HEJÁTKO, Jan, Markéta PERNISOVÁ, Tinka ENEVA, Klaus PALME and Břetislav BRZOBOHATÝ. CKI1, a putative sensor histidine kinase is essential for proper female gametophyte formation in Arabidopsis thaliana. In Boook of Abstracts, Cytokinematics 2004, Microscopy of Live Cells in the Post Genomics Era. The 8th Symposium on Light Microscopy & Live Cells in Hradec Kralove. Hradec Králové: RNDr. F. Skopec, CSc.-NUCLEUS HK, 2004, p. 22. ISBN 80-86225-60-7.
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Basic information
Original name CKI1, a putative sensor histidine kinase is essential for proper female gametophyte formation in Arabidopsis thaliana.
Name in Czech CKI1, predpokladana receptorova histidinkinaza je nezbytna pro normalni vyvoj samiciho gametofytu u Arabidopsis thaliana.
Authors HEJÁTKO, Jan (203 Czech Republic), Markéta PERNISOVÁ (203 Czech Republic), Tinka ENEVA (100 Bulgaria), Klaus PALME (276 Germany) and Břetislav BRZOBOHATÝ (203 Czech Republic, guarantor).
Edition Hradec Králové, Boook of Abstracts, Cytokinematics 2004, Microscopy of Live Cells in the Post Genomics Era. The 8th Symposium on Light Microscopy & Live Cells in Hradec Kralove, p. 22-22, 2004.
Publisher RNDr. F. Skopec, CSc.-NUCLEUS HK
Other information
Original language English
Type of outcome Proceedings paper
Field of Study Genetics and molecular biology
Country of publisher Germany
Confidentiality degree is not subject to a state or trade secret
WWW URL
RIV identification code RIV/00216224:14310/04:00010681
Organization unit Faculty of Science
ISBN 80-86225-60-7
Keywords in English female gametophyte development; two-component signaling; sensor histidine kinase; early seed development; genomic imprinting
Tags early seed development, female gametophyte development, genomic imprinting, sensor histidine kinase, two-component signaling
Changed by Changed by: doc. RNDr. Jan Hejátko, Ph.D., učo 2658. Changed: 28/4/2006 17:31.
Abstract
Embryo sac formation is a fundamental step in plant sexual reproduction. However, the key players driving female gametophyte development remain elusive. Employing reverse genetics, we have identified CKI1, a putative sensor histidine kinase, as a key regulatory component during female gametophyte formation in Arabidopsis thaliana. Using PCR-based screen we have identified a line carrying insertion of the autonomous transposable element En-1 in the coding region of CKI1 gene. Distorted genotype ratios and distribution of the insertional mutant allele cki1-i in the progeny of the identified mutant plant suggested lowered viability and/or function of the cki1-i gametes. In accordance to that, the results of reciprocal back-crosses have shown that cki1-i cannot be transmitted through the female germ line. Confocal laser scanning microscopy (CLSM) analysis of developing embryo sacs from cki1-i/CKI1 pistils did not reveal any deviations from the wild type phenotype in the first four developmental stages of megagametogenesis, FG1 through FG4. First anatomically distinguishable defects (distortion of the central vacuole, changes in the nuclei positions and partial degradation of the embryo sac) were identified in late FG5. The results of CLSM analysis 24 hours after flower emasculation (HAE) have confirmed that half of the embryo sacs from cki1-i/CKI1 pistils are unable to develop beyond the FG5. CLSM analysis 48 HAE revealed dynamic nature of the progressive degradation of mutant embryo sacs, very probably as a result of the central vacuole disintegration. The transcriptional activity of CKI1 during megagametogenesis was identified using in situ CKI1 mRNA analysis on paraffin sections of the developing embryo sacs. We have found weak but distinct signal throughout the embryo sac development, suggesting very early transcriptional activation of CKI1 during megagametogenesis. The results were confirmed by the histochemical analysis of stable transformants carrying fusion of the CKI1 promoter region with marker gene uidA. The GUS activity in developing embryo sacs was detectable as early as in the FG1 and remained detectable throughout megagametogenesis, even after the embryo sacs reached complete maturity at FG7. CKI1 expression was found not only just before but also early after fertilization in developing seed endosperm, which might suggest the role of CKI1 also in a newly formed sporophytic tissue. Surprisingly, transcriptional activation of the paternally transmitted uidA gene under control of CKI1 promoter very early after fertilization suggests potential transcriptional activity of at least part of the male genome during early seed development in Arabidopsis.
Abstract (in Czech)
Tvorba embryonalniho vaku je nezbytnou soucasti pohlavni reprodukce rostlin. Presto zustavaji zakladni faktory ridici tvorbu samiciho gametofytu nezname. Za pouziti reverzni genetiky jsme identifikovali CKI1, predpokladanou receptorovou histidinkinazu jako klicovou regulacni komponentu behem tvorby samiciho gametofytu u Arabidopsis thaliana. Pomoci PCR vyhledavani jsme identifikovali lini nesouci inzerci kukuricneho autonomniho elementu En-1 v kodujici oblasti genu CKI1. Zmena v segregacnich pomerech a distribuce inzercni mutantni alely cki1-i v potomstvu identifikovane mutantni rostliny nazancovaly snizenou zivotnost, resp. funkcnost gamet nesoucich mutantni alelu cki1-i. Ve shode s tim, vysledky zpetnych reciprokych krizeni potvrdily, ze alela cki1-i nemuze byt do dalsiho potomstva prenesena prostrednictvim samici zarodecne linie. Analyza embryonalnich vaku u rostlin cki1-i/CKI1 pomoci laserove konfokalni mikroskopie (CLSM), ukazala normalni vyvoj vsech embryonalnich vaku do stadia FG4. Prvni anatomicky odlisitelne odchylky od normalniho vyvoje byly identifikovany teprve v pozdnim stadiu FG5. CLSM analyza 24 hodin po kvetni emaskulaci (HAE)potvrdila, ze polovina z embryonalnich vaku v rostlinach cki1-i/CKI1 je neschopna dokoncit stadium FG5. Vysledky teto analyzy 48 HAE prakazaly dynamickou povahu progresivni degradace muatnich embryonalnich vaku, pravdepodobne jako vysledek rozpadu centralni vakuoly. Aktvita transkripce genu CKI1 behem samici gametogeneze byla identifikovana pomoci in situ lokalizace CKI1 mRNA na parafinovych rezech. Pritomnost slabeho signalu byla zjistena behem celeho prunehu megagametogeneze, a to od velmi rannych stadii. Transkripcni aktivita genu CKI1 od sameho pocatku megagametogeneze byla potvrzena pomoci histochemicke analyzy stabilnich transformantnich linii nesoucich markrovy gen uidA pod kontrolou promotorove oblasti genu CKI1. GUS aktivita byla identifikovatelna od stadia FG1 a dale behem cele megagametogeneze. Exprese CKI1 byly identifikovana nejen tesne pred ale i po oplozeni v endospermu vyvijejiciho se semene, coz by mohlo znamenat potencialni roli CKI1 v nove vytvorenem sporofytu. Prekvapive byla transkripcni aktivita paternalni alely CKI1 identifikovana velmi brzy po oplozeni, coz nanznacuje aktivaci alespon casti parentalniho genomu behem ranych stadii vyvoje semene u Arabidopsis.
Links
LN00A081, research and development projectName: Signální dráhy u rostlin
MSM 143100008, plan (intention)Name: Genomy a jejich funkce
Investor: Ministry of Education, Youth and Sports of the CR, Genomes and their functions
VS96096, research and development projectName: Laboratoř molekulární fyziologie rostlin
Investor: Ministry of Education, Youth and Sports of the CR, Laboratory of Molecular Plant Physiology
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