A High-Speed Congenic Strategy Using First-Wave Male Germ Cells

BACKGROUND: In laboratory mice and rats, congenic breeding is essential for analyzing the genes of interest on specific genetic backgrounds and for analyzing quantitative trait loci. However, in theory it takes about 3-4 years to achieve a strain carrying about 99% of the recipient genome at the tenth backcrossing (N10). Even with marker-assisted selection, the so-called 'speed congenic strategy', it takes more than a year at N4 or N5. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a new high-speed congenic system using round spermatids retrieved from immature males (22-25 days of age). We applied the technique to three genetically modified strains of mice: transgenic (TG), knockin (KI) and N-ethyl-N-nitrosourea (ENU)-induced mutants. The donor mice had mixed genetic backgrounds of C57BL/6 (B6):DBA/2 or B6:129 strains. At each generation, males used for backcrossing were selected based on polymorphic marker analysis and their round spermatids were injected into B6 strain oocytes. Backcrossing was repeated until N4 or N5. For the TG and ENU-mutant strains, the N5 generation was achieved on days 188 and 190 and the proportion of B6-homozygous loci was 100% (74 markers) and 97.7% (172/176 markers), respectively. For the KI strain, N4 was achieved on day 151, all the 86 markers being B6-homozygous as early as on day 106 at N3. The carrier males at the final generation were all fertile and propagated the modified genes. Thus, three congenic strains were established through rapid generation turnover between 41 and 44 days. CONCLUSIONS/SIGNIFICANCE: This new high-speed breeding strategy enables us to produce congenic strains within about half a year. It should provide the fastest protocol for precise definition of the phenotypic effects of genes of interest on desired genetic backgrounds

Western Pacific Air-Sea Interaction Study

A01: Dynamics of Atmospheric CompositionA Study on the Production and Emission of Marine-Derived Volatile Halocarbons / Y. Yokouchi, A. Ooki, S. Hashimoto and N. Itoh : 05w-pass_001.pdfMeasurements of Gaseous Peroxides in the Oceanic Lower Atmosphere / S. Hatakeyama and T. Akatsuka : 06w-pass_027.pdfPhase Partitioning of NH3 and Gas to Particle Conversion / K. Osada : 07w-pass_033.pdfNew Particle Formation of Marine Aerosols / K. Miura, H. Furutani, Y. Iwamoto, K. Nagano, H. Kobayashi, M. Mochida, H. Mukai, S. Hashimoto, M. Takami and M. Uematsu : 08w-pass_037.pdfA Study of the Chemical Processes in Aerosols and Their Impacts on the Environment Using X-ray Absorption Fine Structure Spectroscopy / Y. Takahashi, M. Higashi, T. Furukawa, T. Miyoshi, M. Fujiwara and M. Uematsu : 09w-pass_043.pdfVariability in Mineral Dust Deposition over the North Pacific and Its Potential Impact on the Ocean Productivity / H. Fukushima : 10w-pass_051.pdfAtmosphere-Ocean Interaction through Atmospheric Aerosol Particles Observed in a Single Nanoparticle Aspect / H. Furutani, J. Jinyoung and M. Uematsu : 11w-pass_061.pdfSimultaneous Measurements of Hygroscopic Property and Cloud Condensation Nucleus Activity of Aerosol Particles of Marine Biogenic Origin / M. Mochida : 12w-pass_071.pdfEruption of Mt. Kilauea Impacted Cloud Droplet and Radiation Budget over North Pacific / I. Uno, K. Eguchi and K. Yumimoto : 13w-pass_083.pdfA02: Variability of Gas Exchanges at the Air-Sea InterfaceHigh-Resolution Measurement of Volatile Organic Compounds Dissolved in Seawater Using Equilibrator Inlet-Proton Transfer Reaction-Mass Spectrometry (EI-PTR-MS) / H. Tanimoto, S. Kameyama, Y. Omori, S. Inomata and U. Tsunogai : 14w-pass_089.pdfStudy of the Production Processes of Marine Biogenic Methane and Carbonyl Sulfide Using Stable Isotope Analysis / S. Toyoda, K. Yamada, Y. Ueno, K. Koba and O. Yoshida : 15w-pass_117.pdfLong-Term Changes of Greenhouse Gases in the Ocean and Their Feedback Effects on the Climate / Y. W. Watanabe, I. Yasuda and N. Tsurushima : 16w-pass_123.pdfTemporal and Spatial Variations in Carbonate System and Air-Sea CO2 Flux in the Kuroshio and Kuroshio Extension / H. Yoshikawa-Inoue, T. Midorikawa and T. R. Takamura : 17w-pass_151.pdfA03: Dynamics of the Marine EcosystemBioavailability and Biogeochemical Processes of Trace Metals in the Surface Ocean / S. Takeda, H. Obata, A. Okubo, M. Sato and Y. Kondo : 18w-pass_163.pdfDetailed Variations in Bioactive Elements in the Surface Ocean and Their Interaction with Microbiological Processes / H. Ogawa, K. Kogure, J. Kanda, F. Hashihama and M. Suzumura : 19w-pass_177.pdfPhotoheterotrophic Process in Surface Seawater Environments / K. Hamasaki, Y. Sato-Takabe, A. Taniguchi and Y. Tada : 20w-pass_199.pdfEcological Study of Bacterial Populations Related to Biogenic Gas Transformation in Marine Environments / K. Hamasaki, R. Kaneko, A. Mouri, Y. Tada, N. Kasamatsu-Takasawa and I. Nagao : 21w-pass_203.pdfA04: Modelling of the Interaction between the Ocean and the AtmosphereModeling for Evaluation and Prediction of Effects of Short-Term Atmospheric Disturbance on Air-Sea Material Cycling / M. Fujii and A. Tanaka : 22w-pass_211.pdfRelating Phytoplankton Pnysiology to North Pacific Biogeochemistry / S. L. Smith, M. N. Aita, M. Shigemitsu and Y. Yamanaka : 23w-pass_223.pdfCoupling of Physical and Bio-Geochemical Process and Monitoring Ocean Circulation Using Data Assimilation System / Y. Ishikawa, T. Awaji, M. Ikeda and T. Toyoda : 24w-pass_237.pdfPart of "Western Pacific Air-Sea Interaction Study

Western Pacific Air-Sea Interaction Study

A01: Dynamics of Atmospheric CompositionA Study on the Production and Emission of Marine-Derived Volatile Halocarbons / Y. Yokouchi, A. Ooki, S. Hashimoto and N. Itoh : 05w-pass_001.pdfMeasurements of Gaseous Peroxides in the Oceanic Lower Atmosphere / S. Hatakeyama and T. Akatsuka : 06w-pass_027.pdfPhase Partitioning of NH3 and Gas to Particle Conversion / K. Osada : 07w-pass_033.pdfNew Particle Formation of Marine Aerosols / K. Miura, H. Furutani, Y. Iwamoto, K. Nagano, H. Kobayashi, M. Mochida, H. Mukai, S. Hashimoto, M. Takami and M. Uematsu : 08w-pass_037.pdfA Study of the Chemical Processes in Aerosols and Their Impacts on the Environment Using X-ray Absorption Fine Structure Spectroscopy / Y. Takahashi, M. Higashi, T. Furukawa, T. Miyoshi, M. Fujiwara and M. Uematsu : 09w-pass_043.pdfVariability in Mineral Dust Deposition over the North Pacific and Its Potential Impact on the Ocean Productivity / H. Fukushima : 10w-pass_051.pdfAtmosphere-Ocean Interaction through Atmospheric Aerosol Particles Observed in a Single Nanoparticle Aspect / H. Furutani, J. Jinyoung and M. Uematsu : 11w-pass_061.pdfSimultaneous Measurements of Hygroscopic Property and Cloud Condensation Nucleus Activity of Aerosol Particles of Marine Biogenic Origin / M. Mochida : 12w-pass_071.pdfEruption of Mt. Kilauea Impacted Cloud Droplet and Radiation Budget over North Pacific / I. Uno, K. Eguchi and K. Yumimoto : 13w-pass_083.pdfA02: Variability of Gas Exchanges at the Air-Sea InterfaceHigh-Resolution Measurement of Volatile Organic Compounds Dissolved in Seawater Using Equilibrator Inlet-Proton Transfer Reaction-Mass Spectrometry (EI-PTR-MS) / H. Tanimoto, S. Kameyama, Y. Omori, S. Inomata and U. Tsunogai : 14w-pass_089.pdfStudy of the Production Processes of Marine Biogenic Methane and Carbonyl Sulfide Using Stable Isotope Analysis / S. Toyoda, K. Yamada, Y. Ueno, K. Koba and O. Yoshida : 15w-pass_117.pdfLong-Term Changes of Greenhouse Gases in the Ocean and Their Feedback Effects on the Climate / Y. W. Watanabe, I. Yasuda and N. Tsurushima : 16w-pass_123.pdfTemporal and Spatial Variations in Carbonate System and Air-Sea CO2 Flux in the Kuroshio and Kuroshio Extension / H. Yoshikawa-Inoue, T. Midorikawa and T. R. Takamura : 17w-pass_151.pdfA03: Dynamics of the Marine EcosystemBioavailability and Biogeochemical Processes of Trace Metals in the Surface Ocean / S. Takeda, H. Obata, A. Okubo, M. Sato and Y. Kondo : 18w-pass_163.pdfDetailed Variations in Bioactive Elements in the Surface Ocean and Their Interaction with Microbiological Processes / H. Ogawa, K. Kogure, J. Kanda, F. Hashihama and M. Suzumura : 19w-pass_177.pdfPhotoheterotrophic Process in Surface Seawater Environments / K. Hamasaki, Y. Sato-Takabe, A. Taniguchi and Y. Tada : 20w-pass_199.pdfEcological Study of Bacterial Populations Related to Biogenic Gas Transformation in Marine Environments / K. Hamasaki, R. Kaneko, A. Mouri, Y. Tada, N. Kasamatsu-Takasawa and I. Nagao : 21w-pass_203.pdfA04: Modelling of the Interaction between the Ocean and the AtmosphereModeling for Evaluation and Prediction of Effects of Short-Term Atmospheric Disturbance on Air-Sea Material Cycling / M. Fujii and A. Tanaka : 22w-pass_211.pdfRelating Phytoplankton Pnysiology to North Pacific Biogeochemistry / S. L. Smith, M. N. Aita, M. Shigemitsu and Y. Yamanaka : 23w-pass_223.pdfCoupling of Physical and Bio-Geochemical Process and Monitoring Ocean Circulation Using Data Assimilation System / Y. Ishikawa, T. Awaji, M. Ikeda and T. Toyoda : 24w-pass_237.pdfPart of "Western Pacific Air-Sea Interaction Study