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Vikas Kumar

Publications and source records attributed to Vikas Kumar.

2 recordsLinked to original sources

Ancient DNA unveils distinctive ancestries in the Bronze and Iron Ages of East Tianshan.

The East Tianshan Mountains occupy a key corridor between Central and East Asia, but their population history remains poorly understood. Here we report genome-wide data from 135 ancient individuals from 11 archaeological sites. We identify a previously unrecognized Bronze Age admixture between populations related to Yellow River millet farmers and steppe pastoralists associated with the Chemurchek culture. In contrast, we find little genetic contribution from contemporaneous middle-to-late Bronze Age steppe pastoralists, despite their eastward expansion across the Eurasian Steppe. By the Iron Age, regional populations had become more heterogeneous, incorporating additional eastern and steppe-related sources while retaining variable contributions from Early Bronze Age groups. These results reveal sustained demographic interactions in eastern Central Asia nearly 1800 years preceding the establishment of the historic Silk Road.

DNA, Ancient

First complete mitochondrial genome of Uzelothrips scabrosus (Thysanoptera: Uzelothripidae) provides insights into gene rearrangements and phylogenetic position within Terebrantia.

The family Uzelothripidae is represented by a single genus Uzelothrips and can be distinguished from others by the presence of whip-like antennae, a circular ventral sensorium on antennal segment III, a well-developed tentorium, and a membranous ovipositor. Here, we generated the first complete mitochondrial genome of Uzelothrips scabrosus (15,674 bp) using next-generation sequencing to explore the gene rearrangements and phylogenetic relationships. It consists of 13 protein-coding genes, 22 transfer RNAs, two ribosomal RNAs, and two putative control regions. The genome exhibits strong AT bias (71.35%) with negative AT and GC skew. Codon usage analyses indicate a strong bias towards A/U-ending codons and influenced by both natural selection and mutation pressure. All PCGs were under purifying selection, with cox1 being the most conserved and nad4L the most variable. The gene order of the family Uzelothripidae is highly rearranged compared to the ancestral insect gene order. Comparative analysis revealed that gene block B was the most widely conserved, whereas the remaining gene blocks exhibited family or lineage-specific conservation patterns, reflecting extensive mitochondrial gene rearrangements during the evolution of the Thysanoptera. Moreover, 228 synapomorphic and 68 autapomorphic gene boundaries were identified across thysanopteran mitogenomes. Phylogenies indicated that the family Uzelothripidae is in a sister relationship with Stenurothripidae, and the Uzelothripidae + Stenurothripidae clade is sister to Thripidae. This study provides the first mitogenomic insights into Uzelothripidae and highlights the need for broader taxon sampling and nuclear genomic data to resolve deep evolutionary relationships within Thysanoptera.

Comparative analysis