scholarly journals Antimicrobial functions of lactoferrin promote genetic conflicts in ancient primates and modern humans

2016 ◽  
Author(s):  
Matthew F. Barber ◽  
Zev N. Kronenberg ◽  
Mark Yandell ◽  
Nels C. Elde
Keyword(s):  
Positive Selection ◽  
Pathogenic Bacteria ◽  
Modern Human ◽  
Human Populations ◽  
Human Genetic Variation ◽  
Cationic Protein ◽  
Protein Functions ◽  
Genetic Conflicts ◽  
New Protein

Lactoferrin is a multifunctional mammalian immunity protein that limits microbial growth through sequestration of nutrient iron. Additionally, lactoferrin possesses cationic protein domains that directly bind and inhibit diverse microbes. The implications for these dual functions on lactoferrin evolution and genetic conflicts with pathogens remain unclear. Here we show that lactoferrin has been subject to recurrent episodes of positive selection during primate divergence predominately at antimicrobial peptide surfaces consistent with long-term antagonism by pathogens. An abundant lactoferrin polymorphism in human populations and Neanderthals also exhibits signatures of positive selection across primates, linking ancient host-microbe conflicts to modern human genetic variation. Rapidly evolving sites in lactoferrin further correspond to molecular interfaces with pathogenic bacteria causing meningitis, pneumonia, and sepsis. Because microbes actively target lactoferrin to acquire iron, we propose that the emergence of antimicrobial activity provided a pivotal mechanism of adaptation sparking evolutionary conflicts via acquisition of new protein functions.

scholarly journals Limits of long-term selection against Neandertal introgression

2019 ◽  
Vol 116 (5) ◽  
pp. 1639-1644 ◽  
Author(s):  
Martin Petr ◽  
Svante Pääbo ◽  
Janet Kelso ◽  
Benjamin Vernot
Keyword(s):  
Negative Selection ◽  
Modern Human ◽  
Model Parameters ◽  
Human Populations ◽  
Modern Humans ◽  
High Coverage ◽  
Protein Coding ◽  
The Past ◽  
Wide Range

Several studies have suggested that introgressed Neandertal DNA was subjected to negative selection in modern humans. A striking observation in support of this is an apparent monotonic decline in Neandertal ancestry observed in modern humans in Europe over the past 45,000 years. Here, we show that this decline is an artifact likely caused by gene flow between modern human populations, which is not taken into account by statistics previously used to estimate Neandertal ancestry. When we apply a statistic that avoids assumptions about modern human demography by taking advantage of two high-coverage Neandertal genomes, we find no evidence for a change in Neandertal ancestry in Europe over the past 45,000 years. We use whole-genome simulations of selection and introgression to investigate a wide range of model parameters and find that negative selection is not expected to cause a significant long-term decline in genome-wide Neandertal ancestry. Nevertheless, these models recapitulate previously observed signals of selection against Neandertal alleles, in particular the depletion of Neandertal ancestry in conserved genomic regions. Surprisingly, we find that this depletion is strongest in regulatory and conserved noncoding regions and in the most conserved portion of protein-coding sequences.

Distribution of Enteric Viruses and Microorganisms in Long-Term Sewage-Treated Soil

1983 ◽  
Vol 15 (5) ◽  
pp. 129-135 ◽  
Author(s):  
Z Filip ◽  
K Seidel ◽  
H Dizer
Keyword(s):  
Soil Bacteria ◽  
Pathogenic Bacteria ◽  
Sewage Treatment ◽  
Anaerobic Bacteria ◽  
Enteric Viruses ◽  
Sewage Irrigation ◽  
Groundwater Samples ◽  
West Berlin ◽  
Aerobic Soil

To determine whether long-term sewage treatment can take place without a pollution risk for soil and groundwater, samples from sewage irrigation fields in West Berlin which have been in use since about 1890 were analyzed for enteric viruses and microorganisms. Enteric viruses were detected in only seven samples from a total number of eighty seven taken from different soil depths. With only one exception, no viruses were found below 60 cm. No viruses were detected in groundwater samples. Long-term sewage irrigation did not result in significant changes in the colony courts of aerobic soil bacteria, but the counts of anaerobic bacteria and actinomycetes were slightly elevated and those of microscopic fungi slightly decreased. Potentially pathogenic bacteria were not detected in soil below 90 cm.

scholarly journals Long-lasting renewable antibacterial porous polymeric coatings enable titanium biomaterials to prevent and treat peri-implant infection

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shuyi Wu ◽  
Jianmeng Xu ◽  
Leiyan Zou ◽  
Shulu Luo ◽  
Run Yao ◽  
...  
Keyword(s):  
Dental Implant ◽  
Pathogenic Bacteria ◽  
Titanium Surface ◽  
Polymeric Coating ◽  
Antibacterial Efficacy ◽  
Polymeric Coatings ◽  
Implant Infection ◽  
Titanium Surfaces

AbstractPeri-implant infection is one of the biggest threats to the success of dental implant. Existing coatings on titanium surfaces exhibit rapid decrease in antibacterial efficacy, which is difficult to promisingly prevent peri-implant infection. Herein, we report an N-halamine polymeric coating on titanium surface that simultaneously has long-lasting renewable antibacterial efficacy with good stability and biocompatibility. Our coating is powerfully biocidal against both main pathogenic bacteria of peri-implant infection and complex bacteria from peri-implantitis patients. More importantly, its antibacterial efficacy can persist for a long term (e.g., 12~16 weeks) in vitro, in animal model, and even in human oral cavity, which generally covers the whole formation process of osseointegrated interface. Furthermore, after consumption, it can regain its antibacterial ability by facile rechlorination, highlighting a valuable concept of renewable antibacterial coating in dental implant. These findings indicate an appealing application prospect for prevention and treatment of peri-implant infection.

α-Oxoaldehyde metabolism and diabetic complications

2003 ◽  
Vol 31 (6) ◽  
pp. 1358-1363 ◽  
Author(s):  
P.J. Beisswenger ◽  
S.K. Howell ◽  
R.G. Nelson ◽  
M. Mauer ◽  
B.S. Szwergold
Keyword(s):  
Diabetic Complications ◽  
Complex Mixture ◽  
Therapeutic Interventions ◽  
Diabetic Patients ◽  
Human Populations ◽  
Control Mechanisms ◽  
Protective Mechanisms ◽  
Glycation End Products ◽  
End Products

The factors responsible for variable susceptibility to diabetic nephropathy are not clear. According to the non-enzymatic glycation hypothesis, diabetes-related tissue damage occurs due to a complex mixture of toxic products, including α-oxoaldehydes, which are inherently toxic as well as serving as presursors for advanced glycation end-products. Protective mechanisms exist to control this unavoidable glycation, and these are determined by genetic or environmental factors that can regulate the concentrations of the reactive sugars or end-products. In diabetes these protective mechanisms become more important, since glycation stress increases, and less efficient defence systems against this stress could lead to diabetic complications. Some of these enzymatic control mechanisms, including those that regulate α-oxoaldehydes, have been identified. We have observed significant increases in production of the α-oxoaldehydes methylglyoxal and 3-deoxyglucosone in three human populations with biopsy-proven progression of nephropathy. The increase in methylglyoxal could be secondary to defects in downstream glycolytic enzymes (such as glyceraldehyde-3-phosphate dehydrogenase) that regulate its production, or in detoxification mechanisms such as glyoxalase. Other mechanisms, however, appear to be responsible for the observed increase in 3-deoxyglucosone levels. We present results of our studies on the mechanisms responsible for variable production of α-oxoaldehydes by measuring the activity and characteristics of these enzymes in cells from complication-prone and -resistant diabetic patients. New therapeutic interventions designed to control these endogenous mechanisms could potentially enhance protection against excessive glycation and prevent or reverse complications of long-term diabetes.

scholarly journals Functional relationship between dental macrowear and diet in Late Pleistocene and recent modern human populations

2018 ◽  
Vol 28 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Luca Fiorenza ◽  
Stefano Benazzi ◽  
Gregorio Oxilia ◽  
Ottmar Kullmer
Keyword(s):  
Late Pleistocene ◽  
Functional Relationship ◽  
Modern Human ◽  
Human Populations

scholarly journals The Genome of a Mongolian Individual Reveals the Genetic Imprints of Mongolians on Modern Human Populations

2014 ◽  
Vol 6 (12) ◽  
pp. 3122-3136 ◽  
Author(s):  
Haihua Bai ◽  
Xiaosen Guo ◽  
Dong Zhang ◽  
Narisu Narisu ◽  
Junjie Bu ◽  
...  
Keyword(s):  
Modern Human ◽  
Human Populations

scholarly journals An Ancient Baboon Genome Demonstrates Long-Term Population Continuity in Southern Africa

2020 ◽  
Vol 12 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Iain Mathieson ◽  
Federico Abascal ◽  
Lasse Vinner ◽  
Pontus Skoglund ◽  
Cristina Pomilla ◽  
...  
Keyword(s):  
Southern Africa ◽  
Nonhuman Primates ◽  
Demographic History ◽  
Structured Populations ◽  
Human Populations ◽  
Papio Ursinus ◽  
Anthropological Research ◽  
Population Continuity ◽  
High Degree

Abstract Baboons are one of the most abundant large nonhuman primates and are widely studied in biomedical, behavioral, and anthropological research. Despite this, our knowledge of their evolutionary and demographic history remains incomplete. Here, we report a 0.9-fold coverage genome sequence from a 5800-year-old baboon from the site of Ha Makotoko in Lesotho. The ancient baboon is closely related to present-day Papio ursinus individuals from southern Africa—indicating a high degree of continuity in the southern African baboon population. This level of population continuity is rare in recent human populations but may provide a good model for the evolution of Homo and other large primates over similar timespans in structured populations throughout Africa.

The Anthropology of Modern Human Teeth: Dental Morphology and Its Variation in Recent Human Populations

1998 ◽  
Vol 100 (3) ◽  
pp. 807-808
Author(s):  
John T. Mayhall
Keyword(s):  
Modern Human ◽  
Human Populations ◽  
Dental Morphology ◽  
Human Teeth

scholarly journals Codiversification of gut microbiota with humans

2021 ◽  
Author(s):  
Taichi A. Suzuki ◽  
Liam Fitzstevens ◽  
Victor T. Schmidt ◽  
Hagay Enav ◽  
Kelsey Huus ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Vertical Transmission ◽  
Evolutionary History ◽  
Human Populations ◽  
African Origin ◽  
Strain Transfer ◽  
Close Proximity ◽  
Different Populations ◽  
Specific Health

Some gut microbes have cospeciated with hominids, but whether they further codiversified with human populations is unclear. Here, we identify predominant gut microbial species sharing a parallel evolutionary history with human populations. Patterns of strain transfer between populations are generally consistent with an African origin, and suggest long-term vertical transmission over thousands of generations. We show the same strains also faithfully transmit between mothers and their children. Consistent with the development of intimate symbiosis, species with strongest patterns of codiversification have the smallest genomes. This study reveals long-term fidelity of gut microbiota with human populations through transmission among individuals living in close proximity. Dominance of specific strains in different populations is based in part on vertical transmission and they may provide population-specific health benefits.

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