This study focused on the genomic analysis of Anopheles kleini and Anopheles pullus, both vectors of vivax malaria within the Anopheles Hyrcanus group. Using Illumina NovaSeq600 and Oxford Nanopore platforms, we identified 126 and 116 contigs, along with 40,420 and 32,749 genes from An. kleini and An. pullus, respectively. The assembled genome sizes were 282 Mb for An. kleini and 247 Mb for An. pullus, which are within a similar range to the sizes previously estimated by digital PCR (249 Mb and 226 Mb). We are currently also estimating the genome sizes of other Anopheles spp. and manually curating key genes determining vectorial capacity.
Parasites have co-evolved with their host for a long period of time, resulting in unique parasitic systems tailored to each host species. This makes them suitable for research on physiological function control through cross-species molecules like miRNA. The body louse, a vector of bacterial pathogens, is particularly valuable as a model insect due to their frequent feeding on human blood, which results in the continuous ingestion of human-derived miRNA and injection of salivary gland-derived miRNA into the human body. In this study, we conducted miRNA sequencing on body lice with mixed stages and identified 105 miRNAs, including 50 novel miRNAs. Sequence analysis of human miRNAs remaining in body lice and the functional analysis of these miRNAs are in progress.
Six mosquito species in the Anopheles Hyrcanus group are known as vectors responsible for transmitting vivax malaria in South Korea. In this study, seasonal dynamics of Anopheles Hyrcanus group species and knockdown resistance (kdr) mutations in malaria-endemic sites, Paju and Gimpo, were monitored over two years. In August 2023, all six species were observed simultaneously in one of the Paju collecting sites, and kdr mutations were newly identified in all species except Anopheles kleini. Although Anopheles pullus was revealed as a relatively resistant species among five species populations without kdr mutation via bioassays, there were no critical differences in the voltage-sensitive sodium channel sequence. These findings suggest variability in pyrethroid resistance mechanisms among Anopheles Hyrcanus Group species.
Medically significant indoor/ectoparasitic insect populations, including bed bugs and head lice, have developed considerable resistance to insecticides due to limited introduction of new genetic traits and the absence of an overwintering barrier. In contrast, outdoor pests like Anopheles and Culex mosquitoes exhibit fluctuating resistance patterns, likely influenced by factors such as overwintering barriers and relatively wider open habitats. Mosquitoes also face selection pressure from diverse sources beyond public health insecticides unlike bed bugs or head lice. Understanding different factors driving resistance among pests is essential for effective resistance management.
The Varroa mite, Varroa destructor, a parasitic mite that afflicts honey bees, has become increasingly resistant to acaricides like fluvalinate due to its widespread use. The target site insensitivity mechanism, mediated by the L925V/M/I mutations in the voltage-gated sodium channel, plays a major role in resistance. Additionally, cytochrome P450 monooxygenases (Cyp450s) appear to function as a metabolic resistance factor; however, no Cyp450-mediated resistance mechanism has been reported to date. The aim of this study was to identify and characterize Cyp450s associated with fluvalinate resistance. A synergistic bioassay confirmed the involvement of Cyp450s in conferring tolerance or resistance to fluvalinate. Correlation analysis between mortality data and the expression levels of Cyp450 genes led to the identification of several candidates that may play a crucial role in fluvalinate resistance. Analysis of tissue distribution patterns revealed that these genes were most abundantly expressed in the cuticle and synganglion. This suggests that, despite their relatively low expression level, they may play a critical role in protecting the target site from fluvalinate due to its predominant expression in neuronal tissues. Functional analysis, in conjunction with baculovirus expression, demonstrated that fluvalinate has high inhibition rates against the recombinant candidate Cyp450s, suggestive of their strong interaction with fluvalinate. We discussed the potential utilization of their expression levels as a molecular marker for diagnosing metabolic resistance in field-collected Varroa mites.
Si Eun Lee, Hyojin Park, Chae-Yeong Lee, Hyeon-Jong Choi, Hyoyeon Kim, Minyeon Kim, Jeongho Hong, DoHyeon Yu, Tae Sung Hwang, Hee Chun Lee, Jae-Hoon Lee, Dongbin Lee
A 13-year-old mixed dog was referred to the animal medical center, Gyeongsang National University. Lung masses were diagnosed at the left cranial and caudal lobes through diagnostic imaging, and consequently, left pneumonectomy was performed using a self-cutting linear endoscopic stapler. The pulmonary arteries, veins, and bronchus of each lung lobe were sealed and resected at once, and any air leakage or bleeding was not observed after the surgery. Compared to the conventional ligation method, the self-cutting linear endoscopic stapler has the advantage of significantly reducing the operation time and enabling simple and reliable sealing.