Parasitoid Serpins Evolve Novel Functions to Manipulate Host Homeostasis.

Parasitoids introduce various virulence factors when parasitism occurs, and some taxa generate teratocytes to manipulate the host immune system and metabolic homeostasis for the survival and development of their progeny. Host-parasitoid interactions are extremely diverse and complex, yet the evolutionary dynamics are still poorly understood. A category of serpin genes, named CvT-serpins, was discovered to be specifically expressed and secreted by the teratocytes of Cotesia vestalis, an endoparasitoid of the diamondback moth Plutella xylostella. Genomic and phylogenetic analysis indicated that the C. vestalis serpin genes are duplicated and most of them are clustered into 1 monophyletic clade. Intense positive selection was detected at the residues around the P1-P1' cleavage sites of the Cv-serpin reactive center loop domain. Functional analyses revealed that, in addition to the conserved function of melanization inhibition (CvT-serpins 1, 16, 18, and 21), CvT-serpins exhibited novel functions, i.e. bacteriostasis (CvT-serpins 3 and 5) and nutrient metabolism regulation (CvT-serpins 8 and 10). When the host-parasitoid system is challenged with foreign bacteria, CvT-serpins act as an immune regulator to reprogram the host immune system through sustained inhibition of host melanization while simultaneously functioning as immune effectors to compensate for this suppression. In addition, we provided evidence that CvT-serpin8 and 10 participate in the regulation of host trehalose and lipid levels by affecting genes involved in these metabolic pathways. These findings illustrate an exquisite tactic by which parasitoids win out in the parasite-host evolutionary arms race by manipulating host immune and nutrition homeostasis via adaptive gene evolution and neofunctionalization.

Characterization of Molting Process during the Different Developmental Stages of the Diamondback Moth Plutella xylostella.

The molting process of the lepidopteran insects is observed for many species. However, the detailed description of the morphological transformation and behavioral sequence during molting are rarely provided and visualized. Here, we described the molting process of the diamondback moth Plutella xylostella by providing the duration and photographic details of staging criteria of each stage using stereo microscopy and a digital video camera. We divided the morphological transformation of egg development and hatching into five stages, the larval-larval ecdysis and the larval-pupal metamorphosis into five stages, the pupal development and eclosion into three stages, and the post-eclosion behavior into four stages. Several new characters in the molting process that were not previously described in other lepidopteran insects were found, i.e., the larvae contracted anterior-posteriorly then dorsal-ventrally during pre-ecdysis, and the antennae waved backward then forward in the post-eclosion behavior. Our findings will deepen the knowledge of the molting biology of lepidopteran insects and facilitate the study of the underlying mechanisms.

[Clinical manifestation and influential factors in patients with acute arsenic poisoning].

OBJECTIVE: To investigate the clinical characteristics of acute arsenic poisoning and its influential factors. METHODS: Clinical data of 47 cases of arsenic poisoning were collected and analyzed. Two cases of observation, 40 cases of mild acute poisoning, and 5 severe acute poisoning were investigated in this group. RESULTS: Myocardial enzyme activity was correlated with age and urine arsenic concentrations. Myocardial enzyme, the liver ALT, total bilirubin (TBil) and indirect bilirubin (IBil) were negatively correlated with vomiting frequency, with statistical significance (P < 0.05). Urine arsenic concentration was correlated with vomiting frequency and amount of soup drunk, with statistically significant difference (P < 0.05). Despite no statistical significance in age and amount of soup drunk, the patients with more vomiting or diarrhea had less urine arsenic concentrations, cardiac enzymes and liver enzyme concentration. CONCLUSION: Acute arsenic poisoning can lead to multiple organ damage. The damage is relevant with amount of arsenic intake, vomiting, diarrhea and urinary frequency arsenic concentration. So early use of gastric lavage, vomiting, poison discharges, and adequate application of effective antidote (Na-DMPS) as soon as possible, symptomatic treatment and the reinforced monitoring, are the rescue key for patients with acute arsenic poisoning.