A Novel MicroRNA and the Target Gene TAB2 Can Regulate the Process of Sucking Blood in and the Spawn Rate of Hyalomma asiaticum (Acari: Ixodidae) Ticks

Abstract

Ticks are blood-sucking parasites that are harmful to humans and animals. MicroRNAs are a class of conserved small noncoding RNAs that play regulatory roles in the expression of many genes at the posttranscriptional level. Here, a novel miRNA (nov-miR-17) was identified from a small RNA data library of Hyalomma asiaticum by next-generation sequencing. PCR was used to obtain precursor nov-miR-17 by RACE using mature loop primers. The secondary structure was predicted with UNAFold. The interaction of nov-miR-17 with its target gene TAB2 was predicted using RNAhybrid software and identified in vitro by luciferase assays. Moreover, the interaction was confirmed in vivo by phenotype rescue experiments in which dsTAB2 was used for RNA interference (RNAi) and an antagomir of nov-miR-17 was used for miRNA silencing. The expression levels of nov-miR-17 and TAB2 in ticks at different developmental stages and the expression of nov-miR-17 in different tissues were analyzed by real-time qPCR. All data were analyzed using GraphPad Prism version 5. Results: The results showed that TAB2 was a target gene of nov-miR-17. When the blood-sucking process of larval, nymph and adult ticks was prolonged, the expression of nov-miR-17 was decreased, and TAB2 expression was increased. However, the level of nov-miR-17 in the midgut of engorged ticks was highest at all stages. Therefore, nov-miR-17 plays an important role in the blood-sucking process. The overexpression of nov-miR-17 indicated that this miRNA affected the engorged weight (P < 0.001) and spawn rate (P < 0.001) of female ticks. RNAi of TAB2 also had the same effect. dsRNA not only impacted the weight (P < 0.01) but also reduced the spawn rate (P < 0.001) of the ticks. Furthermore, significant recovery was observed in nov-miR-17-silenced ticks after TAB2 silencing by RNAi. nov-miR-17 silencing by antagomir not only impacted the engorged weight of the female ticks (P < 0.001) but also the number of days that the females needed to progress from engorgement to spawning (P < 0.001). The study showed that nov-miR-17, as a new miRNA, plays an important role along with its target gene TAB2 in the blood-sucking and spawning processes in female ticks.

Role of Recognition MicroRNAs in Hemaphysalis longicornis and Theileria orientalis Interactions

“…Differential expression is an important piece of information to consider when analyzing differences in the expression of factors in different treatment groups. In this study, miRNAs were predicted from sRNAs using rules established for miRNA identification [10], and the candidate miRNAs were compared between all species in the miRBase database (https://mirbase.org, accessed on 5 March 2023). After comparison and analysis, the miR-NAs of tick origin were ultimately identified.…”

“…MicroRNAs (miRNAs) are a class of endogenous noncoding small RNAs of approximately 18–22 nt. A microRNA can exert its functions, such as cell development, immune response, and disease occurrence, by binding to the 3′-UTR or 5′-UTR of target genes (mRNAs) at the posttranscriptional level [ 10 , 11 , 12 , 13 , 14 ]. The main reason is that mRNAs play an important role in the pathogenesis of T. orientalis [ 15 , 16 ].…”

Dynamic Analysis of microRNAs from Different Life Stages of Rhipicephalus microplus (Acari: Ixodidae) by High-Throughput Sequencing

“…The results of length analysis can be used as an important basis for determining the reliability of sequencing data and can indirectly reflect the characteristics of the distribution of different kinds of small RNAs. These results provide an important reference for data analysis and useful information for the physiological functions of ticks analyzed based on the spatiotemporal expression patterns of small RNAs [ 8 ]. In our study, miRNAs accounted for a large proportion of the 18,162,337, 8,090,736, and 11,807,326 sequences acquired from different developmental stages, indicating that miRNAs have an important function in regulating the posttranscriptional expression level of target genes.…”

“…Affected by enzyme digestion, the 5′ and 3′ ends of miRNA are mainly uracil (U), and the middle of the sequence is mainly adenine (A). Mature miRNAs show high similarity in different species, especially with regard to the base at positions 2–8, which is absolutely conserved in the same miRNA molecule [ 8 ]. This region is called the “seed region”, which can be divided into the (a) region and (b) region.…”

The use of RNA interference for the management of arthropod pests in livestock farms

“…RNAi also plays an important role in the efficiency of blood‐sucking processes in ticks. Luo et al (2022) identified a new miRNA (nov‐miR‐17) in Hyalomma asiaticum , which plays an important role in the blood suction process and rate of female's fertility by targeting the TAB2 gene. The overexpression of nov‐miR‐17 indicated that this miRNA affected the engorged weight ( p < 0.001) and spawn rate ( p < 0.001) of female ticks.…”