Breeding of Cav2.3 Deficient Mice Reveals Mendelian Inheritance in Contrast to Complex Inheritance in Cav3.2 Null Mutant Breeding.

High voltage-activated Ca v 2.3 R-type Ca 2+ channels and low voltage-activated Ca v 3.2 T-type Ca 2+ channels were reported to be involved in numerous physiological and pathophysiological processes. Many of these findings are based on studies in Ca v 2.3 and Ca v 3.2 deficient mice. Recently, it has been proposed that inbreeding of Ca v 2.3 and Ca v 3.2 deficient mice exhibits significant deviation from Mendelian inheritance and might be an indication for potential prenatal lethality in these lines. In our study, we analyzed 926 offspring from Ca v 3.2 breedings and 1142 offspring from Ca v 2.3 breedings. Our results demonstrate that breeding of Ca v 2.3 deficient mice shows typical Mendelian inheritance and that there is no indication of prenatal lethality. In contrast, Ca v 3.2 breeding exhibits a complex inheritance pattern. It might be speculated that the differences in inheritance, particularly for Ca v 2.3 breeding, are related to other factors, such as genetic specificities of the mutant lines, compensatory mechanisms and altered sperm activity.