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Archiv-Übersicht     Angebot Nr. 13430

Angebotsdatum: 21. Mai 2019
Art der Stelle: Doktorarbeit / Diplomarbeit
Fachgebiet: Biologie > Entwicklungsbiologie
Titel des Themas: Epigenetic Control of Plant Stem Cell Formation

Institut: Biologie
Prof. Thomas Laux
Schänzlestr. 1
79104 Freiburg im Breisgau
Tel.:    Fax.:
Bundesland: Baden-Württemberg
Homepage: http://www.biologie.uni-freiburg.de/LauxLab/
E-Mail Kontakt: mail

Beschreibung: We are seeking highly motivated candidates for a newly funded PhD position in plant embryo development. The goal is to investigate how the stem cells of the shoot meristem are formed during embryo development. The PhD position covers the entire length of the PhD (typically 3-4 years) providing a competitive salary, health care and additional benefits. The program includes participation in international scientific meeting and training courses.

Background: Unlike most animals where stem cells give rise specific cell types, stem cells in the plant shoot meristem give rise to new complete organs throughout their lifespan. Furthermore, many differentiated plant cells can undergo dedifferentiation and give rise to new meristems if necessary. These phenomena make totipotency of plant stem cells a fascinating area of study. Our group had previously shown that the stem cells of the shoot meristem are regulated by the homeodomain transcription factor WUSCHEL, which turned out to be a universal mechanism to control totipotency in plants1-3. One longstanding question in stem cell research is: how are totipotent stem cells made in the first place and how are they organized into a functional meristem? We have recently shown that the initiation of shoot meristem stem cells during embryogenesis is controlled by a WUSCHEL-related transcription factor that fine tunes the balance of the phytohormones auxin and cytokinin4. During this process the precursor cells of the stem cells are epigenetically primed to become totipotent.

Goal: Understand the genetic and epigenetic networks that establish shoot meristem stem cells during embryo development in the model plant Arabidopsis:
(1) Analyze the transcriptome dynamics and epigenetic changes during stem cell initiation.
(2) Use synthetic biology to simulate stem cell formation.
(3) Collaborate with international partners for the agricultural use of meristem formation.

References: (1) Schoof, H. et al. Cell 100, 635-644 (2000). (2) Mayer, K. F. X. et al. Cell 95, 805-815 (1998). (3) Sarkar, A. et al. Nature 446, 811-814 (2007). (4) Zhang, Z. et al. Dev Cell 40, 264-277 (2017).
Methoden: Genetics: crosses, segregation analysis.
Developmental studies: phenotype analysis, confocal microscopy of gene expression, live imaging.
Molecular biology: besides standard methods, the project will provide training in transcriptome and chromatin analysis.
Bioinformatic: analysis of deep sequencing data, meta-analysis of different data sets.
Anfangsdatum: 21. Mai 2019
Geschätzte Dauer: 3,5 Jahre
Bezahlung: 65% E13 (ca 1600 Euro netto)
Papers: Robert et al,(2018). Maternal auxin supply contributes to early embryo patterning in Arabidopsis. Nat Plants 4, 548-553.

Ueda et al, (2017). Transcriptional integration of paternal and maternal factors in the Arabidopsis zygote. Genes Development, 31, 617-627.

Zhao et al, (2017) RETINOBLASTOMA RELATED1 mediates germline entry in Arabidopsis. Science, 356.

Zhang et al, (2017). A molecular framework for the embryonic initiation of shoot meristem stem cells. Developmental Cell, 40, 264–277.

Knauer et al, (2013). A Protodermal miR394 Signal Defines a Region of Stem Cell Competence in the Arabidopsis Shoot Meristem. Developmental Cell 24,125-132

Ueda, et al,(2011). Transcriptional activation of Arabidopsis axis patterning genes WOX8/9 links zygote polarity to embryo development. Developmental Cell 20, 264-270.

Sarkar et al, (2007). Conserved factors regulate signaling in Arabidopsis shoot and root stem cell organizers. Nature 446, 811-814.

Schoof et al, (2000). The stem cell population of Arabidopsis shoot meristems is maintained by a regulatory loop between the CLAVATA and WUSCHEL genes. Cell 100, 635-644.
Sonstiges: The project is part of the "CIBSS-Centre for Integrative Biological Signalling Studies" (https://www.cibss.uni-freiburg.de) awarded by the German Excellence Program to the University of Freiburg.