Salt Sensitive Tet-Off-Like Systems to Knockdown Primordial Germ Cell Genes for Repressible Transgenic Sterilization in Channel Catfish, Ictalurus punctatus
Hanbo Li,
Baofeng Su,
Guyu Qin,
Zhi Ye,
Ahmed Alsaqufi,
Dayan A. Perera,
Mei Shang,
Ramjie Odin,
Khoi Vo,
David Drescher,
Dalton Robinson,
Dan Zhang,
Nermeen Abass,
Rex A. Dunham
Affiliations
Hanbo Li
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Baofeng Su
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Guyu Qin
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Zhi Ye
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Ahmed Alsaqufi
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Dayan A. Perera
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Mei Shang
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Ramjie Odin
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Khoi Vo
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
David Drescher
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Dalton Robinson
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Dan Zhang
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Nermeen Abass
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Rex A. Dunham
School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA
Repressible knockdown approaches were investigated for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC) marker genes, nanos and dead end, were targeted for knockdown, and an off-target gene, vasa, was monitored. Two potentially salt sensitive repressible promoters, zebrafish adenylosuccinate synthase 2 (ADSS) and zebrafish racemase (Rm), were each coupled with four knockdown strategies: ds-sh RNA targeting the 5′ end (N1) or 3′ end (N2) of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA) and ds-sh RNA targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with sodium chloride as the repressor compound. Spawning rates of full-sibling P1 fish exposed or not exposed to the constructs as treated and untreated embryos were 93% and 59%, respectively, indicating potential sterilization of fish and repression of the constructs. Although the mRNA expression data of PGC marker genes were inconsistent in P1 fish, most F1 individuals were able to downregulate the target genes in untreated groups and repress the knockdown process in treated groups. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but more data from F2 or F3 are needed for evaluation.
