Maria A Nieves-Colon

Successful enrichment and recovery of whole mitochondrial genomes from ancient human dental calculus

ABSTRACT Objectives Archaeological dental calculus is a rich source of host‐associated biomolecules. Importantly, however, dental calculus is more accurately described as a calcified microbial biofilm than a host tissue. As such, concerns regarding destructive analysis of human remains may not apply as strongly to dental calculus, opening the possibility of obtaining human health and ancestry information from dental calculus in cases where destructive analysis of conventional skeletal remains is not permitted. Here we investigate the preservation of human mitochondrial DNA (mtDNA) in archaeological dental calculus and its potential for full mitochondrial genome (mitogenome) reconstruction in maternal lineage ancestry analysis. Materials and Methods Extracted DNA from six individuals at the 700‐year‐old Norris Farms #36 cemetery in Illinois was enriched for mtDNA using in‐solution capture techniques, followed by Illumina high‐throughput sequencing. Results Full mitogenomes (7–34×) were successfully reconstructed from dental calculus for all six individuals, including three individuals who had previously tested negative for DNA preservation in bone using conventional PCR techniques. Mitochondrial haplogroup assignments were consistent with previously published findings, and additional comparative analysis of paired dental calculus and dentine from two individuals yielded equivalent haplotype results. All dental calculus samples exhibited damage patterns consistent with ancient DNA, and mitochondrial sequences were estimated to be 92–100% endogenous. DNA polymerase choice was found to impact error rates in downstream sequence analysis, but these effects can be mitigated by greater sequencing depth. Discussion Dental calculus is a viable alternative source of human DNA that can be used to reconstruct full mitogenomes from archaeological remains. Am J Phys Anthropol 160:220–228, 2016.

Extensive Regulatory Changes in Genes Affecting Vocal and Facial Anatomy Separate Modern from Archaic Humans

Changes in gene regulation are broadly accepted as key drivers of phenotypic differences between closely related species. However, identifying regulatory changes that shaped human-specific traits is a very challenging task. Here, we use >60 DNA methylation maps of ancient and present-day human groups, as well as six chimpanzee maps, to detect regulatory changes that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting vocalization and facial features went through particularly extensive methylation changes. Specifically, we identify silencing patterns in a network of genes (SOX9, ACAN, COL2A1 and NFIX), and propose that they might have played a role in the reshaping of the human face, and in forming the 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that may have shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.Summary Regulatory changes are broadly accepted as key drivers of phenotypic divergence. However, identifying regulatory changes that underlie human-specific traits has proven very challenging. Here, we use 63 DNA methylation maps of ancient and present-day humans, as well as of six chimpanzees, to detect differentially methylated regions that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting the face and vocal tract went through particularly extensive methylation changes. Specifically, we identify widespread hypermethylation in a network of face- and voice-affecting genes (SOX9, ACAN, COL2A1, NFIX and XYLT1). We propose that these repression patterns appeared after the split from Neanderthals and Denisovans, and that they might have played a key role in shaping the modern human face and vocal tract.Identifying changes in gene regulation that shaped human-specific traits is critical to understanding human adaptation. Here, we use dozens of ancient and present-day DNA methylation maps to detect regulatory changes that emerged in modern humans. We show that genes affecting vocalization and facial features went through particularly extensive changes in methylation. Especially, we identify expansive changes in a network of genes regulating skeletal development (SOX9, ACAN and COL2A1), and in NFIX, which controls facial projection and voice box (larynx) development. We propose that these changes played a key role in shaping the human face, and in forming the human 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.

Genetic diversity in populations across Latin America: implications for population and medical genetic studies

Hispanic/Latino (H/L) populations, although linked by culture and aspects of shared history, reflect the complexity of history and migration influencing the Americas. The original settlement by indigenous Americans, followed by postcolonial admixture from multiple continents, has yielded localized genetic patterns. In addition, numerous H/L populations appear to have signatures of pre-colonization and post-colonization bottlenecks, indicating that tens of millions of H/Ls may harbor signatures of founder effects today. Based on both population and medical genetic findings we highlight the extreme differentiation across the Americas, providing evidence for why H/Ls should not be considered a single population in modern human genetics. We highlight the need for additional sampling of understudied H/L groups, and ramifications of these findings for genomic medicine in one-tenth of the worlds population.

Comparison of two ancient DNA extraction protocols for skeletal remains from tropical environments

OBJECTIVES The tropics harbor a large part of the worlds biodiversity and have a long history of human habitation. However, paleogenomics research in these climates has been constrained so far by poor ancient DNA yields. Here we compare the performance of two DNA extraction methods on ancient samples of teeth and petrous portions excavated from tropical and semi-tropical sites in Tanzania, Mexico, and Puerto Rico (N = 12). MATERIALS AND METHODS All samples were extracted twice, built into double-stranded sequencing libraries, and shotgun sequenced on the Illumina HiSeq 2500. The first extraction protocol, Method D, was previously designed for recovery of ultrashort DNA fragments from skeletal remains. The second, Method H, modifies the first by adding an initial EDTA wash and an extended digestion and decalcification step. RESULTS No significant difference was found in overall ancient DNA yields or post-mortem damage patterns recovered from samples extracted with either method, irrespective of tissue type. However, Method H samples had higher endogenous content and more mapped reads after quality-filtering, but also higher clonality. In contrast, samples extracted with Method D had shorter average DNA fragments. DISCUSSION Both methods successfully recovered endogenous ancient DNA. But, since surviving DNA in ancient or historic remains from tropical contexts is extremely fragmented, our results suggest that Method D is the optimal choice for working with samples from warm and humid environments. Additional optimization of extraction conditions and further testing of Method H with different types of samples may allow for improvement of this protocol in the future.

Extensive Regulatory Changes in Genes Affecting Vocal and Facial Anatomy Separate Modern Humans from Neanderthals and Denisovans

Changes in gene regulation are broadly accepted as key drivers of phenotypic differences between closely related species. However, identifying regulatory changes that shaped human-specific traits is a very challenging task. Here, we use >60 DNA methylation maps of ancient and present-day human groups, as well as six chimpanzee maps, to detect regulatory changes that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting vocalization and facial features went through particularly extensive methylation changes. Specifically, we identify silencing patterns in a network of genes (SOX9, ACAN, COL2A1 and NFIX), and propose that they might have played a role in the reshaping of the human face, and in forming the 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that may have shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.Summary Regulatory changes are broadly accepted as key drivers of phenotypic divergence. However, identifying regulatory changes that underlie human-specific traits has proven very challenging. Here, we use 63 DNA methylation maps of ancient and present-day humans, as well as of six chimpanzees, to detect differentially methylated regions that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting the face and vocal tract went through particularly extensive methylation changes. Specifically, we identify widespread hypermethylation in a network of face- and voice-affecting genes (SOX9, ACAN, COL2A1, NFIX and XYLT1). We propose that these repression patterns appeared after the split from Neanderthals and Denisovans, and that they might have played a key role in shaping the modern human face and vocal tract.Identifying changes in gene regulation that shaped human-specific traits is critical to understanding human adaptation. Here, we use dozens of ancient and present-day DNA methylation maps to detect regulatory changes that emerged in modern humans. We show that genes affecting vocalization and facial features went through particularly extensive changes in methylation. Especially, we identify expansive changes in a network of genes regulating skeletal development (SOX9, ACAN and COL2A1), and in NFIX, which controls facial projection and voice box (larynx) development. We propose that these changes played a key role in shaping the human face, and in forming the human 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.

Recent regulatory changes shaped human facial and vocal anatomy

Changes in gene regulation are broadly accepted as key drivers of phenotypic differences between closely related species. However, identifying regulatory changes that shaped human-specific traits is a very challenging task. Here, we use >60 DNA methylation maps of ancient and present-day human groups, as well as six chimpanzee maps, to detect regulatory changes that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting vocalization and facial features went through particularly extensive methylation changes. Specifically, we identify silencing patterns in a network of genes (SOX9, ACAN, COL2A1 and NFIX), and propose that they might have played a role in the reshaping of the human face, and in forming the 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that may have shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.Summary Regulatory changes are broadly accepted as key drivers of phenotypic divergence. However, identifying regulatory changes that underlie human-specific traits has proven very challenging. Here, we use 63 DNA methylation maps of ancient and present-day humans, as well as of six chimpanzees, to detect differentially methylated regions that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting the face and vocal tract went through particularly extensive methylation changes. Specifically, we identify widespread hypermethylation in a network of face- and voice-affecting genes (SOX9, ACAN, COL2A1, NFIX and XYLT1). We propose that these repression patterns appeared after the split from Neanderthals and Denisovans, and that they might have played a key role in shaping the modern human face and vocal tract.Identifying changes in gene regulation that shaped human-specific traits is critical to understanding human adaptation. Here, we use dozens of ancient and present-day DNA methylation maps to detect regulatory changes that emerged in modern humans. We show that genes affecting vocalization and facial features went through particularly extensive changes in methylation. Especially, we identify expansive changes in a network of genes regulating skeletal development (SOX9, ACAN and COL2A1), and in NFIX, which controls facial projection and voice box (larynx) development. We propose that these changes played a key role in shaping the human face, and in forming the human 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.

Recent Regulatory Changes Shaped Human Facial and Vocal Anatomy [Revised]

Changes in gene regulation are broadly accepted as key drivers of phenotypic differences between closely related species. However, identifying regulatory changes that shaped human-specific traits is a very challenging task. Here, we use >60 DNA methylation maps of ancient and present-day human groups, as well as six chimpanzee maps, to detect regulatory changes that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting vocalization and facial features went through particularly extensive methylation changes. Specifically, we identify silencing patterns in a network of genes (SOX9, ACAN, COL2A1 and NFIX), and propose that they might have played a role in the reshaping of the human face, and in forming the 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that may have shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.Summary Regulatory changes are broadly accepted as key drivers of phenotypic divergence. However, identifying regulatory changes that underlie human-specific traits has proven very challenging. Here, we use 63 DNA methylation maps of ancient and present-day humans, as well as of six chimpanzees, to detect differentially methylated regions that emerged in modern humans after the split from Neanderthals and Denisovans. We show that genes affecting the face and vocal tract went through particularly extensive methylation changes. Specifically, we identify widespread hypermethylation in a network of face- and voice-affecting genes (SOX9, ACAN, COL2A1, NFIX and XYLT1). We propose that these repression patterns appeared after the split from Neanderthals and Denisovans, and that they might have played a key role in shaping the modern human face and vocal tract.Identifying changes in gene regulation that shaped human-specific traits is critical to understanding human adaptation. Here, we use dozens of ancient and present-day DNA methylation maps to detect regulatory changes that emerged in modern humans. We show that genes affecting vocalization and facial features went through particularly extensive changes in methylation. Especially, we identify expansive changes in a network of genes regulating skeletal development (SOX9, ACAN and COL2A1), and in NFIX, which controls facial projection and voice box (larynx) development. We propose that these changes played a key role in shaping the human face, and in forming the human 1:1 vocal tract configuration that is considered optimal for speech. Our results provide insights into the molecular mechanisms that shaped the modern human face and voice, and suggest that they arose after the split from Neanderthals and Denisovans.