집어등 포획어종의 시각수용체와 LED 파장별 광반응 분석

Abstract

Most vertebrates have two type of photoreceptor cells, rod cell for scotopic vision and cone cell for photopic vision. Rhodopsin, a dim –light photoreceptor, has been used as a model system for structure function study of G Protein-coupled receptors transmitting extracelluar signals such as neurotransmitters, hormones, light, smells, and tastants. To study the light response in fish, rod opsin genes of squid Todarodes pacificus, mackerel Scomber japonicus were isolated. Opsin gene were obtained by PCR amplification of genomic DNA. Primers F1 and R1 containing EcoR I and Xho I recognition sequence, at their 5’ and 3’ end, respectly, were used for PCR amplification to faciliate the cloning into pMT4 for heterologous expression. Recombinant rod opsin were expressed in COS cell and analyzed by western blot analysis. Expressed in COS cells transfected with pMT4 vector containing opsin gene. Upon reconstitution with 11-cis retinal, UV/VIS Spectra were taken on the dark and after illumination to analyzed the absorption maxima. In order to study the light response relation with LED wavelength, LED modules with 4 different wavelengths(red, blue, cyan, white) were constructed for light response experiment. Optical characteristic of LED modules were measured by using radiometer and integrating sphere. Water tank (diameter 3m) was equipped with LED module and underwater acoustic camera were used for the experiment. Underwater acoustic camera was used for measuring on the frequency and behavioral responses of fish upon LED illumination. Experimental fish were accommodated for 30 minutes in dark room condition. Fish movement were recored for 5 minute in the dark and upon illumination. Faster movement of fish were detected under LED illumination of cyan LED as compared to Red, Blue and White LED. This suggests that light with wavelength close to absorption maxima of rhodopsin in move effective for light response.