A Genetics-ben közölt dolgozat (181: 367-377, 2009) publikációs költségének térítése
Title in English
Refunding the publication cost of a paper published in Genetics (181: 367-377, 2009)
Keywords in Hungarian
Genetics, dolgozat, költségtérítés
Keywords in English
Genetics, paper, refunding
Discipline
Genomics, comparative genomics, functional genomics (Council of Medical and Biological Sciences)
50 %
General biochemistry and metabolism (Council of Medical and Biological Sciences)
50 %
Ortelius classification: Molecular biology
Panel
Publications Panel
Department or equivalent
Department of Medical Biology (University of Szeged)
Starting date
2010-01-01
Closing date
2010-04-30
Funding (in million HUF)
0.396
FTE (full time equivalent)
0.05
state
closed project
Summary in Hungarian
A Drosophila melanogaster HorkaD domináns negatív mutációja megakadályozza a kromoszómák pontos szegregációját a sejtosztódások során. HorkaD oly nagy gyakorisággal okoz rendellenes kromoszóma szegregációt az oo- és az embriógenezis folyamán, hogy a HorkaD-t hordozó nőstények sterilek. HorkaD a spermatogenezis során instabillá teszi a kromoszómákat, amelyek az utódok életének kezdetén elvesznek, miáltal diplo/haplo mozaikok képződnek, köztük XX/X0 nőstény/hím mozaikok, günanderek is. A HorkaD-vel azonosított gén funkciójának hiánya anyai-hatású letalitást eredményez. A horkanull/horkanull nőstények embriói az ún. mitotikus katasztrófa eredményeként elpusztulnak: bennük abnromális centroszómák, tökéletlen magorsófonalak és kromatin-hidak képződnek módfelett nagy gyakorisággal. A mitotikus katasztrófa ismérvei arra utalnak, hogy az ép gén termékére a sejtosztódások során van szükség. Dolgozatunkban leírtuk, hogy HorkaD az ún. lodestar gént azonosítja, a helikáz-szerű géncsalád egyik tagját. A HorkaD mutáció egyetlen bázispár-csere típusú mutáció nyomán képződött, a vele kapcsolatos abnormalitások oka pedig egy Ala777 - Thr aminosav-csere. Úgy tűnik, hogy a kromatinhoz kapcsolódó „ragadós” A777T-Lodestar fehérje a kromoszóma instablitás, a gyakori kromoszómavesztés eredendő okozója. Azt gondoljuk, hogy a Lodestar fehérje a metafázis/anafázis átmenet során a kromatin fellazításában játszik szerepet.
Summary
Correct segregation of chromosomes is particularly challenging during the rapid nuclear divisions of early embryogenesis. This process is disrupted by HorkaD, a dominant-negative mutation in Drosophila melanogaster that causes female sterility due to chromosome tangling and nondisjunction during oogenesis and early embryogenesis. HorkaD also renders chromosomes unstable during spermatogenesis, which leads to the formation of diplo//haplo mosaics, including the gynandromorphs. Complete loss of gene function brings about maternal-effect lethality: embryos of the females without the HorkaD-identified gene perish due to disrupted centrosome function, defective spindle assembly, formation of chromatin bridges, and abnormal chromosome segregation during the cleavage divisions. These defects are indicators of mitotic catastrophe and suggest that the gene product acts during the meiotic and the cleavage divisions, an idea that is supported by the observation that germ-line chimeras exhibit excessive germ-line and cleavage function. The gene affected by the HorkaD mutation is lodestar, a member of the helicase-related genes. The HorkaD mutation results in replacement of Ala777 with Thr, which we suggest causes chromosome instability by increasing the affinity of Lodestar for chromatin. It appears that the Lodestar mutation plays a key role in rendering the chromatin lose during the metaphase/anaphase transition.
Final report
Results in Hungarian
Ez itt a megjelent doglozat absztraktja:
Correct segregation of chromosomes is particularly challenging during the rapid nuclear divisions of early
embryogenesis. This process is disrupted by HorkaD, a dominant-negative mutation in Drosophila melanogaster
that causes female sterility due to chromosome tangling and nondisjunction during oogenesis and early
embryogenesis. HorkaD also renders chromosomes unstable during spermatogenesis, which leads to the formation of diplo//haplo mosaics, including the gynandromorphs. Complete loss of gene function brings
about maternal-effect lethality: embryos of the females without the HorkaD-identified gene perish due to
disrupted centrosome function, defective spindle assembly, formation of chromatin bridges, and abnormal
chromosome segregation during the cleavage divisions. These defects are indicators of mitotic catastrophe
and suggest that the gene product acts during the meiotic and the cleavage divisions, an idea that is
supported by the observation that germ-line chimeras exhibit excessive germ-line and cleavage function. The
gene affected by the HorkaD mutation is lodestar, a member of the helicase-related genes. The HorkaD mutation results in replacement of Ala777 with Thr, which we suggest causes chromosome instability by increasing the affinity of Lodestar for chromatin.
Results in English
Abstract:
Correct segregation of chromosomes is particularly challenging during the rapid nuclear divisions of early
embryogenesis. This process is disrupted by HorkaD, a dominant-negative mutation in Drosophila melanogaster
that causes female sterility due to chromosome tangling and nondisjunction during oogenesis and early
embryogenesis. HorkaD also renders chromosomes unstable during spermatogenesis, which leads to the formation of diplo//haplo mosaics, including the gynandromorphs. Complete loss of gene function brings
about maternal-effect lethality: embryos of the females without the HorkaD-identified gene perish due to
disrupted centrosome function, defective spindle assembly, formation of chromatin bridges, and abnormal
chromosome segregation during the cleavage divisions. These defects are indicators of mitotic catastrophe
and suggest that the gene product acts during the meiotic and the cleavage divisions, an idea that is
supported by the observation that germ-line chimeras exhibit excessive germ-line and cleavage function. The
gene affected by the HorkaD mutation is lodestar, a member of the helicase-related genes. The HorkaD mutation results in replacement of Ala777 with Thr, which we suggest causes chromosome instability by increasing the affinity of Lodestar for chromatin.
