Summary Because the oMT1a‐oGH transgene in mice can be regulated by dietary zinc, it provides a potential model for selection studies designed to increase growth rate. To determine the effect of oMT1a‐oGH on growth, fat content, and reproduction in the genetic background and environment in which selection would be conducted, males homozygous for the transgene were mated to females from high‐growth (M16) and control (ICR) lines to create hemizygous transgenics, TM and TC, respectively. Progeny either did (Z) or did not receive (C) 25 mm ZnSo4 from 3 (weaning) to 8 weeks. TM mice had larger (p < 0.001) weekly body weights than TC from 3 to 10 weeks, and Z mice were larger than C from 5 to 10 weeks in TC and from 6 to 10 weeks in TM. Significant (p < 0.01) line‐treatment interactions for weekly body weights from 4 to 8 weeks were caused by TC responding more to the transgene than TM mice. Compared to controls, male mice given zinc had reduced (p < 0.001) epididymal and subcutaneous fat‐pad weights as a percentage of body weight, but liver percentage was increased (p < 0.001). TC mice given zinc had reduced (p < 0.05) testis weights as a percentage of body weight, while there was no difference in TM mice. TM mice had larger liver (p < 0.01) and epididymal fat‐pad (p < 0.08) percentages than TC. Mating of Z females 2 weeks after discontinuation of zinc stimulation of transgene expression resulted in no significant differences between Z and C females in percentage infertile matings, days from exposure to a male to littering, and number of dead pups on day of birth; however, Z females had larger (p < 0.007) litters. This transgenic model is suitable for selection studies involving growth. When transgene expression is stimulated by exogenous zinc, growth rate is increased and there is no negative effect on female reproductive fitness when zinc supplement is discontinued. Zusammenfassung Ovines Wachstumshormontransgen in Selektionsversuchen auf Mäusewachstum Nachdem das oMT1a‐oGH Transgen in Mäusen mittels Zinkgaben reguliert werden kann, bietet es ein interessantes Modell zur Untersuchung von Wachstumsselektionsversuchen. Um seine Wirkung auf Wachstum, Fettanteile, Fortpflanzung in verschiedenen genetische Milieu und verschiedenen Umwelten untersuchen zu können, wurden transgen homozygote Mäusemännchen an Weibchen einer wachstumsselektierten (M16) und einer Kontrollinie (ICR) zur Erzeugung von hemizygoten transgenischen TM‐, TC —Tieren gepaart. Nachkommen erhielten (Z) oder nicht (C) 25 mm ZnSO4 von 3 Wochen (absetzen) bis zum Alter von 8 Wochen. TM‐Mäuse hatten größere wöchentilche Zuwächse als die TC‐Mäuse von 3 bis 10 Wochen und Z‐Mäuse waren größer als C von 5 bis 10 Wochen in TC und von 6 bis 10 Wochen in TM. Signifikante Linien mal Behandlungsinteraktionen für wöchentliche Körpergewichte von 4 bis 8 Wochen waren darauf zurückzuführen, daß die TC mehr auf das Transgen angesprochen haben als TM. Im Vergleich zu Kontrollen haben Mäusemännchen nach Zinkgaben reduzierte Nebenhoden‐und subkutane Fettgewichte aber höheren...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.