Selected Grantee Publications
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- 8 results found
- Aquatic Vertebrate Models
- CRISPR
- Preservation
Establishment of a Practical Sperm Cryopreservation Pathway for the Axolotl (Ambystoma mexicanum): A Community-Level Approach to Germplasm Repository Development
Coxe et al., Animals (Basel). 2024.
https://pubmed.ncbi.nlm.nih.gov/38254376/
The axolotl (Ambystoma mexicanum) is an important biomedical research model for organ regeneration, but housing and maintaining live animals is expensive and risky as new transgenic lines are developed. The authors report an initial practical pathway for sperm cryopreservation to support germplasm repository development. They assembled a pathway through the investigation of axolotl sperm collection by stripping, refrigerated storage in various osmotic pressures, cryopreservation in various cryoprotectants, and in vitro fertilization using thawed sperm. This work is the first report of successful production of axolotl offspring with cryopreserved sperm and provides a general framework for pathway development to establish Ambystoma germplasm repositories for future research and applications. Supported by ORIP (R24OD010441, R24OD028443, P40OD019794).
Conduction-Dominated Cryomesh for Organism Vitrification
Guo et al., Advanced Science. 2024.
https://pubmed.ncbi.nlm.nih.gov/38018294/
Vitrification-based cryopreservation via cryomesh is a promising approach for maintaining biodiversity, health care, and sustainable food production via long-term preservation of biological systems. Here, researchers conducted a series of experiments aimed at optimizing the cooling and rewarming rates of cryomesh to increase the viability of various cryopreserved biosystems. They found that vitrification was significantly improved by increasing thermal conductivity, reducing mesh wire diameter and pore size, and minimizing the nitrogen vapor barrier of the conduction-dominated cryomesh. Cooling rates increased twofold to tenfold in a variety of biosystems. The conduction-dominated cryomesh improved the cryopreservation outcomes of coral larvae, Drosophila embryos, and zebrafish embryos by vitrification. These findings suggest that the conduction-dominated cryomesh can improve vitrification in such biosystems for biorepositories, agriculture and aquaculture, and research. Supported by ORIP (R24OD028444, R21OD028758, R24OD034063, R21OD028214), NIDDK, and NIGMS.
Zebrafish as a High Throughput Model for Organ Preservation and Transplantation Research
Da Silveira Cavalcante et al., The FASEB Journal. 2023.
https://faseb.onlinelibrary.wiley.com/doi/10.1096/fj.202300076R
Organ transplantation increases the quality of life and life expectancy of patients with chronic end-stage diseases, but the preservation of organs for transplantation remains a significant barrier. In the current study, researchers demonstrate the value of zebrafish as a high-throughput model organism in the fields of solid-organ preservation and transplantation, with a focus on heart preservation via partial freezing. Their techniques have the potential to advance research in the fields of cryobiology and solid-organ transplantation. Supported by ORIP (R24OD031955) and NHLBI.
MIC-Drop: A Platform for Large-scale In Vivo CRISPR Screens
Parvez et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/34413171/
CRISPR screens in animals are challenging because generating, validating, and keeping track of large numbers of mutant animals is prohibitive. These authors introduce Multiplexed Intermixed CRISPR Droplets (MIC-Drop), a platform combining droplet microfluidics, single-needle en masse CRISPR ribonucleoprotein injections, and DNA barcoding to enable large-scale functional genetic screens in zebrafish. In one application, they showed that MIC-Drop could identify small-molecule targets. Furthermore, in a MIC-Drop screen of 188 poorly characterized genes, they discovered several genes important for cardiac development and function. With the potential to scale to thousands of genes, MIC-Drop enables genome-scale reverse genetic screens in model organisms. Supported by ORIP (R24OD017870), NIGMS, and NHLBI.
TGF-β1 Signaling Is Essential for Tissue Regeneration in the Xenopus Tadpole Tail
Nakamura et al., Biochemical and Biophysical Research Communications. 2021.
https://www.sciencedirect.com/science/article/pii/S0006291X21008731
Amphibians, such as Xenopus tropicalis, exhibit a remarkable capacity for tissue regeneration after traumatic injury. Nakamura et al. show that inhibition of TGF-β1 function prevents tail regeneration in Xenopus tropicalis tadpoles. CRISPR-mediated knock-out (KO) of tgfb1 retards tail regeneration; the phenotype of tgfb1 KO tadpoles can be rescued by injection of tgfb1 mRNA. Cell proliferation, critical for tissue regeneration, is downregulated in tgfb1 KO tadpoles; tgfb1 KO reduces the expression of phosphorylated Smad2/3 (pSmad2/3). These results show that TGF-β1 regulates cell proliferation through the activation of Smad2/3. They propose that TGF-β1 plays a critical role in TGF-β receptor-dependent tadpole tail regeneration in Xenopus. Supported by ORIP (P40OD010997, R24OD030008).
Identification of Basp1 as a Novel Angiogenesis-regulating Gene by Multi-Model System Studies
Khajavi et al., FASEB Journal. 2021.
https://pubmed.ncbi.nlm.nih.gov/33899275/
The authors previously used genetic diversity in inbred mouse strains to identify quantitative trait loci (QTLs) responsible for differences in angiogenic response. Employing a mouse genome-wide association study (GWAS) approach, the region on chromosome 15 containing Basp1 was identified as being significantly associated with angiogenesis in inbred strains. To investigate its role in vivo, they knocked out basp1 in transgenic kdrl:zsGreen zebrafish embryos using a widely adopted CRISPR-Cas9 system. They further showed that basp1 promotes angiogenesis by upregulating β-catenin gene and the Dll4/Notch1 signaling pathway. These results provide the first in vivo evidence to indicate the role of basp1 as an angiogenesis-regulating gene. Supported by ORIP (R24OD017870) and NEI.
Endogenous Zebrafish Neural Cre Drivers Generated by CRISPR/Cas9 Short Homology Directed Targeted Integration
Almeida et al., Scientific Reports. 2021.
https://pubmed.ncbi.nlm.nih.gov/33462297/
Almeida et al. previously reported precision targeted integration of reporter DNA in zebrafish using CRISPR/Cas9. Here, they isolated zebrafish Cre recombinase drivers. A 2A-Cre recombinase transgene with 48 bp homology arms was targeted into proneural genes ascl1b, olig2 and neurod1. They observed high rates of germline transmission from 10 to 100% (10% olig2; 20% neurod1; 100% ascl1b). The lines Tg(ascl1b-2A-Cre)is75, Tg(olig2-2A-Cre)is76, and Tg(neurod1-2A-Cre)is77 expressed functional Cre recombinase in the cell populations. Results demonstrate Cre recombinase expression is driven by the native promoter and regulatory elements of targeted genes. This approach is a cost-effective method to generate cell type specific zebrafish Cre and CreERT2 drivers. Supported by ORIP (R24OD020166).
3-D Printed Customizable Vitrification Devices for Preservation of Genetic Resources of Aquatic Species
Tiersch et al., Aquacultural Engineering. 2020.
https://www.sciencedirect.com/science/article/pii/S0144860920300406
Sperm vitrification as an alternative approach to conventional cryopreservation allows quick and low-cost sample preservation and is suitable for small-bodied aquatic species with miniscule testis, fieldwork at remote locations, and small-scale freezing for research purposes. Tiersch et al. report the developing of operational prototypes of 3-dimensional (3-D) printed vitrification devices. This study demonstrated the feasibility of developing standardized low-cost devices fabricated by 3-D printing with functions including vitrification, volume control, labeling, protection, and storage. These prototypes can be further developed to assist development of germplasm repositories to protect the genetic resources of aquatic species by breeders, hatcheries, aquariums, and researchers. Supported by ORIP (R24OD010441).