Alvaro Sagasti, Ph.D.

Professor


Research Interests
Morphogenesis is the process by which cells adopt their specific shapes, sizes, and relationships with neighboring cells. Our lab studies the morphogenesis of developing skin cells and sensory neurons, which together mediate touch sensation. The skin at early developmental stages consists of two epithelial layers, each with distinct functions and morphologies. Sensory neurons project elaborately branched cellular processes called peripheral axons into the territory between the two skin layers to detect touch stimuli. We investigate how each of these cell types adopts its distinct morphological features and how skin cells and neurons influence each other’s morphogenesis. To study these questions we use zebrafish embryos and larvae as a model. Because zebrafish eggs are externally fertilized and their embryos are optically clear, cellular behaviors can be imaged in live animals. Transgenic lines allow us to visualize specific cells and subcellular processes, laser-based techniques allow us to damage cells at precise times and places to study repair, and genetic manipulations provide insight into the molecular underpinnings of cellular behaviors. By studying basic cellular processes we hope to shed light on how they are impacted by damage and disease.
Biography

 

Dr. Sagasti received his PhD from UCSF, where he worked with Cori Bargmann studying celll specification and left/right asymmetry in the nervous system of the nematode C. elegans. He began using zebrafish as a model at the Skirball Institute, NYU Medical Center as a post-doc with Alex Schier. In the summer of 2005 he was a Grass Foundation Fellow at the Marine Biological Labs in Woods Hole, Massachussetts. He began as a UCLA faculty member in the MCDB department in September 2005. His lab uses a combination of imaging, molecular, and genetic approaches in zebrafish to investigate on the morphogenesis of sensory axons and skin cells during development and repair.

 

Publications

A selected list of publications:

Vargas Mauricio Enrique, Yamagishi Yuya, Tessier-Lavigne Marc, Sagasti Alvaro   Live Imaging of Calcium Dynamics during Axon Degeneration Reveals Two Functionally Distinct Phases of Calcium Influx The Journal of neuroscience : the official journal of the Society for Neuroscience, 2015; 35(45): 15026-38.
Rasmussen Jeffrey P, Sack Georgeann S, Martin Seanna M, Sagasti Alvaro   Vertebrate epidermal cells are broad-specificity phagocytes that clear sensory axon debris The Journal of neuroscience : the official journal of the Society for Neuroscience, 2015; 35(2): 559-70.
O’Donnell Kelley C, Lulla Aaron, Stahl Mark C, Wheat Nickolas D, Bronstein Jeff M, Sagasti Alvaro   Axon degeneration and PGC-1α-mediated protection in a zebrafish model of α-synuclein toxicity Disease models & mechanisms, 2014; 7(5): 571-82.
O’Donnell Kelley C, Vargas Mauricio E, Sagasti Alvaro   WldS and PGC-1α regulate mitochondrial transport and oxidation state after axonal injury The Journal of neuroscience : the official journal of the Society for Neuroscience, 2013; 33(37): 14778-90.
Palanca Ana Marie S, Lee Sung-Ling, Yee Laura E, Joe-Wong Carlee, Trinh Le A, Hiroyasu Elizabeth, Husain Majid, Fraser Scott E, Pellegrini Matteo, Sagasti Alvaro   New transgenic reporters identify somatosensory neuron subtypes in larval zebrafish Developmental neurobiology, 2013; 73(2): 152-67.
Wang Fang, Wolfson Sean N, Gharib Arash, Sagasti Alvaro   LAR receptor tyrosine phosphatases and HSPGs guide peripheral sensory axons to the skin Current biology : CB, 2012; 22(5): 373-82.
Villegas Rosario, Martin Seanna M, O’Donnell Kelley C, Carrillo Simon A, Sagasti Alvaro, Allende Miguel L   Dynamics of degeneration and regeneration in developing zebrafish peripheral axons reveals a requirement for extrinsic cell types Neural development, 2012; 7(6): 19.
Martin Seanna M, O’Brien Georgeann S, Portera-Cailliau Carlos, Sagasti Alvaro   Wallerian degeneration of zebrafish trigeminal axons in the skin is required for regeneration and developmental pruning Development (Cambridge, England), 2010; 137(23): 3985-94.
O’Brien Georgeann S, Martin Seanna M, Söllner Christian, Wright Gavin J, Becker Catherina G, Portera-Cailliau Carlos, Sagasti Alvaro   Developmentally regulated impediments to skin reinnervation by injured peripheral sensory axon terminals Current biology : CB, 2009; 19(24): 2086-90.
Sagasti, A Guido, MR Raible, DW Schier, AF.   Repulsive interactions shape the morphologies and functional arrangement of zebrafish peripheral sensory arbors Current biology , 2005; 15(9): 804-14.
O’Brien Georgeann S, Rieger Sandra, Wang Fang, Smolen Gromoslaw A, Gonzalez Robert E, Buchanan JoAnn, Sagasti Alvaro   Coordinate development of skin cells and cutaneous sensory axons in zebrafish The Journal of comparative neurology, 2012; 520(4): 816-31.
Rasmussen Jeffrey P, Vo Nhat-Thi, Sagasti Alvaro   Fish Scales Dictate the Pattern of Adult Skin Innervation and Vascularization Developmental cell, 2018; 46(3): 344-359.e4.
Madigan Cressida A, Cambier C J, Kelly-Scumpia Kindra M, Scumpia Philip O, Cheng Tan-Yun, Zailaa Joseph, Bloom Barry R, Moody D Branch, Smale Stephen T, Sagasti Alvaro, Modlin Robert L, Ramakrishnan Lalita   A Macrophage Response to Mycobacterium leprae Phenolic Glycolipid Initiates Nerve Damage in Leprosy Cell, 2017; 170(5): 973-985.e10.
Inaba Yasuko, Chauhan Vasudha, van Loon Aaron Paul, Choudhury Lamia Saiyara, Sagasti Alvaro   Keratins and the plakin family cytolinker proteins control the length of epithelial microridge protrusions eLife, 2020; 9: .
Jiang Nan, Rasmussen Jeffrey P, Clanton Joshua A, Rosenberg Marci F, Luedke Kory P, Cronan Mark R, Parker Edward D, Kim Hyeon-Jin, Vaughan Joshua C, Sagasti Alvaro, Parrish Jay Z   A conserved morphogenetic mechanism for epidermal ensheathment of nociceptive sensory neurites eLife, 2019; 8(9): R327-R329.
van Loon Aaron P, Erofeev Ivan S, Maryshev Ivan V, Goryachev Andrew B, Sagasti Alvaro   Cortical contraction drives the 3D patterning of epithelial cell surfaces The Journal of cell biology, 2020; 219(3): .
Julien Donald P, Chan Alex W, Barrios Joshua, Mathiaparanam Jaffna, Douglass Adam, Wolman Marc A, Sagasti Alvaro   Zebrafish expression reporters and mutants reveal that the IgSF cell adhesion molecule Dscamb is required for feeding and survival Journal of neurogenetics, 2018; 32(4): 336-352.
Cokus Shawn J, De La Torre Maricruz, Medina Eric F, Rasmussen Jeffrey P, Ramirez-Gutierrez Joselyn, Sagasti Alvaro, Wang Fang   Tissue-Specific Transcriptomes Reveal Gene Expression Trajectories in Two Maturing Skin Epithelial Layers in Zebrafish Embryos G3 (Bethesda, Md.), 2019; 9(10): 3439-3452.