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Updated: Aug 23, 2026

Generation of Maternal Mutants Using zpc:cas9 Knock-in Zebrafish
Published on: July 22, 2025
Maternal genotype can influence the outcome of a study on mutant animals
Dóra Zelena1, Zsuzsa Mergl, Gábor B Makara
1Institute of Experimental Medicine, PO Box 67, H-1450 Budapest, Hungary. zelena@koki.hu
Abstract:
The hypothalamo-pituitary-adrenal (HPA) axis plays a crucial role in stress. One of its central regulatory components is arginine-vasopressin (AVP). We studied the role of AVP in acute restraint in AVP-deficient mutant Brattleboro rats (AVP-), but our results were variable. The early life period is important in the later stress reactivity of the animals. We realized that our AVP- pups could be born from AVP+ (heterozygous) or from AVP- mothers. Therefore, we asked whether the genotype of the mother could explain the variability. Adult rats from AVP+ and AVP- mothers were stressed with 60 min of restraint. Trunk blood was collected for measuring hormone content by radioimmunoassay. All offspring of AVP+ mothers had similar adrenocorticotropic hormone (ACTH) responses to restraint, whereas the AVP- rats born to AVP- mothers showed reduced ACTH reactivity. Our results show that the AVP- genotype of the mother can decrease the stress reactivity of AVP- Brattleboro rats. In mutant/knockout animals, family background should be taken into account as well as the genotype of the studied animals.
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