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Is the Human Embryo an Organism?
Published in Nicholas Colgrove, Bruce P. Blackshaw, Daniel Rodger, Agency, Pregnancy and Persons, 2023
Finally, the possibility that twin embryos could develop independently in close proximity to each other has been directly tested (Otsuki et al. 2012). In all cases, when two embryos are experimentally induced within the zona pellucida (see Figure 1.1), the twin embryos rapidly annealed to form a single, chimeric embryo. This result strongly indicates that even if early blastomeres were able to somehow separate, the resulting twin embryos would rapidly fuse to form a single embryo.
Order Martellivirales: Bromoviridae
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
Gellért et al. (2012) performed a thorough ab initio structure prediction for the CuMV particles, selected putative epitopes of the coat of porcine circovirus type 2 (PCV2) from the Cirlivirales order (Chapter 10), and generated a prospective live virus-based vaccine against PCV infection in pigs. The predicted PCV2 coat epitopes FNLKDPPLKP and DDNFVTKATALTYDPYVNYS were inserted at aa position 131 of the CuMV coat. N. clevelandii Gray and N. tabacum L. cv. Xanthi plants were inoculated with the recombinant and control in vitro transcripts in the presence of CuMV RNA 1 and 2 transcripts. The systemic symptoms were observed 6–8 days after the inoculation in the case of the control infection, after 8–10 days in the case of the chimera carrying 10-aa epitope, but symptoms never were observed in the case of the chimera carrying the 20-aa epitope. The chimeric virus was further propagated on N. clevelandii Gray plants and the yield of the purified chimeric virus was like that of the wild-type CuMV. Nevertheless, after five to six months of propagation and serial passages on the N. clevelandii or other tobacco plants, the complete deletion of the PCV2 epitope was observed. The chimeric virions were able to induce PCV-specific antibody response in mice, while the challenge experiment with PCV2 carried out in immunized pigs showed partial protection against the infection (Gellért et al. 2012).
The Downless (dl) and Sleek (Dlslk) Mutations, Chromosome 10
Published in John P. Sundberg, Handbook of Mouse Mutations with Skin and Hair Abnormalities, 2020
Downless mice have been used to study the basic biology of skin. Chimeras made using dl/dl and +/+ cells developed patterns of transverse stripes of normal and abnormal hair, supporting the hypothesis that both epidermis and dermis proliferate by lateral coherent clonal growth.8
Human Brain Surrogates Research: The Onrushing Ethical Dilemma
Published in The American Journal of Bioethics, 2021
A second approach is to make human/non-human chimeras. Chimeras are creatures that have cells and tissues from more than one individual integrated in them, sometimes from the same species and sometimes from different ones (Greely 2003). Humans with organ transplants are intra-specific chimeras; humans with heart valves taken from pigs are inter-specific chimeras. For this research, non-human animals have had some human cells or tissues added to them. That approach has been used for many decades for, say, studying human tumors by transplanting them into mice. But in the last two decades, we have transplanted more cells and tissues from humans directly into non-human animals’ brains. The increase reflects our improving ability to understand and exploit stem cells, to deal with the hosts’ immune systems to prevent them from destroying the human cells, and generally to more understanding of brain function.
A bovine lactoferricin-lactoferrampin-encoding Lactobacillus reuteri CO21 regulates the intestinal mucosal immunity and enhances the protection of piglets against enterotoxigenic Escherichia coli K88 challenge
Published in Gut Microbes, 2021
Weichun Xie, Liying Song, Xueying Wang, Yigang Xu, Zengsu Liu, Dongfang Zhao, Shubo Wang, Xiaolong Fan, Zhaorui Wang, Chong Gao, Xiaona Wang, Li Wang, Xinyuan Qiao, Han Zhou, Wen Cui, Yanping Jiang, Yijing Li, Lijie Tang
Antimicrobial peptides (AMPs) are short cationic molecules (12–50 aa) with amphipathic structures, and these molecules play essential roles in host defense against microbial infection.9 Bovine lactoferricin (Lfcin B) and lactoferrampin (Lfampin) are two antimicrobial peptides released by gastric pepsin cleavage of bovine lactoferrin (LF).10 Lfcin B consists of a positively charged looped peptide containing residues 17–41, Lfampin comprises residues 268–284 in the N1 domain of LF.11 Recent reports have suggested that the fusion of Lfcin B with Lfampin (LFCA) broadens their antimicrobial spectra in vitro.12,13 In addition to its antimicrobial activity, the chimera has also been reported to be involved in improving performance, immune function and intestinal mucosal morphology.14 The synthesis and purification of AMPs are costly and time-consuming.15Lactobacillus has been considered a good delivery vehicle to express AMPs for preserving the mucosal integrity, improving intestinal microbiota and ameliorating DSS-induced intestinal injury.16,17
Common light chain chickens produce human antibodies of high affinity and broad epitope coverage for the engineering of bispecifics
Published in mAbs, 2021
Kathryn H. Ching, Kimberley Berg, Kevin Reynolds, Darlene Pedersen, Alba Macias, Yasmina N. Abdiche, William D. Harriman, Philip A. Leighton
Breeding: All animal experiments were done in accordance with protocols approved by Ligand Pharmaceuticals’ Institutional Animal Care and Use Committee. The animal facility is accredited by the Association for Assessment and Accreditation of Laboratory Animal Care. CmLC1 chimeras were produced by injecting embryos with either single clones, or pooled cells from several clones.48 Germline transmission from chimeras made with pooled clones (average rate, 30% from 13 chimeras) was very similar to that from chimeras made with single clones (average rate, 31% in 24 chimeras made with 4 clones). Transgenic chicks were confirmed for the correct insertion of the CmLC1 construct by PCR upon hatch. Founder CmLC1 transgenics were obtained by breeding to Cre/IgL KO/IgH KO birds49 to remove selectable markers. To obtain OmniClic birds with the genotype CmLC1/IgL KO; SynVH/IgH KO, crosses between CmLC1/+; IgH KO/+ and IgL KO/+; SynVH/+ birds were performed. Progeny was genotyped by PCR using DNA obtained from comb biopsy. Males and females were kept for analysis.