  
Economic Factors ◽  
The Public ◽  
Cost Minimisation ◽  
Farm Business ◽  
The Eu ◽  
Free Animal

Swedish farmers were surveyed about their perceptions of genetically modified (GM) feed. Livestock in the EU are frequently given feed containing imported genetically modified (GM) crops, with GM fodder often being cheaper for farmers. However, there is also a growing market for ‘GM-free’ animal-based products. While public concerns about GMOs have been studied extensively, less is known about farmers’ views. The limited literature on farmers and GMOs tends to focus on the economic factors influencing their adoption. The present study contributes the perspective of farmers as members of the general public, thus including a broader set of factors known to be relevant for the public perception of GMOs. The results indicated that farmers were worried about: i) unforeseen consequences for the environment, ii) un­foreseen consequences for human and animal health, and iii) the dominance of multinational companies. Farmers who could expect their farm businesses to benefit from existing GMOs were more positive, whereas those who were unlikely to experience any benefits or who could expect their farm business to be adversely affected were more negative. Nevertheless, adherence to a broader set of positive or negative values suggests that Swedish farmers’ perspectives on GMOs go further than pure considerations of farm management.

scholarly journals Effect of Massa Medicata Fermentata on the Gut Microbiota of Dyspepsia Mice Based on 16S rRNA Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xiaorui Zhang ◽  
Hongling Zhang ◽  
Qinwan Huang ◽  
Jilin Sun ◽  
Renchuan Yao ◽  
...  
Keyword(s):  
16S Rrna ◽  
Intestinal Microflora ◽  
Intestinal Flora ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Blank Group ◽  
Intestinal Microorganisms ◽  
Specific Pathogen ◽  
Rrna Gene Sequencing ◽  
Aseptic Conditions

Massa Medicata Fermentata (MMF) is a traditional Chinese medicine (TCM) for treating indigestion and its related disorders. This study analyzes the effect of MMF on intestinal microorganisms in dyspepsia mice based on 16S rRNA technology. We take a dyspepsia model caused by a high-protein, high-calorie, high-fat diet. The 60 specific-pathogen free Kunming (SPF KM) mice were randomly divided into a model group n=12, an MMF group (LSQ group, n=12), a Jianweixiaoshi group (JWXS group, n=12), a domperidone group (DP group, n=12), and a blank group n=12. On the seventh day of administration, mice were fasted and deprived of water. After 24 h, take the second feces of stress defecation in mice under strict aseptic conditions and quickly transfer them to a sterile cryotube. This study comprehensively evaluates the α-diversity, β-diversity, flora abundance and composition of each group of miceʼs intestinal microorganisms, and their correlation with functional dyspepsia based on the 16S rRNA gene sequencing technology. After modeling, some dyspepsia reactions, proximal gastric relaxation reduction, and intestinal microflora changes were noted. Dyspepsia mice showed dyspepsia reactions and proximal gastric relaxation reduction, characterized by a significant decrease of contents of gastrin P<0.01 and cholinesterase P<0.01. MMF can improve dyspepsia symptoms and promote proximal gastric relaxation. Significant intestinal flora disorders were found in dyspepsia mice, including downregulation of Bacteroidetes, Lactobacillus, and Prevotellaceae and upregulation of Proteobacteria, Verrucomicrobia, Epsilonbacteraeota, Firmicutes, Lachnospiraceae NK4A136 group, and Lachnospiraceae. MMF could alleviate intestinal microflora disturbance, and the regulation effect of MMF on Bacteroidetes, Verrucomicrobia, and Epsilonbacteraeota was more reliable than that of Jianweixiaoshi tables and domperidone. The intestinal microflora may be correlated with the promoted digestion of MMF.

scholarly journals Generic Homo sapiens and Unique Mus musculus: Establishing the Typicality of the Modeled and the Model Species

2019 ◽  
Vol 93 (2-3) ◽  
pp. 122-136 ◽  
Author(s):  
Barbara L. Finlay
Keyword(s):  
Neural Development ◽  
Functional Organization ◽  
Homo Sapiens ◽  
Laboratory Mouse ◽  
Mouse Strains ◽  
Human Species ◽  
Model Species ◽  
Brain Mass ◽  
Multiple Strategies ◽  
Neural Architecture

The question of how complex human abilities evolved, such as language or face recognition, has been pursued by means of multiple strategies. Highly specialized non-human species have been examined analytically for formal similarities, close phylogenetic relatives have been examined for continuity, and simpler species have been analyzed for the broadest view of functional organization. All these strategies require empirical evidence of what is variable and predictable in both the modeled and the model species. Turning to humans, allometric analyses of the evolution of brain mass and brain components often return the interesting, but disappointing answer that volumetric organization of the human brain is highly predictable seen in its phylogenetic context. Reconciling this insight with unique human behavior, or any species-typical behavior, represents a serious challenge. Allometric analyses of the order and duration of mammalian neural development show that, while basic neural development in humans is allometrically predictable, conforming to adult neural architecture, some life history features deviate, notably that weaning is unusually early. Finally, unusual deviations in the retina and central auditory system in the laboratory mouse, which is widely assumed to be “generic,” as well as severe deviations from expected brain allometry in some mouse strains, underline the need for a deeper understanding of phylogenetic variability even in those systems believed to be best understood.

98 VITRIFICATION OF ZYGOTES SUPPORTS FULL-TERM DEVELOPMENT IN RABBITS

2008 ◽  
Vol 20 (1) ◽  
pp. 129
Author(s):  
J. Xu ◽  
J. Zhang ◽  
Y. Chen ◽  
M. Cater ◽  
X. Yang ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Genetic Material ◽  
Full Term ◽  
Human Reproduction ◽  
Blastocyst Development ◽  
Cold Surface ◽  
Cell Stage ◽  
Disease Study ◽  
The University

Rabbit can serve as an excellent model for human reproduction and relevant disease study. The objective of the study was to develop an effective procedure to preserve the rabbit genome by vitrifying zygotes. Sexually matured New Zealand White rabbits maintained under a 16 h light:8 h dark cycle were superovulated with a regime of two 0.3-mg, two 0.4-mg, and two 0.7-mg injections of FSH with an interval of 12 h between, followed by an injection of 200 IU hCG and mating. Presumptive zygotes were flushed from the oviducts and collected by midventral lapartomy 18 h after hCG injection. One-cell-stage embryos were assigned to pre-equilibration at 38.5�C in HEPES-buffered TCM199 supplemented with 20% FBS + 7.5% ethylene glycol (EG) (v/v) + 7.5% dimethylsulphoxide (DMSO) (v/v) (dehydration medium) for 3 min, and subsequently to 1.0 ml of vitrification medium (TCM199 supplemented with 20% FBS + 20% EG and 20% DMSO), as described by Vajta et al. (1998 Mol. Reprod. Dev. 51, 53–58), at room temperature for 3 min. Five to six embryos per group were then vitrified in a micro-droplet (approximately 1–2 µL) by directly dropping them into a thin layer of liquid nitrogen on the solid surface that generated a super cold surface for vitrification. Vitrified embryos were sequentially warmed, rehydrated in 20% FBS M199 with different concentrations of sucrose, and washed in 20% FBS M199 for 5 min. Warmed embryos were assigned either for further in vitro culture or for embryo transfer to test corresponding developmental potentials. Dutch rabbits were used as recipients in the procedure of asynchronous ovulation induction (22-h delay to zygote donors) by an intramuscular injection of 15 µg of GnRH per doe. Three or four warmed zygotes were surgically transferred into the recipients on the same day of thawing. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post-embryo transfer (ET); C-sections were performed on Day 31 to retrieve full-term developed newborns. Preliminary results showed that a 96% (n = 35) post-warming survival rate was achieved with vitrified rabbit zygotes; subsequent cleavage and blastocyst development were 41.6 and 33.3%, respectively. Transfer of a total of 23 warmed embryos into 6 recipients resulted in 5 pregnancies (83.3%, 5/6). Five live kits (21.7%, 5/23) were delivered. Our study suggests that vitrification of rabbit zygotes is a feasible approach for preserving rabbit genetic material. The establishment of suitable conditions for the vitrification of rabbit zygotes could be useful as a model for vitrification of human 1-celled embryos. The authors thank the staff of the animal facility at the University of Connecticut for animal care and maintenance. This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261-01.

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