Forensic Genetics and Genomic
Cristoforo Pomara, Vittorio Fineschi in Forensic and Clinical Forensic Autopsy, 2020
Current and next challenges in forensic applications are undoubtedly linked with the massively parallel sequencing (MPS) technologies, also termed as NGS, both in nonhuman and in human applications. For example, DNA barcoding is an approach that involves the sequencing of short DNA sequences for food and wildlife forensic species identification (Staats et al., 2016). Moreover, these new technologies are becoming increasingly popular and alternative to STR typing (Xue et al., 2018). The future challenges for the scientific community are related to the forensic use of MPS. Indeed, even if this technology is routinely used in other genetic diagnostic disciplines (such as oncogenetics and clinical genetics), it is still far from being a routine forensic tools. The main criticisms that should be resolved in the next future involve the full comprehension of the data obtained, the possibility to discuss the results obtained with MPS in a court, the method standardization, and which information is necessary in a forensic investigation report (de Knijff, 2019).
Ethnobotany Post-Genomic Horizons and Multidisciplinary Approaches for Herbal Medicine Exploration: An Overview
T. Pullaiah, K. V. Krishnamurthy, Bir Bahadur in Ethnobotany of India, 2017
Next-Generation Sequencing (NGS) produces millions of short DNA sequence in short time with less cost. It includes template preparation, sequencing and imaging, and data analysis in which protocol distinguishes one technology from another and by the amount of the data produced from each platform. In the NGS techniques, DNA templates are randomly read along the entire genome in a massively parallel sequencing by splitting the entire genome into small pieces followed by adapter ligation to the fragmented DNA (Zhang et al., 2011). DNA barcoding is meant to identify small, standardized gene sequences in a rapid, accurate, and cost-effective manner in the plant materials. Chloroplast/ nuclear regions are used by researchers as universal barcodes for the authentication/adulteration of phyto-medicines. Plastome sequencing/ superbarcode is an enhanced progress in DNA barcoding through Next Generation Sequencing. It identifies the presence of various plant species in herbal mixtures. By using DNA barcoding technologies, integrity and authenticity of herbal medicines can easily be identified and it also protects the health of mankind from adulteration of herbal products. Barcode databases available for plants are as follows: GenBank - USA, BOLD - Canada, Medicinal Materials DNA Barcode database - China (Balachandran et al., 2015).
An Overview of Parasite Diversity
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2015
Sequence data are used with ever greater frequency as a tool to discover new parasites and reveal their relationships. The genes selected for study are diverse. There has also been a growing trend to document for many to all eukaryotic organisms the sequence of a particular gene that can serve as a convenient species-specific marker. Just as a supermarket uses distinctive barcodes to identify its products, the goal of DNA barcoding is to use the sequence of the mitochondrial cytochrome c oxidase 1 gene (CO1) as such a marker. This is possible because the CO1 gene is widely represented in eukaryotic genomes and, at least for animals, a 648-base-pair stretch of the gene is sufficiently variable among species to provide a distinctive reference point. In general, mitochondrial genes are prone to higher rates of mutation than genes contained in the nucleus. The higher mutation rate may result from their proximity to reactive oxygen species that are produced in the mitochondria during respiration and that are capable of causing damage. The variability of CO1 contrasts with the SSU rRNA gene discussed earlier that has worked effectively for building a tree of life incorporating very disparate organisms but that is too invariant to serve as a species marker.
Use of Molecular Methods to Authenticate Animal Species and Tissue in Bovine Liver Dietary Supplements
Published in Journal of Dietary Supplements, 2022
Olive J. Dahm, Georgia L. Sampson, Anthony J. Silva, Rosalee S. Hellberg
Current molecular laboratory methods for detecting animal or plant ingredients in dietary supplements include real-time PCR and DNA barcoding. Real-time PCR is a targeted approach that uses species-specific primers to identify species in real-time (Köppel et al. 2011, 2013). The combination of species-specific primers in a multiplex, real-time PCR assay allows for multiple species to be detected simultaneously. For example, Köppel et al. (2011) developed a multiplex real-time PCR assay with the commercial name AllHorseTM that simultaneously detects domestic cattle (Bos taurus) and several common substitute species, including pig (Sus scrofa), horse (Equus caballus), and sheep (Ovis aries). On the other hand, DNA barcoding uses universal primers that amplify a short, standardized region of DNA (Hebert et al. 2003). For DNA barcoding of animal tissues, the most common target is a ∼655 base pair (bp) region of the mitochondrial gene coding for cytochrome c oxidase subunit I (COI). Because DNA degradation can occur during processing, test methods for animal species in processed products often target mini-barcodes, which are shorter regions (< 300 bp) of the DNA barcode (Hellberg et al. 2019; Wu et al. 2019; Zahn et al. 2020). For example, one study reported increased success when using DNA mini-barcoding compared to full-length DNA barcoding for the detection of species in shark cartilage dietary supplements (Hellberg et al. 2019). A novel DNA mini-barcode assay was developed specifically for the identification of animal species in processed foods; however, it has not yet been tested with dietary supplements (Wu et al. 2019).
Multiplex protein analysis for the study of glaucoma
Published in Expert Review of Proteomics, 2021
Gülgün Tezel
A DNA-based assay that couples DNA barcoding and antibody sensing technologies can analyze the expression profiles of multiple proteins with high reproducibility and single-cell sensitivity. This multiplexing strategy enables to measure cell surface proteins and gene expression in parallel. By simultaneously performing proteome and transcriptome analysis, DNA barcoding approaches, such as RNA expression and protein sequencing or cellular indexing of transcriptomes and epitopes by sequencing, allow to compare the gene and protein expression data in biological samples [24–26].
Phylogenetic analysis of Uncaria species based on internal transcribed spacer (ITS) region and ITS2 secondary structure
Published in Pharmaceutical Biology, 2018
Shuang Zhu, Qiwei Li, Shanchong Chen, Yesheng Wang, Lin Zhou, Changqing Zeng, Jun Dong
DNA barcoding using short genetic markers or gene regions for species identification has potential for use in the detection and protection of endangered and valuable species (Hebert et al. 2003; CBOL Plant Working Group 2009; Hollingsworth et al. 2011). The Consortium for the Barcode of Life (CBOL) has proposed combined plastid barcoding with matK and rbcL genes as an alternative for species identification among plants (CBOL Plant Working Group 2009). Several chloroplast gene sequences such as psbA–trnH, trnL–trnF, ycf1, and rpoC1 have been evaluated as potential DNA barcodes (CBOL Plant Working Group 2009; Dong et al. 2015; Yu et al. 2016). In addition to plastid barcoding, internal transcribed spacer (ITS) regions of ribosomal genes have been proposed as supplemental barcodes for matK and rbcL. The ITS region includes the ITS1 and ITS2 regions, separated by the 5.8S gene, and is situated between the 18S and 28S genes in the nrDNA repeat unit (Bellemain et al. 2010). Despite problems associated with the ITS region such as incomplete concerted evolution, fungal contamination, and difficulties in amplifying and sequencing in some species, it provides enough variable sites for differentiating among species (Chen et al. 2010; Yao et al. 2010; China Plant BOL Group 2011; Lee et al. 2016; Wang et al. 2017). Compared to the ITS region, the ITS2 region is easy to amplify and sequence, and also provides sufficient information for phylogenetic analysis. Moreover, the secondary structure of the ITS2 region can offer additional information for species identification. The ITS2 RNA transcript contains a core structure of two helices with hallmark characteristics that are important for ribosomal RNA processing (Coleman 2007). This secondary structure allows the detection of sequencing errors and pseudogenes in the ITS2 region (Coleman 2007; Rampersad 2014).