VA Greater Los Angeles Healthcare System 2 articles published in JoVE Developmental Biology Displacement Analysis of Myocardial Mechanical Deformation (DIAMOND) Reveals Segmental Heterogeneity of Cardiac Function in Embryonic Zebrafish Junjie Chen1, René R. Sevag Packard1,2,3 1Division of Cardiology, Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, 2Ronald Reagan UCLA Medical Center, 3Veterans Affairs West Los Angeles Medical Center The goal of this protocol is to detail a novel method for the assessment of segmental cardiac function in embryonic zebrafish under both physiological and pathological conditions. Immunology and Infection High-throughput Parallel Sequencing to Measure Fitness of Leptospira interrogans Transposon Insertion Mutants During Golden Syrian Hamster Infection Kristel Lourdault1,2, James Matsunaga1,2, Karen V. Evangelista1,2, David A. Haake1,2,3,4 1Veterans Affairs Greater Los Angeles Healthcare System, 2Departments of Medicine, David Geffen School of Medicine at University of California Los Angeles, 3Departments of Urology, David Geffen School of Medicine at University of California Los Angeles, 4Departments of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles We describe here a technique that combines transposon mutagenesis with high-throughput sequencing to identify and quantify transposon leptospiral mutants in tissues after a challenge of hamsters. This protocol can be used to screen mutants for survival and dissemination in animals and can also be applied to in vitro studies.