Comparative Proteomic Analysis Between The Near-isogenic Line Of Silkworm Stony (st) Mutant And Its Backcross Parent

Silkworm（Bombyx mori）has a history of thousands of years of breeding in China, astypical representatives of the Lepidoptera, it not only has a significant economic value, andis also an important model organism. With the completion of silkworm genome sequencing,the domestic and foreign research focus will gradually shift to functional genomicsresearch. Proteins are implementers of gene function, and is the direct embodiment of life,no analysis of proteins at an advanced, you cannot understand the nature of biologicalproblems.New mutations is an important object of genetic study, also is the main material offunction gene research. Numerous results of genetic study are benefited from the study ofmutated genes. There are more than400mutation of silkworm, stony mutant(st) is one ofthe typical shape mutation. Its main feature is the tight skin, hard body, swelling of thetrailing edge in each link. And such traits is the most evident in the glutonous period of5thinstar, when before wandering stage.Currently, two-dimensional gel electrophoresis combined with mass spectrometrytechnology is the most widely used in proteomic studies, which just provides a goodopportunity to study mutations material. Using its principle simple, operations convenientof research features, through comparing the mutation of silkworm body and normalsilkworm body tissue samples, you can find the key proteins related to mutation function,fully illustrate the genetic basis of mutation, expand the research using.In this study, firstly, the near-isogenic line of st mutant C8, which has the samegenetic background with C108, was established by multiple hybridization and backcrosswith C108. Through the research of the difference of C8and C108, we can know thedifferences between st mutant and wild type. Comparing C8and C108cuticular chitincontent, found C8chitin content is slightly lower than C108, but the difference is notsignificant. The relationships of chitin content and this mutation character still need tofurther study. Secondly, we comparing the protein composition differences of cuticle, fatbody, midgut tissue in C8and C108by using2-D electrophoresis. And we selected39proteins spots from the differences by software, then identified them byMALDI-TOF-MS,31proteins are successful identified, including enzymes, structureprotein, transcription factors, heat shock protein, glycoprotein, transporters, etc. and more,there are five function unknown protein we have found.In order to validate the2-D electrophoresis results, we choose five differential proteingene GSTd2、GSTs1、Pglym、Tpi、Pdi to check the differences at transcription level, byusing Real-time PCR. The results are consistent with2-D electrophoresis, but only theGSTs1、Pglym、Tpi gene differences reached significant level(P＜0.05). How the threegenes affect regulation the formation of mutant character required further study.