Resistance to drug treatments is common in prostate cancer (PCa), and the gain-of-function mutations in human androgen receptor (AR) represent one of the most dominant drivers of progression to resistance to AR pathway inhibitors (ARPI). Previously, we evaluated the in vitro response of 24 AR mutations, identified in men with castration-resistant PCa, to five AR antagonists. In the current work, we evaluated 44 additional PCa-associated AR mutants, reported in the literature, and thus expanded the study of the effect of darolutamide to a total of 68 AR mutants. Unlike other AR antagonists, we demonstrate that darolutamide exhibits consistent efficiency against all characterized gain-of-function mutations in a full-length AR. Additionally, the response of the AR mutants to clinically used bicalutamide and enzalutamide, as well as to major endogenous steroids (DHT, estradiol, progesterone and hydrocortisone), was also investigated. As genomic profiling of PCa patients becomes increasingly feasible, the developed “AR functional encyclopedia” could provide decision-makers with a tool to guide the treatment choice for PCa patients based on their AR mutation status.
A synthetic gene drive that targets haplolethal genes on the X chromosome can skew the sex ratio toward males. Like an “X-shredder,” it does not involve “homing,” and that has advantages including the reduction of gene drive resistance allele formation. We examine this “X-poisoning” strategy by targeting 4 of the 11 known X-linked haplolethal/haplosterile genes of Drosophila melanogaster with CRISPR/Cas9. We find that targeting the wupA gene during spermatogenesis skews the sex ratio so fewer than 14% of progeny are daughters. That is unless we cross the mutagenic males to X^XY female flies that bear attached-X chromosomes, which reverses the inheritance of the poisoned X chromosome so that sons inherit it from their father, in which case only 2% of the progeny are sons. These sex ratio biases suggest that most of the CRISPR/Cas9 mutants we induced in the wupA gene are haplolethal but some are recessive lethal. The males generating wupA mutants do not suffer from reduced fertility; rather, the haplolethal mutants arrest development in the late stages of embryogenesis well after fertilized eggs have been laid. This provides a distinct advantage over genetic manipulation strategies involving sterility which can be countered by the remating of females. We also find that wupA mutants that destroy the nuclear localization signal of shorter isoforms are not haplolethal as long as the open reading frame remains intact. Like D. melanogaster, wupA orthologs of Drosophila suzukii and Anopheles mosquitos are found on X chromosomes making wupA a viable X-poisoning target in multiple species.
The coastal rock pool mosquito, Aedes togoi, is among the few saline-tolerant mosquito species who lay their eggs in seawater pools where their larvae develop in water that spans dilute freshwater to hyper-saline conditions. Ae. togoi is found in a relatively restricted range spanning the North Pacific coast of North America and coastal regions of Asia from subtropical to subarctic latitudes. Here, we present a de-novo chromosome-scale genome assembly and gene annotation for Ae. togoi, highlighting its relatively small genome size and novel chromosomal arrangements compared to other available genomes of Aedine mosquitoes. As part of the annotation process, we detail repeat content and distribution and curate several key multi-gene families, focusing on ion-transport proteins enriched in the larval salt-secreting gland that are candidates for facilitating hyperosmotic urine formation during development in saline water. Using these new resources, we gain mechanistic insight into the ion regulatory capabilities that power the remarkable saline tolerance of the larvae of Ae. togoi. Altogether, we have contributed to the growing body of genomic and transcriptomic resources for diverse mosquito species and provided mechanistic insights into the molecular adaptations required for an insect to thrive in highly dynamic environments such as coastal rock pools.