Orphan Genes and the evolution of the human genome.
One of the biggest surprises in the new era of genomics is that all genomes have a surprising number of genes that are not found in close relatives. These taxonomically-restricted genes (TRGs) can be specific to taxa at any level, including species, and many human-specific TRGs have already been discovered. Because the origins of these TRGs are obscure, they are often called orphan genes.
Our laboratory is currently engaged in two projects related to the evolution of orphan genes in the human genome. Firstly, we seek to discover these genes and infer their evolutionary origin and mechanism. For this work, we are engaging a variety of computational tools involving sequence alignment, etc. Secondly, since orphan genes are a logical resource to explore the genetics of human uniqueness, we are interested in understanding what role these genes played in the evolution of humans and other hominins (Neanderthals, Denisovans).
Our laboratory has recently developed DNA-based tools for the rapid detection and identification of plant species from trace biological evidence, including pollen. We are now engaged in an effort to discover and characterize microsatellite DNA (STRs) in specific plant species in order to develop a strategy for forensic DNA fingerprinting of household plants, an untapped resource in forensic investigations.
Postmortem changes in the human microbiome.
The human microbiome is the complete diversity of bacteria and other microorganisms that live in, on, and around the human body. We are currently exploring how the human microbiome changes upon the death of the human host. We have collected bacterial swabs from living and deceased human persons and are analyzing the respective bacterial diversity through next-generation metagenomic sequencing. The goal of this research is to discover changes in the bacterial populations that occur upon the death of the human host in a predictable pattern and schedule. Such a discovery could become a major tool in establishing time of death and other information of use in a death investigation.