Characterization of two Bursicon genes and their association with wing development in the brown citrus aphid, Aphis citricidus.

The tanning hormone, Bursicon, is a neuropeptide secreted by the insect nervous system that functions as a heterodimer composed of Burs-α and Burs-ß subunits. It plays a critical role in the processes of cuticle tanning and wing expansion in insects. In this study, we successfully identified the AcBurs-α and AcBurs-ß genes in Aphis citricidus. The open reading frames of AcBurs-α and AcBurs-ß were 480 and 417 bp in length, respectively. Both AcBurs-α and AcBurs-ß exhibited 11 conserved cysteine residues. AcBurs-α and AcBurs-ß were expressed during all developmental stages of A. citricidus and showed high expression levels in the winged aphids. To investigate the potential role of AcBurs-α and AcBurs-ß in wing development, we employed RNA interference (RNAi) techniques. With the efficient silencing of AcBurs-α (44.90%) and AcBurs-ß (52.31%), malformed wings were induced in aphids. The proportions of malformed wings were 22.50%, 25.84%, and 38.34% in dsAcBurs-α-, dsAcBur-ß-, and dsAcBurs-α + dsAcBur-ß-treated groups, respectively. Moreover, feeding protein kinase A inhibitors (H-89) also increased the proportion of malformed wings to 30.00%. Feeding both double-stranded RNA and inhibitors (H-89) significantly downregulated the wing development-related genes nubbin, vestigial, notch and spalt major. Silence of vestigial through RNAi also led to malformed wings. Meanwhile, the exogenous application of 3 hormones that influence wing development did not affect the expression level of AcBursicon genes. These findings indicate that AcBursicon genes plays a crucial role in wing development in A. citricidus; therefore, it represents a potential molecular target for the control of this pest through RNAi-based approaches.

Characterization and transcriptional expression of ABCG genes in Bactrocera dorsalis: Insights into their roles in fecundity and insecticidal stress response.

The ATP-binding cassette (ABC) transporters are essential for regulating various physiological processes and insecticide resistance across different living organisms. ABCG subfamily genes have diverse functions in insects, but little is known about the function of ABCGs in a serious agricultural pest, Bactrocera dorsalis. In this study, 15 BdABCG genes were identified, and BdABCG6 and BdABCG11 were highly expressed in the pupal and adult stages, especially during the transition period from pupae to adults. Silencing of these two genes resulted in a significant reduction of egg production in B. dorsalis, confirming their importance in reproduction. Analysis of tissue expression patterns showed that most genes, including BdABCG1, 3, 8, and 14, exhibited tissue-specificity, with significantly higher expression levels observed in the intestine, Malpighian tubule, and fat body compared to other tissues. Meanwhile, the induction of malathion and avermectin can significantly upregulate the expression of the above four genes. Furthermore, knockdown of BdABCG3 by RNAi significantly increased the mortality of B. dorsalis upon exposure to avermectin, which suggested that BdABCG3 is involved in the transport or metabolism of avermectin in B. dorsalis. Overall, our work provides valuable insights into the function of BdABCGs involved in the reproduction and detoxification system of B. dorsalis.

Molecular phylogenetic analysis of the Amiota taurusata species group within the Chinese species, with descriptions of two new species.

The relationships among six species of the Amiota taurusata Takada, Beppu, & Toda (Diptera: Drosophilidae) species group were investigated based on DNA sequence data of the mitochondrial NADH dehydrogenase subunit 2 ( ND2) gene, using three species of the genus Amiota as outgroups. A mitochondrial gene, cytochrome c oxidase I ( COI), can be used to discriminate between species of the taurusata group. Two new species are described from South China: A. protuberantis Shao et Chen, sp. nov. and A. shennongi Shao et Chen, sp. nov. A key to all the species of the taurusata group based on morphological characters is provided.

[Detecting testis- and epididymis-specific methylated promoters in human cell-free seminal DNA by MeDIP-qPCR].

OBJECTIVE: To establish a method of methyl-DNA immunoprecipitation (MeDIP)-real time quantitative PCR (qPCR) for detecting the promoter methylation level in cell-free seminal DNA (cfsDNA). METHODS: We obtained cfsDNA samples from 6 normozoospermia men (the NZ group) and 6 post-vasectomy patients (the PV group), and mixed the samples from different individuals of each group, respectively. Then we made DNA fragments by ultrasonication, separated the methylated DNA fragments by MeDIP, and determined the methylation level of the promoters in cfsDNA by qPCR. RESULTS: The methylation levels of the promoters PRAME, PEG10, MORC1, GML, HOXA5, DNMT3L, SNURF, MSH4, DAZ1 and CLPB were 14.93, 2.64, 0.69, 2.66, 17.50, 21.10, 5.98, 2.28, 13.50 and 3.86%, respectively, in the NZ group, obviously lower than 121.25, 73.62, 16.25, 42.90, 76.74, 112.40, 59.79, 25.85, 91.90 and 64.53% in the PV group. The results of MeDIP-qPCR for the methylation of PRAME, MORC1, GML, HOXA5, DNMT3L, SNURF, MSH4 and DAZ1 were coincident with the results of genome-wide promoter methylation microarray. CONCLUSION: MeDIP-qPCR can quantitatively measure the promoter methylation level in cfsDNA, and effectively determine the testis- and epididymis-specific methylated promoters in human semen.

Phylogenetic relationship among East Asian species of the Stegana genus group (Diptera, Drosophilidae).

The phylogenetic relationship among 27 East Asian species of the Stegana genus group was reconstructed using DNA sequences of mitochondrial (COI and ND2) and nuclear (28S) genes. The results lent support to the current generic/subgeneric taxonomic classification in the genus group with the exceptions of the paraphyly of the genus Parastegana and the subgenus Oxyphortica in the genus Stegana. The ancestral areas and divergence times in the genus group were reconstructed/estimated, and accordingly, the biogeographical history of this important clade was discussed. It was proposed that, the evolution of the plant family Fagaceae, especially Quercus, may have played a certain role in facilitating the diversification of the Stegana genus group.

Molecular phylogenetic analysis of the Stegana ornatipes species group (Diptera: Drosophilidae) in China, with description of a new species.

A new species of the Stegana (Steganina) ornatipes species group (Diptera: Drosophilidae) is described from Hainan, China, S. (S.) xipengi sp. nov. Based on the mitochondrial ND2 and COI gene sequences, the relationships among eight species from mainland China of the ornatipes group, and their relationships to the undulata, nigrolimbata and shirozui species groups of the same subgenus, are investigated, using two species of the subgenus Stegana, S. emeiensis and S. quadrata, as outgroups. The result shows that S. (S.) mengla is debarred from the ornatipes group.