Animals ; Disease Models, Animal ; Hematology ; Mice ; Mice, Transgenic

Cre-lox recombination system consists of two elements: Cre recombinase enzyme and lox sites. Cre recombinase can recombine the lox site sequences by specifically detecting and cutting them. The direction and position of lox sites determine the functional effects of Cre enzyme such as deletion, inversion or chromosomal translocation. The hematopoietic system of mouse consists of multi-lineages and various developmental stage hematopoietic cells that are differentiated from hematopoietic stem cells (hematopoietic stem cells, HSC). The hematopoietic stem cells are maintained in the bone marrow microenvironment (niche). Currently, a variety of floxed conditional-knockout mice, recognized by Cre-lox recombination system, are used for the study of the hematopoietic system. This review summarizes the commonly used Cre transgenic mice and their applications in the study of hematopoietic system.
Animals ; Hematopoietic Stem Cells ; cytology ; metabolism ; Integrases ; Mice ; Mice, Transgenic

Animals ; Cardiomyopathy, Dilated ; Disease Models, Animal ; Mice ; Mice, Transgenic

Cortical interneurons can be categorized into distinct populations based on multiple modalities, including molecular signatures and morpho-electrical (M/E) properties. Recently, many transcriptomic signatures based on single-cell RNA-seq have been identified in cortical interneurons. However, whether different interneuron populations defined by transcriptomic signature expressions correspond to distinct M/E subtypes is still unknown. Here, we applied the Patch-PCR approach to simultaneously obtain the M/E properties and messenger RNA (mRNA) expression of >600 interneurons in layer V of the mouse somatosensory cortex (S1). Subsequently, we identified 11 M/E subtypes, 9 neurochemical cell populations (NCs), and 20 transcriptomic cell populations (TCs) in this cortical lamina. Further analysis revealed that cells in many NCs and TCs comprised several M/E types and were difficult to clearly distinguish morpho-electrically. A similar analysis of layer V interneurons of mouse primary visual cortex (V1) and motor cortex (M1) gave results largely comparable to S1. Comparison between S1, V1, and M1 suggested that, compared to V1, S1 interneurons were morpho-electrically more similar to M1. Our study reveals the presence of substantial M/E variations in cortical interneuron populations defined by molecular expression.
Mice ; Animals ; Neocortex/physiology* ; Mice, Transgenic ; Interneurons/physiology*

In our previous study, normal and fertile mice were successful produced from oocytes following intracytoplasmic sperm injection (ICSI). In the present study, the possibility of producing transgenic embryos and offspring with this procedure was evaluated. After freezing-thawed once using HEPES-CZB medium without cryoprotectants, the cauda sperm from KM fertile male were exposed to the circular or linear pEGFP-N1 DNA for 1 min and then co-injected into metaphase II oocytes of B6D2F1 strain. When the zygotes with two pronuclei were cultured in CZB medium to day 3.5, 39.1% (9/23) of them, derived from oocytes co-injected with sperm head and pEGFP-N1 plasmid DNA, were expressed GFP protein. After transfer of the ICSI embryos with two pronuclei from co-injection of sperm head and foreign DNA, seven recipients delivered 30 pups (23.8%, 30/126). Southern blot results revealed that three of sixteen offspring integrated with GFP and neomycin genes together (18.8 %). Interestingly, all of them were produced from oocytes co-injected sperm head and linear DNA (33.3%, 3/9), while none of seven ICSI offspring integrated either GFP or neomycin gene in the group of co-injection of sperm head and circular plasmid DNA. These results indicated that the high efficiency of transgenic mouse could be produced by ICSI. It may be shown that linear DNA is more easily to integrate into host genome than circular DNA when ICSI was used to produce transgenic animals.
Animals ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Inbred DBA ; Mice, Transgenic ; genetics ; Sperm Injections, Intracytoplasmic ; methods

The genetically engineered mice require special husbandry care and are mainly housed in Individually Ventilated Cage (IVC) systems and Static Micro Isolator Cages (SMIC) to minimize the risk for spreading undesirable microorganisms. However, the static micro isolation cage housing like SMIC are being replaced with IVC systems in many facilities due to a number of benefits like a higher density housing in limited space, better protection from biohazards and allergens and decreased work load due to decreased frequency of cage changing required in this system. The purpose of this study was to examine the reproductive performance of genetically engineered mice housed in individually ventilated cages (IVC) and Static Micro Isolator Cages (SMIC). When the B6C3-Tg (APPswe, PSEN1dE9) 85Dbo/Mmjax transgenic mice were housed in these two housing systems, the number of litters per dam, number of pups born per dam and number of pups weaned per dam were found to be slightly higher in the IVC as compared to the SMIC but the difference was not significant (P<0.05). In case of Growth Associated Protein 43 (GAP-43) knockout mice, the number of litters born per dam and the number of pups born per dam were marginally higher in the IVC as compared to those housed in SMIC but the difference was not significant (P<0.05). Only the number of pups weaned per dam were found to be significantly higher as compared to those housed in the SMIC system at P<0.05.
Allergens ; Animals ; GAP-43 Protein ; Hazardous Substances ; Housing* ; Mice* ; Mice, Knockout ; Mice, Transgenic

OBJECTIVETo establish homozygous transgenic mouse strain expressing human tau isoform with P301L mutation.

METHODSFive transgenic mice expressing human tau isoform with P301L mutation were obtained by microinjection into male nuclei. Homozygote and hemizygote were identified by PCR and real-time fluorescent quantitative PCR.

RESULTSNinety five homozygous transgenic mice were selected, and the results indicated that homozygous transgenic mice were superior to hemizygote in simulating the changes of biological characteristics.

CONCLUSIONExogenous gene tau is able to stably transmit to next generation and the combination of SYBR Green real-time fluorescent quantitative PCR with the traditional mating is a fast, reliable and economical way to screen homozygous and hemizygous transgenic mice.

Animals ; Female ; Homozygote ; Humans ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Microinjections ; Mutation ; tau Proteins ; genetics

Exposure to chronic hypoxia is considered to be a risk factor for deficits in brain function in adults, but the underlying mechanisms remain largely unknown. Since active myelinogenesis persists in the adult central nervous system, here we aimed to investigate the impact of chronic hypoxia on myelination and the related functional consequences in adult mice. Using a transgenic approach to label newly-generated myelin sheaths (NG2-CreER
Animals ; Clemastine ; Hypoxia/complications* ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Myelin Sheath ; Oligodendroglia

BACKGROUND: Disparities of Minor H antigens can induce graft rejection after MHC-matched transplantation. H60 has been characterized as a dominant antigen expressed on hematopoietic cells and considered to be an ideal model antigen for study on graft-versus-leukemia effect. METHODS: Splenocytes from C57BL/6 mice immunized with H60 congenic splenocytes were used for establishment of H60-specific CTL clones. Then the clones were characterized for proliferation capacity and cytotoxicity after stimulation with H60. Clone #14, #15, and #23 were tested for the TCR binding avidity to H60-peptide/H-2Kb and analyzed for TCR sequences. RESULTS: H60-specific CTL clones showed different levels of proliferation capacity and cytotoxic activity to H60-stimulation. Clones #14, #15, and #23 showed high proliferation activity, high cytotoxicity, and low activities on both aspects, respectively, and have TCRs with different binding avidities to H60-peptide/H-2Kb with t 1/2 values of 4.87, 6.92, and 13.03 minutes, respectively. The TCR usages were Valpha12D-3-01+Jalpha11-01 and Vbeta12-1-01+Dbeta1-01+J2-7-01 for clone #14, Valpha13D-1-02+Jalpha34-02 and Vbeta13-1-02+Dbeta2-01+Jbeta2-7-01 for clone #15, and Valpha16D+Jalpha45-01 and Vbeta12-1-01+Dbeta1-01+Jbeta2-5-01 for clone #23. CONCLUSION: The results will be useful for modeling GVL and generation TCR transgenic mouse.
Animals ; Clone Cells ; Graft Rejection ; Histocompatibility ; Histocompatibility Antigens ; Mice ; Mice, Transgenic ; Transplants

Human studies of brain stimulation have demonstrated modulatory effects on the perception of pain. However, whether the primary somatosensory cortical activity is associated with antinociceptive responses remains unknown. Therefore, we examined the antinociceptive effects of neuronal activity evoked by optogenetic stimulation of primary somatosensory cortex. Optogenetic transgenic mice were subjected to continuous or pulse-train optogenetic stimulation of the primary somatosensory cortex at frequencies of 15, 30, and 40 Hz, during a tail clip test. Reaction time was measured using a digital high-speed video camera. Pulse-train optogenetic stimulation of primary somatosensory cortex showed a delayed pain response with respect to a tail clip, whereas no significant change in reaction time was observed with continuous stimulation. In response to the pulse-train stimulation, video monitoring and local field potential recording revealed associated paw movement and sensorimotor rhythms, respectively. Our results show that optogenetic stimulation of primary somatosensory cortex at beta and gamma frequencies blocks transmission of pain signals in tail clip test.
Animals ; Brain ; Humans ; Mice ; Mice, Transgenic ; Neurons ; Optogenetics ; Pain Perception* ; Reaction Time ; Somatosensory Cortex* ; Tail*