• A novel Lozenge gene in silkworm, Bombyx mori regulates the melanization response of hemolymph

      Xu, M.; Wang, X.; Tan, J.; Zhang, K.; Guan, X.; Patterson, Laurence H.; Ding, H.; Cui, H. (2015-11)
      Runt-related (RUNX) transcription factors are evolutionarily conserved either in vertebrate or invertebrate. Lozenge (Lz), a members of RUNX family as well as homologue of AML-1, functions as an important transcription factor regulating the hemocytes differentiation. In this paper, we identified and characterized RUNX family especially Lz in silkworm, which is a lepidopteran model insect. The gene expression analysis illustrated that BmLz was highly expressed in hemocytes throughout the whole development period, and reached a peak in glutonous stage. Over-expression of BmLz in silkworm accelerated the melanization process of hemolymph, and led to instantaneously up-regulation of prophenoloxidases (PPOs), which were key enzymes in the melanization process. Further down-regulation of BmLz expression by RNA interference resulted in the significant delay of melanization reaction of hemolymph. These findings suggested that BmLz regulated the melanization process of hemolymph by inducing PPOs expression, and played a critical role in innate immunity defense in silkworm.
    • Characterization and identification of the integrin family in silkworm, Bombyx mori

      Zhang, K.; Xu, M.; Su, J.; Sun, Z.; Li, Y.; Zhang, W.; Hou, J.; Shang, Lijun; Cui, H. (2014)
      As an important economic insect, Bombyx mori is also a useful model organism for lepidopteran insect. Integrins are evolutionarily conserved fromsponges to humans, and play vital roles inmany physiological and pathological processes. To explore their diverse functions of integrins in insect, eleven integrins including sixα and five β subunitswere cloned and characterized fromsilkworm. Our results showed that integrins fromsilkwormown more family members compared to other invertebrates. Among those α subunits, integrins α1, α2, and the other four subunits belong to PS1, PS2, and PS3 groups, respectively. The β subunits mainly gather in the insect βν group except the β1 subunit which belongs to the insect β group. Expression profiles demonstrated that the integrins exhibited distinct patterns, but were mainly expressed in hemocytes. α1 and β2 subunits are the predominant ones either in the embryogenesis or larva stages. Interestingly, integrins were significantly up-regulated after stimulated by 20-hydroxyecdysone (20-E) in vivo. These results indicate that integrins performdiverse functions in hemocytes of silkworm. Overall, our results provide a newinsight into the functional and evolutionary features of integrins.