Mitochondrial capture and subsequent genetic divergence generates a novel haplogroup: evidence from ancient and ongoing hybridization in mule and white-tailed deer

• Published in: Journal of mammalogy 2022-06, Vol.103 (3), p.723-736
• Main Authors: Wright, Emily A., Roberts, Emma K., Platt, Roy N., Bayouth, Jacob V., Conway, Warren C., Bradley, Robert D.
• Format: Article
• Language: English
• Subjects: captura mitocondrial; Cytochrome b gene; divergencia genética; gen citocromo-b; genetic divergence; mitochondrial capture; Norteamérica; North America; Odocoileus; Odocoileus spp
• ISSN: 0022-2372; 1545-1542
• DOI: 10.1093/jmammal/gyab156

Odocoileus virginianus (white-tailed deer) and O. hemionus (mule deer) are sympatric across much of North America. Molecular evidence suggests that up to 24% of individuals in some populations are a product of hybrid ancestry. Several studies have alluded to ancient and recent introgression between Odocoileus spp.; however, no divergence dates were proposed. Herein, phylogenetic analyses of DNA sequences obtained from the mitochondrial Cytochrome b gene in 690 individuals identified three clades corresponding to black-tailed deer, white-tailed deer, or a unique combination of both white-tailed deer and mule deer. White-tailed deer and mule deer diverged from a common ancestor of approximately 3.13 mya followed by an ancient hybridization event of approximately 1.32 mya, in which the white-tailed deer mitochondrial genome was “captured” by mule deer. This hybridization event produced a novel haplogroup for white-tailed deer and mule deer located west of the Appalachian Mountains and east of the Cascade Range, south to Veracruz, Mexico, and north to the Yukon Territory, Canada. The ancestral mule deer-like mitochondrial genome appears to be restricted to black-tailed deer distributed along the western portion of the Cascade and Sierra Nevada Ranges of the United States and Canada, whereas the ancestral white-tailed deer-like mitochondrial genome is restricted to the eastern United States and portions of Latin America and Caribbean regions. The “captured mitochondrial genome” has continued on an independent evolutionary trajectory and represents a unique and broadly distributed haplogroup that is 7.25% and 2.84% different from the ancestral mule deer and ancestral white-tailed deer haplogroups, respectively. Odocoileus virginianus (ciervo de cola blanca) y O. hemionus (cievo mulo) son simpátricos a lo largo de Norte América. Evidencia molecular sugiere que en algunas poblaciones un 24% de individuos son el producto de linajes híbridos. Varios estudios aluden introgresiones antiguas y recientes entre Odocoileus spp. sin embargo, no proponen fecha de tal divergencia. En este estudio, los análisis filogenéticos de secuencias de ADN obtenidas del gen mitocondrial citocromo-b de 690 individuos, identificaron tres clados que corresponden al ciervo de cola negra, ciervo de cola blanca, o una combinación única de ciervo de cola blanca y ciervo mulo. El ciervo de cola blanca y el ciervo mulo divergieron de un ancestro común hace aproximadamente 2.65 Ma, seguido de un