The piggyBac (PB) transposon is the most widely used vector for generating transgenic silkworms. The stability of the PB transposon in the receptor is a serious concern that requires attention because of biosafety concerns. In this study, we found that the transgene silkworm developed loss of reporter gene traits. To further investigate the regularity, we traced the genes and traits of this silkworm. After successful alteration of the silkworm genome with the MASP1 gene (named red-eyed silkworm; RES), silkworm individuals with lost reporter genes were found after long-term transgenerational breeding and were designated as the white-eyed silkworm (WES). PCR amplification indicated that exogenous genes had been lost in the WES. Testing was conducted on the PB transposons, and the left arm (L arm) did not exist; however, the right arm (R arm) was preserved. Amino acid analysis showed that the amino acid content of the WES changed versus the common silkworm and RES. These results indicate that the migration of PB transposons in Bombyx mori does occur and is unpredictable. This is because the silkworm genome contains multiple PB-like sequences that might influence the genetic stability of transgenic lines. When using PB transposons as a transgene vector, it is necessary to fully evaluate and take necessary measures to prevent its re-migration in the recipient organism. Further experiments are needed if we want to clarify the regularity of the retransposition phenomenon and the direct and clear association with similar sequences of transposons.

piggyBac（PB）转座子是用于产生转基因蚕的最广泛使用的载体。由于生物安全性的考虑，PB转座子在受体中的稳定性是一个需要引起重视的严重问题。在这项研究中，我们发现转基因家蚕发展了报告基因特性的丧失。为了进一步研究其规律性，我们追踪了这种蚕的基因和特征。用MASP1基因成功地改变了蚕的基因组（称为红眼蚕； RES）后，经过长期的世代繁殖，发现了丢失了报道基因的蚕个体，并被称为白眼蚕（WES）。PCR扩增表明外源基因已在WES中丢失。在PB转座子上进行了测试，并且左臂（L臂）不存在。然而，右臂（R臂）被保留。氨基酸分析表明，与普通家蚕和RES相比，WES的氨基酸含量发生了变化。这些结果表明PB转座子在家蚕确实会发生并且是不可预测的。这是因为家蚕基因组包含多个PB样序列，可能会影响转基因品系的遗传稳定性。当使用PB转座子作为转基因载体时，有必要进行充分评估并采取必要措施，以防止其在受体生物体中重新迁移。如果我们想弄清重新转座现象的规律性以及与转座子相似序列的直接和清楚的联系，则需要进一步的实验。