and Ecole Guelph, of avian cells. Shen Ccllulaire. University M.2, embryonic Etclles R.2 Pain U.1, Cochran 1~1.2, Clarck Snlllarut &II. 1 Laboratoire de Biologic Mol6culaire Normale Superieure de Lyon. France. *Department of Animal and Poultry N IG2W I, Canadn. PAYS laurent, HEMMING fiona et SAXOD raymond Laboratoire de Neurobiologie du DBveloppement CERMO, Universitd Joseph Fourier, BP53 38041 Grenoble cedex 9 France Innervation in bird skin is essentially dermic and presents a typical pattern consisting of nerve rings around the base of each feather fqllicle. In an attempt to disrupt the relationship between the feather and the nerve ring, hydrocortisone treatment was used to obtain embryos largely devoid of feathers. The nerve pattern then only developed in the areas with feathers but remained disorganized in the neoformed apteria. Feather and nerve ring morphogenesis could not be dissociated in this experiment. In order to clarify the phenomena associating feather development with nerve ring formation, the expression patterns of various matrix molecules were compared in feather areas of both treated and control embryos at several developmental stages. Only one chondroitin sulphate (CS) epitope (recognized by the 289 antibody) showed any difference in distribution after the hydrocortisone treatment, suggesting that the antigen is probably not fundamentally involved in cutaneous morphogenesis. On the other hand, other antigens in the developing feathers displayed the same spatio-temporal variations with or without treatment : fibronectin throughout the:dermis, tenascin showing an uneven dermic distribution, and two other CS epitopes (recognized by the 9BA12 and CS56 antibodies) at their base, in areas avoided by the nerve rings. These molecules are therefore likely to be involved in the morphogenesis of both the skin and its innervation. CNRS. of INRA, Gelpb, The identification and growth in cullure of embryonic totipofent cells (ES cells) has been well documented in the mouse. These cells are able to colonize injected into early host embryos. The s0111atic and germ lines when identification and cultivation of similar cells in avians would open quite in expertmental embryology and for zootechnic promising approaches applications. demonstrated the occurence of such cells in Some of us have previously early chicken embryos (stage X according to Eyal Giladi). collected from either We have developped a culture technique for cells several monoclonal antibodies we quail or chicken stage X embryos. Using vi/m which exhibit antigens previously could identify cells produced ia identified as characteristic of marine ES cells. Some detected antigens were also specific of murine and nvian PFCs. We could then set up culture candilions using combinations of various cytokines which allow the multiplication of these cells in culture. To test their potentralities in viva these grown cells were grafted into irradiated early recipient embryos. The contributions of the grafted cells to somatic and germ lines were nssessed through expression of plumage markers and by mating the chimeric animals. The data on the nntigenic characterization and the morphogenetic potentialities of the cultivated embryonic cells will be presented. SEVERAL RECEPTOR TYROSINE KINASE GENES OF THE EPH FAMILY ARE SEGMENTALLY EXPRESSED IN THE DEVELOPING HINDBRAIN GILARDI-HEBENSTREIT Pascaleâ, BECKER Nathalie, SEITANIDOU Tania, MURPHY Paula and CHARNAY Patrick Unith INSERM 368, Ecole Normale Sup&ieure, 46 rue dâUlm, 75230 Paris Cedex 05, France. *Unit6 INSERM 412, Ecoie Normale Supkrieure, 46 all&e dâltalie, 69364 Lyon Cedex 07, France. Pattern formation in the hindbrain involves a segmentation process leading to the formation of metameric units known as rhombomeres (r). In search for genes involved in cell-cell interactions during hindbrain segmentation, we have screened for protein kinase genes with restricted expression patterns in this region of the CNS. Five novel mouse genes, Sek-1 to 5, members of the Eph subfamily of transmembrane receptor protein tyrosine kinase (RTKs) have been identified, and their expression patterns have been analysed with h &IJ hybridisation studies. Sek-l is expressed in r3 and r5 (GILARDIHEBENSTREIT P. et al., (1992). Oncogene. 7, 2499-2506). In addition, Sek-1 expression occurs in two stripes that correlate the formation of somites (NIETO A. et al.,(1992). Deve@ment. 116. 1137-1150). These data suggest that Sek-1 could be involved in the segmental patterning of both of these tissues. Using baculovirus expression system, we demonstrate that Sek-I is phosphorylated on tyrosines in vivo, and that in vitro it has the capacity for autophosphotylation on tyrosine residues. Sek-2 is transcribed in a transverse stripe corresponding to prospective r4 and the adjacent mesoderm, suggesting possible roles both in hindbrain segmentation and signalling between neuroepithelium and mesoderm. Sek-3 and Sek-4 have common domains of expression including r3, r5 and part of the midbrain as well as specific domains in the diencephalon, telencephalon, spinal cord and in mesodermal and neural crest derivatives (BECKER N. et al., (1994) Mechanism of development, 47, 3-17). Sek-5 is expressed in r2 to r6. These data indicate that members of the Eph family of RTKs may cooperate in the segmental patterning of the hindbrain. AVIAN OLFACTORY RECEPTOR GENES LElI3OVlCI Michel, LAPOINTE Franqoise and AYER-LE LIEVRE Christiane. Institut dâEmbryologie Cellulaire et Mokulaire, 49 bis Avenue de la Belle Gabrielle. 94130 Nogent sur Marne Tel l-48736090, lkx l-48734377, E-Ma2 ayer@citiZ.fr. The perception of odorant molecules starts with their binding to specific receptors present on rhe cilia of olfactory neurons. These receptors belong to the superfamily of 7 transmembrnne domain receptors linked to G proteins. We cloned and characterized in the Chick three genes coding Chick Olfactory Receptors (COR). The following informations were obtained from their molecular analysis: I- These genes have a similar degree of homology (40 lo 50%) with each other and with known genes of odornnt receptors in other species. 2- Some odorant receptor genes are gathered into clusters in the Chick genome. 3- These 3 genes belong to 3 separate subfamilies of 1 IO 6 genes wirh high sequence homologies (above 80% identity). 4- These identified in the Chick are conserved in gene subfamilies, Quail and Duck species, except for one of them. This last subfamily may thus be involved in a specific perception 01 odors by the Chick. Our results give new informations on the evolution of this rnultigenic family of odorant receptors. The cluster organization of this large repertoire of genes may be a key element in the hierarchical regulation of the olfactory receptor expression.
Biology of the Cell – Wiley
Published: Jan 1, 1995
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera