Voltage-Gated Sodium Channel (Vgsc) Mutation-Based Pyrethroid Resistance in Aedes aegypti Populations of Three Endemic Dengue Risk Areas of Sri Lanka

Background. Pyrethroid insecticides are widely used in many countries for chemical-based control of Ae. aegypti. Regardless of their efficacy, the constant use of insecticides has induced insecticide resistance mechanisms, such as knockdown resistance (kdr) in mosquitoes. Sri Lankan Vector Controlling Entities (VCE) have been using a variety of pyrethroid insecticides as the primary approach for dengue control. However, development of any resistance among the Aedes mosquitoes has been limitedly studied in the country. Therefore, the current study was conducted to evaluate the prevalence of F1534C, V1016G, and S989P mutations among Ae. aegypti mosquito populations in three dengue endemic high-risk regions of Sri Lanka. Methodology. Immature (both pupae and larvae) stages of Ae. aegypti mosquitoes were collected from Colombo, Gampaha, and Kandy districts of Sri Lanka from February 2018 to December 2019. Polymerase Chain Reaction- (PCR-) based assay for molecular genotyping of mutations was performed to identify the prevalence of kdr mutations in collected Ae. aegypti populations, separately. The frequencies of the resistant and susceptible kdr alleles were determined by using the Hardy–Weinberg equilibrium. Results. The Ae. aegypti populations from Colombo, Gampaha, and Kandy districts showed 46%, 42%, and 22% of F1534C mutation allele frequencies, along with 15%, 12%, and 6% of V1016G mutation allele frequencies, respectively. The mutation allele frequencies of S989 in Colombo, Gampaha, and Kandy districts were 9.5%, 8.5%, and 4.5%, respectively. The wild-type (PP) genotype remained predominant within all the three districts, whereas the homogenous (QQ) mutation genotype occurred only in minority. The abundance of Q allele frequency in Ae. aegypti mosquitoes was relatively higher for all the three mutations in Colombo. Conclusions. The findings clearly indicate that long-term insecticide applications and multiple use of pyrethroids have led to the acquisition of kdr mutations, leading to the development of insecticide resistance among local Ae. aegypti populations, especially in the Colombo and Gampaha districts. Therefore, evaluation of the prevalence levels of these kdr mutations highlights the necessity for shifting towards novel vector control strategies.

Genetic Diagnostics of FANC1BY Mutation in Representatives of the Holstein Breed and Its Crosses

The article is devoted to the development and use of a method for diagnosing the source of Brachyspina Syndrome, or short spine, in the Holstein breed and its crossbreeds. Representatives of this breed are the most highly productive animals in the world for milk. The development of a diagnostic method for breed-specific hereditary carriers is an important task in dairy farming. In this regard, the authors have proposed a Patent and a Reagent Kit for the detection of normal FANC1TY and mutant FANC1BY alleles in the Holstein breed and its crossbreeds. The frequency of occurrence of genotypes formed by these alleles in different sex and age groups of animals in the Holstein breed and its high-blooded hybrids was studied. Historical data related to the founders, from whom the spread of the mutant FANC1BY allele within the Holstein breed itself and its crossis in the USA, Canada and Russia began, has presented. The development of a diagnostic method for the mutant FANC1BY allele will make it possible to stop spreading of the Brachyspina Syndrome source. The proposed method will make it possible, in the early stages, to form healthy groups of breeding animals (bulls, replacement bulls, bull-reproducing cows), thereby laying the foundation for creating a high-quality livestock in the regions where the Holstein breed and its numerous crossbreeds are bred. cattle, Holstein breed, crossis, genotype, FANC1BY mutation, allele, Brachyspina syndrome

Identification of CCR5 Δ32 Allele in Different Ethnic Groups of Nepal

The chemokine receptor CCR5 exhibits an important role for the CD-4 mediated entry of HIV-1. Previous studies revealed that Δ32 mutation on the CCR5 gene results in truncated protein and hence confers protection against HIV-1 infection and AIDS progression, as observed in Caucasian population. However, the status of Δ32 mutation on CCR5 is still unknown in many Nepali ethnic groups though detection of heterozygous CCR5 Δ32 mutation allele has been reported from Chidimar and Thakali ethnic groups. We studied the presence of the Δ32 mutation in 300 blood samples from 11 ethnic groups of Nepal by analyzing PCR product of CCR5 gene region flanking the Δ32 mutation region. The primer set (forward -5’ CTC CCA GGA ATC ATC TTT ACC 3’ and reverse - 5’ TCA TTT CGA CAC CGA AGC AG 3’) flanks the site of the Δ32 deletion region of CCR5 gene. This results in a PCR fragment of 200 base pairs for the CCR5 wild allele and 168 base pairs for a Δ32 deletion mutation allele. All samples were found to exhibit wild type CCR5 gene; but no Δ32 mutation observed. Absence of Δ32 mutation in CCR5 gene indicates that Nepali population is not genetically resistant to HIV infection, if other genes are not considered.

Sex determines the presentation and outcomes in MPN and is related to sex-specific differences in the mutational burden

The factors underlying the variable presentation and clinical course of myeloproliferative neoplasms (MPNs) remain unclear. The aim of this study was to evaluate the independent effect of sex on MPN presentation and outcomes. A total of 815 patients with essential thrombocytosis, polycythemia vera, or primary myelofibrosis were evaluated between 2005 and 2019, and the association of sex with presenting phenotype, JAK2 V617F burden, progression, and survival was examined. Men presented more often with primary myelofibrosis vs essential thrombocytosis (relative risk, 3.2; P < .001) and polycythemia vera (relative risk, 2.1; P < .001), had higher rates of transformation to secondary myelofibrosis (hazard ratio [HR], 1.55; P = .013) and acute myeloid leukemia (HR, 3.67; P < .001), and worse survival (HR, 1.63; P = .001) independent of age, phenotype at diagnosis, and MPN-specific mutation. Men had higher JAK2 V617F allele burdens in their CD34+ cells (P = .001), acquired more somatic mutations (P = .012) apart from the MPN-specific mutations, and had an increased frequency of 1 (odds ratio, 2.35; P = .017) and 2 (odds ratio, 20.20; P = .011) high-risk mutations independent of age, phenotype, and driver mutation. Male sex is an independent predictor of poor outcomes in MPNs. This seems to be due to an increased risk of non–MPN-specific somatic mutations, particularly high-risk mutations, rather than MPN-specific mutation allele frequency. Conversely, disease progression in female subjects is more dependent on JAK2 mutation allele burden than on acquisition of other somatic mutations. Sex should be considered in prognostic models and when evaluating therapeutic strategies in MPNs.