Abstract：
Polyglycylation is a post-translational modification that generates glycine side chains in the C-terminal domains of both α- and β-tubulins. To date, the patterns and significance of polyglycylation across insect species remain largely unknown. The TTLL3B was thought to be a polyglycylase and be essential for polyglycylation in dipteran insects. In this study, the TTLL3B of Bactrocera dorsalis (BdTTLL3B) was identified and characterized. The BdTTLL3B expressed remarkably higher in adult males, especially in testes. The spatio-temporal patterns of polyglycylation were consistent with that of BdTTLL3B. Along with spermatogenesis, the intensity of polyglycylation was enhanced steadily and concentrated in elongated flagella. The expression of recombinant BdTTLL3B in Hela cells, which are genetically deficient in polyglycylation, catalyzed intracellular polyglycylation, validating the identity of BdTTLL3B as a polyglycylase. Knockout of BdTTLL3B significantly suppressed polyglycylation in testes and impaired male fertility, probably due to abnormal morphology of mitochondrial derivatives and over-accumulation of paracrystalline. Taken together, these findings indicated that the BdTTLL3B-mediated polyglycylation is involved in the spermatogenesis and play an important role in fertility of adult B. dorsalis. Therefore, the BdTTLL3B can be considered as a candidate target gene for the management of B. dorsalis, such as developing gene silencing/knockout-based sterile insect technology (SIT).
摘要：
多糖基化是在α-和β-微管蛋白的C-末端结构域中产生甘氨酸侧链的翻译后修饰。迄今为止,跨昆虫物种的多甘醇化的模式和意义仍然未知。TTLL3B被认为是一种多甘氨化酶，对于双翅目昆虫的多甘醇化至关重要。在这项研究中,鉴定并表征了背细菌的TTLL3B（BdTTLL3B）。BdTTLL3B在成年男性中表达明显更高，尤其是睾丸。多糖基化的时空模式与BdTTLL3B的时空模式一致。随着精子发生，多甘醇化的强度稳步增强，并集中在细长的鞭毛中。重组BdTTLL3B在Hela细胞中的表达,它们在遗传上缺乏多甘醇，催化的细胞内聚糖基化，验证BdTTLL3B作为聚甘氨酰酶的身份。BdTTLL3B基因敲除显着抑制睾丸中的多甘醇化和男性生育力受损，可能是由于线粒体衍生物的形态异常和旁晶体的过度积累。一起来看,这些发现表明，BdTTLL3B介导的多甘醇化参与了成体背双歧杆菌的精子发生，并在其生育能力中起重要作用。因此,BdTTLL3B可以被认为是治疗背芽孢杆菌的候选靶基因，例如开发基于基因沉默/敲除的不育昆虫技术（SIT）。
