Dr. Lloyd designs mouse models of human disease using transgenics, ES cell targeting, and CRISPR/Cas9 –based genome editing technologies. He also conducts studies to develop improved means to preserve and resuscitate mutant mouse strains. The rate at which genetically-altered mouse strains are being created is exceeding the rate at which these strains can be studied in hypothesis-based biomedical research. To keep these strains alive as breeding colonies places them at risk of disease, genetic drift, and catastrophic loss. Several new methods for preservation of mouse embryos, germplasm, ovaries, and somatic tissues are being developed which ensures that a strain discontinued as a live colony can be recovered at a later time. Dr. Lloyd works on new methods for preserving sperm, including cryopreservation, freeze-drying, and evaporative drying, and the requisite techniques to ensure resuscitation by IVF and ICSI. Dr. Lloyd is also working on methods to enhance and improve somatic cell cloning as a means to preserve mouse strains that can be maintained as frozen pieces of somatic tissue from which nuclei can be recovered and used for intracytoplasmic nuclear injection (ICNI) to resuscitate the mouse strain.
Mouse Biology and Mutagenesis
The UC Davis Mouse Biology Program has multiple component laboratories, including the Murine Molecular Constructs Laboratory, the Murine Targeted Genomics Laboratory, the Murine Genetic Analysis Laboratory, the Murine Cryopreservation and Recovery Laboratory, and the Murine Stem Cell Laboratory. Dr. Lloyd is engaged in technology development to enhance the resources, services, products, and procedures available through the Mouse Biology Program and the associated NIH-funded projects, including the Mutant Mouse Resource and Research Center (MMRRC), the Knockout Mouse Production and Phenotyping (KOMP2) projects, and the Mouse Metabolic Phenotyping Center.
Lee AY-F and Lloyd KCK. Conditional targeting of Ispd using paired Cas9 nickase and a single DNA template in mice. FEBS Open Bio. 2014;4:637-642. PubMed PMID: in progress; PubMed Central PMCID: PMC4141200.
Takeo T, Fukumoto K, Kondo T, Haruguchi Y, Takeshita Y, Nakamuta Y, Tsuchiyama S, Yoshimoto H, Shimizu N, Li M-W, Kinchen K, Vallelunga J, Lloyd KCK, Nakagata N. Investigations of motility and fertilization potential in thawed cryopreserved mouse sperm from cold-stored epididymides. Cryobiology. 2014;68:12-17. PubMed PMID: 24201107; PubMed Central PMCID: PMC4140441.
Li M-W, Willis BJ, Evans KD, Araiza RS, Lee AYF, Lloyd KCK. Rescue of germline transmission from chimeras by IVF after sperm analysis. Transgenic Res. 2014 July Epub ahead of print. PubMed PMID: 25080098; PubMed Central PMCID: in progress
Lee AY, Evans K, Willis B, Lloyd KC. Combining sperm plug genotyping and coat color chimerism predicts germline transmission. Transgenic Res. 2013 Dec;22(6):1265-72. doi: 10.1007/s11248-013-9731-6. Epub 2013 Jul 17. PubMed PMID: 23860911; PubMed Central PMCID: PMC3838463.
Karp NA, Meehan TF, Morgan H, Mason JC, Blake A, Kurbatova N, Smedley D, Jacobsen J, Mott JF, Iyer V, Matthews P, Melvin DG, Wells S, Flenniken AM, Masuya H, Wakana S, White JK, Lloyd KCK, Reynolds CL, Paylor R, West DB, Svenson KL, Chesler EJ, Hrabě de Angelis MH, Tocchini-Valentini GP, Sorg-Guss T, Herault Y, Parkinson H, Mallon A-M, Brown SD. Applying the ARRIVE guidelines to an in vivo database. PLoS Biol 2015 May 20;13(5):e1002151. doi: 10.1371/journal.pbio.1002151. eCollection 2015. PMID: 25992600; PMCID: PMC4439173.
West DB, Engelhard EK, Adkisson M, Nava AJ, Kirov J, Cipollone A, Willis BJ, Rapp J, de Jong P, Lloyd KCK. Transcriptome analysis of targeted mouse mutations reveals the topography of local changes in gene expression. PLOS Genetics 2016 Feb 3;12(2):e1005691. doi: 10.1371/journal.pgen.1005691. eCollection 2016 Feb. PubMed PMID: 26839965; PMCID (in progress)
Kirov JV, Adkisson M, Nava AJ, Cipollone A, Willis B, Engelhard EK, Lloyd KCK, de Jong Pieter, West DB. Reporter gene silencing in targeted mouse mutants is associated with promoter CpG island methylation. PLoS One 2015 Aug 14;10(8):e0134155. doi: 10.1371/journal.pone. 0134155. eCollection 2015. PMID: 26275310; PMCID: PMC4537176.