Hexamerins are large hemolymph-proteins that have been discovered in all insect species. According to the present study, hexamerins are not only storage proteins that provide amino acids and energy, but also transport hormones such as ecdysteroids. The hexamerin family genes cDNA from the grasshopper Locusta migratoria were cloned using RT-PCR and RACE methods. The biological functions of LmiHx5 were studied by RNA interference (RNAi), and qRT-PCR was performed to detect LmiHx transcripts after RNAi. Compared to the transcription database previously obtained, four family members (LmiHx1, LmiHx2, LmiHx4 and LmiHx5) of different LmiHx were determined. Homologous sequence alignments showed that the consistency of the amino acid sequence of LmiHx family members was 32%–43% and their encoded protein have the same three hemocyanin domains: hemocyanin-C, hemocyanin-N and hemocyanin-M. Gene expression patterns in different tissues and at different developmental stages showed that the LmiHx family genes are widely expressed in both female and male adults and at all developmental stages. The expression showed cyclical fluctuation with the nymphs molt. In addition, LmiHx2 mRNA expression level was the highest in fat body. LmiHx5 mRNA levels substantially decreased at 12, 24 and 48 h after dsLmiHx5 injection compared to the negative controls and almost not expressed at 96 h after dsRNA injection. The relative expression levels of other hexamerin family members showed varying degrees of increase after LmiHx5 RNAi. We speculate that hexamerin family gene members showed functional compensation.

The complete mitochondrial genome of Mekongiella kingdoni, which was collected from the Tibetan Plateau, is determined here. It is 15,932 bp in length and contains 73.1% AT. All M. kingdoni protein-coding sequences except for the cox1 start with a typical ATN codon. Instead, CCG, which is a rare but possible initiation codon, is located at the initiation context of cox1. The usual termination codons (TAA and TAG) and incomplete stop codons (TA or T) are found from 13 PCGs. All tRNA genes can be folded into the typical cloverleaf secondary structure, except trnS(AGN) due to the lacking of dihydrouridine arm. The sizes of the large and small ribosomal RNA genes are 1313 and 837 bp, respectively. The AT content of the A + T-rich region is 78.4%.

The complete mitochondrial genome of Orinhippus tibetanus, which was collected from the Tibetan Plateau, is reported here. It is 15,611 bp in length and contains 74.2% AT. All O. tibetanus protein-coding sequences except for the cox1 start with a typical ATN codon. The usual termination codons (TAA or TAG) and incomplete stop codons (T or TA) are found from 13 protein-coding genes. All tRNA genes could be folded into the typical cloverleaf secondary structure, except trnS(AGN) lacking of dihydrouridine (D) arm. The sizes of the large and small ribosomal RNA genes are 1317 and 854 bp, respectively. The AT content of the A + T-rich region is 84.8%.

Locusta migratoria is one of the global destructive migratory agricultural pests. The species serves as a model insect for the study of morphology, physiology, developmental biology, and neurosciences and so on. In recent years, there has been growing interest in the research of the cell and molecular biology of L. migratoria, and a lot of genes of signalling pathways have been cloned. The Hedgehog (Hh) signalling pathway is essential for cellular proliferation and differentiation during embryonic development. Fused (Fu) is a conserved component of the Hh signalling pathway, and it plays a central role in embryonic development. The Fu gene was cloned from the grasshopper L. migratoria. The gene encodes a 717 amino acid protein. Then, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression pattern of the Lm-Fu gene at different development stages and tissues. The result showed that the gene was upregulated at the embryonic period and second instar, and the expression level was the highest in the head at the different tissues. Western blotting was used to assess the abundance of the Lm-Fu protein, which was expressed at different development stages. The embryogenesis of L. migratoria was examined by immunohistochemical staining, and the Lm-Fu protein was detected in the head, prothorax and legs. The results showed that the Lm-Fu gene plays an important role during embryonic development.