Developmental Stages Of Mouse Embryo Research Articles

Histone Deacetylase 3 Unconventional Splicing Mediates Endothelial-to-mesenchymal Transition through Transforming Growth Factor β2

Histone deacetylase 3 (HDAC3) plays a critical role in the maintenance of endothelial integrity and other physiological processes. In this study, we demonstrated that HDAC3 undergoes unconventional splicing during stem cell differentiation. Four different splicing variants have been identified, designated as HD3α, -β, -γ, and -δ, respectively. HD3α was confirmed in stem cell differentiation by specific antibody against the sequences from intron 12. Immunofluorescence staining indicated that the HD3α isoform co-localized with CD31-positive or α-smooth muscle actin-positive cells at different developmental stages of mouse embryos. Overexpression of HD3α reprogrammed human aortic endothelial cells into mesenchymal cells featuring an endothelial-to-mesenchymal transition (EndMT) phenotype. HD3α directly interacts with HDAC3 and Akt1 and selectively activates transforming growth factor β2 (TGFβ2) secretion and cleavage. TGFβ2 functioned as an autocrine and/or paracrine EndMT factor. The HD3α-induced EndMT was both PI3K/Akt- and TGFβ2-dependent. This study provides the first evidence of the role of HDAC3 splicing in the maintenance of endothelial integrity.

αA- and αB-Crystallins Interact with Caspase-3 and Bax to Guard Mouse Lens Development

The small heat shock protein, α-crystallin, exists in two isoforms, αA and αB, and displays strong ability against stress-induced apoptosis. Regarding their functional mechanisms, we and others have demonstrated that they are able to regulate members in both caspase and Bcl-2 families. In addition, we have also shown that αA and αB may display differential anti-apoptotic mechanisms under certain stress conditions. While αA-crystallin regulates activation of the AKT signaling pathway, αB negatively regulates the MAPK pathway to suppress apoptosis induced by UV and oxidative stress. Although previous studies revealed that αA and αB could regulate members in both caspase and Bcl-2 families, the molecular mechanism, especially the in vivo regulation still waits to be elucidated. In the present communication, we present both in vitro and in vivo evidence to further demonstrate the regulation of caspase-3 and Bax by αA and αB. First, Surface Plasmon Resonance (SPR) and yeast two-hybrid selection analysis demonstrate that αA and αB directly bind to caspase-3 and Bax with differential affinities. Second, immunohistochemistry reveals that αA and αB regulate caspase-3 and Bax at different developmental stages of mouse embryo. Third, coimmunoprecipitation shows that αA and αB form in vivo interacting complexes with caspase-3 and Bax. Together, our results further confirm that αA and αB regulate caspase-3 and Bax in vitro and in vivo to regulate lens differentiation.

Expression of Tsga10 sperm tail protein in embryogenesis and neural development: From cilium to cell division

Tsga10 has been localised in sperm tail as a fibrous sheath protein. In this study, we showed its expression during developmental stages of mouse embryo, in adult mice brain, and in some malignancies. RT-PCR and immunohistochemistry study show that Tsga10 expression starts in 4.5–7.5 dpc mouse embryos and continues throughout embryogenesis. Then we showed that the Tsga10 is expressed in adult brain and in the cells with neural crest origin, olfactory epithelium, and human germ cell tumour. It is expressed with two transcripts in sperm and whole embryos but just with the long transcript in brain embryo as a result of its exon 16 splicing. Our finding of the Tsga10 perinuclear localisation and its expression pattern suggests that it may be involved in active cell division, differentiation, and migrating cells. The results of the experiments in this project hypothesize the presence of Tsga10 protein wherever there is a conserved ciliary structure.

Optimized β-galactosidase staining method for simultaneous detection of endogenous gene expression in early mouse embryos

beta-Galactosidase (beta-gal) is one of the popular reporters for detecting the expression of endogenous or exogenous genes. Here we report 6-chloro-3-indoxyl-beta-D-galactopyranoside (S-gal) is more sensitive for beta-gal activity than 5-bromo-4-chloro-3-indolyl-beta-D-galactoside (X-gal), particularly during the early developmental stages of mouse embryos. Further, we successfully combined beta-gal staining with S-gal and in situ hybridization using DIG-labeled probes in both whole and sections of early stage embryos due to the sensitivity and color compatibility of S-gal.

Developmental hematopoiesis from fly to human

Developmental hematopoiesis is an exciting multi-disciplinary field at the crossroads of developmental biology, hematopoiesis, stem cell biology and genetics. This field began nearly a century ago with detailed observations on the formation of the first blood cells, the primitive erythrocytes, in

Somite as a Morphological Reference for Staging and Axial Levels of Developing Structures in Mouse Embryos

Background: The embryonic staging system based on the number of days post coitum is not always adequate to describe the rapid changes that occur during early organogenesis, and appropriate morphological features that can be easily referred to are important in descriptive embryology. Aims: The present study aims to ascertain whether somites can be used to determine both the developmental stage of mouse embryos and the axial level of embryonic structures from 9.5 days post coitum onwards. Results: The somite number could be easily counted after cresyl violet staining from 9.5 to 12.5 days post coitum, and the first few somites started to de-epithelialize by 10.0 days post coitum. However, from 12.5 days post coitum onwards, somites became difficult to count because of the thick surface epithelium. Vital dye labelling followed by whole embryo culture demonstrated that somites, limb buds and various regions of the neural tube did not undergo any major positional shift in relation to each other. Conclusions: From 9.5 to 12.5 days post coitum, the ease of somite count and the minimal positional shift in somites, limb buds and the neural tube implicate that the somite can be a convenient morphological reference for both the embryonic stage and the axial level of developing structures including limb buds and different regions of the neural tube during this period.

Sister-chromatid exchange induced by three mutagens in early developmental stage of mouse embryos in utero

Sister-chromatid exchange induced by three mutagens in early developmental stage of mouse embryos in utero

Sister-chromatid exchanges induced by two typical mutagens in the early developmental stage of mouse embryos in utero

Sister-chromatid exchanges induced by two typical mutagens in the early developmental stage of mouse embryos in utero

Expression of tumor necrosis factor at a specific developmental stage of mouse embryos

We investigated the expression of the tumor necrosis factor (TNF) gene during development of mouse embryos, and observed its transient expression on Days 9 and 10 of gestation. We also detected a 25-kDa protein showing immunological cross-reactivity with mouse TNF antibody in an extract of 10-day embryos. These results suggest that TNF plays a role in mammalian ontogenesis.

A family of octamer-specific proteins present during mouse embryogenesis: evidence for germline-specific expression of an Oct factor.

We have analysed various adult organs and different developmental stages of mouse embryos for the presence of octamer-binding proteins. A variety of new octamer-binding proteins were identified in addition to the previously described Oct1 and Oct2. Oct1 is ubiquitously present in murine tissues, in agreement with cell culture data. Although Oct2 has been described as a B-cell-specific protein, similar complexes were also found with extracts from brain, kidney, embryo and sperm. In embryo and brain at least two other proteins, Oct3 and Oct7, are present. A new microextraction procedure allowed the detection of two maternally expressed octamer-binding proteins, Oct4 and Oct5. Both proteins are present in unfertilized oocytes and embryonic stem cells, the latter containing an additional protein, Oct6. Whereas Oct4 was not found in sperm or testis, it is expressed in male and female primordial germ cells. Therefore Oct4 expression is specific for the female germline at later stages of germ cell development. Our results indicate that a family of octamer-binding proteins is present during mouse development and is differentially expressed during early embryogenesis. Protease clipping experiments of Oct4 and Oct1 suggest that both proteins contain similar DNA-binding domains.