Sensitivity of the mosquito Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma components

The phagostimulants from the cellular fraction of blood induce gorging of Aedes aegypti (L.), and this process is enhanced by some plasma components. This project examines the responses of the labral apical chemoreceptors to plasma components enhancing phagostimulation. From the electrophysiological responses of the labral apical chemoreceptors four cells were identified by the waveform of their action potentials. Three of the cells (Cell 2, Cell 3 and Cell 4) responded in a dose dependent manner to NaCl. The responses of Cell 2 and Cell 3 to NaCl concentrations from 1 to 500 mmol/l can be described by a logarithmic equation. The response of Cell 2 to 150 mmol/l NaCl is modulated when a buffer is added. The magnitude of the modulation of the response is determined by the nature of the buffer: NaHCO(3) inhibits while Na(2)HPO(4) enhances the response. High osmotic pressure inhibits the response of Cell 4, regardless of how it is achieved. Cell 4 responds with a high frequency to the presence of L-alanine, the C-terminal amino acid of albumin, but shows a reduced response to the same concentration of albumin. From these results it can be concluded that labral apical chemoreceptors of A. aegypti are capable of detecting the plasma components involved in blood recognition.     

The pessimist's and optimist's views of adult neurogenesis

The reports by Bonaguidi et?al. (in this issue of Cell) and Encinas et?al. (in Cell Stem Cell) come to differing conclusions about whether and how the proliferation of radial glia-like stem cells of the adult hippocampus impacts their long-term potential for neurogenesis.     

Cbx proteins help ESCs walk the line between self-renewal and differentiation

The Polycomb repressive complexes (PRC) regulate self-renewal and differentiation in embryonic stem cells (ESCs). In this issue of Cell Stem Cell, Morey et al. (2012) and O'Loghlen et al. (2012) report that dynamic interchange of PRC subunits modulates the balance between self-renewal and lineage commitment in ESCs.     

The origins of blood: induction of hematopoietic stem cells from different sources

Ex vivo hematopoiesis from embryonic sources offers exciting promises in basic research and medicine. In this issue of Cell Stem Cell, Ledran et al. (2008) describe human embryonic stem cell (hESC)-derived hematopoiesis, while Taoudi et al. (2008) define the origin of definitive hematopoietic stem cells (HSCs) from the mouse aorta-gonad-mesonephros (AGM) region.     

Human ES cell profiling broadens the reach of bivalent domains

In this issue of Cell Stem Cell, Pan et al. (2007) and Zhao et al. (2007) report genome-wide histone H3 trimethylations at lysines 4 and 27 in human embryonic stem (ES) cells. Similar gene sets arise via different experimental systems, advancing our understanding of stem cell epigenetics.     

The yin and yang of polycomb repression in regenerating muscle

Tumor necrosis factor-α (TNF-α) has complex effects on muscle regeneration. In this issue of Cell Stem Cell, Palacios et al. (2010) report that TNF-α-activated p38α kinase controls differentiation of muscle stem cells by promoting polycomb repressive complex 2 (PRC2) silencing of the Pax7 promoter.     

Improving the efficiency of wheat microspore culture methodology: evaluation of pretreatments,gradients, and epigenetic chemicals

Plant Cell, Tissue and Organ Culture (PCTOC) - Cell suspension culture of Linum usitatissimum is a great source of the novel and multipurpose medicinal compounds lignans and neolignans....     

Elicitors derived from endophytic fungi Chaetomium globosum and Paraconiothyrium brasiliense enhance paclitaxel production in Corylus avellana cell suspension culture

Plant Cell, Tissue and Organ Culture (PCTOC) - Paclitaxel is an impressive chemotherapeutic agent that shows biological activity against a wide range of cancers. Cell suspension culture of Corylus...     

Metabolomics reveals ionones upregulation in MeJA elicited Cinnamomum camphora (camphor tree) cell culture

Plant Cell, Tissue and Organ Culture (PCTOC) - Cell suspension culture offers an approach for elucidating secondary metabolites biosynthetic pathways and its regulatory mechanism. In this work,...     

Human ES Cells and a Blastocyst from One Embryo: Exciting Science but Conflicting Ethics?

In this issue of Cell Stem Cell, Chung et al. (2008) remove a single blastomere to generate a human embryonic stem cell (hESC) line without prejudicing the development of the biopsied embryo. Their method stimulates new ideas about hESC formation, but ethicopolitical concerns remain.     

The Greek Goddess,Artemis, reveals the secrets of her cleavage

A recent paper in Cell by Ma et al. [Cell 8 (2002) 781] showed that the protein Artemis cleaves a hairpin intermediate during V(D)J recombination. Peter O'Neill and Penny Jeggo discuss this finding in the light of evidence that Artemis also functions to repair radiation damage [Cell 105 (2001) 177]. The findings suggest that Artemis may function in double strand break repair by "tidying up" double strand ends with associated base damage. The development of genetic diversity during immune development, therefore, seems to exploit damage response mechanisms that function to maintain genetic stability in other cell lineages.     

Moving Forward in Human Mammary Stem Cell Biology and Breast Cancer Prognostication Using ALDH1

In this issue of Cell Stem Cell, the seminal work of Ginestier et al. (2007) elegantly demonstrates that aldehyde dehydrogenase 1 (ALDH1) facilitates the identification and isolation of normal and malignant human mammary stem cells in vitro, in vivo, and in situ in fixed tissues.     

Kinship and Descent: Redefining the Stem Cell Compartment in the Adult Hippocampus

Identifying multipotent, self-renewing neural stem cells (NSCs) within the adult hippocampus in vivo has been somewhat elusive. In this issue of Cell Stem Cell, Suh et al. (2007) show that Sox2-expressing cells in the subgranular zone (SGZ) of the dentate gyrus not only have NSC characteristics but also display an unexpected degree of heterogeneity.     

Cancer: Inappropriate Expression of Stem Cell Programs?

Cancer stem cells (CSCs) are a subpopulation of cancer cells that possess characteristics, including self-renewal, associated with normal stem cells. In this issue of Cell Stem Cell, Wong et al. (2008) define a core embryonic stem cell (ESC)-like gene expression program that may be important for CSC function in multiple epithelial cancers.     

Common signaling networks characterize leukemia-initiating cells in acute myeloid leukemia

Identification and characterization of leukemia-initiating cells (LICs) is important to understand leukemogenesis and develop novel therapies for leukemia. In this issue of Cell Stem Cell, Gibbs et?al. (2012) demonstrate that common active signaling pathways in LICs may be targeted to treat acute myeloid leukemia.     

Nodal/Activin signaling: a novel target for pancreatic cancer stem cell therapy

Targeting of cancer stem cells (CSCs) has the potential to address the recalcitrance of pancreatic cancer to chemotherapy. In this issue of Cell Stem Cell, Lonardo et al. (2011) demonstrate that Nodal/Activin signaling is crucial for the maintenance and tumor-initiating capacity of pancreatic CSCs.     

Does N-Cadherin Regulate Interaction of Hematopoietic Stem Cells with Their Niches?

In this issue of Cell Stem Cell, Kiel et al. (2007) demonstrate that N-cadherin is not expressed on repopulating hematopoietic stem cells (HSCs) and that reduction of osteoblasts does not affect HSC frequency, suggesting that other molecular pathways may also modulate the interaction of HSCs with their niches.