Intrauterine air impairs embryonic postimplantation development in mice.

Objective: Although most embryologists load air bubbles into the catheter along with embryos during embryo transfer, the effects of these air bubbles on embryo transfer success rate are not clear.

Study Design: Air bubbles were nonsurgically injected into unilateral uterine horns of mice to demonstrate the negative effects of intrauterine air bubbles on embryonic development.

Results: Our data showed that when air bubbles are nonsurgically injected into unilateral uterine horns of pregnant 4days mice the litter size is significantly decreased.

Dry ice is a reliable substrate for the distribution of frozen mouse spermatozoa: A multi-centric study.

Disseminating mouse stocks as frozen materials offers both ethical and logistical advantages over live animal shipment, minimizing the welfare issues and avoiding some of the complex custom regulations that are associated with live animal transportation. Embryo freezing in liquid nitrogen (LN) at -196 °C has traditionally been the method of choice for archiving mouse lines. However, spermatozoa freezing is emerging as a more convenient alternative due to the application of innovative cryopreservation and recovery protocols.

Contemporary techniques for freezing mouse spermatozoa.

Each year, thousands of new mouse models are generated around the world to further biomedical research. Unfortunately, the cost of maintaining mouse colonies makes it uneconomical to keep strains on the shelf that are not part of active research programs. Ideally, these retired strains should be archived.

In vitro fertilization in mice using the MBCD-GSH protocol.

Historically, timed mating of either naturally cycling or superovulated females has been the mainstay of pre-implantation embryo production. However, rising cage costs and the rapid expansion of biomedical research programs has necessitated the development of high-throughput approaches to mouse embryo production. In vitro fertilization (IVF) represents one such versatile tool offering many advantages to busy mouse facilities in terms of efficient use of space and resources.

Transporting mouse embryos and germplasm as frozen or unfrozen materials.

The 21st century has seen a huge proliferation in the availability of genetically altered mice. The availability of these resources has been accompanied by ever greater opportunities for international collaborations between laboratories involving the exchange of mouse strains. This exchange can involve significant costs in terms of animal welfare and transportation expenses.

Conservation of mouse models through embryo freezing.

The ability to interrogate the entire coding sequence of the mouse combined with the tools to manipulate the genome has firmly established the mouse as the model organism of choice for studying the causes of human disease. Consequently, a huge number of novel mouse models are generated each year to support active research programs. However, it is neither ethically justifiable, nor economically viable to maintain mouse colonies on the shelf that are not part of active research programs.

Alanine scanning mutagenesis of hepatitis C virus E2 cysteine residues: Insights into E2 biogenesis and antigenicity.

Envelope glycoprotein 2 (E2) of hepatitis C virus contains 18 conserved cysteine (Cys) residues in its ectodomain. By cysteine-alanine mutagenesis and function analysis, six Cys in H77 E2 (C494, C508, C552, C564, C607 and C644) were found to be indispensable for recognition by conformation-dependent mAb H53. Removal of any of these Cys residues did not affect E2 heterodimerization with E1, but notably reduced E1E2 transmembrane transportation.

HCV J6/JFH1 tilts the capability of myeloid-derived dendritic cells to favor the induction of immunosuppression and Th17-related inflammatory cytokines.

Purpose: How HCV virus affects the function of dendritic cells (DCs) and their ability to induce CD4+ T cell response remains not fully understood. This study was done to elucidate the impact of HCV on the function of DCs and on DC's capability to induce CD4+ T-cell response.

Methods: Monocyte-derived DCs (MoDCs) were treated with cell-culture HCV (HCVcc).

The Arg719 residue at the C-terminal end of the stem region in hepatitis C virus JFH-1 E2 glycoprotein promotes viral infection.

Hepatitis C virus (HCV) envelope glycoprotein E2 is involved in virus assembly and initial entry into host cells. The tertiary organization of the E2 ectodomain is mainly composed of domains I-III, followed by the stem (ST) region and transmembrane (TM) domain. The ST region is critical for reorganizing the envelope glycoproteins during the membrane fusion process.

Overview of new developments in and the future of cryopreservation in the laboratory mouse.

The large-scale mutagenesis programmes underway around the world are generating thousands of novel GA mouse strains that need to be securely archived. In parallel with advances in mutagenesis, the procedures used to cryopreserve mouse stocks are being continually refined in order to keep pace with demand. Moreover, the construction of extensive research infrastructures for systematic phenotyping is fuelling demand for these novel strains of mice and new approaches to the distribution of frozen and unfrozen embryos and gametes are being developed in order to reduce the dependency on the transportation of live mice.

Three different functional microdomains in the hepatitis C virus hypervariable region 1 (HVR1) mediate entry and immune evasion.

High genetic heterogeneity is an important characteristic of hepatitis C virus (HCV) that contributes to its ability to establish persistent infection. The hypervariable region 1 (HVR1) that includes the first 27 amino acid residues of the E2 envelope glycoprotein is the most variable region within the HCV polyprotein. HVR1 plays a major role in both HCV cell entry and immune evasion, but the respective contribution of specific amino acid residues is still unclear.

Significance of palmitoylation of CD81 on its association with tetraspanin-enriched microdomains and mediating hepatitis C virus cell entry.

CD81, a co-receptor for hepatitis C virus (HCV), is a member of the tetraspanin superfamily and is heavily palmitoylated in the juxtamembrane cysteine residues. Palmitoylation plays an important role in protein-protein interactions and association with cholesterol-rich domains of membranes. In this study, Huh7 cells expressing wild-type or palmitoylation-defective CD81 were generated to analyze whether palmitoylation of CD81 is involved in HCV cell entry.

Ultrasound enhanced methanol penetration of zebrafish (Danio rerio) embryos measured by permittivity changes using impedance spectroscopy.

Studies on permittivity changes in fish embryos measured by impedance spectroscopy after ultrasound treatment during exposure to cryoprotectant is reported here for the first time. The permittivity changes of zebrafish embryos in cryoprotectant solutions before and after ultrasound treatment were measured using impedance spectroscopy. Zebrafish (Danio rerio) embryos at 50% epiboly stage were exposed to 2 M methanol for 25 min before ultrasound treatment for 5 min at 22 degrees C.

Cryopreservation of cynomolgus monkey (Macaca fascicularis) spermatozoa in a chemically defined extender.

Aim: To establish a method for cynomolgus monkey sperm cryopreservation in a chemically defined extender.

Methods: Semen samples were collected by electro-ejaculation from four sexually mature male cynomolgus monkeys. The spermatozoa were frozen in straws by liquid nitrogen vapor using egg-yolk-free Tes-Tris mTTE synthetic extender and glycerol as cryoprotectant.