Abstract：
:An electron microscopic investigation of the events associated with meiosis in Lilium has revealed a number of changes in both the organellar population and the other cytoplasmic components. Ribosome numbers decrease significantly in early prophase and are later replenished in the tetrads, a process most likely involving the newly arising cytoplasmic nucleoloids. The organelles show a cycle of de- and redifferentiation and later in meiosis unusual internal structures can be seen before these organelles enter a division phase resulting in increased numbers. The localization of acid phosphatase during these changes has also been studied using electron microscopic cytochemical methods. In early prophase, considerable amounts of acid phosphatase are found in vesicles scattered through the cytoplasm; activity is also found in association with most membranous surfaces and often markedly associated with condensing mitochondria. Later in prophase the enzyme activity decreases to normal levels. Electron microscopic autoradiography revealed that DNA is synthesized in both plastids and mitochondria during meiotic prophase with activity reaching a peak during zygotene and ceasing by diakinesis and tetrad formation. These changes point to a certain independence of organelles from nuclear control during meiosis. The events are also evaluated in relation to a cytoplasmic clearing mechanism, which may occur in preparation for the changeover from sporophytic to gametophytic control and the development of gametes.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Bird J,Porter EK,Dickinson HGsubject
Has Abstractpub_date
1983-01-01 00:00:00pages
27-42eissn
0021-9533issn
1477-9137journal_volume
59pub_type
杂志文章abstract：:Diversity of cell lineages within glandular organs is generated postnatally by differentiation of committed progenitor cells. Fundamental regulatory aspects of this process are not understood. The mouse submandibular salivary gland (SSG) served as model to assess the role of epidermal growth factor (EGF) receptor sign...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1995-06-01 00:00:00
abstract：:Intracellular signal transduction occurs through cascades of reactions involving dozens of proteins that transmit signals from the cell surface, through a crowded cellular environment filled with organelles and a filamentous cytoskeleton, to specific targets. Numerous signaling molecules are immobilized or transiently...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01122
更新日期：2004-06-01 00:00:00
abstract：:We have examined the pattern of expression of four different matrix metalloproteinases (MMPs), collagenase, stromelysin, 92 kD gelatinase, and 72 kD gelatinase, by primary and passaged cultures of rabbit corneal fibroblasts. Primary cultures of this cell type have previously been shown to reproduce the normal tissue r...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1990-10-01 00:00:00
abstract：:The Na(+)/H(+) exchanger NHE1 is involved in intracellular pH homeostasis and cell volume regulation and accumulates with actin in the lamellipodia of fibroblasts. In order to determine the role of NHE1 following epithelial transformation and the acquisition of motile and invasive properties, we studied NHE1 expressio...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2000-10-01 00:00:00
abstract：:Cell migration is a complex process requiring density and rigidity sensing of the microenvironment to adapt cell migratory speed through focal adhesion and actin cytoskeleton regulation. ICAP-1 (also known as ITGB1BP1), a β1 integrin partner, is essential for ensuring integrin activation cycle and focal adhesion forma...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.200139
更新日期：2017-02-01 00:00:00
abstract：:Serial sections of mitotic spindles of the marine cryptophycean alga, Cryptomonas, were analysed to determine what types of microtubules they contained and which of these microtubules came close enough to each other (50 nm or less) for the commonly described crossbridging to be possible. Interpolar microtubules were r...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1978-06-01 00:00:00
abstract：:The extracellular matrix (ECM) regulates cell behavior by influencing cell proliferation, survival, shape, migration and differentiation. Far from being a static structure, the ECM is constantly undergoing remodeling--i.e. assembly and degradation--particularly during the normal processes of development, differentiati...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.006064
更新日期：2008-02-01 00:00:00
abstract：:The main pathology of cystic fibrosis results from obstruction of ducts in several organs by mucous secretions. The cause of this obstruction remains unclear. We have examined expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and of the major pancreatic mucin, MUC1, in primary pancreatic duc...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1993-06-01 00:00:00
abstract：:The median cell cycle of synchronized NHIK3025 cells grown in Eagle's MEM with 10% foetal calf serum was 23.6 h, compared to 18 h observed earlier in Puck's E2a medium with 30% serum (20% human and 10% horse). This difference is due to prolongation of both G1 and G2 in the MEM type medium. Testosterone and 4-androsten...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1981-04-01 00:00:00
abstract：:The iron-storage protein ferritin was found to be associated with highly purified coated vesicles (CV) from chicken liver. Chicken liver ferritin was morphologically similar to ferritin from horse spleen and could be isolated using a specific anti-ferritin monoclonal antibody. This antibody recognized a 240 X 10(3) Mr...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1989-02-01 00:00:00
abstract：:The dipeptide glycyl-l-phenylalanine 2-naphthylamide (GPN) is widely used to perturb lysosomes because its cleavage by the lysosomal enzyme cathepsin C is proposed to rupture lysosomal membranes. We show that GPN evokes a sustained increase in lysosomal pH (pHly), and transient increases in cytosolic pH (pHcyt) and Ca...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.223883
更新日期：2019-02-01 00:00:00
abstract：:Targeting of the NG2 proteoglycan to cellular retraction fibers was studied by expressing mutant NG2 molecules lacking specific structural elements of the proteoglycan. Both the cytoplasmic domain and the chondroitin sulfate chain of NG2 appear to have roles in sorting NG2 to subcellular microdomains destined to becom...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-06-01 00:00:00
abstract：:Rapid endocytosis of lipoprotein receptors involves NPxY signals contained in their cytoplasmic tails. Several proteins, including ARH and Dab2, can bind these sequences, but their importance for endocytosis may vary in different cell types. The lipoprotein receptor megalin is expressed in the visceral endoderm (VE), ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.02650
更新日期：2005-11-15 00:00:00
abstract：:The number of human genetic disorders shown to be due to defects in membrane trafficking has greatly increased during the past five years. Defects have been identified in components involved in sorting of cargo into transport carriers, vesicle budding and scission, movement of vesicles along cytoskeletal tracks, as we...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.03303
更新日期：2006-12-15 00:00:00
abstract：:While the basic cellular contributions to bone differentiation and mineralization are widely accepted, the regulation of these processes at the intracellular level remains inadequately understood. Our laboratory recently identified annexin 2 as a protein involved in osteoblastic mineralization. Annexin 2 was overexpre...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00909
更新日期：2004-01-26 00:00:00
abstract：:Endothelial permeability induced by thrombin and histamine is accompanied by actin stress fibre assembly and intercellular gap formation. Here, we investigate the roles of the Rho family GTPases Rho1, Rac1 and Cdc42 in regulating endothelial barrier function, and correlate this with their effects on F-actin organizati...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-04-01 00:00:00
abstract：:The events that accompany sporogenesis in the apogamous fern Dryopteris borreri parallel those seen in sexually reproducing ferns. Organelles dedifferentiate and redifferentiate, and form a discrete band across the equator of dyads; nuclear vacuoles and lipid spherosomes appear during prophase, and the major part of t...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1983-09-01 00:00:00
abstract：:The molecular mechanisms regulating skeletal muscle regeneration and differentiation are not well understood. We analyzed the expression of connexins (Cxs) 40, 43 and 45 in normal and regenerating tibialis anterior muscle and in primary cultures of differentiating myoblasts in adult and newborn mice, respectively. Cxs...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01553
更新日期：2005-01-01 00:00:00
abstract：:Immediately following embryonic cleavage, the cells of Astrephomene have four equal-sized basal bodies, two of which are connected by a striated distal fibre and two striated proximal fibres. The four microtubular rootlets, which alternate between having 3/1 and 2 members, are arranged cruciately. The two basal bodies...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1983-09-01 00:00:00
abstract：:During mitosis, the cell sequentially constructs two microtubule-based spindles to ensure faithful segregation of chromosomes. A bipolar spindle first pulls apart the sister chromatids, then a central spindle further separates them away. Although the assembly of the first spindle is well described, the assembly of the...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.231118
更新日期：2019-05-16 00:00:00
abstract：:The relative sensitivities of the motors for mitotic chromosome movements and saltatory motion were compared using a nonhydrolyzable analog of ATP, AMP-PNP. K+AMP-PNP was microinjected into PtKl cells at the time of nuclear envelope disassembly or at anaphase onset. To produce a dose-response curve for the effect of A...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1989-11-01 00:00:00
abstract：:Truncated Bid (tBid) releases cytochrome c from mitochondria by inducing Bak (and Bax) pore formation in the outer membrane. An important issue is whether a second tBid action, independent of Bak and Bax, is also required to enhance cytochrome c mobility in the intermembrane spaces. To investigate this, we developed a...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.021303
更新日期：2008-03-01 00:00:00
abstract：:The identification and characterization of scaffold and targeting proteins of the ERK/MAP kinase pathway is important to understand the function and intracellular organization of this pathway. The F-actin binding protein leukocyte-specific protein 1 (LSP1) binds to PKCbetaI and expression of B-LSP1, an LSP1 truncate c...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00955
更新日期：2004-04-15 00:00:00
abstract：:Cell-free extracts of Xenopus eggs support nuclear assembly and DNA replication in vitro. Extracts supplemented with the protein phosphatase inhibitor microcystin-LR displayed various inhibitory effects at different concentrations of the toxin. In the presence of cycloheximide, additions of microcystin did not induce ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:Embryonal rhabdomyosarcomas (ERMSs) show elevated levels of PAX7, a transcription factor that marks quiescent adult muscle stem (satellite) cells and is important for proliferation and survival of activated satellite cells and whose timely repression is required for myogenic differentiation. However, the mechanism of ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.136259
更新日期：2014-04-15 00:00:00
abstract：:Dictyostelium discoideum secretes a number of lysosomal enzymes during axenic growth and upon suspension in a low ionic strength, non-nutrient buffer (standard secretion conditions). These secretory characteristics have allowed us to identify 74 lysosomal enzyme secretory mutants generated by N-methyl-N'-nitro-N-nitro...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1990-07-01 00:00:00
abstract：:Transcriptional activation of the major histocompatibility complex (MHC) by IFNgamma is a key step in cell-mediated immunity. At an early stage of IFNgamma induction, chromatin carrying the entire MHC locus loops out from the chromosome 6 territory. We show here that JAK/STAT signalling triggers this higher-order chro...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.012328
更新日期：2007-09-15 00:00:00
abstract：:The complex formed by Rad9, Rad1 and Hus1 (9-1-1) protects against genomic instability by activating DNA damage checkpoint and DNA damage repair pathways, mainly in response to replication fork collapse and UV lesions. Here we compare the role of Rad9A (also known as Rad9) with the human paralogue Rad9B. Unlike Rad9A,...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.091124
更新日期：2012-03-01 00:00:00
abstract：:Kit ligand (Kitl), the ligand for the Kit receptor tyrosine kinase, plays important roles in hematopoiesis, gametogenesis and melanogenesis. Kitl is synthesized as a membrane-anchored precursor that can be processed to produce the soluble growth factor. Here, we evaluated the role of ADAM (a disintegrin and metallopro...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.03403
更新日期：2007-03-15 00:00:00
abstract：:It is generally accepted that global translation varies during the cell cycle and is low during mitosis. However, addressing this issue is challenging because it involves cell synchronization, which evokes stress responses that, in turn, affect translation rates. Here, we have used two approaches to measure global tra...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.220327
更新日期：2018-09-03 00:00:00
