Skip to main content
Skip to main content

Biology Faculty and Staff - Sigrid Jacobshagen

Sigrid Jacobshagen, Ph.D. Free University of Berlin

Sigrid Jacobshagen, Ph.D. Free University of Berlin


Office:  Skyteach 07
Phone:  270-745-5994


BIOL 400(G) Plant Physiology

BIOL/CHEM 446(G) Biochemistry I

BIOL/CHEM 446(G) on-line Biochemistry I

BIOL/CHEM 447(G) Biochemistry Laboratory

BIOL/CHEM 467(G) Biochemistry II

BIOL/CHEM 562 Advanced Biochemistry


Research in my lab is concerned with the circadian clock. We are using the unicellular green alga Chlamydomonas as a model organism to study the circadian clock, because we can measure its daily rhythm of swimming towards light in an automated fashion. The rhythm is very similar to the daily sleep/wake cycle in humans. Projects in the lab center on the photoreceptor proteins that are able to reset the circadian clock using physiological, molecular, biochemical and cell biological techniques. We are also interested in understanding how the circadian clock regulates genes so that they show a circadian rhythm in their expression. A third interest is the use of mathematical equations to model the circadian clock.


Ph.D. 1988 Plant Biochemistry, Free University of Berlin, Germany

M.S. 1985 Biology, Justus-Liebig-University of Giessen, Germany

Recent Publications

Forbes-Stovall J., Howton J., Young M., Davis G., Chandler T., Kessler B., Rinehart C.A., and Jacobshagen S. (2014) Chlamydomonas reinhardtii strain CC-124 is highly sensitive to blue light in addition to green and red light in resetting its circadian clock, with the blue-light photoreceptor plant cryptochrome likely acting as negative modulator.  Plant Physiology and Biochemistry  75, 14-23.

Gaskill C., Forbes-Stovall J., Young M., Kessler B., Rinehart C.A., and Jacobshagen S. (2010) Improved automated monitoring and new analysis algorithm for circadian phototaxis rhythms in Chlamydomonas. Plant Physiology and Biochemistry 48, 239-246.

Jacobshagen S., Kessler B., and Rinehart C.A. (2008) At least four distinct circadian regulatory mechanisms are required for all phases of rhythms in mRNA amount. Journal of Biological Rhythms 23, 511-524.


Note: documents in Portable Document Format (PDF) require Adobe Acrobat Reader 5.0 or higher to view,
download Adobe Acrobat Reader.

Note: documents in Excel format (XLS) require Microsoft Viewer,
download excel.

Note: documents in Word format (DOC) require Microsoft Viewer,
download word.

Note: documents in Powerpoint format (PPT) require Microsoft Viewer,
download powerpoint.

Note: documents in Quicktime Movie format [MOV] require Apple Quicktime,
download quicktime.

 Last Modified 9/25/14