Paternal Leakage of Mitochondrial DNA in the Raccoon Dog (Nyctereutes Procyonoides Gray 1834)

Abstract

the aim of the study was to describe the mechanism of mitochondrial dna inheritance in a group of farmed raccoon dogs. the study involved 354 individuals. Whole peripheral blood was the research material. dna was isolated and Pcr was performed for two fragments of mitochondrial genes: coX1 (cytochrome oxidase subunit 1 gene) and coX2 (cytochrome oxidase subunit 2 gene). the Pcr products were sequenced and subjected to bioinformatics analyses. three mitochondrial haplotypes were identified in the coX1 gene fragment and two in the coX2 gene fragment. the analysis of mtDNA inheritance in the paternal line confirmed the three cases of paternal mtDNA inheritance, i.e. the so-called "paternal leakage" in the analysed population. in two families, all offspring inherited paternal mitochondrial dna, whereas in one family one descendant inherited paternal mtdna and another one inherited maternal mtdna. the lineage data indicated that one female which inherited maternal mitochondrial dna transferred it onto the next generation. To sum up, the results of the study for the first time demonstrated the phenomenon of "paternal leakage" in farmed raccoon dogs, which facilitated description of mitochondrial dna inheritance in the paternal line.

The perspective of the incompatible of nucleus and mitochondria in interspecies somatic cell nuclear transfer for endangered species

“…mtDNA heteroplasmy occurs mainly in cloned animals, because in normal fertilization the mitochondria contributed by the spermatozoa are targeted for active destruction by ubiquitin‐mediated proteolysis and maternal inheritance of mtDNA is regarded as the major rule of mtDNA transmission in most animal taxa (Song et al., 2014; Sutovsky et al, 2004). Nevertheless, some studies have demonstrated that sometimes inheritance of mtDNA can occur in the paternal line, for example in mice (Gyllensten et al., 1991), poultry (Alexander et al., 2015), sheep (Zhao et al., 2004) or raccoon dogs (Nisztuk‐Pacek et al., 2019). However, in clones, studies report varying degree of mitochondrial distribution, from animals displaying complete homoplasmy, to animals displaying heteroplasmy in highly variable manner, even within copy number of mtDNA molecules differing among somatic cells, embryonic cells and oocytes within the same cloned animals (Beyhan et al., 2007; Hiendleder et al., 2003; Takeda, 2013).…”