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  • genome
  • This type of chromatin contains the most highly condensed structure of DNA-wrapped nucleosomes in the genome, presenting a challenge for newly induced transcription factors to overcome the barriers to entry into such condensed chromatin. (onclive.com)
  • Such a revolutionary perspective has been accompanied and triggered by the development of powerful technologies for profiling short RNAs expression, both at the high-throughput level (genome-wide identification) or as single-candidate analysis (steady state accumulation of specific species). (jove.com)
  • The new embryo develops autonomously around the four-cell stage, when maternal supplies are exhausted and the zygotic genome is activated in mice. (mdpi.com)
  • This oocyte-to-embryo transition needs an efficient and tightly regulated translation of the maternally-inherited mRNAs, which likely contributes to embryonic genome activation. (mdpi.com)
  • This suggests that what the genome encodes ultimately is a set of dynamic, flexible behaviors by which the cells are able to make adjustments to build specific complex structures. (healthcanal.com)
  • germ
  • Embryonic gonad formation involves intimate contact between germ cells and specialized somatic cells along with the complex morphogenetic movements necessary to create proper gonad architecture. (biologists.org)
  • Formation of this organ requires that germ cells and somatic gonadal precursors (SGPs), which are initially specified far apart from each other, undergo a complex morphogenetic program to form a properly patterned embryonic gonad. (biologists.org)
  • Organs
  • The somatic precursor of gonads, the genital ridge is formed at the mid-gestation stage and gives rise to one of two organs, a testis or an ovary. (springer.com)
  • chromatin
  • Two new studies from the laboratory of Dr. Alex Mazo at the Sidney Kimmel Cancer Center (SKCC) at Thomas Jefferson University, along with collaborators from SKCC, the Vickie and Jack Farber Institute for Neuroscience and other institutions, provide new insights into the structure of chromatin and its implications for cellular differentiation. (onclive.com)
  • Author Dr. Mazo explains, "We found that shortly following induction of differentiation, the newly formed nucleosomes on nascent DNA (just after replication) are devoid of the H3K27me3 mark, so the chromatin at this stage is very de-condensed, thus allowing an easy association of any transcription factor with its target site. (onclive.com)
  • Intriguingly, more primitive types of HPCs exhibit a very rapid association of nascent DNA with the repressive H3K27me3 histone mark, suggesting that HPCs may utilize special mechanisms of chromatin modification for recruitment of specific transcription factors during the early stages of their lineage specification. (onclive.com)
  • Then, the zygote must resume the mitotic cell cycle, remodel the chromatin, activate transcription, and initiate the embryonic developmental program [ 2 , 3 ] ( Figure 1 ). (mdpi.com)
  • Methyl groups coupled to cytosines in cytosine-guanine (CpG) dinucleotides and modifications of histones that package the DNA are the two main molecular marks that compose this information and regulate chromatin structure and DNA accessibility ( 2 ). (pnas.org)
  • Binding of MBDs and further recruitment of histone deacetylase (HDAC) repressor complexes result in histone deacetylation and inactive chromatin structures that are repressive for transcription ( 1 ). (pnas.org)
  • mutants
  • Expression of DE-cadherin from a ubiquitous ( tubulin ) promoter still results in gonad-specific accumulation of DE-cadherin, which is strongly reduced in foi mutants. (biologists.org)
  • organize
  • Thus, the Tubifex D quadrant micromeres have the ability to organize axis formation, but they lack the ability to induce neuroectodermal tissues, a characteristic common to chordate primary embryonic organizers. (biologists.org)
  • In addition, the present study provides the first direct evidence that annelid D quadrant cells have the ability to organize the embryonic axis (see below). (biologists.org)
  • mRNA
  • The mature miRNA forms a component of the RNA-induced silencing complexes (miRISC) and guides these complexes to mRNA targets via sequence-specific pairing between the miRNA seed sequence (the first 7 nt of the miRNA starting from position 2) and the mRNA. (biomedcentral.com)
  • mechanisms
  • our categorizations of a specific system as using intrinsic or extrinsic/stochastic mechanisms below reflect either the biased use of one mechanism over the other or that our understanding of one mechanism is more complete than our understanding of the other in that system. (springer.com)
  • Quantitative analysis of terminal cell branch number, branch organization and individual branch shape, can be used to provide information about the role of specific genetic mechanisms in the making of a branched cell. (jove.com)
  • secondary
  • miRNAs are transcribed in the nucleus into long polyadenylated RNAs known as primary (pri)-miRNAs that contain ~60-90 nt secondary hairpin structures termed precursor (pre)-miRNAs. (biomedcentral.com)
  • extracellular
  • Normal valve structures consist of stratified layers of specialized extracellular matrix (ECM) interspersed with valve interstitial cells (VICs) and surrounded by a monolayer of valve endothelial cells (VECs). (jove.com)
  • mouse
  • We identified the expression of 294 known miRNAs in the E15.5 developing mouse brain, which were mostly represented by let-7 family and other brain-specific miRNAs such as miR-9 and miR-124 . (biomedcentral.com)
  • Conditional genetic removal of Hnf4α in the mouse liver confirmed its crucial role in hepatic functions and epithelium integrity ( 9 , 10 ). (aacrjournals.org)
  • severe
  • In contrast, the Tufts research team found that in tadpoles with severe malformations, the facial structures shifted dramatically in order to repair those malformations. (healthcanal.com)
  • otic
  • They then characterized changes in the shape and position of the craniofacial structures, such as jaws, branchial arches, eyes, otic capsules and olfactory pits, through "geometric morphometric analysis," which measured positioning of a total of 32 landmarks on the top and bottom sides of the tadpoles. (healthcanal.com)
  • primitive
  • The eye field primordial clusters that emerged from differentiating PSCs developed into whole eyeball-like, self-organized, three-dimensional, miniature structures consisting of retinal primordia, corneal primordia, a primitive eyelid-like outer covering and ciliary margin zone-like adnexal tissues in a stepwise maturation process within 15 weeks. (biologists.org)