In chickens, primordial germ cells (PGCs) are effective targets for advanced genome editing, including gene knock-in. Although a long-term culture system has been established for chicken PGCs, it is necessary to select a gene-editing tool that is efficient and precise for editing the PGC genome while maintaining its ability to contribute to the reproductive system. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) and CRISPR-mediated precise integration into the target chromosome (CRIS-PITCh) methods are superior as the donor vector is easier to construct, has high genome editing efficiency, and does not select target cells, compared to the homologous recombination method, which has been conventionally used to generate knock-in chickens. In this study, we engineered knock-in chicken PGCs by integrating a fluorescent protein gene cassette as a fusion protein into the chicken vasa homolog (CVH) locus of chicken PGCs using the CRIS-PITCh method. The knock-in PGCs expressed the fluorescent protein in vitro and in vivo, facilitating the tracking of PGCs. Furthermore, we characterized the efficiency of engineering double knock-in cell lines. Knock-in cell clones were obtained by limiting dilution, and the efficiency of engineering double knock-in cell lines was confirmed by genotyping. We found that 82% of the analyzed clones were successfully knocked-in into both alleles. We suggest that the production of model chicken from the knock-in PGCs can contribute to various studies, such as the elucidation of the fate of germ cells and sex determination in chicken. 相似文献
Current knowledge of the nature of the antigens and of the host immune responses in vaccinal immunity to Marek's disease is reviewed. It is suggested that a two-step mechanism of resistance operates. The first step involves humoral and cell-mediated responses directed against viral antigens; the second step occurs after challenge with Marek's disease virus and consists of cellmediated responses directed against tumour cells. 相似文献
This paper reports the milk protein polymorphism, the allele frequencies of variants and the possible linkages among various combinations of milk protein phenotypes in the Kangayam cattle of south India. Milk samples from 156 Kangayam cows were typed by starch gel and polyacrylamide gel electrophoresis for caseins and whey proteins, respectively. All the four milk protein components studied, 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">s1-casein, 9w4550174220k7w/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-casein, 9w4550174220k7w/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-lactoglobulin and 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-lactalbumin, exhibited polymorphism with high allele frequencies of 0.9231±0.0151 for 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">s1-casein C, 0.9263±0.0148 for 9w4550174220k7w/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-casein A, 0.9135±0.0159 for 9w4550174220k7w/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-lactoglobulin B and a relatively high frequency of 0.6218±0.0275 for 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-lactalbumin A. The mean heterozygosity estimated over all the four milk protein loci was 0.2420. Genetic equilibrium was observed among all the loci studied, except 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-lactalbumin. Linkage analysis confirmed the non-independence between 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">s1- and 9w4550174220k7w/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-caseins and between caseins and 9w4550174220k7w/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-lactalbumin phenotypes. 相似文献
In the last century, vaccines have been one of the most powerful tools for preventing infectious diseases. Smallpox has been eradicated and other diseases such as poliomyelitis or measles have been reduced to very low levels in many regions of the world. However, infectious diseases remain the leading cause of death worldwide. Thus, the development of vaccines to prevent diseases for which no vaccine currently exists such as AIDS or malaria as well as the improvement of efficacy and safety of existing vaccines remains a high priority. Achieving such ambitious goals in a near future will certainly require a strong modification of the methods that have been used so far to identify vaccine candidates. In particular, modern vaccinology could strongly benefit of the latest developments of molecular biology and immunology. Here, we will discuss some potential applications of the increasing knowledge of pathogen genomes as well as the immune system for the discovery of new antigenic targets and the development of new strategies of vaccination. 相似文献
Biological weapons are considered as mass destruction and terror weapons. Terrorism including bioterrorism is the major threat in the future conflicts for our nations. The aim of bioterrorism is more related to the potential disorganisation of the society than to the lethal effects of the agents used. The dramatic consequences cannot be discarded, especially if contagious agents such viral are used. The preparation of specific defence measures is a major challenge for our countries.
The knowledge acquired from the struggle against natural infectious diseases and recent events are essential to improve behaviours to face the biological weapon threats. The defence attitude is based on the anticipation of the threat, the management of the victims, and the restoration of the operational capabilities. This global defence attitude implies six important functions: (i) alert, (ii) detection and diagnosis, (iii) availability of pharmaceutical countermeasures such as vaccine, sera and anti-infectious medicine and products, (iv) medical management of victims, (v) training and information, (vi) research and development.
Passive and active immunoprevention and immuntherapy belong to the approaches discussed in the context of bioterrorism countermeasures. Further researches might be focused on these topics. 相似文献
Foot-and-mouth disease virus (FMDV) is an aphthovirus of the family Picornaviridae and the etiological agent of the economically most important animal disease. As a typical picornavirus, FMD virions are nonenveloped particles of icosahedral symmetry and its genome is a single stranded RNA of about 8500 nucleotides and of positive polarity. FMDV RNA is infectious and it replicates via a complementary, minus strand RNA. FMDV RNA replication is error-prone so that viral populations consist of mutant spectra (quasispecies) rather than a defined genomic sequence. Therefore FMDV in nature is genetically and antigenically diverse. This poses important challenges for the diagnosis, prevention and control of FMD. A deeper understanding of FMDV population complexity and evolution has suggested requirements for a new generation of anti-FMD vaccines. This is relevant to the current debate on the adequacy of non-vaccination versus vaccination policies for the control of FMD.
R9;sum9;
Le virus de la fièvre aphteuse est un aphtovirus de la famille des Picornaviridae et l'agent de la maladie animale la plus importante sur le plan 9;conomique. En tant que picornavirus typique, le virus de la fièvre aphteuse est nu, sous forme d'icosaèdre et son g9;nome comprend un acide ribonucl9;ique monobrin avec environ 8500 nucl9;otides et une polarit9; positive. L'acide ribonucl9;ique de ce virus est infectieux et il se r9;plique par l'interm9;diaire d'un brin d'ARN moins, compl9;mentaire. La r9;plication de l'acide nucl9;ique de ce virus conduit à des erreurs, de telle sorte que les populations virales comprennent un ensemble de mutants (quasi espèce) plutôt qu'une s9;quence g9;nomique bien d9;finie. Par suite, le virus de la fièvre aphteuse est g9;n9;tiquement et antig9;niquement vari9;. Ceci entraîne des difficult9;s importantes pour le diagnostic, la pr9;vention et la maîtrise de la fièvre aphteuse. Une connaissance plus approfondie de la complexit9; et de l'9;volution de la population de ce virus a conduit à des besoins pour une nouvelle g9;n9;ration de vaccines aphteux. Ceci est li9; au d9;bat actuel sur le choix d'une politique de vaccination ou de non-vaccination dans la lutte contre la fièvre aphteuse. 相似文献