Tài liệu miễn phí Sinh học

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Positional plasticity in regenerating Amybstoma mexicanum limbs is associated with cell proliferation and pathways of cellular differentiation

The endogenous ability to dedifferentiate, re-pattern, and re-differentiate adult cells to repair or replace damaged or missing structures is exclusive to only a few tetrapod species. The Mexican axolotl is one example of these species, having the capacity to regenerate multiple adult structures including their limbs by generating a group of progenitor cells, known as the blastema, which acquire pattern and differentiate into the missing tissues.

12/29/2020 5:20:53 PM +00:00

The developmental basis of mesenchymal stem/stromal cells (MSCs)

Mesenchymal Stem/Stromal Cells (MSCs) define a population of progenitor cells capable of giving rises to at least three mesodermal lineages in vitro, the chondrocytes, osteoblasts and adipocytes. The validity of MSCs in vivo has been questioned because their existence, either as a homogeneous progenitor cell population or as a stem cell lineage, has been difficult to prove.

12/29/2020 5:20:46 PM +00:00

Meis2 is essential for cranial and cardiac neural crest development

TALE-class homeodomain transcription factors Meis and Pbx play important roles in formation of the embryonic brain, eye, heart, cartilage or hematopoiesis. Loss-of-function studies of Pbx1, 2 and 3 and Meis1 documented specific functions in embryogenesis, however, functional studies of Meis2 in mouse are still missing.

12/29/2020 5:20:32 PM +00:00

3D structured illumination microscopy of mammalian embryos and spermatozoa

Super-resolution fluorescence microscopy performed via 3D structured illumination microscopy (3D-SIM) is well established on flat, adherent cells. However, blastomeres of mammalian embryos are non-adherent, round and large. Scanning whole mount mammalian embryos with 3D-SIM is prone to failure due to the movement during scanning and the large distance to the cover glass.

12/29/2020 5:20:25 PM +00:00

Not all the number of skeletal muscle fibers is determined prenatally

The investigation of skeletal muscle development is of importance in stock farming and biomedicine. It is still ambiguous that whether animals are born with the full set of skeletal muscle fibers or if the number of myofibers continues to increase postnatally.

12/29/2020 5:20:16 PM +00:00

Med14 cooperates with brg1 in the differentiation of skeletogenic neural crest

An intricate gene regulatory network drives neural crest migration and differentiation. How epigenetic regulators contribute to this process is just starting to be understood.

12/29/2020 5:20:07 PM +00:00

MiR-21 is required for efficient kidney regeneration in fish

Acute kidney injury in mammals, which is caused by cardiovascular diseases or the administration of antibiotics with nephrotoxic side-effects is a life-threatening disease, since loss of nephrons is irreversible in mammals. In contrast, fish are able to generate new nephrons even in adulthood and thus provide a good model to study renal tubular regeneration.

12/29/2020 5:20:00 PM +00:00

Stable and bicistronic expression of two genes in somite- and lateral plate-derived tissues to study chick limb development

Components of the limb musculoskeletal system have distinct mesoderm origins. Limb skeletal muscles originate from somites, while the skeleton and attachments (tendons and connective tissues) derive from limb lateral plate. Despite distinct mesoderm origins, the development of muscle, skeleton and attachments is highly coordinated both spatially and temporally to ensure complete function of the musculoskeletal system.

12/29/2020 5:19:49 PM +00:00

Muscleblind-like 1 is required for normal heart valve development in vivo

Development of the valves and septa of the heart depends on the formation and remodeling of the endocardial cushions in the atrioventricular canal and outflow tract. These cushions are populated by mesenchyme produced from the endocardium by epithelial-mesenchymal transition (EMT).

12/29/2020 5:19:39 PM +00:00

A loss-of-function and H2B-Venus transcriptional reporter allele for Gata6 in mice

The GATA-binding factor 6 (Gata6) gene encodes a zinc finger transcription factor that often functions as a key regulator of lineage specification during development. It is the earliest known marker of the primitive endoderm lineage in the mammalian blastocyst.

12/29/2020 5:19:31 PM +00:00

Conservation analysis of sequences flanking the testis-determining gene Sry in 17 mammalian species

Sex determination in mammals requires expression of the Y-linked gene Sry in the bipotential genital ridges of the XY embryo. Even minor delay of the onset of Sry expression can result in XY sex reversal, highlighting the need for accurate gene regulation during sex determination.

12/29/2020 5:19:24 PM +00:00

Intrinsic factors and the embryonic environment influence the formation of extragonadal teratomas during gestation

Pluripotent cells are present in early embryos until the levels of the pluripotency regulator Oct4 drop at the beginning of somitogenesis. Elevating Oct4 levels in explanted post-pluripotent cells in vitro restores their pluripotency.

12/29/2020 5:19:15 PM +00:00

Cooperative and independent functions of FGF and Wnt signaling during early inner ear development

In multiple vertebrate organisms, including chick, Xenopus, and zebrafish, Fibroblast Growth Factor (FGF) and Wnt signaling cooperate during formation of the otic placode. However, in the mouse, although FGF signaling induces Wnt8a expression during induction of the otic placode, it is unclear whether these two signaling pathways functionally cooperate.

12/29/2020 5:19:08 PM +00:00

The pattern of congenital heart defects arising from reduced Tbx5 expression is altered in a Down syndrome mouse model

Nearly half of all individuals with Down Syndrome (DS) have some type of congenital heart defect (CHD), suggesting that DS sensitizes to CHD but does not cause it. We used a common mouse model of DS, the Ts65Dn mouse, to study the contribution of Tbx5, a known modifier of CHD, to heart defects on a trisomic backgroun.

12/29/2020 5:19:01 PM +00:00

Sox7 is dispensable for primitive endoderm differentiation from mouse ES cells

Primitive endoderm is a cell lineage segregated from the epiblast in the blastocyst and gives rise to parietal and visceral endoderm. Sox7 is a member of the SoxF gene family that is specifically expressed in primitive endoderm in the late blastocyst, although its function in this cell lineage remains unclear.

12/29/2020 5:18:51 PM +00:00

Monitoring brain development of chick embryos in vivo using 3.0 T MRI: Subdivision volume change and preliminary structural quantification using DTI

Magnetic resonance imaging (MRI) has many advantages in the research of in vivo embryonic brain development, specifically its noninvasive aspects and ability to avoid skeletal interference. However, few studies have focused on brain development in chick, which is a traditional animal model in developmental biology. We aimed to serially monitor chick embryo brain development in vivo using 3.0 T MRI.

12/29/2020 5:18:44 PM +00:00

Morphologically defined sub-stages of C. elegans vulval development in the fourth larval stage

During the fourth larval (L4) stage, vulval cells of C. elegans undergo extensive morphogenesis accompanied by changes in gene expression. This phase of vulval development, occurring after the well-studied induction of vulval cells, is not well understood but is potentially a useful context in which to study how a complex temporal sequence of events is regulated during development.

12/29/2020 5:18:37 PM +00:00

Validating reference microRNAs for normalizing qRT-PCR data in bovine oocytes and preimplantation embryos

MicroRNAs (miRNAs) are small noncoding RNAs that act as post-transcriptional regulators of gene targets. Accurate quantification of miRNA expression using validated internal controls should aid in the understanding of their role in epigenetic modification of genome function.

12/29/2020 5:18:31 PM +00:00

Mantle margin morphogenesis in Nodipecten nodosus (Mollusca: Bivalvia): New insights into the development and the roles of bivalve pallial folds

Despite extensive knowledge on bivalve anatomy and development, the formation and differentiation of the mantle margin and its associated organs remain largely unclear. Bivalves from the family Pectinidae (scallops) are particularly promising to cast some light on these issues, because they exhibit a complex mantle margin and their developmental stages are easily obtained from scallop farms.

12/29/2020 5:18:20 PM +00:00

The Aurora A-HP1γ pathway regulates gene expression and mitosis in cells from the sperm lineage

HP1γ, a well-known regulator of gene expression, has been recently identified to be a target of Aurora A, a mitotic kinase which is important for both gametogenesis and embryogenesis.

12/29/2020 5:18:12 PM +00:00

Myc regulates programmed cell death and radial glia dedifferentiation after neural injury in an echinoderm

Adult echinoderms can completely regenerate major parts of their central nervous system even after severe injuries. Even though this capacity has long been known, the molecular mechanisms that drive fast and complete regeneration in these animals have remained uninvestigated.

12/29/2020 5:18:04 PM +00:00

Sprouty gene dosage influences temporal-spatial dynamics of primary enamel knot formation

The mouse embryonic mandible comprises two types of tooth primordia in the cheek region: progressive tooth primordia of prospective functional teeth and rudimentary tooth primordia in premolar region – MS and R2. Mice lacking Sprouty genes develop supernumerary tooth in front of the lower M1 (first molar) primordium during embryogenesis.

12/29/2020 5:17:56 PM +00:00

Cropped, Drosophila transcription factor AP-4, controls tracheal terminal branching and cell growth

Endothelial or epithelial cellular branching is vital in development and cancer progression; however, the molecular mechanisms of these processes are not clear. In Drosophila, terminal cell at the end of some tracheal tube ramifies numerous fine branches on the internal organs to supply oxygen.

12/29/2020 5:17:49 PM +00:00

An optimised whole mount in situ hybridisation protocol for the mollusc Lymnaea stagnalis

The ability to visualise the expression of individual genes in situ is an invaluable tool for developmental and evolutionary biologists; it allows for the characterisation of gene function, gene regulation and through inter-specific comparisons, the evolutionary history of unique morphological features.

12/29/2020 5:17:41 PM +00:00

Spontaneous long-range calcium waves in developing butterfly wings

Butterfly wing color patterns emerge as the result of a regular arrangement of scales produced by epithelial scale cells at the pupal stage. These color patterns and scale arrangements are coordinated throughout the wing. However, the mechanism by which the development of scale cells is controlled across the entire wing remains elusive.

12/29/2020 5:17:33 PM +00:00

Development and origins of Zebrafish ocular vasculature

The developing eye receives blood supply from two vascular systems, the intraocular hyaloid system and the superficial choroidal vessels. In zebrafish, a highly stereotypic and simple set of vessels develops on the surface of the eye prior to development of choroidal vessels.

12/29/2020 5:17:26 PM +00:00

Human Dental pulp stem cells (hDPSCs): Isolation, enrichment and comparative differentiation of two sub-populations

Human dental pulp represents a suitable alternative source of stem cells for the purpose of cell-based therapies in regenerative medicine, because it is relatively easy to obtain it, using low invasive procedures. This study characterized and compared two subpopulations of adult stem cells derived from human dental pulp (hDPSCs).

12/29/2020 5:17:19 PM +00:00

Neural stem and progenitor cell fate transition requires regulation of Musashi1 function

There is increasing evidence of a pivotal role for regulated mRNA translation in control of developmental cell fate transitions. Physiological and pathological stem and progenitor cell self-renewal is maintained by the mRNA-binding protein, Musashi1 through repression of translation of key mRNAs encoding cell cycle inhibitory proteins.

12/29/2020 5:17:12 PM +00:00

An automated system for quantitative analysis of Drosophila larval locomotion

Drosophila larvae have been used as a model to study to genetic and cellular circuitries modulating behaviors. One of the challenges in behavioral study is the quantification of complex phenotypes such as locomotive behaviors.

12/29/2020 5:17:05 PM +00:00

Embryonic and larval development in the Midas cichlid fish species flock (Amphilophus spp.): A new evo-devo model for the investigation of adaptive novelties and species differences

Central American crater lake cichlid fish of the Midas species complex (Amphilophus spp.) are a model system for sympatric speciation and fast ecological diversification and specialization. Midas cichlids have been intensively analyzed from an ecological and morphological perspective.

12/29/2020 5:16:55 PM +00:00