 |
|
|
3258 TAMU Office: Fax: 979-845-2891 |
Biography |
| Helmut Sauer received his doctoral degree Dr. rer. nat. under Friedrich Seidel from the Phillips University at Marburg, Germany. After postdoctoral work at the McArdle Laboratory for Cancer Research in Madison and appointments to the faculties of Heidelberg, Konstanz and Wurzburg Universities, he joined the Texas A&M faculty in 1981 and now is a Professor of Biology. He is also an honorary professor of Wurzburg University. Dr. Sauer teaches courses in Developmental Biology, is involved in a modern re-evaluation of the classical concepts of Driesch, Boveri, and Spemann, and he is interested in theories that apply to biological change in general, i.e. phylogeny and ontogeny. | |
| Developmental Biology and the Cell Cycle | |
|
My doctoral work was concerned with the detailed description of the development of the basic insect body plan with a particular interest in cell movements and the timing and location of nuclear divisions. My postdoctoral work dealt with a remarkable organism, the slime mold Physarum. Its life cycle displays mutually exclusive stages of growth and differentiation. The most extraordinary life cycle stage of Physarum is the plasmodium. It is a giant single multinucleated cell. All hundred million nuclei in a common protoplasm of 8 cm. diameter divide with precise natural synchrony every ten hours. This unique quality has made Physarum a model for cell cycle studies -- if not cancer -- for the last 30 years. Current research is focused on three aspects of the basic cell cycle: the control of mitosis, the organization of the S phase (in particular the origin of replication), and the elusive endogenous cell cycle oscillator. MPF, the maturation/mitosis promoting factor seems to be a heterodimer of two conserved gene products, cdc2 kinase and cyclin, a regulatory subunit. According to the current paradigm of mitotic control oscillatory accumulation and destruction of cyclin drives the cell cycle. This is not so in Physarum. Rather than an odd exception, these results obtained in an unperturbed cell cycle may reveal the ground rules of cellular reproduction, by controls of the cdc2 kinase yet to bediscovered. During S phase, the chromatin replicates in a definitive temporal order. As a rule, with a notable exception, among developmentally controlled genes, those that replicate early are the ones which are actively transcribed. We have suggested that"replication-transcription coupling" adds a layer of pretranscription control to developmental biology. If so, "replicon-switching" would constitute a causal link between the controls of cell proliferation and differentiation. Therefore, a major focus of the lab is the characterization of origins of replication using 2D replicon mapping techniques and nuclear run - on experiments. |
|
| Selected Publications | |
|
Moritz, K.B. and H.W. Sauer. 1996. Boveri's contributions to developmental biology-a challenge for today. Int. J. Dev. Biol. 40: 27-47. Cho, J.W. and H.W. Sauer. 1994. A non-cycling mitotic cyclin in the naturally synchronous cell cycle of Physarum polycephalum. Eur. J. of Cell. Biol. 65: 94-102. Diller, J.D. and H.W. Sauer. 1993. Two early replicated developmentally controlled genes of Phasarum display different patterns of replication by two-dimensional agarose gel electrophoresis. Chromosoma 102: 563-574. Belyavskyi, M. and H.W. Sauer. 1992. Intrinsic fluctuations of phosphoinositol levels are involved in the progression of the naturally synchronous cell cycles in Physarum polycephalum. Eur. J. Cell. Biol. 58:371-376. |
|
Administrative | Research | Facilities | Phonebooks | Seminars | Calendars |
|