De novo assembly of mitochondrial genomes provides insights into genetic diversity and molecular evolution in wild boars and domestic pigs

Multiple Domestication Centers of the Indian Pig Population

The domestication of animals is a major milestone in human history and has been studied in various fields. Pig domestication, in particular, has been widely studied, and it is believed that India is one of at least six domestication centers. However, there is a lack of systematic studies using high-resolution genetic markers, including complete mitogenomes, to investigate the domestication and genetic roots of pigs in India. In the present study, we investigated the origin and evolution of Indian pigs using mitochondrial genetic data to complement archaeological data sets. The phylogenetic status of Indian pig breeds was determined by analyzing all available mitochondrial data, incorporating a global data set of 239 mitogenomes. The Bayesian and maximum likelihood tree analyses unveiled at least eight haplogroups diverging from three main branches, two of which are geographically restricted to India. We propose that the North Indian domestic haplogroup might represent an independent in situ domestication event in North India, probably dating before ∼5,000 YBP. An additional North East Indian domestic haplogroup is nested within a widespread Asian clade that also includes Indian mitogenomes from the Andaman and Nicobar Islands that diverged more recently from distinct East and Southeast Asian roots. In conclusion, we propose that North Indian farmers could have been responsible for the independent domestication of local wild boars giving rise to the current domestic lineage identified in North India. At least one additional domestic lineage arrived in India more recently and remained mainly localized in the northeast. Domestic mitogenomes from the Indian islands show a notable connection with pig populations from Vietnam, and their arrival might be related to Austroasiatic-speaking human populations. Overall, this study provides valuable insights into the complex dynamics of pig domestication in India.

Ancient Faunal History Revealed by Interdisciplinary Biomolecular Approaches

Starting four decades ago, studies have examined the ecology and evolutionary dynamics of populations and species using short mitochondrial DNA fragments and stable isotopes. Through technological and analytical advances, the methods and biomolecules at our disposal have increased significantly to now include lipids, whole genomes, proteomes, and even epigenomes. At an unprecedented resolution, the study of ancient biomolecules has made it possible for us to disentangle the complex processes that shaped the ancient faunal diversity across millennia, with the potential to aid in implicating probable causes of species extinction and how humans impacted the genetics and ecology of wild and domestic species. However, even now, few studies explore interdisciplinary biomolecular approaches to reveal ancient faunal diversity dynamics in relation to environmental and anthropogenic impact. This review will approach how biomolecules have been implemented in a broad variety of topics and species, from the extinct Pleistocene megafauna to ancient wild and domestic stocks, as well as how their future use has the potential to offer an enhanced understanding of drivers of past faunal diversity on Earth.

Maternal genomic variability of the wild boar (Sus scrofa) reveals the uniqueness of East-Caucasian and Central Italian populations

The phylogeography of the European wild boar was mainly determined by postglacial recolonization patterns from Mediterranean refugia after the last ice age. Here we present the first analysis of SNP polymorphism within the complete mtDNA genome of West Russian (n = 8), European (n = 64), and North African (n = 5) wild boar. Our analyses provided evidence of unique lineages in the East-Caucasian (Dagestan) region and in Central Italy. A phylogenetic analysis revealed that these lineages are basal to the other European mtDNA sequences. We also show close connection between the Western Siberian and Eastern European populations. Also, the North African samples were clustered with the Iberian population. Phylogenetic trees and migration modeling revealed a high proximity of Dagestan sequences to those of Central Italy and suggested possible gene flow between Western Asia and Southern Europe which was not directly related to Northern and Central European lineages. Our results support the presence of old maternal lineages in two Southern glacial refugia (i.e., Caucasus and the Italian peninsula), as a legacy of an ancient wave of colonization of Southern Europe from an Eastern origin.