With the advancement of scientific research, the demand for gene-edited rabbit models is increasing. However, there are limited pregnancy and feeding management systems for gene-edited rabbits, leading to low survival rates among gene-edited rabbits prepared by many inexperienced researchers. Therefore, proper guidance is essential. This article summarizes the pregnancy and feeding practices for genetically modified rabbits developed in the author's laboratory and outlines a set of fundamental processes. These include pregnancy diagnosis, antenatal care, midwifery, assisted breastfeeding, weaning, and other procedures, along with the rescue and care of weak newborn rabbits. Compared to the traditional natural childbirth and nurturing methods used in rabbit farms, this approach involves more refined management, requiring additional time and effort but significantly increasing the survival rate of suckling rabbits. The methods described in this article are suitable for most laboratory breeding scenarios involving gene-edited or embryo-transferred rabbits and provide a straightforward and effective reference for other researchers.
To investigate the effects of methanol extract of Celastrus orbiculatu (MECO) on synovial hyperplasia and cartilage erosion and degradation in rheumatoid arthritis (RA), and explore the possible mechanisms to provide clues for new drug development for RA treatment.The articular synovium from patients with RA and normal articular cartilage were co-implanted into the back of severe combined immunodeficient (SCID)mice to establish the chimeric model SCID- HuRAg. Four weeks later, the mice were given MECO intragastrically at 30 mg/day, leflunomide at 500 microg/day or distilled water, respectively, for 4 consecutive weeks. After completion of the treatments, the histological scores of the grafts for synovial hyperplasia, cartilage invasion by synoviocyte and cartilage degradation around the chondrocytes were evaluated, and serum level of tumor necrosis factor-alpha (TNF-alpha) was measured with radioimmunoassay. The expression of TNF-alpha mRNA and the cell apoptosis in the synovium were detected with in situ hybridization (ISH) and TUNEL, respectively, and the results were analyzed with the image analysis system.The grafts survived in the mice till the end of experiment. MECO and leflunomide, in comparison with distilled water, significantly lowered the scores for synovial hyperlasia (2.00+/-0.76 and 2.25+/-0.89 vs 3.63+/-0.52), cartilage erosion (1.69+/-0.80 and 2.00+/-1.36 vs 3.75+/-0.53), cartilage degradation (1.88+/-0.83 and 2.13+/-0.83 vs 3.63+/-0.74) and serum TNF-alpha level (0.84+/-0.09 and 0.83+/-0.12 vs 0.99+/-0.11 ng/ml). Cell apoptosis of the synovium increased significantly with MECO and leflunomide treatments, but the expression of TNF-alpha mRNA in the synovium decreased significantly in MECO group.MECO can effectively suppress synovial hyperplasia and cartilage erosion and degradation SCID-HuRAg mice by reducing TNF-alpha production in the synovium and promoting synovial apoptosis. MECO can be comparable with leflunomide in their effect, but the former is more effective in suppressing TNF-alpha expression in the synovium.
Objective To investigate the radiotoxicity to bone marrow after 89Sr therapy radiosensitized by nicotinamide and carbogen. Methods Chinese Kunming, NIH, BALB/c and F1 mice were divided into five groups: negative control (saline), positive control (89Sr), 89Sr+nicotinamide, 89Sr+carbogen and 89Sr+nicotinamide+carbogen. 89SrCl containing activities of 7400 kBq (200 μCi) in 200 μl of saline was administrated by injection into the tail vein. An equal volume of saline only was given to the negative control group. Chinese Kunming and NIH mice were killed on days 1, 2, 3, 4, 6, 8, 15, 20, 30, 60 and 90 after injection. BALB/c and F1 mice were killed on days 60 and 90. Femoral marrow reticulocytes were separated for assay of micronuclei. Results The average frequency of the reticulocytes is shown in a dual-peak curve after injection. The first maximum frequency occurred between the second and the fourth days, and the second between the tenth and the 14th days. A significant statistical difference in frequency was found between the negative and the positive control groups (P<0.001, F=15.517), while no difference was found among the 89Sr+nicotinamide+carbogen, 89Sr, 89Sr+nicotinamide and 89Sr+carbogen groups (P>0.05, F=0.717) and among the NIH groups, 89Sr, 89Sr+nicotinamide, 89Sr+carbogen and 89Sr+nicotinamide+carbogen (P>0.05, F=1.734). There is also no significant difference in the frequency of reticulocytes between Chinese Kunming, NIH, BALB/c and F1 mice (P>0.05). Although the intervention of the radiosensitizer accelerated the occurrence of micronuclei in reticulocytes, there was no significant statistical difference between the group with radiosensitizer and the groups without it. Conclusions The administration of radiosensitizer did not aggravate the toxicity on bone marrow.
Objective To analyze the mitochondrial DNA (mtDNA) D-loop region sequence variation in Tibet Mini-Pigs in relation to the blood parameters and provide the molecular genetic basis for developing new species of laboratory animals. Methods The genomic DNA was extracted from the whole blood samples of 59 Tibet mini-pigs to amplifying the mtDNA D-loop for sequence analysis. Nine physiological and nine biochemical blood parameters of Tibet mini-pigs were measured . Results Based on the variation of the tandem repeat motif, the mtDNA D-loop region of Tibet mini-pigs was classified into two types, namely type A and B with the percentage of 57.6% and 42.4%, respectively, roughly matching the 3 transform sites (305, 500, 691) at the 5' end. In the 18 blood parameters, only red blood cell count showed significant differences between types A and (P Conclusion Based on the sequence variation of the mtDNA D-loop region, Tibet mini-pigs can be divided into two types that show a significant difference in red blood cell count.
To observe testis injuries induced by in situ electroporation in specific pathogen-free (SPF) adult male Kunming mice.With two sets of parameters of high and low voltages, respectively, in situ electroporation of the testis was performed in vivo by fixing the testis and epididymis of the mice between a pair of rectangular tweezer-type electrodes. Two weeks after electroporation, the mice were killed and the testis and epididymis separated and fixed with 4% paraformaldehyde after recording the weight of the testis. Routine histological sections were prepared and observed under optical microscope after HE staining. The epididymis was transferred into M16 medium for spermatozoa separation, and after dilution of the spermatozoa suspension, the spermatozoa viability was observed under optical microscope.Two weeks after high-voltage electroporation, examination of spermatozoa viability and microscopy of the testis sections revealed irreversible testis injury, and the testis weight was significantly reduced in comparison with that of control mice (P<0.01). Low-voltage electroporation, in contrast, only caused reversible injuries of the testis, and the male mice retained their reproductive capacity after a certain length of recovery period. The testis weight after low-voltage electroporation showed no significant difference from that of the control mice (P>0.05).Appropriate setting of the parameters for in vivo electroporation may avoid severe impact on the reproductive capacity of the testis in SPF male Kunming mice. This technique also provides a possibility for exogenous gene transfer into the reproductive cells.
To investigate the injuries of intestinal mitochondria induced by different doses of whole-body radiation in Tibet minipigs.Eighteen Tibet minipigs were randomized into 5 radiation groups (n=3) and a control group (n=3). The minipigs in the radiation groups were subject to a total body X-ray radiation at 2, 5, 8, 11, or 14 Gy, and 72 h after the exposure, the mRNA expressions of the intestinal mitochondrial genes were examined using RT-PCR. The changes in the respiratory chain complexes I-IV and the respiratory functions of succinate and NADH were assayed, and the intestinal ultrastructures were observed using transmission electron microscopy (TEM) following the exposures.Compared with those in the control group, the expression levels of the related mitochondrial genes, the activities of the respiratory chain complexes and the function of the respiratory chain were significantly lowered in the radiation groups. At the doses below 8 Gy, the exposures caused significant reduction in the measurements as the radiation doses increased, but at higher doses, these measurements showed no further reductions. Ultrastructurally, exposures at 2 and 5 Gy caused mitochondrial expansion and mild reduction of the density, whereas radiation at 8 Gy or greater resulted in vacuolar changes and obvious expansion of the mitochondria with damages of the mitochondrial cristae and membranes.Below the doses of 8 Gy, intestinal mitochondrial damages in the minipigs increase with the radiation dose, but at higher doses, the damages do not further increase with the radiation dose.
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