Investigating DAZL gene editing in goat embryos using the CRISPR/Cas9 system and somatic cell nuclear transfer techniques

Document Type : Research Paper

Authors

1 Ph.D. Student in Animal Breeding and Genetics, Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran

2 Associate Professor, Department of Animal Science, Faculty of Agricultural Sciences, University of Guilan, Rasht, Iran

3 Professor, Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran

4 Professor, Animal Sciences Department, Isfahan branch, Islamic Azad University, Iran

5 Associate Professor, Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran

6 Assistant Professor, Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran

Abstract

Introduction: The CRISPR/Cas9 (Clustered Regularly Interspaced Palindromic Repeats/CRISPR-associated Protein9) method can create a nucleotide sequence complementary to the target sequence in the desired gene by Guide-RNA (gRNA) together with the Cas9 protein, which is a cutting enzyme for cutting in the both DNA strands of the desired sequence accurately and clearly. The DAZL (Deleted in azoospermia-like) gene encodes potential RNA-binding proteins that are expressed in male and female germ cells before and after birth. DAZL, which acts by post-transcriptionally binding mRNA in 3' untranslated regions, regulates the germ cell cycle. DAZL initiates the sexual differentiation of embryonic germ cells. The transfer and transplantation of gene-edited germ cells into recipient males is an effective method for targeted mutagenesis engineering. In mice knocked out for the Dazl gene, the number of testicular stem cells was reduced and it was found that the DAZL gene plays an important role in the differentiation of spermatogonial cells. The purpose of the current research is to edit the DAZL gene by knocking it out using the CRISPR/Cas9 technique and transferring the somatic cell nucleus into the genome of the Bakhtiari goat embryo. The inactivation of the gene will be investigated both at the level of the embryonic cell and the resulting embryo. There are no reports on the production of Bakhtiari goat cells and embryos edited for the DAZL gene by CRISPR technique and somatic nuclear transfer to improve any traits, including reproductive ones.
Materials and methods: To target the DAZL gene and explore (predict) potential off-target genomic sites, guide RNA (20 bp sequences) immediately upstream of each 5′-NGG in the DAZL gene was designed using the CHOOPCHOOP tool. Plasmid pX459 (9151 bp) was used to insert the gRNA sequence into the CAS9 vector and determine the characteristics and replication of the vector. This plasmid encodes the Cas9 protein along with the puromycin resistance gene under the promoter/enhancer, CAGGS, as well as the gRNA scaffold under the U6 promoter. Plasmid pX459 was digested by BbsI-HF (NEB #R3539) at 37°C for 10 min, followed by purification by NucleoSpin Gel and PCR Clean-up Midi kit (#740,986.20, Machery/Nagel). The purified piece was kept at -20°C for later use. Ligation of oligoduplex carrying diluted gRNA sequence (1:20 ratio from 10 μM source) (1 μL), digested pX459 vector (50 ng), 10x T4DNA ligase buffer (2 μL), and T4DNA ligase (1 μL) in the final concentration of 20 μL of the reaction was carried out. Ligation mixture transformation was performed with NEB 5-alpha Competent E. coli (#C2987I) and then placed on agar culture medium with 100 μg/mL ampicillin and incubated at 37°C overnight. From the cultured plate, five colonies were selected and each was cultured in LB culture medium, followed by miniprep plasmid extraction (Genejet Plasmid miniPrep kit, #K0502). Plasmids carrying the CRISPR system were transferred into cells through an electroporation system.
Results and discussion: The present results proved the possibility of knocking out the DZAL gene using the CRISPR/Cas9 technique in both fibroblast cell lines and Bakhtiari goat embryos. We performed somatic cell nuclear transfer (SCNT) to examine the embryonic developmental capacity to transition to the cleavage and blastocyst stages. The embryos created by knocking out the DAZL gene could grow and develop. The sequencing analysis using DECODR (Deconvolution of Complex DNA Repair) software showed the knock-out rate of the DAZL gene in fibroblast cells was 83.3% and in cloned blastocysts, it was 55.3%. The rate of blastocyst formation resulting from the cloning process with knockout cells was not significantly different from the control group. Based on these studies, we decided to edit the DAZL gene to produce knockout goat embryos by SCNT. The embryos were examined and evaluated with the help of PCR-RFLP test and sequencing. It turned out that in the first iteration, a knockout of 60.66% (the first ten embryos were paid), and in the second iteration, a knockout of 49.99% (the second ten embryos were paid) were achieved. Such mutations have not been described or detected in Iranian Bakhtiari goats, although polymorphisms have been identified. Using genetic sequencing, the mutations were of the INDEL type and were all in the form of frameshift, which resulted in a change in the protein.
Conclusions: The CRISPR/Cas9 system easily influences the desired gene and can be used as a strategy to produce livestock animals that are superior in milk and meat production, reproduction, quality, disease resistance, etc. This research demonstrated the possibility of gene editing using the CRISPR/Cas9 technique in fibroblast cell lines and Bakhtiari goat embryos. The blastocytes produced can be used for transfer to the recipient animal and production of DAZL gene knockout goats for further study and optimization of spermatogonial stem cell transplantation.

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Abdoli, R., Zamani, P., Mirhosseini, S. Z., Ghavi Hossein-Zadeh, N., & Nadri, S. (2016). A review on prolificacy genes in sheep. Reproduction in Domestic Animals, 51, 631-637. doi: 10.1111/rda.12733
Badbarin, N., Mirhoseini, S. Z., Rabiei, B., & Ghavi Hossein-Zadeh, N. (2014). Identification of QTL for litter size on chromosome 1 in Markhoz goats using SSR markers. Animal Production Research, 3(3), 73-81. [In Persian]
Begagic, E., Beculic, H., Duzic, N., Dzidic-Krivic, A., Pugonja, R., Muharemovic, A., & Pojskic, M. (2024). CRISPR/Cas9-Mediated Gene Therapy for Glioblastoma: A Scoping Review. Biomedicines, 12(1), 238. doi: 10.3390/biomedicines12010238
Bertho, S., Clapp, M., Banisch, T. U., Bandemer, J., Raz, E., & Marlow, F. L. (2021). Zebrafish dazl regulates cystogenesis and germline stem cell specification during the primordial germ cell to germline stem cell transition. Development, 148(7), dev187773. doi: 10.1242/dev.187773
Diskin, M. G. (2018). Review: Semen handling, time of insemination and insemination technique in cattle. Animal, 12(s1), s75-s84. doi: 10.1017/S1751731118000952
Doudna, J. A., & Charpentier, E. (2014). Genome editing. The new frontier of genome engineering with CRISPR-Cas9. Science, 346(6213), 1258096. doi: 10.1126/science.1258096
Ghavi Hossein-Zadeh, N. (2024). An overview of recent technological developments in bovine genomics. Veterinary and Animal Science, 25, 100382. doi: 10.1016/j.vas.2024.100382
Gill, M. E., Hu, Y.-C., Lin, Y., & Page, D. C. (2011). Licensing of gametogenesis, dependent on RNA binding protein DAZL, as a gateway to sexual differentiation of fetal germ cells. Proceedings of the National Academy of Sciences, 108(18), 7443-7448. doi: 10.1073/pnas.1104501108
González, R., & Dobrinski, I. (2015). Beyond the mouse monopoly: studying the male germ line in domestic animal models. ILAR journal, 56(1), 83-98. doi: 10.1093/ilar/ilv004
Hashemi, M. S., Mozdarani, H., Ghaedi, K., & Nasr‐Esfahani, M. (2018). Among seven testis‐specific molecular markers, SPEM 1 appears to have a significant clinical value for prediction of sperm retrieval in azoospermic men. Andrology, 6(6), 890-895. doi: 10.1111/andr.12528
Horvath, P., Romero, D. A., Coute-Monvoisin, A. C., Richards, M., Deveau, H., Moineau, S., & Barrangou, R. (2008). Diversity, activity, and evolution of CRISPR loci in Streptococcus thermophilus. Journal of Bacteriology, 190(4), 1401-1412. doi: 10.1128/JB.01415-07
Houston, D. W., & King, L. (2000). A critical role for Xdazl, a germ plasm-localized RNA, in the differentiation of primordial germ cells in Xenopus. Development, 127(3), 447-456. doi: 10.1242/dev.127.3.447.
Hsu, P. D., Lander, E. S., & Zhang, F. (2014). Development and applications of CRISPR-Cas9 for genome engineering. Cell, 157(6), 1262-1278. doi: 10.1016/j.cell.2014.05.010
Jung, H. J., Song, H., & Yoon, M. J. (2014). Stage-dependent DAZL localization in stallion germ cells. Animal Reproduction Science, 147(1-2), 32-38. doi: 10.1016/j.anireprosci.2014.03.011
Kee, K., Angeles, V. T., Flores, M., Nguyen, H. N., & Reijo Pera, R. A. (2009). Human DAZL, DAZ and BOULE genes modulate primordial germ-cell and haploid gamete formation. Nature, 462(7270), 222-225. doi: 10.1038/nature08562
Labun, K., Montague, T. G., Krause, M., Torres Cleuren, Y. N., Tjeldnes, H., & Valen, E. (2019). CHOPCHOP v3: expanding the CRISPR web toolbox beyond genome editing. Nucleic Acids Res, 47(W1), W171-W174. doi: 10.1093/nar/gkz365
Lara, N. L., Goldsmith, T., Rodriguez-Villamil, P., Ongaratto, F., Solin, S., Webster, D., &  Bondareva, A. (2023). DAZL knockout pigs as recipients for spermatogonial stem cell transplantation. Cells, 12(21), 2582. doi: 10.3390/cells12212582
Li, H., Liang, Z., Yang, J., Wang, D., Wang, H., Zhu, M., &  Xu, E. Y. (2019). DAZL is a master translational regulator of murine spermatogenesis. National Science Review, 6(3), 455-468.
Li, T., Wang, X., Zhang, H., Chen, H., Liu, N., Xue, R.,  & Ma, Y. (2020). Gene expression patterns and protein cellular localization suggest a novel role for DAZL in developing Tibetan sheep testes. Gene, 731, 144335. doi: 10.1016/j.gene.2020.144335
Nasr-Esfahani, M. H., Hosseini, S. M., Hajian, M., Forouzanfar, M., Ostadhosseini, S., Abedi, P., &  Vojgani, H. (2011). Development of an optimized zona-free method of somatic cell nuclear transfer in the goat. Cell Reprogram, 13(2), 157-170. doi: 10.1089/cell.2010.0083
Schrans-Stassen, B. H., Saunders, P. T., Cooke, H. J., & de Rooij, D. G. (2001). Nature of the spermatogenic arrest in Dazl -/- mice. Biology of Reproduction, 65(3), 771-776. doi: 10.1095/biolreprod65.3.771
Seligman, J., & Page, D. C. (1998). TheDazhGene Is Expressed in Male and Female Embryonic Gonads before Germ Cell Sex Differentiation. Biochemical and Biophysical Research Communications, 245(3), 878-882. doi: 10.1006/bbrc.1998.8530
Tan, W., Carlson, D. F., Lancto, C. A., Garbe, J. R., Webster, D. A., Hackett, P. B., & Fahrenkrug, S. C. (2013). Efficient nonmeiotic allele introgression in livestock using custom endonucleases. Proceedings of the National Academy of Sciences, 110(41), 16526-16531. doi: 10.1073/pnas.1310478110
Tang, L., González, R., & Dobrinski, I. (2015). Germline modification of domestic animals. Animal reproduction/Colegio Brasileiro de Reproducao Animal, 12(1), 93.
Vogel, T., Speed, R. M., Ross, A., & Cooke, H. J. (2002). Partial rescue of the Dazl knockout mouse by the human DAZL gene. Molecular Human Reproduction  8(9), 797-804. doi: 10.1093/molehr/8.9.797
Wang, J., Ren, J., Wang, Q., Li, C., Han, Z., Chen, T., & Hai, T. (2023). Nanos3 knockout pigs to model transplantation and reconstruction of the germline. Cell Proliferation, 56(5), e13463. doi: 10.1111/cpr.13463
Wang, X., Yu, H., Lei, A., Zhou, J., Zeng, W., Zhu, H., &  Chen, Y. (2015). Generation of gene-modified goats targeting MSTN and FGF5 via zygote injection of CRISPR/Cas9 system. Scientific Reports, 5(1), 13878. doi: 10.1038/srep13878
Zagore, L. L., Sweet, T. J., Hannigan, M. M., Weyn-Vanhentenryck, S. M., Jobava, R., Hatzoglou, M., Zhang, C., & Licatalosi, D. D. (2018). DAZL regulates germ cell survival through a network of PolyA-proximal mRNA interactions. Cell Reports, 25(5), 1225-1240. e6. doi: 10.1016/j.celrep.2018.10.012