Mutagenesis of the odorant receptor co-receptor (Orco) reveals severe olfactory defects in the crop pest moth Helicoverpa armigera.

BACKGROUND: Odorant receptors (ORs) as odorant-gated ion channels play a crucial role in insect olfaction. They are formed by a heteromultimeric complex of the odorant receptor co-receptor (Orco) and a ligand-selective Or. Other types of olfactory receptor proteins, such as ionotropic receptors (IRs) and some gustatory receptors (GRs), are also involved in the olfactory system of insects. Orco as an obligatory subunit of ORs is highly conserved, providing an opportunity to systematically evaluate OR-dependent olfactory responses. RESULTS: Herein, we successfully established a homozygous mutant (Orco-/-) of Helicoverpa armigera, a notorious crop pest, using the CRISPR/Cas9 gene editing technique. We then compared the olfactory response characteristics of wild type (WT) and Orco-/- adults and larvae. Orco-/- males were infertile, while Orco-/- females were fertile. The lifespan of Orco-/- females was longer than that of WT females. The expressions of most Ors, Irs, and other olfaction-related genes in adult antennae of Orco-/- moths were not obviously affected, but some of them were up- or down-regulated. In addition, there was no change in the neuroanatomical phenotype of Orco-/- moths at the level of the antennal lobe (including the macroglomerular complex region of the male). Using EAG and SSR techniques, we discovered that electrophysiological responses of Orco-/- moths to sex pheromone components and many host plant odorants were absent. The upwind flight behaviors toward sex pheromones of Orco-/- males were severely reduced in a wind tunnel experiment. The oviposition selectivity of Orco-/- females to the host plant (green pepper) has completely disappeared, and the chemotaxis toward green pepper was also lost in Orco-/- larvae. CONCLUSIONS: Our study indicates that OR-mediated olfaction is essential for pheromone communication, oviposition selection, and larval chemotaxis of H. armigera, suggesting a strategy in which mate searching and host-seeking behaviors of moth pests could be disrupted by inhibiting or silencing Orco expression.

An Overview of Embryogenesis: External Morphology and Transcriptome Profiling in the Hemipteran Insect Nilaparvata lugens.

During embryogenesis of insects, the morphological and transcriptional changes are important signatures to obtain a better understanding of insect patterning and evolution. The brown planthopper Nilaparvata lugens is a serious insect pest of rice plants, but its embryogenesis has not uncovered. Here, we described embryonic development process of the pest and found it belongs to an intermediate-germ mode. The RNA-seq data from different times (6, 30, 96, and 150 h, after egg laying) of embryogenesis were then analyzed, and a total of 10,895 genes were determined as differentially expressed genes (DEGs) based on pairwise comparisons. Afterward, 1,898 genes, differentially expressed in at least two comparisons of adjacent embryonic stages were divided into 10 clusters using K means cluster analysis (KMCA). Eight-gene modules were established using a weighted gene co-expression network analysis (WGCNA). Gene expression patterns in the different embryonic stages were identified by combining the functional enrichments of the stage-specific clusters and modules, which displayed the expression level and reprogramming of multiple developmental genes during embryogenesis. The "hub" genes at each embryonic stage with possible crucial roles were identified. Notably, we found a "center" set of genes that were related to overall membrane functions and might play important roles in the embryogenesis process. After parental RNAi of the MSTRG.3372, the hub gene, the embryo was observed as abnormal. Furthermore, some homologous genes in classic embryonic development processes and signaling pathways were also involved in embryogenesis of this insect. An improved comprehensive finding of embryogenesis within the N. lugens reveals better information on genetic and genomic studies of embryonic development and might be a potential target for RNAi-based control of this insect pest.

[Identification of Arg77Cys and Arg174stop double heterozygous mutation in a Chinese family with inherited FXIII deficiency].

OBJECTIVE: To identify the gene mutation type of an inherited coagulation factor XIII (FXIII) deficiency pedigree. METHODS: PCR and DNA sequencing were used to identify the mutations in the 15 exons and the flank sequence of FXIII gene in the proband. The identified mutations were validated by allele specific PCR, PCR restriction fragment length polymorphism technique or DNA sequencing in the family members and 100 healthy volunteers. RESULTS: Arg77Cys and Argl74stop double heterozygous mutations were discovered in the proband. The pedigree analysis showed that Arg77Cys missense mutation inherited from her father, and Arg174stop from her mother. The Arg77Cys missense mutation in exon 3 was not found in her husband and the other 100 healthy volunteers. CONCLUSION: A novel Arg174stop nonsense mutation was discovered in human FXIII gene. A simple DNA assay based on PCR for detection of this mutation was developed. The congenital FXIII deficiency in the proband might be caused by the coinheritance of the Arg77Cys missense mutation in exon 3 and the Arg174stop nonsense mutation in exon 4.

[The differential expression of hypoxia-inducible factor-1alpha in placenta tissues from pregnancy induced hypertension and normal pregnancy].

AIM: To explore the differential expression of hypoxia-inducible factor-1alpha (HIF-1alpha) in placenta tissues from pregnancy induced hypertension and normal pregnancy. METHODS: The expression of HIF-1alpha protein and mRNA was detected by Western blot and real-time PCR, respectively. RESULTS: As compared with the expression levels of HIF-1alpha protein and mRNA in placenta tissues from normal pregnancy, those from pregnancy induced hypertension increased notably (P<0.05). CONCLUSION: The high expression of HIF-1alpha in the placenta tissues pregnancy induced may relate with pathogenesis and pathophysiological process of hypertension.