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Department of Molecular Reproduction, Development and Genetics

  • A typical animal cell. Inside each cell are specialised subunits called organelles that perform different functions. This illustration shows the organelles that you will encounter in the text. The layout of the different organelles will help you better appreciate the millions of different processes that are happening inside you right now.

Image adapted from Imgarcade.

At the Department of Molecular Reproduction, Development and Genetics (MRDG), how the cell functions - under normal conditions and when there is disease - is the focal point of research. 

Gene expression is the process by which information in a gene is transformed into proteins, the final product that actually carries out specific functions. Depending on the kind of cell, different genes are expressed; there is no reason for a cell in the uterus to produce testosterone, for instance. Paturu Kondiah works on how genes in specific cells are turned on and off, especially by hormones like oestrogen. The goal is to investigate how gene regulation and gene expression influence disease processes.

 Hormones are chemical messengers which regulate many of our behavioural and physiological activities. A particular class of hormones, made of carbohydrate chains attached with small proteins, influence reproduction and other important functions. By investigating the molecular structure of the hormones and studying the genetics behind hormone production, Rajan Dighe’s group has been looking at the possibility of making “designer” hormones to treat infertility.

R Medhamurthy’s lab researches the physiology and cell biology of the mammalian ovary, which undergoes dramatic structural and functional changes during the lifespan of a female mammal. The lab uses molecular and cellular biology tools to study ovarian changes in different mammalian model systems, including mice and even female buffaloes.

Arun Kumar’s group is broadly interested in the genetic basis of a variety of disorders - microcephaly, retinitis, anencephaly, otosclerosis, Parkinson’s and Wilson’s disease. They are especially interested in the basis of oral cancers, with the aim of finding easy ways for diagnosing the cancer, and devising strategies for therapy.

Looking at cellular processes in other organisms can provide insight into the basic principles in cell biology, genetics and evolution. Bacteria have “cryptic” genes, which are kept in the “off” mode until the cellular environment demands their expression. Why bacteria maintain these genes is an evolutionary mystery that S Mahadevan and his group are trying to solve. Vidyanand Nanjundiah studies developmental biology of amoeba which start off as free-living organisms but later aggregate and differentiate into different structures. Upendra Nongthoma employs Drosophila (fruit flies) and zebrafish as models to study muscular and neuromuscular disorders such as myopathy and muscle degeneration.

Most of our cells are programmed to perform specific functions - liver cells are different from skin cells which are different from the cells in your retina. Stem cells are those in which the programming has not taken place - they are capable of differentiating into any kind of cell. We have these cells in our bone marrow, and in the umbilical cord just after birth. Annaporni Rangarajan’s lab works on these cells, especially the ones that are cancerous - they are found inside cancerous tissue, and can give rise to all cell types found in a particular cancer sample. The lab is trying to find out the mechanisms that control the ability of stem cells to divide and yet remain unspecialised.

 Deepak Saini‘s goal is to decipher cellular signalling, a process in which biomolecules talk to one another passing on important information from external agents. Live cell imaging as well as biochemical and genetic approaches are used to study signalling in bacteria, and in multicellular organisms. This has a variety of applications: studying bacterial invasions, how a microbe communicates with a host while causing infection, formation of cancers and cell ageing. A more specific mechanism of cell signalling is the focus of Sandhya Visweshariah’s lab - the use of small molecules called cyclic nucleotides. These have an “on” form, which set off a cascade of downstream reactions, and an “off” form.

P B Seshagiri ‘s area of interest is early mammalian development. Sperm biology, development and embryos and stem cell biology are studied which have applications in the management of infertility and reproductive health.

Varsha Singh studies the role of the nervous system in regulating longevity, inborn immunity and other biological processes. She uses Caenorhabditis elegans, a 1 mm long transparent worm that lives in the soil. It has a basic nervous system, which responds to external and internal cues, like our own. More importantly, it gets killed by the same microbes that affect humans, making it a great model system to study the role of the nervous system in regulating biological processes.

Papers:

Najila Arshad from Sandhya Visweshariah’s lab is co-first author of a paper published in the New England Journal of Medicine, one of the most prestigious journals medical journals in the world. A cross-country collaboration gave insight into the molecular basis of a type of diarrhoea that runs in the family - increased cell signalling in the intestines disrupts normal bowel function.

Our body regulates the number and structure of mitochondria, the “powerhouses” of the cell, based on the needs of a particular cell. Muscle cells, for instance, need more mitochondria. In a paper that appeared in the Journal of Cell Science, Mamta Rai and Prasanna Katti from Upendra Nongthomba’s lab worked with the fruit fly Drosophila to find that a particular protein triggers a gene that promotes growth of mitochondria and maintenance of muscles from the pupal stage onwards. 

Though they are so small that they can’t be seen, bacteria get eaten too, by amoeba and tiny worms. A lot of them have evolved ways to avoid predators. Publishing in Proceedings of the Royal Society B, Robert Sonowal and others from S Mahadevan’s group showed that bacteria in soil degrade plant derived compounds to avoid getting eaten.

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