Jiffin Paulose

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  • Post-Doctoral Scholar
  • Biology
  • Biology Education
302B T. H. Morgan Bldg
(859) 257-2289
Research Interests:

Ph.D. Biology - Texas A&M University

B.Sc. Biology - Texas A&M University


Jiffin received his B.Sc. in Biology from Texas A&M University.  It was during his undergraduate studies where he received his first taste of empirical exploration.  Under the tutelage of Dr. Vincent Cassone, Jiffin engaged in what was to him ground-breaking and exciting research on circadian rhythms.  His experiments ultimately led him nowhere scientifically speaking, but it was a lot of fun.

After graduating, Jiffin obtained gainful employment on the campus of A&M as a lab manager in the Department of Entomology under the Texas Agricultural Experiment Station.  Here, Jiffin made full use of his undergraduate training; not in science, but his minor in business administration.  After a year of masterful budgeting and accounting, motivated supervising of equally uninspired undergraduate employees, and horrifying maintenance of various mosquito colonies, Jiffin returned to the laboratory of Dr. Cassone to pursue a Ph.D. in Biology.

Graduate school was a refreshing reprieve for Jiffin.  He soon learned just how practical his undergraduate education in life sciences was:  not very.  It was here, in the graduate program, where Jiffin learned how to think.

It was a hot and humid Summer of 2008 when Jiffin heard the call from the University of Kentucky.    The most interesting aspect of the call was that it wasn't even his phone that rang.  The offer to move was given to his mentor, Dr. Cassone; and with that offer, a terrible choice.  One door led away from Texas, the only academic home he had ever known.  It was safe, it was comfortable, it was home.  This foreign land of Kentucky was a place he thought he would only know in his dreams.  The birthplace of bourbon, bluegrass music, and Johnny Depp was scary, yet intriguing; distant, yet manageable by car; foreign, yet still within the borders of the continental U.S.  The other door led to the same lab and a similar life, but without the physical presence of his mentor.  That seemed boring, so Jiffin took the first option.

Jiffin successfully defended his Ph.D. thesis and continues as a Post-doctoral researcher in the Biology Department.  His current work investigates how circadian rhythms - the biological clock that synchronizes biological processes to the daily environment - influence the gastrointestinal tract and its resident microbiome.  

Although Jiffin is ever closer to ending his tenure at the University of Kentucky, he is still unsure of where to go from here.  As has always been the case, he hopes that Science will lead the way.



Circadian rhythms in the aging gastrointestinal tract

Previous research in the Cassone lab has shown that the colon expresses circadian rhythms in gene expression, contractility, and motility.  Our research has also shown that the gut is capable of maintaining rhythmicity in the absence of signaling from the master clock in the brain, the suprachiasmatic nucleus.  Currently, we are investigating how aging affects the clock at the molecular and physiological levels.  To do this, we have collected gut tissue and stool samples every 4 hours for 24 hours from young (2months)-, middle(12months)-, and old(24month)-aged mice.  From these tissue, we quantified mRNAs associated with the molecular clock, immune-associated, and gut motility-associated genes.  These data so far have shown that the molecular clockworks within the gut are largely unperturbed by aging, similar to data from other peripheral tissues such as liver and heart.  Remarkably, the genes affected by aging are those regulating melatonin production in the gut.  Decreased melatonin output as a result of aging has been shown to affect sleep, but these are the first data to show an effect of aging on melatonin production in the gut.  This disruption may be associated with age-related gastrointestinal issues and disease states such as IBS and Crohn's Disease.

Circadian rhythms in the gut microbiome

Recently, the Cassone lab has shown that a member of the human gut microbiome, Enterobacter aerogenes, exhibits circadian rhythms in motility that is markedly increased in the presence of the brain and gut hormone melatonin.  When grown in the presence of physiological levels of melatonin, E. aerogenes exhibits swarming behavior that cycles with a period of ~25 hours.  We have captured real-time expression of this rhythm and have established that temperature also affects its expression.  Currently, we have several projects aimed at characterizing this clock: identifying the genes responsible using both forward and reverse genetics approaches, generating reporter strains of the bacteria that can be visualized using bioluminescence and fluorescence imaging, and determining how this bacterium behaves in vivo by colonization of the mouse gastrointestinal tract and colonic enteroid cell culture.  These studies will further our understanding of how circadian rhythms are established in the microbiome and by which mechanisms the resident bacteria in our bodies may communicate with us, and vice versa.

Selected Publications: 

Paulose, J. K., Cassone, C. V, and V. M. Cassone (2018) Aging, Melatonin Biosynthesis and Circadian Clockworks in the Gastrointestinal System of the Laboratory Mouse. Physiol. Genomics. doi: 10.1152/physiolgenomics.00095.2018


Cassone, V. M., Paulose, J. K., and C. E. Harpole (2017) Aging and the circadian control of the gastrointestinal system: from the brain to the gut microbiome (and back). In S. M. Jazwinski, V. P. Belancio, and S. M. Hill (Eds.), Circadian Rhythms and Their Impact on Aging (pp. 83-102). Cham, Switzerland: Springer International.


Cassone, V. M., Paulose, J. K., Harpole, C. E., Li, Y., and M. Whitfield-Rucker (2017) Avian Circadian Organization. Biological Timekeeping: Clocks, Rhythms, and Behavior. Springer 10.1007/978-81-322-3688-7


Paulose, J. K. and V. M. Cassone (2016) The Melatonin-Sensitive Circadian Clock of the Enteric Bacterium Enterobacter aerogenes. Gut Microbes DOI: 10.1080/19490976.2016.1208892.


Paulose, J. K., J. M. Wright, A. G. Patel, and V. M. Cassone (2016) Human Gut Bacteria Are Sensitive to Melatonin and Express Endogenous Circadian Rhythmicity. PLoS One 11(1):e0146643.


Collett, J. A., J. K. Paulose, V. M. Cassone, and J. L. Osborne (2015) Kidney-Specific Reduction of Oxidative Phosphorylation Genes Derived from Spontaneously Hypertensive Rat. PLoS One 10(8):e0136441.


Paulose, J. K., E. B. Rucker, and V. M. Cassone (2015) Analysis of circadian rhythms in embryonic stem cells. Methods Mol. Biol. 1235:73-9.


Wang, G., C. E. Harpole, J. K. Paulose, and V. M. Cassone (2014) The role of the pineal gland in the photoperiodic control of bird song frequency and repertoire in the house sparrow, Passer domesticus. Horm. Behav. 65(4):372-379.


Paulose, J. K., E. B. Rucker, and V. M. Cassone (2012) Toward the beginning of time: circadian rhythms in metabolism precede rhythms in clock gene expression in mouse embryonic stem cells. PLoS One 7(11):e49555.


Malloy, J. N., J. K. Paulose, and V. M. Cassone (2012) Circadian rhythms of gastrointestinal function are regulated by both central and peripheral oscillators. Am. J. Physiol. Gastrointest Liver Physiol. 303(4):G461-73.



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