Picosecond UV laser induced morphological, biochemical and biological changes in Bombyx mori

Background: In the light of various applications of UV laser in biological system, we have investigated the effect of picosecond UV laser radiation on silkworm Bombyx mori. Materials and Methods: The eggs of NB4D2 of different stages were exposed to pico second pulse laser at 355 nm from Nd:YAG laser for different durations. Results: Due to irradiation alterations in crescent larval body markings, pupae with transpositioned antennae, pseudo abdominal and caudal legs were produced from 2 and 8 hr old embryos irradiated for 30 and 50 seconds respectively. Moths devoid of antennae and underdeveloped legs were also produced from 16 and 8 hr old embryos irradiated for 60 and 50 seconds respectively. The morphological anomalies were found highest in picosecond (6.16%) compare to nanosecond (1%) irradiated embryos at 8 and 16 hrs respectively and it is duration dependent. SDS-PAGE analysis of embryo revealed the occurrence of a 41 kDa new protein and delayed utilization of yolk proteins in the irradiated embryos. The larval haemolymph protein profile also exhibited 24, 25 and 6.2 kDa new protein bands. Embryo hatching, larval weight and cocooning rate was significantly affected and declined as duration of irradiation increases. Conclusion: It is clear from the present study that morphological anomalies and distinct variations in egg and haemolymph proteins establish a strong evidence that UV picosecond laser not only cause damage on embryonic cells but also interfere in transcriptional factors encode for organogenesis and proteins. Thus present study envisage the use of UV laser irradiation as a potential tool in investigating the embryonic and postembryonic development and cross-linking between DNA and protein using silkworm B. mori as molecular model. Iran. J. Radiat. Res., 2011 9(2): 127-137