1 research outputs found
A spermium/petesejt együttműködés genetikai boncolása. = Genetic dissection of sperm and egg cell cooperation.
Munkánk cĂ©lja az, hogy a Drosophila HimcaD, HorkaD valamint KompoltD domináns nĹ‘stĂ©ny-steril mutáciĂłibĂłl kiindulva molekuláris szinten ismerjĂĽk meg az Ă©p Himca, Horka Ă©s Kompolt gĂ©nek szerepĂ©t a megtermĂ©kenyĂĽlĂ©sben, az embriĂłgenezis elkezdĹ‘dĂ©sĂ©ben. Megtudtuk, hogy (i) a Himca gĂ©n termĂ©ke az inozitol-1,4,5-trifoszfát (ITF) kináz enzim, amely a Ca2+ ionok belsĹ‘ raktárakbĂłl törtĂ©nĹ‘ felszabadulásáért felelĹ‘s. Ăšgy tűnik, hogy ITF hiányában a Ca2+ ion-hullámok elmaradása okozza a megtermĂ©kenyĂĽlĂ©ssel, a spermiumfarok elhelyezkedĂ©sĂ©vel, illetve az embriĂłgenezis elkezdĹ‘dĂ©sĂ©vel kapcsolatos problĂ©mákat. (ii) A Horka gĂ©n termĂ©ke a transzkripciĂł-termináciĂłs-faktor-2 (TTF2). A TTF2 Ăşgy okoz abortĂv transzkripciĂłt, hogy eltávolĂtja az RNS polimeráz-II-t a DNS-rĹ‘l. A DNS-csip, valamint a Q-RT-PCR technika mĂłdszereivel arra derĂtettĂĽnk fĂ©ny, hogy TTF2 hiányában - a HorkaD/+ Ă©s a horkanull/? hemizigĂłta nĹ‘stĂ©nyek petĂ©iben - 54 olyan Ă©p gĂ©n termĂ©ke bukkan fel, amelyek a vadtĂpusĂş petĂ©kben nincsenek jelen. A szokatlan gĂ©ntermĂ©kek megmĂ©rgezik az embriĂłkat. A HorkaD mutáciĂłbĂłl kiindulva a nĹ‘stĂ©ny-sterilitás eddig ismeretlen tĂpusára derĂtettĂĽnk fĂ©nyt. (iii) Kompolt gĂ©n termĂ©ke egy olyan transzmembrán fehĂ©rje, amely többfĂ©le, több kĂłpiában meglevĹ‘, Ă©s ismert domĂ©nt tartalmaz. A domĂ©noknak a spermium adhĂ©ziĂłban, a sejt-sejt kölcsönhatásban, valamint a szingnáltranszdukciĂłban van szerepe. | We aimed to reveal molecular function of the Himca, Horka Ă©s Kompolt genes in fertilization and in the commencement of embryogenesis in Drosophila. The genes have been previously identified by the HimcaD, HorkaD and the KompoltD dominant female-sterile mutations. It has turned out that (i) product of the Himca gene is the inozitol-1,4,5-triphosphate (ITF) kinase enzyme. ITF is required for release of Ca2+ from the store sites. It appears that Ca2+ waves do not develop in absence of ITF that leads subsequently to abnormal sperm tail positioning in the egg cytoplasm, aberrant fertilization and the lack of commencement of embryogenesis. (ii) The Horka gene encodes the formation of transcription-termination-factor-2 (TTF2). TTF2 has been known to cause abortive transcription through the removal of RNA polymerase-II from the DNA. Making use of the DNA chip technology and the Q-RT-PCR technique we showed that in absence of TTF2 - in eggs of the HorkaD/+ and the horkanull/? hemizygous females - products of 54 genes appear in the egg cytoplasm that are missing in the wild type eggs. The unusual gene products poison the embryos. Starting from the HorkaD mutation we revealed a thus far unknown type of female sterility. (iii) Product of the Kompolt gene is a giant transmembrane protein that contains several copies of several known domains. The domains play role in sperm adhesion, cell-to-cell interaction and signal transduction