The ASPET Mentoring Network: Enhancing Diversity and Inclusion through Career Coaching Groups within a Scientific Society.

Over the past decades, two persisting priorities in science, technology, engineering, and mathematics (STEM) training have been: 1) increasing the knowledge of and access to careers beyond academic scientist; and 2) increasing the diversity of the STEM workforce. Previous studies show that a uniquely constructed career coaching group provides strong support and progress for both priorities. This report extends this design into a more sustainable model that is positioned within the professional context of rising young scientists. This new model is based in the American Society for Pharmacology and Experimental Therapeutics (ASPET)-the ASPET Mentoring Network. Groups of PhD students and postdocs were assigned to an ASPET professional (academic or other career) member (the coach) with an initial meeting held the day before the society's annual meeting. The coaching groups interacted during the meeting and then virtually for a year. Extensive survey and interview evaluation data gathered from the first three cohorts (12 coaching groups) in 2016- 2018 provided strong evidence of the perceived and real benefits of the network. This new version of career coaching groups is both feasible and linked to career success due to its close association with a scientific society, peers, and coaches who share scientific identities and aspirations.

Juvenile hormone mediates a trade-off between primary and secondary sexual traits in stalk-eyed flies.

Trade-offs between developing body parts may contribute to variation in allometric scaling relationships in a variety of taxa. Experimental evidence indicates that both circulating levels of juvenile hormone (JH) and sensitivities of developing body parts to JH can influence morphology in polyphenic insects. However, the extent to which JH may regulate both the development of traits that scale continuously with body size and trade-offs between these traits is largely unknown. Here, I present evidence that the JH analog methoprene applied to final instar larvae of a stalk-eyed fly (Cyrtodiopsis dalmanni) can induce males to produce larger eye-stalks relative to their body size. Examination of testis growth, sperm transfer, and egg maturation indicates that JH induces a trade-off between eye-span and gonad development in adult males, but not females. Age at sexual maturity was unaffected by larval JH applications to either sex. Collectively, these results are consistent with JH-mediated allocation of resources to eye-span at the expense of testes, and indicate potential costs for the production of an exaggerated trait.

Sperm survival in female stalk-eyed flies depends on seminal fluid and meiotic drive.

Sperm competition is common in many insect species; however, the mechanisms underlying differences in sperm precedence are not well understood. In the stalk-eyed fly, Cyrtodiopsis whitei (Diptera, Diopsidae), sperm precedence is influenced by the presence of sex chromosome meiotic drive. When drive-carrying males compete with non-driving males for fertilizations within a female, the number of progeny sired by drive males is significantly fewer than predicted by sperm mixing alone. Thus, drive males apparently suffer not only a reduction in the number of viable sperm produced, but also a reduction in sperm competitive ability. In this study, we manipulated the amount and source of seminal fluid and sperm received by females by interrupting copulations before sperm, but after seminal fluid, was transferred. We find that seminal fluid from another male influences the number of progeny sired by a drive-carrying male when both males mate with the same female. Sperm viability staining reveals that sperm from drive males are incapacitated by seminal fluid from other males within the female reproductive tract. These results suggest that multiple mating by females enables seminal fluid products to interact differentially with sperm and may reduce the transmission advantage of the drive chromosome.