Xu Man, Wang Xue, Tan Juan, Zhang Kui, Guan Xi, Patterson Laurence H, Ding Hanfei, Cui Hongjuan
State Key Laboratory of Silkworm Genome Biology (Southwest University), 400715, China.
Institute of Cancer Therapeutics, University of Bradford, West Yorkshire BD7 1DP, UK.
Dev Comp Immunol. 2015 Nov;53(1):191-8. doi: 10.1016/j.dci.2015.07.001. Epub 2015 Jul 9.
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.
runt相关（RUNX）转录因子在脊椎动物和无脊椎动物中都是进化保守的。菱形（Lz）是RUNX家族的成员之一，也是AML-1的同源物，作为一种重要的转录因子，调节血细胞的分化。在本文中，我们在鳞翅目模式昆虫家蚕中鉴定并表征了RUNX家族，特别是Lz。基因表达分析表明，BmLz在整个发育时期的血细胞中高度表达，并在蛹期达到峰值。在家蚕中过表达BmLz加速了血淋巴的黑化过程，并导致前酚氧化酶（PPOs）瞬间上调，PPOs是黑化过程中的关键酶。通过RNA干扰进一步下调BmLz的表达导致血淋巴黑化反应显著延迟。这些发现表明，BmLz通过诱导PPOs的表达来调节血淋巴的黑化过程，并在家蚕的先天免疫防御中发挥关键作用。
