In the recent past, we demonstrated that a great deal is going on in the salivary glands of Drosophila in the interval after they release their glycoprotein-rich secretory glue during pupariation. The early-to-mid prepupal salivary glands undergo extensive endocytosis with widespread vacuolation of the cytoplasm followed by massive apocrine secretion. Here, we describe additional novel properties of these endosomes. The use of vital pH-sensitive probes provided confirmatory evidence that these endosomes have acidic contents and that there are two types of endocytosis seen in the prepupal glands. The salivary glands simultaneously generate mildly acidic, small, basally-derived endosomes and strongly acidic, large and apical endosomes. Staining of the large vacuoles with vital acidic probes is possible only after there is ambipolar fusion of both basal and apical endosomes, since only basally-derived endosomes can bring fluorescent probes into the vesicular system. We obtained multiple lines of evidence that the small basally-derived endosomes are chiefly involved in the uptake of dietary Fe3+ iron. The fusion of basal endosomes with the larger and strongly acidic apical endosomes appears to facilitate optimal conditions for ferrireductase activity inside the vacuoles to release metabolic Fe2+ iron. While iron was not detectable directly due to limited staining sensitivity, we found increasing fluorescence of the glutathione-sensitive probe CellTracker Blue CMAC in large vacuoles, which appeared to depend on the amount of iron released by ferrireductase. Moreover, heterologous fluorescently-labeled mammalian iron-bound transferrin is actively taken up, providing direct evidence for active iron uptake by basal endocytosis. In addition, we serendipitously found that small (basal) endosomes were uniquely recognized by PNA lectin, whereas large (apical) vacuoles bound DBA lectin.

• Klíčová slova
• basal and apical endosomes, iron reallocation, metamorphosis, prepupal period, salivary glands, transferrin uptake,
• MeSH
• Drosophila melanogaster anatomie a histologie   cytologie   MeSH
• endozomy metabolismus   MeSH
• fluorescenční barviva chemie   MeSH
• kukla cytologie   MeSH
• slinné žlázy cytologie   metabolismus   MeSH
• sloučeniny železa metabolismus   MeSH
• vakuoly metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fluorescenční barviva MeSH
• sloučeniny železa MeSH

The Drosophila salivary glands (SGs) were well known for the puffing patterns of their polytene chromosomes and so became a tissue of choice to study sequential gene activation by the steroid hormone ecdysone. One well-documented function of these glands is to produce a secretory glue, which is released during pupariation to fix the freshly formed puparia to the substrate. Over the past two decades SGs have been used to address specific aspects of developmentally-regulated programmed cell death (PCD) as it was thought that they are doomed for histolysis and after pupariation are just awaiting their fate. More recently, however, we have shown that for the first 3-4 h after pupariation SGs undergo tremendous endocytosis and vacuolation followed by vacuole neutralization and membrane consolidation. Furthermore, from 8 to 10 h after puparium formation (APF) SGs display massive apocrine secretion of a diverse set of cellular proteins. Here, we show that during the period from 11 to 12 h APF, the prepupal glands are very active in calcium oxalate (CaOx) extrusion that resembles renal or nephridial excretory activity. We provide genetic evidence that Prestin, a Drosophila homologue of the mammalian electrogenic anion exchange carrier SLC26A5, is responsible for the instantaneous production of CaOx by the late prepupal SGs. Its positive regulation by the protein kinases encoded by fray and wnk lead to increased production of CaOx. The formation of CaOx appears to be dependent on the cooperation between Prestin and the vATPase complex as treatment with bafilomycin A1 or concanamycin A abolishes the production of detectable CaOx. These data demonstrate that prepupal SGs remain fully viable, physiologically active and engaged in various cellular activities at least until early pupal period, that is, until moments prior to the execution of PCD.

• Klíčová slova
• Drosophila, anion extrusion, calcium oxalate, fruitfly salivary glands, labial nephridia, prestin,
• MeSH
• aktivní transport fyziologie   MeSH
• Drosophila melanogaster MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny Drosophily genetika   metabolismus   MeSH
• proteiny přenášející anionty biosyntéza   genetika   metabolismus   MeSH
• slinné žlázy metabolismus   MeSH
• šťavelan vápenatý metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fray protein, Drosophila MeSH Prohlížeč
• prestin protein, Drosophila MeSH Prohlížeč
• protein-serin-threoninkinasy MeSH
• proteiny Drosophily MeSH
• proteiny přenášející anionty MeSH
• šťavelan vápenatý MeSH

Cells belonging to the germ lineage segregate physically and molecularly from their somatic neighbors during embryogenesis. While germ line-specific chromatin modifications have been identified at later stages in the Caenorhabditis elegans nematode, none have been found in the single P4 germ line founder cell that arises at the beginning of gastrulation. Using light and electron microscopy, we now report that the chromatin organization in the germ line founder cell of the early C. elegans embryo is distinct from that in the neighboring somatic cells. This unique organization is characterized by a greater chromatin compaction and an expansion of the interchromatin compartment. The ultrastructure of individual chromatin domains does not differ between germ line and somatic cells, pointing to a specific organization mainly at the level of the whole nucleus. We show that this higher order reorganization of chromatin is not a consequence of the P4 nucleus being smaller than somatic nuclei or having initiated mitosis. Imaging of living embryos expressing fluorescent markers for both chromatin and P granules revealed that the appearance of a distinct chromatin organization in the P4 cell occurs approximately 10 min after its birth and coincides with the aggregation of P granules around the nucleus, suggesting a possible link between these two events. The higher order reorganization of chromatin that is reported here occurs during the establishment of definitive germ cell identity. The changes we have observed could therefore be a prerequisite for the programming of chromatin totipotency.

• Klíčová slova
• Caenorhabditis elegans, chromatin, germ line, interchromatin compartment, live cell microscopy,
• MeSH
• Caenorhabditis elegans embryologie   ultrastruktura   MeSH
• chromatin metabolismus   ultrastruktura   MeSH
• embryo nesavčí metabolismus   ultrastruktura   MeSH
• restrukturace chromatinu fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• chromatin MeSH

Fibroblast growth factor (FGF) signalling appears essential for the regulation of limb development, but a full complexity of this regulation remains unclear. Here, we addressed the effect of three different chemical inhibitors of FGF receptor tyrosine kinases (FGFR) on growth and patterning of the chicken wings. The inhibitor PD173074 caused shorter and thinner wing when using lower concentration. Microinjection of higher PD173074 concentrations (25 and 50 mmol/L) into the wing bud at stage 20 resulted in the development of small wing rudiment or the total absence of the wing. Skeletal analysis revealed the absence of the radius but not ulna, deformation of metacarpal bones and/or a reduction of digits. Treatment with PD161570 resembled the effects of PD173074. NF449 induced shortening and deformation of the developing wing with reduced autopodium. These malformed embryos mostly died at the stage HH25-29. PD173074 reduced chondrogenesis also in the limb micromass cultures together with early inhibition of cartilaginous nodule formation, evidenced by lack of sulphated proteoglycan and peanut agglutinin expression. The effect of FGFR inhibition on limb development observed here was unlikely mediated by excessive cell death as none of the inhibitors caused massive apoptosis at low concentrations. More probably, FGFR inhibition decreased both the proliferation and adhesion of mesenchymal chondroprogenitors. We conclude that FGFR signalling contributes to the regulation of the anterior-posterior patterning of zeugopod during chicken limb development.

• Klíčová slova
• chondrogenesis, fibroblast growth factor receptor, mesenchymal condensation, zeugopod,
• MeSH
• benzensulfonáty aplikace a dávkování   farmakologie   MeSH
• inhibitory proteinkinas aplikace a dávkování   farmakologie   MeSH
• křídla zvířecí účinky léků   embryologie   MeSH
• kuřecí embryo MeSH
• pyrimidiny aplikace a dávkování   farmakologie   MeSH
• receptory fibroblastových růstových faktorů antagonisté a inhibitory   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• zvířata MeSH
• Check Tag
• kuřecí embryo MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 4,4,',4'',4'''-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis(benzene-1,3-disulfonate) MeSH Prohlížeč
• benzensulfonáty MeSH
• inhibitory proteinkinas MeSH
• PD 173074 MeSH Prohlížeč
• pyrimidiny MeSH
• receptory fibroblastových růstových faktorů MeSH

Apoptosis during tooth development appears dependent on the apoptotic executioner caspase-3, but not caspase-7. Instead, activated caspase-7 has been found in differentiated odontoblasts and ameloblasts, where it does not correlate with apoptosis. To further investigate these findings, the mouse incisor was used as a model. Analysis of caspase-7-deficient mice revealed a significant thinner layer of hard tissue in the adult incisor. Micro computed tomography scan confirmed this decrease in mineralized tissues. These data strongly suggest that caspase-7 might be directly involved in functional cell differentiation and regulation of the mineralization of dental matrices.

• MeSH
• ameloblasty cytologie   enzymologie   metabolismus   MeSH
• buněčná diferenciace * MeSH
• časové faktory MeSH
• imunohistochemie MeSH
• kaspasa 7 genetika   metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• odontoblasty cytologie   enzymologie   metabolismus   MeSH
• odontogeneze MeSH
• proliferace buněk MeSH
• rentgenová mikrotomografie MeSH
• řezáky embryologie   růst a vývoj   metabolismus   MeSH
• zubní sklovina embryologie   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kaspasa 7 MeSH

The transcription factor c-Myb is involved in the control of cell proliferation, survival and differentiation. As these processes accompany the morphogenesis of developing teeth, this work investigates the possible role of c-Myb during odontogenesis. Analysis of the expression of c-Myb in the monophyodont mouse was followed by similar analysis in a diphyodont species, the pig, which has a dentition more closely resembling that of the human. The distribution of c-Myb was correlated with the pattern of proliferation and apoptosis and the tooth phenotype of c-Myb mutant mice was also assessed. In the mouse, c-Myb expression was detected throughout prenatal development of the first molar tooth. Negative temporospatial correlation was found between c-Myb expression and apoptosis, while c-Myb expression positively correlated with proliferation. c-Myb-positive cells, however, were more abundant than the proliferating cell nuclear antigen positive cells, suggesting other roles of c-Myb in odontogenesis. In the minipig, in contrast to the mouse, there was an asymmetrical arrangement of c-Myb positive cells, with a higher presence on the labial side of the tooth germ and dental lamina. A cluster of negative cells was situated in the mesenchyme close to the tooth bud. At later stages, the number of positive cells decreased and these cells were situated in the upper part of the dental papilla in the areas of future cusp formation. The expression of c-Myb in both species was strong in the odontoblasts and ameloblasts at the stage of dentin and enamel production suggesting a possible novel role of c-Myb during tooth mineralization.

• MeSH
• alely MeSH
• ameloblasty cytologie   metabolismus   MeSH
• apoptóza MeSH
• dentice MeSH
• druhová specificita MeSH
• embryo savčí cytologie   embryologie   metabolismus   MeSH
• imunohistochemie MeSH
• klonování DNA MeSH
• koncové značení zlomů DNA in situ MeSH
• miniaturní prasata MeSH
• myši MeSH
• odontoblasty cytologie   metabolismus   MeSH
• odontogeneze * MeSH
• osteoklasty cytologie   metabolismus   MeSH
• prasata MeSH
• proliferace buněk MeSH
• proliferační antigen buněčného jádra metabolismus   MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• protoonkogenní proteiny c-myb genetika   metabolismus   MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zuby cytologie   embryologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Mybl2 protein, mouse MeSH Prohlížeč
• proliferační antigen buněčného jádra MeSH
• proteiny buněčného cyklu MeSH
• protoonkogenní proteiny c-myb MeSH
• trans-aktivátory MeSH

Four medial neurosecretory cells (MNC) and 4 lateral neurosecretory cells (LNC) in each brain hemisphere, and one pair of cells in each thoracic ganglion (TG) of Galleria larva react with antibodies against bombyxin and insulin. Material secreted from the MNC and LNC is released mainly in the corpora allata, and that from the TG through the ventral median nerves. Intrinsic secretory cells of the corpora cardiaca (CC) also contain bombyxin-like, but not insulin-like material. The immunoreactivities all disappear during molts and reappear with resumption of feeding. In the MNC and TG they reappear for less than a day, but in cells of the CC immunoreactivity reappears for the whole feeding period. Before pupation, the LNC become temporarily immunopositive towards the end of feeding period, and the MNC and TG during the wandering period, i.e. at the time of prothoracic gland stimulation. Immunoreactivity disappears during the pupal molt. In pupae it is present in the 4 pairs of MNC and 1-2 pairs of LNC 12-48 hr after ecdysis, and in cells of the CC from 12 hr after ecdysis until the end of the pupal instar. In adult, immunoreactivity is restricted to 2 pairs of the LNC and to CC cells.

• Publikační typ
• časopisecké články MeSH