Chemosensory receptors play central roles in insect behavior and can potentially be used as new targets for pest control. Athetis lepigone Möschler (Lepidoptera: Noctuidae) is a polyphagous insect pest found in many countries in Europe and Asia. However, systemic identification of the chemosensory receptors in the antennae has not been reported. In the present study, we obtained the antennal transcriptome of A. lepigone using Illumina sequencing technology and identified 80 candidate chemosensory receptors, including 61 transcripts encoding for odorant receptors (ORs) and 19 for ionotropic receptors (IRs). This result is similar to that reported for other lepidopteran species, suggesting that our approach successfully identified ORs and IRs of A. lepigone. RT-PCR was used to determine the sex distribution patterns of all OR and IR genes. Some OR and IR genes showed male- or female-specific/predominant expression. Our results help understand the functions of chemosensory receptor genes in A. lepigone as well as other insects, and suggest that these genes could be potential targets for developing environment-friendly behavioral antagonists and pesticides against A. lepigone.

The water flea Daphnia are planktonic crustaceans commonly found in freshwater environment that can switch their reproduction mode from parthenogenesis to sexual reproduction to adapt to the external environment. As such, Daphnia are great model organisms to study the mechanism of reproductive switching, the underlying mechanism of reproduction and development in cladocerans and other animals. However, little is known about the Daphnia's reproductive behaviour at a molecular level. We constructed a genetic database of the genes expressed in a sexual female (SF) and a parthenogenetic female (PF) of D. similoides using Illumina HiSeq 2500. A total of 1,763 differentially expressed genes (865 up- and 898 down-regulated) were detected in SF. Of the top 30 up-regulated SF unigenes, the top 4 unigenes belonged to the Chitin_bind_4 family. In contrast, of the top down-regulated SF unigenes, the top 3 unigenes belonged to the Vitellogenin_N family. This is the first study to indicate genes that may have a crucial role in reproductive switching of D. similoides, which could be used as candidate genes for further functional studies. Thus, this study provides a rich resource for investigation and elucidation of reproductive switching in D. similoides.

Background Since chemosensory genes play key roles in insect behaviour, they can potentially be used as new targets for pest control. The cabbage beetle, Colaphellus bowringi , is a serious insect pest of cruciferous vegetables in China and other Asian countries. However, a systematic identification of the chemosensory genes expressed in the antennae has not been reported. Results We assembled the antennal transcriptome of C. bowringi by using Illumina sequencing technology and identified 104 candidate chemosensory genes by analyzing transcriptomic data, which included transcripts encoding 26 odorant-binding proteins (OBPs), 12 chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs), 43 odorant receptors (ORs), nine ionotropic receptors (IRs), and ten gustatory receptors (GRs). The data obtained are similar to those found in other coleopteran species, suggesting that our approach successfully identified the chemosensory genes of C. bowringi . The expression patterns of 43 OR genes, some of which were predominately found in the antenna or associated with sex-biased expression, were analyzed using quantitative real time RT-PCR (qPCR). Conclusions Our study revealed that a large number of chemosensory genes are expressed in C. bowringi . These candidate chemosensory genes and their expression profiles in various tissues provide further information on understanding their function in C. bowringi as well as other insects, and identifying potential targets to disrupt the odorant system in C. bowringi so that new methods for pest management can be developed.

The Reads Per Kilobase per Million mapped reads (RPKM) values of CbowOBPs, CSPs, SNMPs, IRs and GRs. (XLSX 10Â kb)