Effects of supplementation of Tris-egg yolk extender with royal jelly on chilled and frozen-thawed ram semen characteristics

This study was conducted to examine the effect of supplementation of Tris-egg yolk extender with lyophilized royal jelly (RJ) on chilled and frozen-thawed ram semen parameters. Ejaculates were collected by artificial vagina from 4 mature rams, twice a week for 4 weeks. Only samples with motility of ≥70% were included, pooled and divided into four equal parts and then diluted in extenders with various concentrations of RJ (0, 1, 3 and 5%, vol/vol) to a final concentration of 200 × 10⁶ sperm/mL and was incubated at 37 °C for 30 min and were subsequently evaluated. After equilibration of extended semen for 2 h at 4 °C, some semen samples were packed in 0.25 mL plastic straws. Then, the straws were frozen in the liquid nitrogen vapor phase for 15 min and stored at −196 °C in liquid nitrogen. The frozen straws were thawed in warm water (37 °C) for 30 s and evaluated; whereas, other semen samples were stored in the refrigerator (4 °C) up to 7 days. The chilled samples were kept in water bath (37 °C) for 5 min and then were evaluated. After dilution, the lowest and highest sperm total abnormality was recorded in 3 and 5% RJ supplemented groups, respectively (P < 0.05). The chilled sperm total motility and membrane integrity were significantly (P < 0.05) higher in 3% than those in 0% and 5% RJ supplemented groups. The chilled sperm progressive motility and viability was significantly (P < 0.05) higher in 1 and 3% than those in 0 and 5% RJ supplemented groups. The frozen-thawed sperm total motility, progressive motility, membrane integrity and viability were significantly higher in 3% RJ supplemented group (P < 0.05). In conclusion, supplementation of Tris-egg yolk extender with 3% lyophilized RJ had a protective effect on chilled and cryopreserved ram spermatozoa.     

The Molecular Mechanism of Cellular Attachment for an Archaeal Virus

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Manufacturing of human Wharton's jelly stem cells for clinical use: selection of serum is important

BackgroundHuman Wharton's jelly–derived mesenchymal stromal cells (hWJSCs) have gained considerable attention for their use in cell therapy. Many of these applications would require manufacturing of millions of hWJSCs. It is, therefore, necessary to develop a Good Manufacturing Practice (GMP)-compliant hWJSC expansion protocol, allowing the generation of a large quantity of cells to meet both clinical and regulatory requirements. Here, we compared human platelet lysate (HPL) and human serum (HS) in supporting clinical-grade hWJSC expansion.MethodshWJSCs were successfully isolated from six different umbilical cords using GMP-compliant dissociation enzymes. Freshly isolated hWJSCs were cultured in media supplemented with 10% of one of the following sera: fetal bovine serum (FBS), HPL and HS. Properties of the expanded hWJSCs were analyzed.ResultsWe showed that GMP-compliant dissociation enzymes were as efficient as research-grade dissociation enzymes in isolating hWJSCs. hWJSC fresh cell yield and cell viability using HPL and HS supplementations were at greater advantages than FBS. Moreover, hWJSCs expanded in HPL and HS supplementations not only preserved classical MSCs phenotypes and differentiation potential to adipocytes, osteocytes and chondrocytes, they also enhanced the migration of skin fibroblasts. However, HS, unlike HPL, did not alter immunogenicity properties of hWJSCs. hWJSCs expanded in HS supplementation also exerted greater immunosuppressive action in inhibiting T-cell proliferation and increased extracellular matrix (ECM) gene expression, making them useful in tissue repair clinical application.ConclusionOur findings indicate that HS can be considered as a promising and safer alternative to FBS, and should be recommended for clinical-grade expansion of hWJSCs.     

Characterization and differentiation of equine umbilical cord-derived matrix cells

Stem cells are being evaluated in numerous human clinical trials and are commercially used in veterinary medicine to treat horses and dogs. Stem cell differentiation, homing to disease sites, growth and cytokine factor modulation, and low antigenicity contribute to their therapeutic success. Bone marrow and adipose tissue are the two most common sources of adult-derived stem cells in animals. We report on the existence of an alternative source of primitive, multipotent stem cells from the equine umbilical cord cellular matrix (Wharton's jelly). Equine umbilical cord matrix (EUCM) cells can be cultured, cryogenically preserved, and differentiated into osteo-, adipo-, chondrogenic, and neuronal cell lineages. These results identify a source of stem cells that can be non-invasively collected at birth and stored for future use in that horse or used as donor cells for treating unrelated horses.     

Selection for life‐history traits to maximize population growth in an invasive marine species

Species establishing outside their natural range, negatively impacting local ecosystems, are of increasing global concern. They often display life‐history features characteristic for r‐selected populations with fast growth and high reproduction rates to achieve positive population growth rates (r) in invaded habitats. Here, we demonstrate substantially earlier maturation at a 2 orders of magnitude lower body mass at first reproduction in invasive compared to native populations of the comb jelly Mnemiopsis leidyi. Empirical results are corroborated by a theoretical model for competing life‐history traits that predicts maturation at the smallest possible size to optimize r, while individual lifetime reproductive success (R₀), optimized in native populations, is near constant over a large range of intermediate maturation sizes. We suggest that high variability in reproductive tactics in native populations is an underappreciated determinant of invasiveness, acting as substrate upon which selection can act during the invasion process.     

Effect of royal jelly on longevity and memory-related traits of Apis mellifera workers

Royal jelly (RJ) is a key factor for honey bee caste determination. The queen bee is fed with RJ by worker bees throughout her life, while the worker bees eat bee bread themselves. This study was designed to explore the effect of nutrient-rich RJ on longevity and learning and memory abilities of workers of the western honey bee Apis mellifera. The newly emerged worker bees were randomly divided into three groups and were fed 50% sucrose solution containing 0%, 10%, and 20% RJ. We found that worker bees fed with 10% and 20% RJ showed significantly improved longevity and higher proboscis extension response success rate compared to bees fed with 50% sucrose containing 0% RJ. Additionally, bees fed with 20% RJ showed significantly higher level of expression of memory related genes (GluRA and Nmdar1) compared to the control group. Furthermore, expression of the Nmdar1 gene of worker bees fed with 10% RJ was also significantly higher than in the control group. These results indicate that RJ has potential effects on the longevity and learning and memory abilities of A. mellifera.     

Xenopus laevis Egg Jelly Contains Small Proteins That Are Essential to Fertilization

The eggs of Xenopus laevis are surrounded by investment layers of egg jelly that interact with the sperm immediately prior to fertilization. Components of these egg jelly layers are necessary for the fertilization of the egg by incoming sperm. Eggs which are stripped of their jelly layers are refractile to fertilization by sperm, but the addition of solubilized jelly promotes fertilization. We have shown previously that the egg jelly layers are composed of a fibrous network of glycoconjugates which loosely hold smaller diffusible components. Extracts of these diffusible components were prepared by incubation of freshly ovulated eggs in high-salt buffers for 12 h at 4°C. This diffusible component extract, when incubated with sperm, promoted the sperm's ability to fertilize dejellied eggs in a dose-dependent manner. In contrast, the high-molecular-weight “structural” glycoconjugates of jelly that remain after extraction of the diffusible components did not increase fertilization efficiency of dejellied eggs nor did nonspecific proteins, carbohydrate polymers, or organic polymers. The diffusible components, analyzed by SDS–PAGE, consisted of a mixture of proteins from 4 to 180 kDa. The protein responsible for fertilization rescue appeared to be <50 kDa and appeared to self-aggregate or to bind to larger proteins. This protein component was required during sperm binding to the egg, its action required an intact egg vitelline envelope, and its action was independent of large soluble polymers such as Ficoll.     

The Trimeric Major Capsid Protein of Mavirus is stabilized by its Interlocked N-termini Enabling Core Flexibility for Capsid Assembly

Icosahedral viral capsids assemble with high fidelity from a large number of identical buildings blocks. The mechanisms that enable individual capsid proteins to form stable oligomeric units (capsomers) while affording structural adaptability required for further assembly into capsids are mostly unknown.Understanding these mechanisms requires knowledge of the capsomers’ dynamics, especially for viruses where no additional helper proteins are needed during capsid assembly like for the Mavirus virophage that despite its complexity (triangulation number T = 27) can assemble from its major capsid protein (MCP) alone. This protein forms the basic building block of the capsid namely a trimer (MCP₃) of double-jelly roll protomers with highly intertwined N-terminal arms of each protomer wrapping around the other two at the base of the capsomer, secured by a clasp that is formed by part of the C-terminus.Probing the dynamics of the capsomer with HDX mass spectrometry we observed differences in conformational flexibility between functional elements of the MCP trimer. While the N-terminal arm and clasp regions show above average deuterium incorporation, the two jelly-roll units in each protomer also differ in their structural plasticity, which might be needed for efficient assembly. Assessing the role of the N-terminal arm in maintaining capsomer stability showed that its detachment is required for capsomer dissociation, constituting a barrier towards capsomer monomerisation. Surprisingly, capsomer dissociation was irreversible since it was followed by a global structural rearrangement of the protomers as indicated by computational studies showing a rearrangement of the N-terminus blocking part of the capsomer forming interface.     

Decellularized Wharton's jelly extracellular matrix as a promising scaffold for promoting hepatic differentiation of human induced pluripotent stem cells

Liver tissue engineering as a therapeutic option for restoring of damaged liver function has a special focus on using native decellularized liver matrix, but there are limitations such as the shortage of liver donor. Therefore, an appropriate alternative scaffold is needed to circumvent the donor shortage. This study was designed to evaluate hepatic differentiation of human induced pluripotent stem cells (hiPSCs) in decellularized Wharton's jelly (WJ) matrix as an alternative for native liver matrix. WJ matrices were treated with a series of detergents for decellularization. Then hiPSCs were seeded into decellularized WJ scaffold (DWJS) for hepatic differentiation by a defined induction protocol. The DNA quantitative assay and histological evaluation showed that cellular and nuclear materials were efficiently removed and the composition of extracellular matrix was maintained. In DWJS, hiPSCs-derived hepatocyte-like cells (hiPSCs-Heps) efficiently entered into the differentiation phase (G1) and gradually took a polygonal shape, a typical shape of hepatocytes. The expression of hepatic-associated genes (albumin, TAT, Cytokeratin19, and Cyp7A1), albumin and urea secretion in hiPSCs-Heps cultured into DWJS was significantly higher than those cultured in the culture plates (2D). Altogether, our results suggest that DWJS could provide a proper microenvironment that efficiently promotes hepatic differentiation of hiPSCs.