Diagnostic single nucleotide polymorphism markers to identify hybridization between dromedary and Bactrian camels

This article sets out findings from a small-scale collaborative project evaluating the use of a self-audit tool to promote the development of information literacy in MA social work students at a university in the north of England. The project involved the use of the audit tool early in the first and second years of a two-year professional masters programme and, alongside this, completion of two evaluation questionnaires. Analysis of the data suggested substantially increased confidence(measured by self-report) in the identified skills over the first year of the programme. The authors recognise that many factors may contribute to improved confidence and skills. Nevertheless, students identified use of the tool and the signposting to resources within it as helpful, and most felt that the stated aims had been met

Genomic signatures of domestication in Old World camels

Domestication begins with the selection of animals showing less fear of humans. In most domesticates, selection signals for tameness have been superimposed by intensive breeding for economical or other desirable traits. Old World camels, conversely, have maintained high genetic variation and lack secondary bottlenecks associated with breed development. By re-sequencing multiple genomes from dromedaries, Bactrian camels, and their endangered wild relatives, here we show that positive selection for candidate genes underlying traits collectively referred to as 'domestication syndrome' is consistent with neural crest deficiencies and altered thyroid hormone-based signaling. Comparing our results with other domestic species, we postulate that the core set of domestication genes is considerably smaller than the pan-domestication set - and overlapping genes are likely a result of chance and redundancy. These results, along with the extensive genomic resources provided, are an important contribution to understanding the evolutionary history of camels and the genomic features of their domestication. Robert R. Fitak et al. investigate the genetic basis for domestication in camels. They found that the positive selection of candidate domestication genes is consistent with neural crest deficiencies and altered thyroid hormone-based signaling. Their work provides insights to the evolutionary history of camels and genetics of domestication.Peer reviewe

Mitogenome Sequencing in the Genus Camelus Reveals Evidence for Purifying Selection and Long-term Divergence between Wild and Domestic Bactrian Camels

The genus Camelus is an interesting model to study adaptive evolution in the mitochondrial genome, as the three extant Old World camel species inhabit hot and low-altitude as well as cold and high-altitude deserts. We sequenced 24 camel mitogenomes and combined them with three previously published sequences to study the role of natural selection under different environmental pressure, and to advance our understanding of the evolutionary history of the genus Camelus. We confirmed the heterogeneity of divergence across different components of the electron transport system. Lineage-specific analysis of mitochondrial protein evolution revealed a significant effect of purifying selection in the concatenated protein-coding genes in domestic Bactrian camels. The estimated dN/dSPeer reviewe

Reconstruction of the major maternal and paternal lineages in the feral New Nealand Kaimanawa horses

New Zealand has the fourth largest feral horse population in the world. The Kaimanawas (KHs) are feral horses descended from various domestic horse breeds released into the Kaimanawa ranges in the 19th and 20th centuries. Over time, the population size has fluctuated dramatically due to hunting, large-scale farming and forestry. Currently, the herd is managed by an annual round-up, limiting the number to 300 individuals to protect the native ecosystem. Here, we genotyped 96 KHs for uniparental markers (mitochondrial DNA, Y-chromosome) and assessed their genetic similarity with respect to other domestic horses. We show that at least six maternal and six paternal lineages contributed unequally to the KH gene pool, and today’s KH population possibly represents two sub-populations. Our results indicate that three horse breeds, namely Welsh ponies, Thoroughbreds and Arabian horses had a major influence in the genetic-makeup of the extant KH population. We show that mitochondrial genetic diversity in KHs (π = 0.00687 ± 0.00355) is closer to that of the Sable Island horses (π = 0.0034 ± 0.00301), and less than other feral horse populations around the world. Our current findings, combined with ongoing genomic research, will provide insight into the population-specific genetic variation and inbreeding among KHs. This will largely advance equine research and improve the management of future breeding programs of these treasured New Zealand horse

Ancient and modern DNA reveal dynamics of domestication and cross-continental dispersal of the dromedary

Dromedaries have been fundamental to the development of human societies in arid landscapes and for long-distance trade across hostile hot terrains for 3,000 y. Today they continue to be an important livestock resource in marginal agro-ecological zones. However, the history of dromedary domestication and the influence of ancient trading networks on their genetic structure have remained elusive. We combined ancient DNA sequences of wild and early-domesticated dromedary samples from arid regions with nuclear microsatellite and mitochondrial genotype information from 1,083 extant animals collected across the species’ range. We observe little phylogeographic signal in the modern population, indicative of extensive gene flow and virtually affecting all regions except East Africa, where dromedary populations have remained relatively isolated. In agreement with archaeological findings, we identify wild dromedaries from the southeast Arabian Peninsula among the founders of the domestic dromedary gene pool. Approximate Bayesian computations further support the “restocking from the wild” hypothesis, with an initial domestication followed by introgression from individuals from wild, now-extinct populations. Compared with other livestock, which show a long history of gene flow with their wild ancestors, we find a high initial diversity relative to the native distribution of the wild ancestor on the Arabian Peninsula and to the brief coexistence of early-domesticated and wild individuals. This study also demonstrates the potential to retrieve ancient DNA sequences from osseous remains excavated in hot and dry desert environments

The evolution of the mitochondrial DNA in tuatara (Sphenodon punctatus) : a thesis presented in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Evolutionary Genetics, Massey University, Auckland, New Zealand

Appendix D content removed due to copyright restrictions: Mohandsen, E., Mowla, S. J., Noobari, A. H., Hofreiter, M. (2008) "Ancient DNA from human and animal remains from north-west Iran", Journal of Sciences, Islamic Republic of Iran 19(1), 3-8. Hay, J. M., Subramanian, S., Millar, C. D., Mohandesan, E., Lambert, D. M. (2008) "Rapid molecular evolution in a living fossil", Trends in Genetics, 24(3), 106-109. Millar, C. D., Huynen, L., Subramanian, S., Mohandesan, E., Lambert, D. M. (2008) "New developments in ancient genomics", Trends in Ecology and Evolution, 23(7), 386-393. Subramanian, S., Hay, J. M., Mohandesan, E., Millar, C. D., Lambert, D. M. (2008) "Molecular and morphological evolution in tuatara are decoupled", Trends in Genetics, 25(1), 16-18.The enigmatic tuatara from New Zealand, occupies a central place in the evolution of vertebrates and tuatara have changed little morphologically since the Cretaceous period approximately 200 millions of years ago. A central aim of this thesis was to examine rates of molecular evolution in tuatara using entire mitochondrial genomes of both ancient and modern samples. A total of 51 complete mitochondrial genomes from 42 modern (from eight island groups) and 9 ancient samples (from eight locations on mainland) were sequenced using Sanger method. These complete genomes were used to investigate the population genetic structure of tuatara. Diverse phylogenetic analyses suggest that Sphenodon is a monotypic genus. This is in contrast to the suggestion made by Daugherty et al. (1990 b) that there are two species of tuatara. This two species model was subsequently almost universally accepted. The current result illustrates that when species are incorrectly identified scarce conservation resources are inappropriately used to ensure their conservation. Using these complete mitochondrial genomes and by employing three very different analytical methods, I have also estimated molecular evolutionary rates for tuatara. Using modern and ancient complete mitochondrial genomes, I showed that the rates of molecular evolution in tuatara are higher than other vertebrates. This result and the stable morphology of tuatara over tens of millions of years suggest a disconnect between molecular and anatomical evolution, as originally suggested by Allan Wilson in the 1970s. From a biological perspective perhaps this is not surprising, since morphological and molecular evolution are governed by very different biological processes. I then explored the possibility that tuatara might be characterised by high mutation rates. Using Roche 454 next generation DNA sequencing, I recovered seven complete mitochondrial genomes in tuatara. A total of 28 potential heteroplasmies were detected among these genomes. These sites were also shown to be polymorphic among the 42 modern aligned genomes suggesting that they are characterised by high mutation rates. This result suggests that a high level of heteroplasmic sites in tuatara mitochondrial genome contributes to the high molecular rates estimated when comparing modern and ancient genomes

Fracture Strength of Implant-supported Full-contoured Titanium and Zirconia Single Crowns Connected to Titanium Cores

Objectives: To investigate the fracture strength and failure mode of implant-supported screw-retained customized 2-piece zirconia and 1-piece titanium restorations, and to evaluate the effect of aging on the mechanical performance of zirconia restorations. Materials and Methods: Thirty identical specimens simulating maxillary first premolar replacements were divided in 3 groups. Groups ZrA and ZrNA consisted of zirconia and Group Ti consisted of titanium restorations, anchored to implants embedded in PMMA. Specimens in Group ZrA underwent chewing simulation. Static load was applied until failure. Results: Group Ti showed the highest fracture strength. The difference was significant between Groups ZrA and Ti. Failures included partial or complete fracture of titanium insert or deformation of restoration with screw fracture. Conclusion: Evidence was inadequate to reject similarity in fracture strength between non-aged zirconia and titanium restorations, or between zirconia restorations with different aging conditions. Aging affected the failure mode of zirconia restorations.M.H.Sc.2017-07-05 00:00:0