Team:IISER-Tirupati India/Description



Coming from a country that has the second-largest population, we understand how the lack of contraception and family planning counseling can lead to overpopulation and consequently slow down the progress of a nation!

Due to the stigma associated with these topics, no one talked to us openly about contraception or family planning in our homes or schools. But as we grew up, we came to realise that the topics spoken in such hush-hush voices since our childhood would turn out to be one of the most integral parts of our life. Contraception is an integral part of every individual's life and it’s importance for global population stabilisation cannot be overlooked.

However, a recent study by the World Health Organization suggests that in developing countries, two-thirds of sexually active women who wished to delay or limit childbearing stopped using contraception for fear of side effects, health concerns, and underestimation of the likelihood of conception. [1]

When we looked into the different methods of contraception used by people around the world, we were appalled by the range of effects that are inflicted on people with uteruses. [2-9]Contraception is an integral part of the life and freedom of uterus owners and it is unfortunate that the current effective methods of contraception are to their health and the environment [10] in both the short and long term. [2-9] One year into the pandemic, UNFPA estimates million women have seen contraceptive interruptions, leading to 1.4 million unintended pregnancies. (Source: UNFPA)

Moreover, the fact most women who are on hormonal birth control have an increased risk of TTS (a condition in which there are increased blood clots and low platelet levels) due to COVID-19 vaccination (Source: CDC), showed us how important it is to develop long term and effective non-hormonal methods of contraception for uterus owners. 

Thus, we started on our journey to come up with an effective, long term and reversible alternative for contraceptives, one that has minimal side effects on the user’s health and on the natural environment. 

We wanted to explore the possibility of introducing a contraceptive that acts on the gamete rather than the body of the uterus owner and the growing research on the commensal microbiome of the reproductive tract and the human gametes inspired us. The work of contraceptive developers, researchers studying the human gametes, and previous iGEM projects (Team Montpellier, iGEM 2018) made us believe that we can also come up with a solution to the aforementioned problems with the help of Synthetic biology. Along with it, the thousands of Comprehensive sexuality educators working in India and around the world gave us the inspiration to talk openly about the tabooed topics of sexuality, contraception, and their significance in our life through our iGEM project. 

“Problems are not stop signs, they are guidelines” /pos

Robert H. Schuller

Our project OviCloak is about employing synthetic biology to design a novel contraceptive for uterus owners. We plan to genetically modify the commensal bacteria found in the fallopian tubes[11-13] to sense the hormonal levels [14] and secrete a natural ovum-specific protease called Ovastacin. This protease specifically acts on the zona pellucida layer of the ovum and brings about a zona hardening reaction by cleaving the ZP2 protein of the zona pellucida [15-16] .Once the zona hardening reaction is initiated, the incoming sperms or male gametes are no longer able to penetrate the ovum [17] and hence, it is an effective block to fertilization

Keeping in view the need for a safe and reversible contraceptive, the bacteria will also be engineered with two inducible kill switches for the reversibility of contraception and biosafety.The bacteria is engineered with a xylose inducible kill switch[18-23] to ensure reversibility of the contraception and a blue-light inducible kill switch[24-28] to kill the bacteria upon any environmental release.

Our project is aimed towards a non-hormonal and environmentally friendly approach to Long Acting Reversible Contraception (LARC). Our project modules have been divided in such a way that they encompass each and every aspect of the goal that we have set to achieve.

We believe that our project is a useful application of synthetic biology as it’s tools and techniques allow us to use a chassis organism to produce a molecule that directly interacts with the gamete and not with the body and thus, comes with minimum side effects. Due to the tools and techniques of synthetic biology, we can also bring about one of the most important features of a contraceptive, which is reversal at will. This is achieved by engineering the bacteria with the inducible kill switch.

Through our project we wish to instigate a fresh perspective towards contraceptives and improve global reproductive health and rights by providing a safe and effective alternative.

IISER Tirupati Logo
Symbol showing ecofriendly attribute of OviCloak


Symbol showing minimum side effects attribute of OviCloak

Minimum side effects

Symbol showing the long term attribute of OviCloak

Long term

Symbol showing non-hormonal attribute of OviCloak


Symbol showing ovum specific attribute of OviCloak

Ovum Specific

Symbol showing reversible attribute of OviCloak


The COVID-19 global pandemic has been affecting the world and India, being the second-most affected country, experienced several spans of complete lockdowns in two consecutive waves of infection. This limited our laboratory access and reduced the availability of resources to carry out this project. We have been rigorously working to provide the mathematical modelling for our project and hope to show the laboratory proof of concept with the experiments designed for the same. With a laboratory access of barely 2 months, we have worked on those experiments in an attempt to provide a proof of concept. While we were not able to carry the complete design, test and rebuild system on the laboratory front, it widened our understanding and engagement with stakeholders. We wish to instigate a fresh perspective towards contraception, and we believe that our project for iGEM 2021 has brought us a lot closer to achieve that and helped us break the dawn on a new era of modern contraception.

References : 

  1. Bellizzi, S., Mannava, P., Nagai, M., & Sobel, H. L. (2020). Reasons for discontinuation of contraception among women with a current unintended pregnancy in 36 low and middle-income countries. Contraception, 101(1), 26-33.
  2. Burkman, R., Schlesselman, J. J., & Zieman, M. (2004). Safety concerns and health benefits associated with oral contraception. American journal of obstetrics and gynecology, 190(4), S5-S22.
  3. Beral, V., Bull, D., Doll, R., Peto, R., Reeves, G., van den Brandt, P. A., & Goldbohm, R. A. (2004). Collaborative group on hormonal factors in breast cancer: breast cancer and abortion: collaborative reanalysis of data from 53 epidemiological studies, including 83000 women with breast cancer from 16 countries. Lancet, 363(9414), 1007-1016.
  4. Smith, J. S., Green, J., de Gonzalez, A. B., Appleby, P., Peto, J., Plummer, M., ... & Beral, V. (2003). Cervical cancer and use of hormonal contraceptives: a systematic review. The Lancet, 361(9364), 1159-1167.
  5. Edlow, A. G., & Bartz, D. (2010). Hormonal contraceptive options for women with headache: a review of the evidence. Reviews In Obstetrics And Gynecology, 3(2), 55.
  6. Hubacher, D., Chen, P. L., & Park, S. (2009). Side effects from the copper IUD: do they decrease over time?. Contraception, 79(5), 356-362.
  7. Cooper, D. B., & Mahdy, H. (2021). Oral contraceptive pills. StatPearls [Internet].
  8. Ramdhan, R. C., Simonds, E., Wilson, C., Loukas, M., Oskouian, R. J., & Tubbs, R. S. (2018). Complications of subcutaneous contraception: a review. Cureus, 10(1).
  9. Shufelt, C. L., & Bairey Merz, C. N. (2009). Contraceptive hormone use and cardiovascular disease. Journal of the American College of Cardiology, 53(3), 221-231.
  10. Lund University. (2016, March 4). Estrogen in birth control pills has a negative impact on fish. ScienceDaily.
  11. Pelzer, E. S., Willner, D., Buttini, M., Hafner, L. M., Theodoropoulos, C., & Huygens, F. (2018). The fallopian tube microbiome: implications for reproductive health. Oncotarget, 9(30), 21541.
  12. Pelzer, E. S., Willner, D., Huygens, F., Hafner, L. M., Lourie, R., & Buttini, M. (2018). Fallopian tube microbiota: evidence beyond DNA. Future microbiology, 13(12), 1355-1361.
  13. Yu, B., Liu, C., Fredricks, D., & Swisher, E. (2020). Microbiome profiling of fallopian tubes. Gynecologic Oncology, 156(3), e26.
  14. Grazon, C., Baer, R. C., Kuzmanović, U., Nguyen, T., Chen, M., Zamani, M., ... & Galagan, J. E. (2020). A progesterone biosensor derived from microbial screening. Nature communications, 11(1), 1-10
  15. Burkart, A. D., Xiong, B., Baibakov, B., Jiménez-Movilla, M., & Dean, J. (2012). Ovastacin, a cortical granule protease, cleaves ZP2 in the zona pellucida to prevent polyspermyOvastacin cleaves ZP2 and prevents polyspermy. The Journal of cell biology, 197(1), 37-44.
  16. Körschgen, H., Kuske, M., Karmilin, K., Yiallouros, I., Balbach, M., Floehr, J., ... & Stöcker, W. (2017). Intracellular activation of ovastacin mediates pre-fertilization hardening of the zona pellucida. MHR: Basic science of reproductive medicine, 23(9), 607-616.
  17. Fahrenkamp, E., Algarra, B., & Jovine, L. (2020). Mammalian egg coat modifications and the block to polyspermy. Molecular reproduction and development, 87(3), 326-340.
  18. Elbaz, M., & Ben-Yehuda, S. (2015). Following the fate of bacterial cells experiencing sudden chromosome loss. mBio, 6(3), e00092–e15. (yqcG)
  19. Holberger, L. E., Garza-Sánchez, F., Lamoureux, J., Low, D. A., & Hayes, C. S. (2012). A novel family of toxin/antitoxin proteins in Bacillus species. FEBS letters, 586(2), 132–136. 
  20. Toxin-Antitoxin systems eliminate defective cells and preserve symmetry in Bacillus subtilis biofilms
    Zohar Bloom-Ackermann, Nitai Steinberg, Gili Rosenberg, Yaara Oppenheimer-Shaanan, Dan Pollack, Shir Ely, Nimrod Storzi, Asaf Levy, Ilana Kolodkin-Gal First published: 23 July 2016. (yqcG and yqcF)
  21. Brantl, S., & Müller, P. (2019). Toxin⁻Antitoxin Systems in Bacillus subtilis. Toxins, 11(5), 262. (General info about toxin anti-toxins in bacillus subtilis)
  22. Ni, L., Tonthat, N. K., Chinnam, N., & Schumacher, M. A. (2013). Structures of the Escherichia coli transcription activator and regulator of diauxie, XylR: an AraC DNA-binding family member with a LacI/GalR ligand-binding domain. Nucleic acids research, 41(3), 1998–2008. (xylR binding unbinding case: E coli)
  23. Bhavsar, A. P., Zhao, X., & Brown, E. D. (2001). Development and characterization of a xylose-dependent system for expression of cloned genes in Bacillus subtilis: conditional complementation of a teichoic acid mutant. Applied and environmental microbiology, 67(1), 403–410. (xylR)
  24. Cameron, D. E., & Collins, J. J. (2014). Tunable protein degradation in bacteria. Nature Biotechnology, 32(12), 1276–1281. (protein degradation by mf-Lon)
  25. The Blue-Light Receptor YtvA Acts in the Environmental Stress Signaling Pathway of Bacillus subtilis
    Tatiana A. Gaidenko, Tae-Jong Kim, Andrea L. Weigel, Margaret S. Brody, Chester W. Price DOI: 10.1128/JB.00691-06 (Ytva to SigB activation)
  26. Ching-Ying Chen, Shao-Chun Lu, Ta-Hsiu Liao
    Cloning, sequencing and expression of a cDNA encoding bovine pancreatic deoxyribonuclease I in Escherichia coli: purification and characterization of the recombinant enzyme, Gene, Volume 206, Issue 2,1998, Pages 181-184. (Bovine Dnase)
  27. Noriko Suzuki, Naoki Takaya, Takayuki Hoshino, Akira Nakamura, Enhancement of a σB-dependent stress response in Bacillus subtilis by light via YtvA photoreceptor, The Journal of General and Applied Microbiology, 2007, Volume 53, Issue 2, Pages 81-88, Released June 14, 2007, Online ISSN 1349-8037, Print ISSN 0022-1260, 
  28. Haldenwang W. G. (1995). The sigma factors of Bacillus subtilis. Microbiological reviews, 59(1), 1–30. (SigB and gsiB)
    from Previous iGEM projects : Vagineering (2018)
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