Diatom Gliding Motility. Группа авторов

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       Dedication to Jeremy D. Pickett-Heaps In Memoriam 1940–2021

      The editors of this volume would like to dedicate this collection to Dr. Jeremy D. Pickett-Heaps, with thanks and gratitude for his leadership and stalwart advocacy in advancing studies of diatoms and diatom motility. Sadly, Jeremy passed away just prior to this volume’s publication. One of the editors (SAC) had the pleasure and honor of studying and working with Jeremy and is proud to write this dedication. In addition, another editor (RG) visited Jeremy in Colorado where he was greatly influenced on his work in diatom morphogenesis.

      Jeremy was truly an international scholar. Born in Mumbai, India, he received his B.A. and Ph.D. in Cambridge, England, and did his postdoctoral work back in his home of Australia. He then worked for almost 20 years as a professor at the University of Colorado Boulder, after which he went back to Melbourne to the University of Melbourne until his retirement. His work on algae was prodigious, as witnessed by the large number of excellent publications listed at the end of this dedication.

      Jeremy was always a strong advocate for live observation of cell behaviors. While Jeremy always understood the value and use of theoretical and in vitro biochemical studies (in fact, early in my career I published a theoretical model of cell division along with him [1.180]), Jeremy would always tell everyone in the lab to let the in vivo living cells tell you what is really going on. While the in vitro studies and electron microscope structural studies could provide direction and constraints, Jeremy always relied on live cell observations to drive his understandings.

      His love of microscopy led Jeremy to not only record cells for research purposes, but to start a new company, Cytographics, in which he used 16 mm and video recordings to make educational materials displaying cellular processes (e.g., [1.128] [1.129] [1.161]). In Jeremy’s own words from his Cytographics site, “As this [electron microscope] work progressed, I became increasingly frustrated at trying to recreate dynamic cellular events solely from static images. A turning point in my career came when I first saw the extraordinary sight of a live diatom undergoing mitosis at high magnification. After borrowing a 16 mm time-lapse camera, I was soon filming algae doing all the things I had studied with the electron microscope. Since then, I have built up a laboratory devoted to the high-resolution video imaging and recording of all sorts of cells and microscopic organisms going about their complex and extraordinary lives. It’s the best peep show around!”

Jeremy was a true trailblazer in the study of algae. Discovering the passage of cell wall material from the Golgi [1.51], the role of microtubules and microtubule organizing centers (e.g., [1.90] [1.94] [1.119] [1.123]), and evolutionary relationships among algae (e.g., [1.93] [1.106] [1.111] [1.113]) Jeremy always tried to look at algae in new ways. His work, and that of his students and colleagues, was instrumental in using the highly organized mitotic spindle in diatoms to understand microtubule organization during cell division [1.61] [1.79] [1.218] [1.224] [1.228]. But among the algae, diatoms have always been special to Jeremy.

      Jeremy was fascinated by the early microscopy work by the botanist Robert Lauterborn and his exquisitely detailed drawings of algal phenomena. In 1984 he published a work with some co-authors on a translation of Lauterborn’s 1896 treatise, along with some modern microscopic observations of the same cells [1.167]. The publication displayed how modern optical and electron microscopy simply confirmed the excellent work of Lauterborn in understanding the dynamics of diatom mitosis. I had the great privilege of seeing a copy of the 1896 document when Jeremy had it briefly on loan to take copies of some of the original images for his publication, and the drawings truly were beautiful and amazingly detailed.

      I was lucky enough to be working in Jeremy’s lab in Boulder during an exciting time in diatom motility. Dr. Lesley Edgar was working in the lab, investigating the underlying ultrastructure of motile diatoms, leading her to develop a model of diatom gliding [1.20] [1.21], and where I had the honor of publishing with her on some aspects of diatom morphogenesis [1.11]. She searched through Boulder for some ponds containing the best diatoms for investigation, one of which I still use as my major source of cells for research. As a graduate student I began working with intracellular motility and the role of microtubules and microtubule organizing centers in forming the diatom valves used in motility. I, too, became enthralled with watching diatoms as they glided, and divided, and formed new cell walls. Using both video and film, under Jeremy’s tutelage the lab analyzed the motile behavior and intracellular movements of the cells, and using scanning electron microscopy I studied the forming raphe and valve structures of diatoms during development and reproduction. Jeremy always wanted to know what cell phenomena members of the lab were watching and seeing, helping us to contemplate both their mystery and their beauty as well as their biological importance. After a short time in Jeremy’s lab I was hooked on diatoms and their movement and have never looked back.

      During my time in his lab, Jeremy always filled the lab with joy and enthusiasm for science and exploration. Any time someone would come up with an idea or suggested an experiment, Jeremy would always encourage us to try it out and see what happens. He was a firm believer in the idea that science is about using new techniques and new approaches to poke at the cells and see what they were trying to tell you. And at every point in the work we were doing, Jeremy would strive for excellence in the microscopy coming out of the lab. Whether it was light microscopy using the newest optical techniques, electron microscopy using the best approaches for serial sectioning, or scanning electron microscopy finding the best angles for imaging, he wanted the cleanest, clearest images possible. He had an innate sense of the images that would not only be the best to show the processes or structures we were trying to explain, but would also be the most beautiful. He was worried far less about dogma or current trends, and far more about trying to find the truth.

I also had the pleasure of working in his lab as a visiting colleague after he had gone back to the University of Melbourne. His enthusiasm was undiminished, and his love for microscopy and for developing educational materials had, if anything, only expanded. His encouragement to test and try new ideas led to investigations into some of the light-based responses of diatoms that I continue to this day. As always, he encouraged everyone in the lab to use the latest techniques to tease the truth out of the cells.

      His care for everyone who came into the lab, whether student, technician, visiting colleague, or postdoc, was always an inspiration. He constantly showed a love of life, a love of science, and a love for his lab personnel, all in equal measure. He helped us understand that science is a way to help organize and understand the world and the fabric of nature, and that the diatoms were a beautiful and glimmering thread in that fabric.

      This dedication would also be remiss if it did not mention the incredible diatom researchers from the Pickett-Heaps Lab who were remarkable colleagues and mentors, but have also unfortunately passed away far too soon. I owe my deepest thanks to the late Drs. Lesley Edgar, Cindy Troxell, and Timothy Spurck. Their friendship, knowledge, humor, and dedication helped foster and guide my research into diatoms. It is to their love of science and diatoms, and to Jeremy’s, that this book is dedicated.

       Bibliography of Jeremy D. Pickett-Heaps

      [1.1] Ackland, J.C., West, J.A., Pickett-Heaps, J., Actin and myosin regulate pseudopodia of Porphyra pulchella (Rhodophyta) archeospores. J. Phycol., 43, 1, 129–138, 2007.

      [1.2] Beech, P.L., Wetherbee, R., Pickett-Heaps, J.D., Transformation of the flagella and associated flagellar components during cell division in the coccolithophorid Pleurochrysis carterae. Protoplasma, 145, 1, 37–46, 1988.

      [1.3] Beech, P.L., Wetherbee, R., Pickett-Heaps, J.D., Secretion and deployment of bristles in Mallomonas splendens (Synurophyceae). J. Phycol., 26, 1, 112–122, 1990.