Chris Winchell

Research summary

My research aims to clarify the source of the replacement germline in Parhyale.  We hypothesize that the fate-switching cells compensating for germline loss derive from the somatic portion of the gonad.  I am exploring this hypothesis with two related sets of experiments that utilize the highly stereotyped lineages produced by Parhyale’s 8-cell-stage blastomeres (Gerberding et al. 2002).  First, through microinjection and genomic integration of heat shock-inducible reporter genes (Pavlopoulos et al. 2009), I am analyzing these blastomeres’ adult clonal domains to determine which of them encompasses the somatic gonad.  Second, I am applying this same transgenesis approach to embryos that I also subject to germline ablation (through microinjection of RNase and DNase into g, the germline progenitor cell).  I expect a transgenic replacement germline to develop only in g-ablated animals that are transgenic in the blastomere lineage that gives rise to the somatic gonad; it follows that these animals should bear offspring exhibiting ubiquitous reporter gene expression.  In addition, I am conducting conditional ablation with the nitroreductase-metronidazole system (Curado et al. 2008) to test whether germline replacement is possible in Parhyale adults, and I am establishing new transgenic lines for the Patel lab’s Parhyale research: one capable of fC31 integrase-mediated transgenesis (Groth et al. 2000), and one expressing DsRed in the germline from a recombineered vasa-containing BAC clone (Parchem et al. 2010).

References

Curado S, Stainier DYR, Anderson RM (2008) Nitroreductase-mediated cell/tissue ablation in zebrafish: a spatially and temporally controlled ablation method with applications in developmental and regeneration studies. Nat Protoc 3:948-954

Gerberding M, Browne WE, Patel NH (2002) Cell lineage analysis of the amphipod crustacean Parhyale hawaiensis reveals an early restriction of cell fates. Development 129:5789-5801

Groth AC, Olivares EC, Thyagarajan B, Calos MP (2000) A phage integrase directs efficient site-specific integration in human cells. P Natl Acad Sci USA 97:5995-6000

Parchem RJ, Poulin F, Stuart AB, Amemiya CT, Patel NH (2010) BAC library for the amphipod crustacean Parhyale hawaiensis. Genomics 95:261-267

Pavlopoulos A, Kontarakis Z, Liubicich DM, Serano JM, Akam M, Patel NH, Averof M (2009) Probing the evolution of appendage specialization by Hox gene misexpression in an emerging model crustacean. P Natl Acad Sci USA 106:13897-13902

Education

Ph.D.   2010.  Ecology and Evolutionary Biology.  UCLA.  Advised by David K. Jacobs.

M.S.    2001.  Zoology.  Washington State University.  Advised by Jon M. Mallatt.

B.A.     1998.  Marine Biology with Highest Honors.  UC Santa Cruz.  Advised by Lynda J. Goff.

Fellowships

California Institute for Regenerative Medicine Postdoctoral Fellowship.  2012

UCLA Graduate Division Dissertation Year Fellowship.  2008/2009 academic year

UCLA Department of EEB Quality of Graduate Education Fellowship.  Summer 2008

UCLA Department of EEB Dissertation Completion Fellowship.  Fall 2007

U.S. Dept. of Education Graduate Assistantship in Areas of National Need.  Fall-Summer

UCLA Center for the Study of Evolution and Origin of Life Graduate Fellowship.  2001/02 academic year2006

Teaching awards

UCLA Department of EEB Schechtman Award for Excellence in Teaching.  2008

UCLA Life Sciences Core Curriculum Honorarium Award for Distinction in Teaching. 2006

Publications

Winchell CJ, Jacobs DK (2013) Expression of the Lhx genes apterous and lim1 in an errant polychaete: implications for bilaterian appendage evolution, neural development, and muscle diversification. EvoDevo 4:4.

Winchell CJ, Valencia JE, Jacobs DK (2010) Expression of Distal-less, dachshund, and optomotor blind in Neanthes arenaceodentata (Annelida, Nereididae) does not support homology of appendage-forming mechanisms across the Bilateria. Dev Genes Evol 220:275-295.

Winchell CJ, Valencia JE, Jacobs DK (2010) Confocal analysis of nervous system architecture in direct-developing juveniles of Neanthes arenaceodentata (Annelida, Nereididae). Front Zool 7:17.

Mallatt J, Winchell CJ (2007) Ribosomal RNA genes and deuterostome phylogeny revisited: more cyclostomes, elasmobranchs, reptiles, and a brittle star. Mol Phylogenet Evol 43:1005-1022.

Jacobs DK, Hughes NC, Fitz-Gibbon ST, Winchell CJ (2005) Terminal addition, the Cambrian radiation, and the Phanerozoic evolution of bilaterian form. Evol Dev 7:498-514.

Winchell CJ, Martin A, Mallatt J (2004) Phylogeny of elasmobranchs based on LSU and SSU ribosomal RNA genes. Mol Phylogenet Evol 31:214-224.

Winchell CJ, Sullivan J, Cameron CB, Swalla BJ, Mallatt J (2002) Evaluating hypotheses of deuterostome phylogeny and chordate evolution with new LSU and SSU ribosomal DNA data. Mol Biol Evol 19:762-776.

Mallatt J, Winchell CJ (2002) Testing the new animal phylogeny: first use of combined large-subunit and small-subunit rRNA gene sequences to classify the protostomes. Mol Biol Evol 19:289-301.

Mallatt J, Sullivan J, Winchell CJ (2001) The relationships of lampreys to hagfishes: a spectral analysis of ribosomal DNA sequences. Pp. 106-118 in P. Ahlberg, ed. Major events in early vertebrate evolution: paleontology, phylogeny, and development. Taylor and Francis Ltd., London.

Gowing MM, Garrison DL, Kunze HB, Winchell CJ (2001) Biological components of Ross Sea short-term particle fluxes in the austral summer of 1995-1996. Deep-Sea Res Pt I 48:2645-2671.

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