title: The role of photo-electric properties of silk cocoon membrane in pupal metamorphosis: A natural solar cell.
abstract: Silkworm metamorphosis is governed by the intrinsic and extrinsic factors. One key intrinsic factor is the temporal electrical firing of the neuro-secretory cells of the dormant pupae residing inside the silk cocoon membrane (SCM). Extrinsic factors are environmental like temperature, humidity and light. The firing pattern of the cells is a function of the environmental factors that eventually controls the pupal development. How does the nervous organization of the dormant pupae sense the environment even while enclosed inside the cocoon shell? We propose that the SCM does this by capturing the incident light and converting it to electricity in addition to translating the variation in temperature and humidity as an electrical signal. The light to electricity conversion is more pronounced with ultraviolet (UV) frequency. We discovered that a UV sensitive fluorescent quercetin derivative that is present on the SCM and pupal body surface is responsible for generating the observed photo current. Based on these results, we propose an equivalent circuit model of the SCM where an overall electrical output transfers the weather information to pupae, directing its growth. We further discuss the implication of this electrical energy conversion and its utility for consumable electricity.
authors.affiliation: Biological Sciences &Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
authors.forename: Brindan
authors.initials: B
authors.lastname: Tulachan
authors.affiliation: Department of Applied Chemistry and Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi, 110042, India.
authors.forename: Shivansh
authors.initials: S
authors.lastname: Srivastava
authors.affiliation: Biological Sciences &Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
authors.forename: Tejas Sanjeev
authors.initials: TS
authors.lastname: Kusurkar
authors.affiliation: Defense Institute of Physiology &Allied Sciences, Defense Research Development Organization, Timarpur, Lucknow Road, Delhi, 110054, India.
authors.forename: Niroj Kumar
authors.initials: NK
authors.lastname: Sethy
authors.affiliation: Defense Institute of Physiology &Allied Sciences, Defense Research Development Organization, Timarpur, Lucknow Road, Delhi, 110054, India.
authors.forename: Kalpana
authors.initials: K
authors.lastname: Bhargava
authors.affiliation: Solid State Physics Laboratory, Defense Research Development Organization, Timarpur, Lucknow Road, Delhi, 110054, India.
authors.forename: Sushil Kumar
authors.initials: SK
authors.lastname: Singh
authors.affiliation: Industrial &Management Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.|Design Program, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
authors.forename: Deepu
authors.initials: D
authors.lastname: Philip
authors.affiliation: Institute Psychiatrist, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Bajpai
authors.affiliation: Biological Sciences &Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.|Design Program, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, 208016, India.
authors.forename: Mainak
authors.initials: M
authors.lastname: Das
mesh_terms: D000818:Animals; D012831:Bombyx / Q000254:growth & development / Q000378:metabolism*; D004560:Electricity; D055664:Electrochemical Techniques; D004566:Electrodes; D006813:Humidity; D008566:Membranes / Q000737:chemistry* / Q000378:metabolism; D008675:Metamorphosis, Biological; D011679:Pupa / Q000254:growth & development / Q000378:metabolism; D011794:Quercetin / Q000737:chemistry; D047011:Silk / Q000737:chemistry / Q000378:metabolism; D012993:Solar Energy; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D047011:Silk; D011794:Quercetin