New insights into the evolutionary history of photoreceptor cells
... suggest a role in eliciting a ciliary-type phototransduction cascade. Second, these brain photoreceptors are also under the control of a developmental regulatory gene, rx, which is homologous to the gene that regulates vertebrate ciliary photoreceptors in development [1]. Finally, morphological data ...
... suggest a role in eliciting a ciliary-type phototransduction cascade. Second, these brain photoreceptors are also under the control of a developmental regulatory gene, rx, which is homologous to the gene that regulates vertebrate ciliary photoreceptors in development [1]. Finally, morphological data ...
Chapter 4 – A Tour of the Cell
... existed as free-living prokaryotes which were engulfed and retained by ancient eukaryotic cells approximately 1.5 billion years ago. • Chloroplasts, the organelles ...
... existed as free-living prokaryotes which were engulfed and retained by ancient eukaryotic cells approximately 1.5 billion years ago. • Chloroplasts, the organelles ...
Wnt Signaling and a Hox Protein Cooperatively Regulate PSA
... and Prospero proteins (Jan and Jan, 2001). In C. elegans, as described below, many asymmetric divisions are regulated by the Wnt-MAPK pathway. Although the respective mechanisms in each of these organisms are used repeatedly during development, the fates of the daughter cells are distinct and depend ...
... and Prospero proteins (Jan and Jan, 2001). In C. elegans, as described below, many asymmetric divisions are regulated by the Wnt-MAPK pathway. Although the respective mechanisms in each of these organisms are used repeatedly during development, the fates of the daughter cells are distinct and depend ...
emboj7601526-sup
... number of taste bud cells), and that for cells of the other types, the fraction of type A cells in the GFP-negative (non-green) cell population can be written as: F = (1-x)fA/((1-x)fA+fB+fC+fN) where x is the fraction of GFP-positive cells in the A subcategory. Taking F = 12/43 = 0.28 (Fig.1E) and f ...
... number of taste bud cells), and that for cells of the other types, the fraction of type A cells in the GFP-negative (non-green) cell population can be written as: F = (1-x)fA/((1-x)fA+fB+fC+fN) where x is the fraction of GFP-positive cells in the A subcategory. Taking F = 12/43 = 0.28 (Fig.1E) and f ...
Cells functions - RMC Science Home
... But sometimes cells need to die… Lysosomes can be used to kill cells when they are supposed to be destroyed ...
... But sometimes cells need to die… Lysosomes can be used to kill cells when they are supposed to be destroyed ...
The TNF and TNFR superfamilies
... Tumor-necrosis factor (TNF) was discovered as a serum factor that was able to kill cancer cells in mice. The TNF receptor (TNFR) led to the discovery of a superfamily of transmembrane proteins. There are 18 ligands and 28 receptors many of which are being targeted for therapeutic purposes. TNFR sig ...
... Tumor-necrosis factor (TNF) was discovered as a serum factor that was able to kill cancer cells in mice. The TNF receptor (TNFR) led to the discovery of a superfamily of transmembrane proteins. There are 18 ligands and 28 receptors many of which are being targeted for therapeutic purposes. TNFR sig ...
Chapter 2: Cells - The Units of Life
... As small as cells are, they are made of even smaller parts, each doing a different job. A cell can be compared to a bakery. The activities of a bakery are inside a building. Electricity is used to run the ovens and other equipment, power the lights, and heat the building. The bakery’s products requi ...
... As small as cells are, they are made of even smaller parts, each doing a different job. A cell can be compared to a bakery. The activities of a bakery are inside a building. Electricity is used to run the ovens and other equipment, power the lights, and heat the building. The bakery’s products requi ...
CT1
... 7. Carbon dioxide is leaving the cell. Oxygen is entering the cell. Both molecules are moving down the concentration gradient. The molecules are being transported by the process called _______________. 8. An amoeba is very hungry and it wants to eat another yet much smaller protist in the water outs ...
... 7. Carbon dioxide is leaving the cell. Oxygen is entering the cell. Both molecules are moving down the concentration gradient. The molecules are being transported by the process called _______________. 8. An amoeba is very hungry and it wants to eat another yet much smaller protist in the water outs ...
The Cell - Phillips Scientific Methods
... motility. Mounting evidence also suggests that the cytoskeleton can transmit mechanical forces exerted by extracellular molecules via surface proteins of the cell to its interior. The cytoskeleton contains three main types of fibers. 1. Microtubules – hollow rods constructed from two types of globul ...
... motility. Mounting evidence also suggests that the cytoskeleton can transmit mechanical forces exerted by extracellular molecules via surface proteins of the cell to its interior. The cytoskeleton contains three main types of fibers. 1. Microtubules – hollow rods constructed from two types of globul ...
Eukaryogenesis: The Beginning of Life as We Know It
... outlined how eukaryotic cells came to possess many of their features (intracellular organelles, organelle genomes and the division of mitochondria and plastids, for example), but did little to elaborate upon how (mechanistically) one ancestral prokaryote could engulf another an event that is rathe ...
... outlined how eukaryotic cells came to possess many of their features (intracellular organelles, organelle genomes and the division of mitochondria and plastids, for example), but did little to elaborate upon how (mechanistically) one ancestral prokaryote could engulf another an event that is rathe ...
Full Text
... then the diameter of the circular blastopore shrinks by constriction (Fig. 18). By the end of gastrulation, the presumptive endoderm is drawn completely inside the embryo (Fig. lC). During gastrulation, a new cavity, called the archenteron, grows from the blastopore as the invagination site at the b ...
... then the diameter of the circular blastopore shrinks by constriction (Fig. 18). By the end of gastrulation, the presumptive endoderm is drawn completely inside the embryo (Fig. lC). During gastrulation, a new cavity, called the archenteron, grows from the blastopore as the invagination site at the b ...
Phosphorylation of initiation factor2 is required for
... Viewing the differentiated state as a permissive environment for PDGF2-IRES mediated translation, we also wished to check the effect of differentiation conditions on the behaviour of additional cellular and viral IRES elements. Although normally the mRNAs of VEGF and c-Myc are not present in diffe ...
... Viewing the differentiated state as a permissive environment for PDGF2-IRES mediated translation, we also wished to check the effect of differentiation conditions on the behaviour of additional cellular and viral IRES elements. Although normally the mRNAs of VEGF and c-Myc are not present in diffe ...
Some Observations on the Flagella and
... Since the description of a ‘ thread-like trunk ’ on cells of Ophidomonas (Thiospirillum) spp. which behaved as an organ of propulsion (Ehrenberg, 1838) numerous observations have been made on the flagella of both living and stained cells of large spirilla (Biitschli, 1902 ; Ellis, 1902; Fuhrmann, 19 ...
... Since the description of a ‘ thread-like trunk ’ on cells of Ophidomonas (Thiospirillum) spp. which behaved as an organ of propulsion (Ehrenberg, 1838) numerous observations have been made on the flagella of both living and stained cells of large spirilla (Biitschli, 1902 ; Ellis, 1902; Fuhrmann, 19 ...
Recent Advances in αβ T Cell Biology: Wnt Signaling
... Wnt proteins [15,16]. Expression of ecto-domains of Frizzled receptors by retroviral transduction as extracellular inhibitors of Wnt signaling in fetal thymus organ culture induces a complete block of early thymocyte development, indicating that secreted Wnt factors are essential for intrathymic T l ...
... Wnt proteins [15,16]. Expression of ecto-domains of Frizzled receptors by retroviral transduction as extracellular inhibitors of Wnt signaling in fetal thymus organ culture induces a complete block of early thymocyte development, indicating that secreted Wnt factors are essential for intrathymic T l ...
Some Observations on the Flagella and
... Since the description of a ‘ thread-like trunk ’ on cells of Ophidomonas (Thiospirillum) spp. which behaved as an organ of propulsion (Ehrenberg, 1838) numerous observations have been made on the flagella of both living and stained cells of large spirilla (Biitschli, 1902 ; Ellis, 1902; Fuhrmann, 19 ...
... Since the description of a ‘ thread-like trunk ’ on cells of Ophidomonas (Thiospirillum) spp. which behaved as an organ of propulsion (Ehrenberg, 1838) numerous observations have been made on the flagella of both living and stained cells of large spirilla (Biitschli, 1902 ; Ellis, 1902; Fuhrmann, 19 ...
Oncogenes and anti-oncogenes in tumorigenesis - HAL
... the src family are partners of cytokihe membrane receptors which have no tyrosine-protein kinase domain of their own. Recently, evidence supporting this hypothesis has been provided for c-Ick, which is expressed in T-lymphocytes and whose kinase activity is increased in response to Tcell activating ...
... the src family are partners of cytokihe membrane receptors which have no tyrosine-protein kinase domain of their own. Recently, evidence supporting this hypothesis has been provided for c-Ick, which is expressed in T-lymphocytes and whose kinase activity is increased in response to Tcell activating ...
Dishevelled 2 signaling promotes self
... of the disease at the molecular level. For neural stem cells, the decision to divide or differentiate is strongly influenced by Wnt signaling, while other factors, such as EGF and FGF, stimulate their proliferation (8-10). Wnt ligands are capable of activating several distinct signal transduction pa ...
... of the disease at the molecular level. For neural stem cells, the decision to divide or differentiate is strongly influenced by Wnt signaling, while other factors, such as EGF and FGF, stimulate their proliferation (8-10). Wnt ligands are capable of activating several distinct signal transduction pa ...
Constitutive caspase-like machinery executes programmed cell
... cytosolic proteins with excess zVAD-fmk prior to treatment with biotinylated VAD-fmk. As seen, upon the addition of zVAD-fmk in the cell culture, the banding pattern is similar to the banding pattern of the untreated sample (Figure 5a). The amounts of VAD-fmk bound protein appear to be correlated to ...
... cytosolic proteins with excess zVAD-fmk prior to treatment with biotinylated VAD-fmk. As seen, upon the addition of zVAD-fmk in the cell culture, the banding pattern is similar to the banding pattern of the untreated sample (Figure 5a). The amounts of VAD-fmk bound protein appear to be correlated to ...
The D-Type Alfalfa Cyclin Gene cycMs4 Complements
... analyzed at high magnification. A region of cortex cells of this section is shown in Figure 4D. Although high levels of cycMs4 mRNA were present in three adjacent cells (indicated by arrowheads in Figure 4D), several cells belonging to the same file did not contain any transcript, indicating that th ...
... analyzed at high magnification. A region of cortex cells of this section is shown in Figure 4D. Although high levels of cycMs4 mRNA were present in three adjacent cells (indicated by arrowheads in Figure 4D), several cells belonging to the same file did not contain any transcript, indicating that th ...
Immunoregulatory T Cell Pathways: The Helper T Cell Clone as Target
... by the interactions of a specialised circuit of regulatory T cells which results in an Ly-l effector cell. Un like helper T cells, the Ly-l effector cell of the contrasuppressor circuit is I-J+ and adheres to the lectin of Vida villosa. Contrasuppressor effector cells have been identified in cultur ...
... by the interactions of a specialised circuit of regulatory T cells which results in an Ly-l effector cell. Un like helper T cells, the Ly-l effector cell of the contrasuppressor circuit is I-J+ and adheres to the lectin of Vida villosa. Contrasuppressor effector cells have been identified in cultur ...
The_Cell_Cylce_and_Hallmarks_of_Cancer
... normal cells could replicate forever was overturned. Normal human and animal cells have a finite capacity to replicate and function whether they are cultured in vitro or transplanted as grafts in vivo. This phenomenon has been interpreted to be aging at the cellular level. Only abnormal somatic cell ...
... normal cells could replicate forever was overturned. Normal human and animal cells have a finite capacity to replicate and function whether they are cultured in vitro or transplanted as grafts in vivo. This phenomenon has been interpreted to be aging at the cellular level. Only abnormal somatic cell ...
10 Smooth Muscle
... filaments and the cytoplasmic dense bodies are oriented obliquely to the long axis, crisscrossing the cell, whereas in the relaxed cell these components generally are parallel to the cell axis. The contractile elements unite the attachment plaques with the dense bodies. During contraction, the contr ...
... filaments and the cytoplasmic dense bodies are oriented obliquely to the long axis, crisscrossing the cell, whereas in the relaxed cell these components generally are parallel to the cell axis. The contractile elements unite the attachment plaques with the dense bodies. During contraction, the contr ...
CHAPTER 3: CELLS
... In physiologic (active) transport mechanisms, substances move from where they are in low concentration to where they are in high concentration at the expense of cellular energy (ATP). Active processes include active transport, endocytosis, exocytosis and transcytosis. ...
... In physiologic (active) transport mechanisms, substances move from where they are in low concentration to where they are in high concentration at the expense of cellular energy (ATP). Active processes include active transport, endocytosis, exocytosis and transcytosis. ...
Distinct Cellular and Subcellular Patterns of Expression Imply
... discovery that human neurofibromatosis 2 (NF2) is caused by mutations in merlin (moesin-ezrin-radixin-like protein), a novel member of the ERM family (Rouleau et al., 1993; Trofatter et al., 1993). The hallmark of NF2 is the presence of bilateral acoustic schwannomas (acoustic neuromas) affecting th ...
... discovery that human neurofibromatosis 2 (NF2) is caused by mutations in merlin (moesin-ezrin-radixin-like protein), a novel member of the ERM family (Rouleau et al., 1993; Trofatter et al., 1993). The hallmark of NF2 is the presence of bilateral acoustic schwannomas (acoustic neuromas) affecting th ...
Cellular differentiation
In developmental biology, cellular differentiation isa cell changes from one cell type to another. Most commonly this is a less specialized type becoming a more specialized type, such as during cell growth. Differentiation occurs numerous times during the development of a multicellular organism as it changes from a simple zygote to a complex system of tissues and cell types. Differentiation continues in adulthood as adult stem cells divide and create fully differentiated daughter cells during tissue repair and during normal cell turnover. Some differentiation occurs in response to antigen exposure. Differentiation dramatically changes a cell's size, shape, membrane potential, metabolic activity, and responsiveness to signals. These changes are largely due to highly controlled modifications in gene expression and are the study of epigenetics. With a few exceptions, cellular differentiation almost never involves a change in the DNA sequence itself. Thus, different cells can have very different physical characteristics despite having the same genome.A cell that can differentiate into all cell types of the adult organism is known as pluripotent. Such cells are called embryonic stem cells in animals and meristematic cells in higher plants. A cell that can differentiate into all cell types, including the placental tissue, is known as totipotent. In mammals, only the zygote and subsequent blastomeres are totipotent, while in plants many differentiated cells can become totipotent with simple laboratory techniques. In cytopathology, the level of cellular differentiation is used as a measure of cancer progression. ""Grade"" is a marker of how differentiated a cell in a tumor is.