Vijay Kumar Sharma, a professor, an extraordinaire chronobiologist, who spent a lifetime investigating the adaptive value of circadian rhythms, an excellent mentor, and an inspiration to young scientists, passed away on 24 October 2016 in Bengaluru, India, at a young age of 49 years.
He earned his Bachelor (Hons.) in 1988 and Master in Science in 1990 in Physics from the University of Calcutta. His contributions are summarized in his close to 150 publications consisting of peer-reviewed research articles, reviews and book chapters in collaboration with researchers around the world. He was a gifted scholar, a compassionate mentor, excellent teacher and a creative scientist who had an unmatched skill to include technology, mathematics, physiology, ecology, behavioral biology and molecular biology tools as demonstrated in his publications. He was truly an interdisciplinary scientist in that sense. He started out as physics major at Calcutta University (1990), but then swerved into biology, receiving his PhD from North Eastern Himalayan University (NEHU) in 1997 in biological rhythms. Later, he held postdoctoral positions in chronobiology laboratory of Prof. M. K. Chandrashekaran, a renowned circadian researcher at Madurai Kamaraj University during 1995–1996. Since then Prof. Chandrashekaran remained a close collaborator of Prof. Vijay Kumar Sharma until his last days, in Evolutionary and Organismal Biology Unit (EOBU) at Jawahar Lal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru. He also had short postdoctoral stints at Norwegian University of Science and Technology (Trondheim), universities of Groningen (The Netherlands) and Tubingen (Germany) between 1998 and 2001. He joined JNCASR in 1998 as a fellow in EOBU and became faculty fellow in 1999 and established one of the first Drosophila chronobiology laboratories in India. He became an associate professor in 2005 and a professor in 2011 and he chaired the unit until his death. Professor Sharma was popularly referred as VKS by colleagues and students.
While 1990s are best remembered for the discovery of transcriptional-translational feedback loops—first handle of our current molecular understanding of circadian rhythms—VKS’s work demonstrating the theoretical and practical validity of precision of circadian clock under natural, semi-natural and artificial laboratory conditions in a variety of organisms ranging from mouse, millipedes, ants, bats, plants and fruit flies cannot be discounted. He made noteworthy contributions in our understanding of how circadian clock synchronizes to external light–dark cycles via phase–response curve experiments in mice and fruit flies. His work in a way unified some inconsistencies of both parametric (Jürgen Aschoff model) and nonparametric models of entrainment (Colin Pittendrigh model). Parametric model suggests that the entrainment of the circadian clock occurs by altering the clock speed, while nonparametric model approach assumes distinct daily phase shifts in circadian clocks. Our current understanding is that circadian clock integrates the light signals at different times in a differential manner to match its internal speed with external cycle by altering phase as well as the circadian period.
In the last decade and a half, Dr. Sharma rigorously established that circadian rhythms have evolved through the process of natural selection to provide adaptive advantage to their owners. VKS and his coworkers empirically tested and validated Pittendrigh’s “Circadian resonance hypotheses” in fruit flies and ants. His other significant contributions are empirical demonstration of the effect of circadian dysfunction (arrhythmia) on longevity, lengthening life span of arrhythmic flies by providing cyclic environments, and establishing non-neuronal control of egg-laying rhythms in Drosophila. Dr. Sharma along with collaborations with researchers at New York University (NYU) and University of California, Irvine (UCI) using whole-cell patch-clamp electrophysiology experiments showed that intracellular calcium and sodium channels regulate circadian rhythms. This group also established the role of a subset of circadian neurons in promoting arousal in Drosophila.
Dr. Sharma had a knack to inspire students through his remarkable communication skills, casual talks, instituting several teaching programs such as INSPIRE, Science and Engineering Research Board (SERB) schools and co-organizing circadian biology workshops like Indian School of Chronobiology, Project Oriented Biological Education (POBE) for young summer trainees. He was honored with numerous awards during his illustrious career; some of them include the 1998 Indian National Science Academy (INSA) Young Scientist Medal, 2001 AK Bose Memorial award and 2010 CNR Rao Oration award. VKS also served as Young Associate for Indian Academy of Science (IAS, Bengaluru), and became fellow of IAS and INSA in 2012 and 2013, respectively. VKS also served as editorial board member for Journal of Circadian Rhythms, Journal of Genetics and Current Science.
Memories of a mentor
VKS was also a wonderful mentor. I was his second graduate student at JNCASR and had the great fortune to be able to work with him during 2001–2006. Having done my masters in Biotechnology, I was fancying joining some random molecular biology laboratory at Indian Institute of Sciences (IISc), a leading research institute in India. At the same time, I was also called in for an interview for PhD program in EOBU at JNCASR. Although I had never heard of EOBU at JNCASR, I was very curious to find out what research program did they offer. It was then, I’m embarrassed to concede that I heard first time about circadian rhythms and chronobiology. The science behind “time and timing of everything,” as explained by Dr. Sharma and Dr. M. K. Chandrashekaran, fascinated me instantly. I sincerely thanked the duo for the interview and returned home to join his newly established lab at JNCASR a month later. Since then I’ve been actively involved in doing research in the circadian rhythms and sleep.
I spent five and a half delightful years in his lab. I was exposed to a new academic world where senior professors, young researchers and colleagues were in sort of collaboration. I was awed by the scope of learning and training in his lab. After embarking on real research projects in his lab, I was also inspired by his teaching skills. He was an energetic teacher who took special interest in training and inspiring students. I vividly remember him explaining various trivia, terminology, and history of chronobiology during my initial year of PhD and in subsequent years. We were thrilled by his apt and incidental anecdotes regarding his personal interactions with big names in the field as we anticipated ourselves there one day. VKS showed unfettered passion in discussing politics, culture, sports, people, ideas, nature, traveling experiences and most importantly food with colleagues, friends and students. He was a big time bon vivant, who cherished cuisines from all over the world. He contributed enormously to the JNCASR community; he was at the forefront in organizing local meetings, cultural festivals, quizzes, counseling students, etc. He detested the idea of elitism in research institution; many of his protégés came from far and remote smaller towns of India, as he held the view that science can be done by anyone who has deep interest, passion and an open mindset to learning. He was all ears listening to young minds inquisitiveness, sporadic problems with meals, and recreations in hostels (students’ boardinghouse) and solving them amicably. The volleyball field at JNCASR would any day remind us of his presence; rain or shine VKS would be there in the evenings spiking the ball. Over the years, initially as a neophyte and now as an experienced circadian researcher I’ve tried to imbibe his passion, rational attitude, energy and eagerness to nurture new breed of researchers and will be passing along those qualities.