Trehalase is the only enzyme known for the irreversible splitting of trehalose and plays a major role in insect growth and development. In this report, we describe a basic study of the trehalase gene fragment encoding a soluble trehalase from Lissorhoptrus oryzophilus (LoTRE1). Sequence alignment and phylogenetic analysis suggested that LoTRE1 was similar to some known insect trehalases and belongs to the Coleoptera trehalase group. Additionally, LoTRE1 was expressed mainly in the fat body. Purified protein was obtained using heterologous expression of LoTRE1 in Escherichia coli, and the recombinant protein exhibited the ability to decompose trehalose. Enzyme–substrate docking indicated the potential involvement of other residues in the catalytic activity, in addition to Asp 333. Moreover, feeding of adults on LoTRE1 dsRNA silenced the transcription of LoTRE1 and thereby reduced the activity of trehalase and increased the trehalose content; it also led to a 12% death rate. This study reveals essential molecular features of trehalase and offers insights into the structural aspects of this enzyme, which might be related to its function. Taken together, the findings demonstrate that LoTRE1 is indispensable for adults of this pest and provide a new target for the control of L. oryzophilus.
The study analyzed the effect of leukocyte elastase (LE) in 460 semen on sperm quality, and explore the reference interval of normal level of LE in semen. The differences of LE levels between normal semen and few, weak and abnormal semen were analyzed. Referring to domestic standards, the samples were divided into normal group (LE ≤ 250 ng/mL), occult infection (250 < LE ≤ 1000 ng/mL), and infection group (LE > 1000 ng/mL), and the differences in semen quality among the groups were compared. According to European standards, the samples were divided into normal group (≤600 ng/mL) and abnormal group (>600 ng/mL), and the differences in semen quality between the 2 groups were compared. The correlation between LE levels in semen and semen quality were analyzed. The positive rates of LE in the normal semen group and abnormal semen groups were 30.7% versus 34.7%, and there was no significant difference between the two groups (
P
> .05). When the semen divided into 3 groups, there was no significant difference between the physicochemical parameters, kinetic parameters, movement trajectory parameters, morphological parameters, and sperm DNA fragmentation index (DFI) (
P
> .05). There were significant differences in sperm morphology and sperm DFI between the two groups at 600 ng/mL (
P
< .05). Spearman correlation analysis showed that there was no significant difference between the level of LE in semen and physicochemical parameters, sperm kinetic parameters, sperm movement trajectory parameters, sperm morphological parameters, and sperm DFI (
P
> .05). It is appropriate to use 600 ng/mL as the threshold for the concentration of LE in semen; the correlation between the level of LE and sperm quality is not significant.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.