pinecone/core-2020-05-10-deduplication huggingface dataset:
The LIN-29 Transcription Factor Is Required for Proper Morphogenesis of theCaenorhabditis elegansMale Tail

AbstractTheCaenorhabditis elegansgenelin-29encodes a zinc-finger transcription factor that is required for hypodermal cell terminal differentiation and proper vulva morphogenesis. Here we demonstrate thatlin-29is also required in males for productive mating. We show thatlin-29males can perform the early mating behaviors including response to hermaphrodite contact and vulva location, but they do not perform the subsequent steps of vulva attachment via spicule insertion and sperm transfer. Consistent with this observation, we found thatlin-29mutant spicules are on average 43% shorter than wild-type spicules while other male mating structures appear unaltered. Inlin-29mutants, spicule development goes awry after the generation of spicule cells, when spicule morphogenesis occurs in wild-type males. We show that LIN-29 accumulates in many cells of the wild-type male tail, including those that form the spicules. We demonstrate, through analysis of genetic mosaics, that the formation of wild-type-length spicules requireslin-29(+)in the AB.p lineage, the lineage that gives rise to the spicules and other male copulatory structures. Our mosaic analysis also reveals a role forlin-29(+)in the P1 lineage, which mainly produces sex muscles, cells of the somatic gonad, and body wall muscles
Patterning an Epidermal Field:DrosophilaLozenge, a Member of the AML-1/Runt Family of Transcription Factors, Specifies Olfactory Sense Organ Type in a Dose-Dependent Manner

AbstractSense organ development in theDrosophilaantenna is initiated by the selection of a founder cell from an epidermal field. This cell is believed to recruit neighbours to form a cluster of cells which then divides to form a mature sense organ. In most systems so far studied, sense organ type appears to be specified by the identity of proneural genes involved in the selection of precursors. The regulation of proneural gene expression is, in turn, controlled by the prepatterning genes. In the antenna, the only known proneural function is that ofatonal,a gene that is involved in founder cell choice in the sensilla coeloconica, and no prepatterning gene function has yet been demonstrated. In this study, we show that Lozenge, a protein which possesses a DNA binding domain similar to that of the Acute myeloid leukemia-1/Runt transcription factors, functions in a dose-dependent manner to specify the fate of the other two types of sense organs in the antenna: the sensilla trichoidea and the sensilla basiconica. Our results suggest that Lozenge may act on the epidermal field, resulting in founder cells acquiring specific cell fates that lead to the development of an appropriate type of sense organ
Activin-Induced Factors MaintaingoosecoidTranscription through a Paired Homeodomain Binding Site

AbstractPrevious studies in bothXenopusand zebrafish have shown thatgoosecoidis one of the first genes to be transcribed at the onset of gastrulation.Goosecoidtranscription still initiates when embryos are treated with protein synthesis inhibitors, indicating that it is mediated by preexisting factors and suggesting thatgoosecoidtranscription is immediately downstream of the maternal mesoderm-inducing signal. However,goosecoidtranscription continues long after this maternal signal has ceased to be active, indicating that there are mechanisms to maintain activin-induced transcription. Our study has focused on understanding the factors required to maintain this transcription. We have defined an element within the zebrafishgoosecoidpromoter that is sufficient for activin inducibility in bothXenopusand zebrafish embryos. This element, the goosecoid activin element, interacts with two developmentally regulated proteins fromXenopusembryos. A maternal protein interacts through cleavage stages until the midblastula transition, and a second protein binds from the onset of gastrulation. The second protein is zygotically expressed, and its binding is required for activin inducibility in our assay system. We suggest that the zygotic protein we have identified is a good candidate to be involved in the maintenance ofgoosecoidtranscription. Furthermore, this zygotic protein is likely to contain a paired class homeodomain since a consensus binding site for such proteins is present within the goosecoid activin element and is essential for its function
A Delayed Role for Nitric Oxide-Sensitive Guanylate Cyclases in a Migratory Population of Embryonic Neurons

AbstractNeuronal differentiation requires a coordinated intracellular response to diverse extracellular stimuli, but the role of specific signaling mechanisms in regulating this process is still poorly understood. Soluble guanylate cyclases (sGCs), which can be stimulated by diffusible free radical gasses such as nitric oxide (NO) and carbon monoxide (CO) to produce the intracellular messenger cGMP, have recently been found to be expressed within a variety of embryonic neurons and implicated in the control of both neuronal motility and differentiation. Using the enteric nervous system (ENS) of the moth,Manduca sexta,we examined the role of NO and NO-sensitive sGCs during the migration and differentiation of an identified set of migratory neurons (the EP cells). Shortly after the onset of their migration, a subset of EP cells began to express NO-sensitive sGC activity (visualized with an anti-cGMP antiserum). Unlike many neurons in the central nervous system, the expression of sGC activity in the EP cells was not transient but persisted throughout subsequent periods of axon elongation and terminal branch formation on the gut musculature. In contrast, nitric oxide synthase activity (visualized using NADPH–diaphorase histochemistry) was undetectable in the vicinity of the EP cells until the period of synapse formation. Manipulations designed to alter sGC and NOS activity in anin vivoembryonic culture preparation had no discernible effect on either the migration or axonal outgrowth of the EP cells. In contrast, inhibition of both of these enzymes resulted in a significant reduction in terminal synaptic branch formation within the postmigratory neurons. These results indicate that while NO-sensitive sGC activity is expressed precociously within the EP cells during their initial migratory dispersal, a role for this signaling pathway can only be demonstrated well after migration is complete, coincident with the formation of mature synaptic connections
Suppressor of Hairless ActivatesBrachyuryExpression in theCionaEmbryo

AbstractTheCiona Brachyurygene (Ci-Bra) is regulated, in part, by a 434-bp enhancer that mediates restricted expression in the notochord. Here we present evidence that aCionaSuppressor of Hairless {Ci-Su(H)} protein functions as an activator of this enhancer. Point mutations that reduce the binding of a GST/Ci-Su(H) fusion proteinin vitrodiminish the expression of mutagenizedCi-Bra/lacZtransgenes in electroporated embryos. Overexpression of a Ci-Su(H) fusion protein containing theDrosophilaHairy repression domain interferes with notochord differentiation, producing mutant tadpoles with shortened tails. Expression of a constitutively activated Xotch receptor in the notochord, endoderm, and CNS also alters tail morphogenesis. These results suggest that a Notch–Su(H) pathway might participate in notochord differentiation inCiona
Inhibition of Small G Proteins byClostridium sordelliiLethal Toxin Activates cdc2 and MAP kinase inXenopusOocytes

AbstractThe lethal toxin (LT) fromClostridium sordelliiis a glucosyltransferase that modifies and inhibits small G proteins of the Ras family, Ras and Rap, as well as Rac proteins. LT induces cdc2 kinase activation and germinal vesicle breakdown (GVBD) when microinjected into full-grownXenopusoocytes. Toxin B fromClostridium difficile,that glucosylates and inactivates Rac proteins, does not induce cdc2 activation, indicating that proteins of the Ras family, Ras and/or Rap, negatively regulate cdc2 kinase activation inXenopusoocyte. In oocyte extracts, LT catalyzes the incorporation of [14C]glucose into a group of proteins of 23 kDa and into one protein of 27 kDa. The 23-kDa proteins are recognized by anti-Rap1 and anti-Rap2 antibodies, whereas the 27-kDa protein is recognized by several anti-Ras antibodies and probably corresponds to K-Ras. Microinjection of LT into oocytes together with UDP-[14C]glucose results in a glucosylation pattern similar to thein vitroglucosylation, indicating that the 23- and 27-kDa proteins arein vivosubstrates of LT.In vivotime-course analysis reveals that the 27-kDa protein glucosylation is completed within 2 h, well before cdc2 kinase activation, whereas the 23-kDa proteins are partially glucosylated at GVBD. This observation suggests that the 27-kDa Ras protein could be thein vivotarget of LT allowing cdc2 kinase activation. Interestingly, inactivation of Ras proteins does not prevent the phosphorylation of c-Raf1 and the activation of MAP kinase that occurs normally around GVBD
Partial Characterization of the Calcium-Releasing Activity of Porcine Sperm Cytosolic Extracts

AbstractInjection of sperm cytosolic extracts into mammalian eggs has been shown to elicit intracellular calcium ([Ca2+]i) oscillations that are similar in amplitude, duration, and frequency to those observed following fertilization. Thus, to characterize the Ca2+-release component(s) in porcine sperm cytosolic extracts, a combination of fractionation techniques was used. The fraction with Ca2+releasing activity was precipitated by 50% saturating solutions of ammonium sulfate and Western blot analysis showed that the pellets contained glucosamine-6-phosphate deaminase (gpd)/oscillin, a protein which has been suggested to be the sperm's active component. Single and double isoelectrofocusing (IEF) of porcine sperm extracts generated fractions with different Ca2+-releasing activities. Fractions with maximal Ca2+-releasing activity did not contain material that was immunoreactive with antibodies against gpd/oscillin; adjacent fractions containing gpd/oscillin had no Ca2+-releasing activity. These findings were confirmed by IEF coupled with size exclusion chromatography on Superose 12 and with hydroxyapatite chromatography. These procedures predict an isoelectric point of our active component of 6.5–7.0 and a relative molecular weight ranging from 29 to 68 kDa. In summary, the data show that the Ca2+release-inducing component(s) of porcine sperm extracts can be fractionated and that gpd/oscillin is not the pig sperm Ca2+oscillogen
Expression of Inositol 1,4,5-Trisphosphate Receptors in Mouse Oocytes and Early Embryos: The Type I Isoform Is Upregulated in Oocytes and Downregulated after Fertilization

AbstractA fertilization-induced increase in intracellular Ca2+is responsible for initiating all of the events of egg activation. In mammals, the Ca2+increase takes the form of a series of Ca2+oscillations showing complex temporal and spatial properties. To understand the nature of these changes, we have investigated the expression patterns of the three isoforms of the inositol trisphosphate receptor (InsP3R) during oocyte maturation and preimplantation development. We find that mouse oocytes express mRNAs for all three InsP3R subtypes. Semiquantitative ratio reverse-transcriptase polymerase chain reaction shows that the type II isoform is the predominant message in mature oocytes, representing 67% of the InsP3R mRNA. In contrast, protein analysis reveals that the type I isoform accounts for all of the detectable InsP3R protein, despite representing only 20% of the InsP3R mRNA. The levels of InsP3R protein were examined to determine whether they correlated with the Ca2+signaling events surrounding the fertilization process. Type I InsP3R protein increased during oocyte maturation and, in addition, within 8 h of fertilization underwent a dramatic decrease. During development to the blastocyst the level of type I InsP3R protein did not return to prefertilization levels and types II and III remained below our detection limit. The decrease in InsP3R protein after fertilization was found to correlate with a decrease in the sensitivity of InsP3-induced Ca2+release. These studies show that the expression of InsP3R mRNA is developmentally regulated, that Ca2+signaling at fertilization is mediated exclusively through the type I InsP3R, and that the InsP3R is downregulated after fertilization
erbBGenes in the Mouse Uterus: Cell-Specific Signaling by Epidermal Growth Factor (EGF) Family of Growth Factors during Implantation

AbstractWe previously described spatiotemporal expression of various epidermal growth factor (EGF)-like ligands and receptor subtypes, ErbB1 and ErbB2, during the peri-implantation period. To better understand the roles of these ligands and their possible signaling schemes in implantation, it is important to define the status of all the ligands and receptor subtypes in the uterus/embryo. No information is available about uterine and embryonic status of ErbB3 or ErbB4 during implantation. We cloned mouseerbB3anderbB4cDNAs and examined their expression and bioactivity in the peri-implantation uterus (days 1–8). TwoerbB3(cytoplasmic and extracellular) and threeerbB4(two cytoplasmic and one extracellular) clones were generated. Both forms of theerbB3clone showed similar transcript profiles, while different transcript profiles were obtained witherbB4clones. The steady-state levels oferbB3anderbB4mRNAs in whole uterine poly(A)+RNA samples showed little changes during the peri-implantation period, while their unique cell-specific accumulation was noted.erbB3is predominantly expressed in the epithelial cells, although decidual and embryonic cells also accumulate this mRNA. In contrast, theerbB4mRNA is primarily expressed in the submyometrial stroma and myometrial connective tissues during this period. Additionally, the extracellular form of theerbB4clone detected signals in a subpopulation of stromal cells. Autophosphorylation and immunoprecipitation studies provided evidence that uterine ErbB3 and ErbB4 are biologically active. This study provides a comprehensive analysis of possible ligand–receptor signaling schemes for EGF-like ligands in implantation
Expression of Adrenomedullin, a Hypotensive Peptide, in the Trophoblast Giant Cells at the Embryo Implantation Site in Mouse

AbstractAdrenomedullin (AM) is a newly discovered hypotensive peptide which is believed to play an important role for blood pressure control in the adult. Although it has been well established that a major production site of AM is vascular endothelial cells, we now show that AM is most highly expressed in trophoblast giant cells, which are derived from the conceptus and are directly in contact with maternal tissues at the implantation site. Northern blot andin situhybridization analyses show that the AM mRNA begins to be detected just after implantation and its level peaks at 9.5 days postconception (d.p.c.) in those cells. Expression then falls dramatically after 10.5 d.p.c., coincident with the completion of the mature chorioallantoic placenta. Immunohistochemical analyses show that the AM peptide is secreted from the trophoblast giant cells into the surrounding tissues, i.e., embryo, decidua, and maternal circulation. In contrast, the expression of an AM receptor was not detected by Northern blot analyses in either embryo or trophoblast giant cells at 7 d.p.c., when the AM gene is most highly expressed in the trophoblast giant cells. This suggests that the AM produced and secreted from the embryo's trophoblast giant cells acts on the maternal tissues rather than on the embryonic tissues. Based on these results, we propose that the high production of AM may be the mechanism by which the embryos survive at the early postimplantation period by pooling maternal blood in the implantation site in order to secure nutrition and oxygen before the establishment of efficient embryo-maternal circulation through the mature placenta
Activation of the Jak–STAT-Signaling Pathway in Embryonic Lens Cells

AbstractPrevious studies showed that lens epithelial cells proliferate rapidly in the embryo and that a lens mitogen, most likely derived from the blood, is present in the anterior chamber of the embryonic eye (Hyatt, G. A., and Beebe, D. C.,Development117, 701–709, 1993). Messenger RNAs for several growth factor receptors have been identified in embryonic lens epithelial cells. We tested several growth factors that are ligands for these receptors for their ability to maintain lens cell proliferation. Embryo serum, PDGF, GM-CSF, and G-CSF maintained lens cell proliferation, but NGF, VEGF, and HGF did not. This and a previous study (Potts, J. D., Harocopos, G. J., and Beebe, D. C.,Curr. Eye Res.12, 759–763, 1993) detected members of the Janus kinase family (Jaks) in the developing lens. Because Jaks are central players in the Jak-STAT-signaling pathway, we identified STAT proteins in the lens and tested whether they were phosphorylated in response to mitogens. STAT1 and STAT3, but not STAT 5 were detected in chicken embryo lens epithelial cells. Only STAT3 was found in terminally differentiated lens fiber cells. STAT1 and STAT3 were phosphorylated in lens cells analyzed immediately after removal from the embryo and when lens epithelial explants were treated with embryo serum, PDGF, or GM-CSF, but not with NGF. Chicken embryo vitreous humor or IGF-1, factors that stimulate lens cell differentiation, but not proliferation, did not cause STAT phosphorylation. When lens epithelial cells were cultured for 4 h in unsupplemented medium, STAT1 and STAT3 declined to nearly undetectable levels. Treatment with PDGF or embryo serum for an additional 15 min restored STAT1 and -3 levels. This recovery was blocked by cycloheximide, but not actinomycin D, suggesting that STAT levels are regulated at the level of translation. STAT levels were maintained in epithelial explants by lens mitogens, but not by factors that stimulated lens fiber differentiation. Both factors that stimulated lens cell proliferation and those that caused fiber differentiation protected cultured lens epithelial cells from apoptosis. These data suggest that the factor(s) responsible for lens cell proliferationin vivoactivates the Jak–STAT-signaling pathway. They also indicate that growth factors maintain STAT protein levels in lens epithelial cells by promoting the translation of STAT mRNA, an aspect of STAT regulation that has not been described previously. Signaling by most of the growth factors and cytokines known to activate the Jak-STAT pathway has been disrupted in mice by mutation or targeted deletion. Consideration of the phenotypes of these mice suggests that the factor responsible for lens cell proliferationin vivomay be a growth factor or cytokine that has not yet been described
Evolutionary Alteration in Anterior Patterning:otx2Expression in the Direct Developing FrogEleutherodactylus coqui

AbstractThe homeobox geneotx2is a key regulator for specifying the rostral part of the vertebrate head. InXenopus, otx2directly controls the differentiation of the cement gland, the anterior-most organ formed in the tadpole. Since embryos of a direct developing frog,Eleutherodactylus coqui,lack a cement gland, we are interested in whether altered expression of theotx2gene is involved in this evolutionary change. We have cloned theE. coquihomologue ofotx2, Ecotx2.The homeodomain of theEcotx2protein is identical to the mouse and zebrafish Otx2 proteins and differs by a single amino acid from theXenopusOtx2 protein. Study of the spatiotemporal expression pattern shows thatEcotx2RNA is progressively restricted to the anterior region of the embryo during gastrulation and becomes further restricted to the future forebrain and midbrain during neural development. InXenopus,in addition to the conserved expression in the anterior neuroectoderm, the expression in ectoderm expands more anteriorly to the cement gland primordium. This anterior expansion ofotx2expression is not found inE. coqui,correlating with the loss of a cement gland. When misexpressed inXenopus laevisectoderm,Ecotx2can activate expression of the cement-gland-specific genesXCGandXAG1,indicating that the function of activating the pathway of cement gland formation is retained by the Ecotx2 protein. Our results indicate that there are modifications in the pathway of cement gland formation, upstream ofotx2expression, in the development ofE. coqui
Tinman Function Is Essential for Vertebrate Heart Development: Elimination of Cardiac Differentiation by Dominant Inhibitory Mutants of thetinman-Related Genes,XNkx2-3andXNkx2-5

AbstractInDrosophila,thetinmangene is absolutely required for development of the dorsal vessel, the insect equivalent of the heart. In vertebrates, thetinmangene is represented by a small family oftinman-related sequences, some of which are expressed during embryonic heart development. At present however, the precise importance of this gene family for vertebrate heart development is unclear. Using theXenopusembryo, we have employed a dominant inhibitory strategy to interfere with the function of the endogenoustinman-related genes. In these experiments, suppression oftinmangene function can result in the complete elimination of myocardial gene expression and the absence of cell movements associated with embryonic heart development. This inhibition can be rescued by expression of wild-typetinmansequences. These experiments indicate that function oftinmanfamily genes is essential for development of the vertebrate heart
Neural Crest Cell Dynamics Revealed by Time-Lapse Video Microscopy of Whole Embryo Chick Explant Cultures

AbstractDiI-labeled cranial neural crest cells were followed in whole embryo chick explant cultures using time-lapse confocal microscopy. Neural crest cells emerged along the dorsal midline of all rhombomeres. There was a small amount of mixing of neural crest cells between adjoining rhombomeres as cells emerged from the dorsal midline; this mixing persisted during their migration out of the neural tube. Neural crest cell-free zones lateral to rhombomere 3 (r3) and r5 resulted from neural crest cells migrating in either rostral or caudal directions to join other neural crest cells exiting adjacent to r2, r4, or r6. Neural crest cells migrated in a wide variety of individual cell behaviors, ranging from rapid unidirectional motion to stationary and even backward movement (toward the neural tube). Neural crest cells also migrated collectively, extending filipodia to form chain-like cell arrangements. In the midbrain and r1 region, many chains stretched from the dorsal midline to just beyond the lateral extent of the neural tube. In the r7 region, cells linked together and stretched laterally from the neural tube to other neural crest cells migrating into the third branchial arch. The unpredictable cell trajectories, the mixing of neural crest cells between adjoining rhombomeres, and the diversity in cell migration behavior within any particular region imply that no single mechanism guides migration. The regional differences in cell migration characteristics suggests that influential factors may vary spatially along the rostrocaudal axis in the head