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C Joly

Publications and source records attributed to C Joly.

At least 37 records · Page 2Linked to original sources
PubMed1994

Domains involved in the specificity of G protein activation in phospholipase C-coupled metabotropic glutamate receptors.

G protein-coupled glutamate receptors (mGluR) have recently been characterized. These receptors have seven putative transmembrane domains, but display no sequence homology with the large family of G protein-coupled receptors. They constitute therefore a new family of receptors. Whereas mGluR1 and mGluR5 activate phospholipase C (PLC), mGluR2, mGluR3, mGluR4 and mGluR6 inhibit adenylyl cyclase (AC) activity. The third putative intracellular loop, which determines the G protein specificity in many G protein-coupled receptors, is highly conserved among mGluRs, and may therefore not be involved in the specific recognition of G proteins in this receptor family. By constructing chimeric receptors between the AC-coupled mGluR3 and the PLC-coupled mGluR1c, we report here that both the C-terminal end of the second intracellular loop and the segment located downstream of the seventh transmembrane domain are necessary for the specific activation of PLC by mGluR1c. These two segments are rich in basic residues and are likely to be amphipathic alpha-helices, two characteristics of the G protein interacting domains of all G protein-coupled receptors. This indicates that whereas no amino acid sequence homology between mGluRs and the other G protein-coupled receptors can be found, their G protein interacting domains have similar structural features.

Amino Acid Sequence↗
PubMed1994

Widespread expression of the Xenopus homeobox gene Xhox3 in zebrafish eggs causes a disruption of the anterior-posterior axis.

The widespread expression of the Xenopus homeobox gene Xhox3 in zebrafish was performed by microinjection of synthetic Xhox3 mRNA into uncleaved fertilized eggs and resulted in embryos displaying varying degrees of anterior-posterior (A-P) axis disruption. The phenotype observed was dose-dependent and showed anomalies, mainly in neural keel development, from microphthalmia to acephaly. Injection of 5 pg to 10 pg of mRNA caused a range of phenotypes in prim 5 stage embryos from normal to acephalic. Anomalies have been categorized according to an index of axis deficiency (Zf-IAD). We further characterized the axis disturbance by analyzing the expression of two genes implicated in axis formation: engrailed (eng) and brachyury (ntl). eng could not be detected in the muscle pioneer cells of embryos injected with Xhox3. The pattern distribution of brachyury (Ntl) protein is abnormal in Xhox3 injected embryos. Evidence for the conservation of the NH2 terminal region of the Xhox3 protein in frogs and fish is provided by the detection of a nuclear Xhox3-like protein in 24 h zebrafish embryos located in posterior mesoderm tissue. Previous results in Xenopus embryo research and the data presented here support the conservation of an A-P patterning mechanism involving the Xhox3 gene.

Animals↗
PubMed1993

The ventral and posterior expression of the zebrafish homeobox gene eve1 is perturbed in dorsalized and mutant embryos.

We have identified and characterized zebrafish eve1, a novel member of the Drosophila even-skipped (eve) gene family. eve1 RNAs are expressed initially in late blastulae with a peak during the gastrula stage, at which time expression is confined to ventral and lateral cells of the marginal zone of the zebrafish embryo. Later, eve1 transcripts are located in the most posterior part of the extending tail tip. We show that LiCl, known to dorsalize Xenopus embryos, has the same effect in zebrafish, resulting in embryos with exaggerated dorsoanterior structures. In LiCl-treated embryos, eve1 transcripts are completely absent. eve1 is therefore a marker of ventral and posterior cells. In the light of its ventroposterior expression domain, the localization of eve1 transcripts was analysed in spadetail (spt) and no tail (ntl), two mutants with abnormal caudal development. In sptb140 homozygous mutants, there is an accumulation of cells in the tail region, resulting from inadequate migratory behaviour of precursors to the trunk somites. These cells, in their abnormal environment, express eve1, emphasizing the correlation between ventroposterior position and eve1 expression. In homozygous mutant embryos for the gene ntl (the homologue of mouse Brachyury, originally called Zf-T), posterior structures are missing (M. E. Halpern, C. B. Kimmel, R. K. Ho and C. Walker, 1993; Cell In press). While mutant and wild-type embryos do not differ in their eve1 transcript distribution during gastrulation, eve1 expression is absent in the caudal region of mutant ntl embryos during early somitogenesis, indicating a requirement for ntl in the maintenance of eve1 expression during tail extension. Our findings suggest that eve1 expression is correlated with a ventral and posterior cell fate, and provide first insights into its regulation.

Amino Acid Sequence↗
PubMed1993

[Ventral and posterior expression of the homeo box gene eve1 in zebrafish (Brachydanio rerio) is repressed in dorsalized embryos].

We have identified and characterized the zebrafish eve1 homeo box gene, a member of the Drosophila even-skipped (eve) gene family. eve1 is expressed in the most posterior part of the tail bud during somitogenesis. During gastrulation, transcripts are confined to ventral and lateral cells of the marginal zone of the embryo. We show that LiCl, known to dorsalize Xenopus embryos, has the same effect in zebrafish embryos. In LiCl-treated embryos, eve1 transcripts are completely absent, suggesting that eve1 marks the ventral specification of mesoderm in zebrafish gastrulae.

Animals↗
PubMed1992

Pro-melanin-concentrating hormone gene (PMCH) is localized on human chromosome 12q and rat chromosome 7.

Melanin-concentrating hormone (MCH) is a cyclic neuropeptide that may be involved in regulation of the stress response and food intake behavior in mammals. MCH and two other putative neuropeptides, NEI and NGE, are encoded by the same precursor, designated pro-melanin-concentrating hormone (PMCH). A panel of somatic cell hybrids segregating either human or rat chromosomes was used to determine the chromosomal localization of the PMCH locus. It was assigned to human chromosome 12q and to rat chromosome 7. This is the first neuropeptide-encoding gene found in this new synteny group conserved in rat and human.

Animals↗
PubMed1992

Effects of 1,2-propanediol on the cytoskeletal organization of the mouse oocyte.

The effects of 1,2-propanediol, a cryoprotectant used for the freezing of embryos, were tested on the organization of microtubules and microfilaments in mouse oocytes arrested in metaphase II. At low doses (less than or equal to 1.0 M), 1,2-propanediol induced disorganization of the meiotic spindle but at 1.5 M and higher, it stabilized the spindle. Cytoplasmic asters were observed at all doses tested. An extensive network of free microtubules was observed at 1.0 M and 2.0 M 1,2-propanediol, the former having the stronger disruptive effect on the spindle. Higher doses of 1,2-propanediol (greater than or equal to 1.5 M) caused the oocytes to form cytoplasmic blebs. These blebs lacked detectable cortical microfilaments. In contrast, the microfilament-rich area of the cell cortex overlying the meiotic spindle was not modified.

Actin Cytoskeleton↗
PubMed1992

Anti-HPA-4b (anti-Yuk(a)) neonatal alloimmune thrombocytopenia: first report in a Caucasian family.

Neonatal alloimmune thrombocytopenia (NAIT) is caused by platelet antigen incompatibility between the mother and fetus. NAIT is mainly due to alloimmunization; the frequency varying among ethnic groups. In Caucasians HPA-1a is the antigen most frequently implicated. In Japan, NAIT due to anti-HPA-4b antibody has already been described, but this is the first case to be reported in Caucasians.

Adult↗
PubMed1992

Expression of a zebrafish caudal homeobox gene correlates with the establishment of posterior cell lineages at gastrulation.

This paper deals with the first identification of a caudal cDNA containing a homeobox of the Drosophila caudal family in the zebrafish. A cDNA library from late gastrula stage embryos was constructed and screened with a mouse Cdx 1 homeobox probe. A 1.6 kb cDNA clone containing a homeobox related to other caudal homeoboxes was isolated and called cdx[Zf-cad1]. Analysis of the predicted 301 amino acid translation product reveals additional regions of homology outside the homeodomain with other members of the caudal family. Particularly, the cdx[Zf-cad1] putative protein shares a conserved N-terminal region with its chicken homolog CHox-cad. Transcripts are first detected just before the onset of gastrulation. At the beginning of gastrulation, a single 1.8 kb cdx[Zf-cad1] transcript is located near the blastoderm margin with a high level of expression restricted to the epiblast. At this stage, the hypoblast is clearly negative. At the end of gastrulation, cdx[Zf-cad1] is widely expressed in vegetal (i.e. prospective posterior) epiblast and hypoblast, with a somewhat weaker expression in the dorsal hypoblast. During somitogenesis, cdx[Zf-cad1] exhibits a posterior regionalization in the neurectoderm. In contrast, no expression is detected in the mesoderm of 22 h embryos (late somitogenesis). Posterior endoderm is also positive at this stage. cdx[Zf-cad1] transcripts cease to be detected about 48 h after fertilization. They are undetectable in the adult, particularly in female gonads. The pattern of cdx[Zf-cad1] expression during and after gastrulation is consistent with its possible involvement in the regionalization of the embryo at these stages.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1990

Primary structure of sorghum malate dehydrogenase (NADP) deduced from cDNA sequence. Homology with malate dehydrogenase (NAD).

Malate dehydrogenase (NADP) (NADP-MDH) is an important enzyme of the photosynthetic CO2 fixation pathway of C4 plants. We have isolated two clones from a sorghum lambda gt11 cDNA library (CM3, 932 bp, and CM7, 1441 bp). Nucleotide sequence analysis of the cDNAs CM3 and CM7 showed the existence of two NADP-MDH mRNA species encoding different enzyme subunits. Microsequencing of the N-terminus of the mature protein indicated that a specific cleavage of 13 amino acids occurred during the purification steps of the enzyme. The full-length cDNA CM7 contains a large open reading frame encoding an NH2-terminal transit peptide of 40 amino acids and a mature protein of 389 amino acids (42.207 kDa). Alignment of the NADP-MDH sequence with those of several malate dehydrogenases revealed some similarities with NAD-MDHs.

Amino Acid Sequence↗
PubMed1989

[Pleuropulmonary colibacillus infection in a 9-year-old boy leading to the diagnosis of Bruton agammaglobulinemia].

A nine-year-old boy was hospitalized for pneumonia of the left lower lobe. A left pleural effusion developed 48 hours later. The same E. coli strain was recovered from five blood cultures, pleural fluid, and middle ear fluid. Recovery was achieved after two months. Pleural lavage was performed twice daily for the first 15 days and parenteral antimicrobial therapy was given for 45 days. Because E. coli is not usually responsible for ENT or lower respiratory tract infections, an immune deficiency was sought for. The index patient had a twin in whom a history of osteomyelitis at the age of 2 and pneumonia at the age of 8 was found. Recurrent otitis had been a problem in both twins from the age of 14 months. In both twins, immunoglobulin assays led to the diagnosis of Bruton agammaglobulinemia. These two children are now receiving intravenous infusions of human immunoglobulins every three weeks. Bruton agammaglobulinemia is infrequently diagnosed at so late an age.

Agammaglobulinemia↗
PubMed1988

Identification of a cDNA clone for sorghum leaf malate dehydrogenase (NADP). Light-dependent mRNA accumulation.

The mechanisms underlying the photoregulation of the synthesis of sorghum leaf malate dehydrogenase (NADP) (EC 1.1.1.82) (NADP-MDH), a key enzyme in C4 photosynthesis, have been investigated. During the greening process a light-dependent increase in enzyme activity took place, accompanied by de novo synthesis of the protein. In vitro translation experiments showed that this chloroplastic protein is synthesized as a precursor (46 kDa) with a 'transit peptide' of about 2.5 kDa. A large increase in NADP-MDH-translatable RNAs was also observed during greening. We describe also the construction and characterization of a cDNA clone for NADP-MDH (pCM18A) in the expression vector lambda gt11. The use of this homologous probe demonstrated a light-dependent mRNA accumulation.

Cloning, Molecular↗
PubMed1983

[Course of ampicillin sensitivity in Haemophilus influenzae responsible for purulent meningitis in children. Therapeutic consequences].

Bacterial meningitis caused by Haemophilus influenzae observed from 1976 to 1980 (10 cases) are compared with those observed in 1981 (9 cases). From 1976 to 1980, 9 strains (90%) are ampicillin-sensitive. In 1981, 5 strains (55,5%) are ampicillin-sensitive and 4 strains (45,5%) are ampicillin-resistant and betalactamase positive. These 9 strains are serotype b. Therefore, since 1981, initial treatment of bacterial meningitis in infancy is a new cephalosporin, in this study is cefotaxime.

Ampicillin↗
PubMed1979

[Histochemical localization of lactate dehydrogenase (LDH) during cartilaginous cell differentiation in pleurodeles (Pleurodeles waltlii Michah].

As revealed in chondrogenetic cells the LDH activity that is very low during cellular migration, suddenly increases at the time of cytodifferentiation and reaches a peak at the onset of the first chondrocyte differentiation. A relationship is likely to exist between this increase in LDH-activity, chondroitin-sulfate synthesis and NAD metabolism.

Animals↗
PubMed1977

[Histochemical localization of lactate dehydrogenase in the trout embryo (Salmo irideus, Gibb) during early organogenesis of the cord and the neural tube].

The histochemical study of the LDH in the Trout embryo during the early organogenesis shows a specific localization in notochord cells, in mesodermic cells of the terminal knob and in some prosencephalic neuroblasts. The role of the LDH in the metabolism of NAD as well as in the energetic metabolism of embryonic cells is discussed.

Animals↗
PubMed1976

[Histochemical localization of lactate dehydrogenase in blastomeres during early development of the rainbow trout embryo (Salmo irideus Gibb)].

During the early development of the trout egg, some blastomers display a certain activity of the L.D.H., variable according to their position in the embryo. At the morula stage, the histochemical ltion of those blastomeres. On the contrary, during the gastrula stage, the blastomeres which have a high L.D.H. activity concentrate in the deep layer of the germ, in the "embryonic button", and in the germinal ring.

Age Factors↗