RESUMEN
Within the neuronal classes of the retina, amacrine cells (ACs) exhibit the greatest neuronal diversity in morphology and function. We show that the selective expression of the transcription factor Gbx2 is required for cell fate specification and dendritic stratification of an individual AC subtype in the mouse retina. We identify Robo1 and Robo2 as downstream effectors that when deleted, phenocopy the dendritic misprojections seen in Gbx2 mutants. Slit1 and Slit2, the ligands of Robo receptors, are localized to the OFF layers of the inner plexiform layer where we observe the dendritic misprojections in both Gbx2 and Robo1/2 mutants. We show that Robo receptors also are required for the proper dendritic stratification of additional AC subtypes, such as Vglut3+ ACs. These results show both that Gbx2 functions as a terminal selector in a single AC subtype and identify Slit-Robo signaling as a developmental mechanism for ON-OFF pathway segregation in the retina.
RESUMEN
Applying to graduate school can be particularly challenging for students from historically minoritized backgrounds due to a hidden curriculum in the graduate admissions process. To address this issue, a team of volunteer STEM trainees established the Científico Latino Graduate Student Mentorship Initiative (CL-GSMI) in 2019 to support applicants from historically minoritized backgrounds. CL-GSMI is designed to improve access to critical resources, including information, mentorship, and financial support, and has assisted 443 students in applying and matriculating to graduate school. Using program evaluation data from 2020 to 2021, we highlight areas in graduate school admissions that can be improved to promote equity and inclusion.
