Dicer-deficient oocytes stained for beta-tubulin and DNA to visualize the meiotic spindle. DNA was counterstained with Sytox green. In the absence of Dicer, mouse oocytes develop abnormal spindles and often fail to complete the first meiotic division, revealing a novel role for small RNAs during meiosis.
motility mutants stab-inoculated on a 0.3% agar motility plate. The “halos” and
“rings” likely reflect the motility of this archaeon following gradients of
attractant or repellent chemicals.
Seaweeds in a a tidepool on the coast of Maine.
Escherichia coli cells with fluorescently labeled chromosomal loci.
Siberian Larch, taken at our field site near Lake Khovsgol in north-central Mongolia. We are analyzing tree-ring width and stable isotopes of the tree rings to reconstruct climate, and Larch responses to climate change, over the past century as the temperature in Mongolia has risen.
The links to the left provide course details including class meeting times and locations. Information such as the course syllabus, faculty office hours, etc. can be found in the course's Canvas site.
University of Pennsylvania /// 102 Leidy Laboratories /// 433 S University Ave. /// Philadelphia, PA 19104-6313 /// P: (215) 898-7121 /// F: (215) 898-8780
© 2014 The Trustees of the University of Pennsylvania