scholarly journals Contrasting Patterns of Polymorphisms at the ABO-Secretor Gene (FUT2) and Plasma α(1,3)Fucosyltransferase Gene (FUT6) in Human Populations

Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 747-756 ◽  
Author(s):  
Yoshiro Koda ◽  
Hidenori Tachida ◽  
Hao Pang ◽  
Yuhua Liu ◽  
Mikiko Soejima ◽  
...  
Keyword(s):  
Natural Selection ◽  
Direct Sequencing ◽  
The Other ◽  
Human Populations ◽  
Allelic Polymorphism ◽  
Neutral Model ◽  
Coding Sequences ◽  
Fucosyltransferase Gene ◽  
Secretor Gene ◽  
Tajima’S D

Abstract The coding sequences (∼1 kb) of FUT2 [ABO-Secretor type α(1,2)fucosyltransferase] and of FUT6 [plasma α(1,3)fucosyltransferase] were analyzed for allelic polymorphism by direct sequencing in five populations. The nucleotide diversities of FUT2 estimated from pairwise sequence differences were 0.0045, 0.0042, 0.0042, 0.0009, and 0.0008 in Africans, European-Africans, Iranians, Chinese, and Japanese, respectively. The nucleotide diversities of FUT6 were 0.0024, 0.0016, 0.0015, 0.0017, and 0.0020 in Africans, European-Africans, Iranians, Chinese, and Japanese, respectively. At FUT2, excesses in pairwise sequence differences compared to the number of polymorphic sites as indicated by a significantly positive Tajima’s D were observed in European-Africans and in Iranians. The data do not fit expectations of the equilibrium neutral model with an infinite number of sites. On the other hand, Tajima’s D’s at FUT6 in each of the five populations and at FUT2 in Africans, Chinese, and Japanese were not significantly different from zero. FST between the Asians and the others measured at FUT2 was higher than at FUT6. These results suggest that natural selection was responsible for the generation of the FUT2 polymorphism in European-Africans and in Iranians.

Selection on X-linked Genes During Speciation in the Drosophila athabasca Complex

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 689-703 ◽  
Author(s):  
Michael J Ford ◽  
Charles F Aquadro
Keyword(s):  
Computer Simulation ◽  
Natural Selection ◽  
Molecular Evolution ◽  
Restriction Site ◽  
Neutral Model ◽  
Background Selection ◽  
Selective Sweeps ◽  
Differential Migration ◽  
Site Survey ◽  
Low Levels

Abstract We present the results of a restriction site survey of variation at five loci in Drosophila athabasca, complimenting a previous study of the period locus. There is considerably greater differentiation between the three semispecies of D. athabasca at the period locus and two other X-linked genes (neon-transient-A and E74A) than at three autosomal genes (Xdh, Adh and RC98). Using a modification of the HKA test, which uses fixed differences between the semispecies and a test based on differences in Fst among loci, we show that the greater differentiation of the X-linked loci compared with the autosomal loci is inconsistent with a neutral model of molecular evolution. We explore several evolutionary scenarios by computer simulation, including differential migration of X and autosomal genes, very low levels of migration among the semispecies, selective sweeps, and background selection, and conclude that X-linked selective sweeps in at least two of the semispecies are the best explanation for the data. This evidence that natural selection acted on the X-chromosome suggests that another X-linked trait, mating song differences among the semispecies, may have been the target of selection.

scholarly journals Novel start codons introduce novel coding sequences in the human genomes

2020 ◽  
Author(s):  
He Zhang ◽  
Yang Xie
Keyword(s):  
Translation Initiation ◽  
Genomic Analysis ◽  
Comparative Genomic ◽  
Human Populations ◽  
The Novel ◽  
Coding Sequences ◽  
Human Genomes ◽  
High Level ◽  
Selection Signal ◽  
Human Specific

AbstractStart-gain mutations can introduce novel start codons and generate novel coding sequences that may affect the function of genes. In this study, we systematically investigated the novel start codons that were either polymorphic or fixed in the human genomes. 829 polymorphic start-gain SNVs were identified in the human populations, and the novel start codons introduced by these SNVs have significantly higher activity in translation initiation. Some of these start-gain SNVs were reported to be associated with phenotypes and diseases in previous studies. By comparative genomic analysis, we found 26 human-specific start codons that were fixed after the divergence between the human and chimpanzee, and high-level translation initiation activity was observed on them. The negative selection signal was detected in the novel coding sequences introduced by these human-specific start codons, indicating the important function of these novel coding sequences. This study reveals start-gain mutations are keeping appearing in the human genomes during the evolution and may be important sources altering the function of genes which may further affect the phenotypes or cause diseases.

scholarly journals Dynamics of natural selection in two generations (on the example of the population of the Kirovograd region)

2021 ◽  
Vol 29 ◽  
pp. 152-156
Author(s):  
K. K. Kovleva ◽  
N.A. Kozak
Keyword(s):  
Natural Selection ◽  
First Generation ◽  
Second Generation ◽  
Selection Index ◽  
Genetic Load ◽  
Modern Medicine ◽  
Reproductive Age ◽  
Human Populations ◽  
Medical Histories ◽  
Total Selection

Aim. In connection with the success of modern medicine, the pressure of natural selection in various civilized human populations is weakening, which leads to the accumulation of a genetic load. The purpose of this work was to trace the change in the intensity of natural selection among population of the Kirovograd region in two successive generations. Methods. The collection of material was carried out in 2020 and 2021. Anonymous questionnaires were conducted and medical histories of women of post-reproductive age of the Kirovograd region were studied. The first generation included 40 women born in 1937–1959; the second generation consists of 273 women born in 1960–1981. Results. The total selection index was 0.27 in the first generation, and 0.37 in the second generation. The percentage of women who have not had pregnancies increased from the first generation to the second from 2.5 to 3.7, respectively. Conclusions. The index of total selection in the Kirovograd region population for one generation increased by almost one and a half times (from 0.27 to 0.37), as well as the index of differential fertility (from 0.25 to 0.35). Keywords: reproductive characteristics, Kirovograd population, Crow's index, selection, generations.

scholarly journals Prognostic Impact of NOTCH1 Hotspot Mutation in TP53-Mutated Patients with Chronic Lymphocytic Leukemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3283-3283
Author(s):  
Barbara Kantorova ◽  
Jitka Malcikova ◽  
Veronika Navrkalova ◽  
Jana Smardova ◽  
Kamila Brazdilova ◽  
...  
Keyword(s):  
Overall Survival ◽  
Chronic Lymphocytic Leukemia ◽  
Tp53 Mutation ◽  
Direct Sequencing ◽  
Lymphocytic Leukemia ◽  
The Other ◽  
Wild Type ◽  
Tp53 Mutations ◽  
Time To First Treatment ◽  
Hotspot Mutation

Abstract Introduction A presence of activating mutations in NOTCH1 gene has been recently associated with reduced survival and chemo-immunotherapy resistance in chronic lymphocytic leukemia (CLL). However, a prognostic significance of the NOTCH1 mutations with respect to TP53mutation status has not been fully explained yet. Methods An examined cohort included 409 patients with CLL enriched for high risk cases; in 121 patients consecutive samples were investigated. To determine the TP53 mutation status, a functional analysis of separated alleles in yeast (FASAY, exons 4-10) combined with direct sequencing was performed; the ambiguous cases were retested using an ultra-deep next generation sequencing (MiSeq platform; Illumina). The presence of NOTCH1 hotspot mutation (c.7544_7545delCT) was analyzed using direct sequencing complemented by allele-specific PCR in the selected samples. In several patients harboring concurrent NOTCH1 and TP53 mutations, single separated cancer cells were examined using multiplex PCR followed by direct sequencing. A correlation between mutation presence and patient overall survival, time to first treatment and other molecular and cytogenetic prognostic markers was assessed using Log-rank (Mantel-cox) test and Fisher's exact test, respectively. Results The NOTCH1 and TP53 mutations were detected in 16% (65/409) and 27% (110/409) of the examined patients, respectively; a coexistence of these mutations in the same blood samples was observed in 11% (19/175) of the mutated patients. The detected increased mutation frequency attributes to more unfavorable profile of the analyzed cohort; in the TP53-mutated patients missense substitutions predominated (75% of TP53 mutations). As expected, a significantly reduced overall survival in comparison to the wild-type cases (147 months) was observed in the NOTCH1-mutated (115 months; P = 0.0018), TP53-mutated (79 months; P < 0.0001) and NOTCH1-TP53-mutated patients (101 months; P = 0.0282). Since both NOTCH1 and TP53 mutations were strongly associated with an unmutated IGHV gene status (P < 0.0001 and P = 0.0007), we reanalyzed the IGHV-unmutated patients only and interestingly, the impact of simultaneous NOTCH1 and TP53 mutation presence on patient survival was missed in this case (P = 0.1478). On the other hand, in the NOTCH1 and/or TP53-mutated patients significantly reduced time to first treatment was identified as compared to the wild-type cases (41 months vs. 25 months in NOTCH1-mutated, P = 0.0075; 17 months in TP53-mutated, P < 0.0001; and 18 months in NOTCH1-TP53-mutated patients, P = 0.0003). The similar results were observed also in the subgroup of the IGHV-unmutated patients, with the exception of patients carrying sole NOTCH1 mutation (P = 0.2969). Moreover, in the NOTCH1-TP53-mutated patients an increased frequency of del(17p)(13.1) was found in comparison to the TP53-mutated patients only (72% vs. 56%); this cytogenetic defect was not detected in the patients with sole NOTCH1 mutation. Our results might indicate, that NOTCH1 mutation could preferentially co-selected with particular, less prognostic negative type of TP53 defects. Notably, in our cohort the NOTCH1 mutation predominated in the patients harboring truncating TP53 mutations localized in a C-terminal part of the TP53 gene behind the DNA-binding domain (P = 0.0128). Moreover, in one of the NOTCH1-TP53-mutated patients the analysis of separated cancer cells revealed a simultaneous presence of NOTCH1 mutation and TP53 in-frame deletion in the same CLL cell. In contrast, in the other examined NOTCH1-TP53-mutated patient the concurrent NOTCH1 mutation and TP53 missense substitution (with presumed negative impact on patient prognosis) were found in different CLL cells. Conclusions The parallel presence of NOTCH1 hotspot mutation might be detected in a significant proportion of TP53-mutated patients and it seems to be associated with less prognostic unfavorable TP53 mutations. Nevertheless, these preliminary data should be further confirmed in a large cohort of patients. This study was supported by projects VaVPI MSMT CR CZ.1.05/1.1.00/02.0068 of CEITEC, IGA MZ CR NT13493-4/2012, NT13519-4/2012 and CZ.1.07/2.3.00/30.0009. Disclosures Brychtova: Roche: Travel grants Other. Doubek:Roche: Travel grants Other.

scholarly journals Unequal signal and coding joint formation in human V(D)J recombination.

1993 ◽  
Vol 13 (7) ◽  
pp. 3900-3906 ◽  
Author(s):  
G H Gauss ◽  
M R Lieber
Keyword(s):  
Cell Lines ◽  
Relative Efficiency ◽  
Chromosomal Rearrangements ◽  
The Other ◽  
Combined Effects ◽  
Recombination Activity ◽  
Coding Sequences ◽  
Joint Formation ◽  
Differential Reaction ◽  
Endogenous Loci

Substrates for studying V(D)J recombination in human cells and two human pre-B-cell lines that have active V(D)J recombination activity are described. Using these substrates, we have been able to analyze the relative efficiency of signal joint and coding joint formation. Coding joint formation was five- to sixfold less efficient than signal joint formation in both cell lines. This imbalance between the two halves of the reaction was demonstrated on deletional substrates, where each joint is assayed individually. In both cell lines, the inversional reaction (which requires formation of both a signal and a coding joint) was more than 20-fold less efficient than signal joint formation alone. The signal and coding sequences are identical in all of these substrates. Hence, the basis for these differential reaction ratios appears to be that coding joint and signal joint formation are both inefficient and their combined effects are such that inversions (two-joint reactions) reflect the product of these inefficiencies. Physiologically, these results have two implications. First, they show how signal and coding joint formation efficiencies can affect the ratio of deletional to inversional products at endogenous loci. Second, the fact that not all signal and coding joints go to completion implies that the recombinase is generating numerous broken ends. Such unresolved ends may participate in pathologic chromosomal rearrangements even when the other half of the same reaction may have proceeded to resolution.

“Data for the Problem of Evolution in Man. V. On the Correlation between Duration of Life and the Number of Offspring”

1901 ◽  
Vol 35 (6) ◽  
pp. 458-479
Author(s):  
M. Beeton ◽  
G. U. Yule ◽  
Karl Pearson
Keyword(s):  
Natural Selection ◽  
Breeding Season ◽  
The Other ◽  
Similar Statement ◽  
Men And Women ◽  
Darwinian Theory ◽  
Theory Of Evolution ◽  
Biennial Plants ◽  
Long Life ◽  
Breeding Seasons

According to the Darwinian theory of evolution the members of a community less fitted to their environment are removed by death. But this process of natural selection would not permanently modify a race, if the members thus removed were able before death to propagate their species in average numbers. It then becomes an important question to ascertain how far duration of life is related to fertility. In the case of many insects death can interfere only with their single chance of offspring; they live or not for their one breeding season only. A similar statement holds good with regard to annual and biennial plants. In such cases there might still be a correlation between duration of life and fertility, but it would be of the indirect character, which we actually find in the case of men and women living beyond sixty years of age—a long life means better physique and better physique increased fertility. On the other hand, there is a direct correlation of fertility and duration of life in the case of those animals which generally survive a number of breeding seasons, and it is this correlation which we had at first in view when investigating the influence of duration of life on fertility in man. The discovery of the indirect factor in the correlation referred to above was therefore a point of much interest. For it seems to show that the physique fittest to survive is really the physique which is in itself (and independently of the duration of life) most fecund.

scholarly journals The emergence of latent infection in the early evolution of Mycobacterium tuberculosis

2016 ◽  
Vol 283 (1831) ◽  
pp. 20160499 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
Mark M. Tanaka
Keyword(s):  
Mathematical Model ◽  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Genetic Variation ◽  
Natural Selection ◽  
Natural History ◽  
Latent Infection ◽  
Human Populations ◽  
Safe Harbour ◽  
Active Disease

Mycobacterium tuberculosis has an unusual natural history in that the vast majority of its human hosts enter a latent state that is both non-infectious and devoid of any symptoms of disease. From the pathogen perspective, it seems counterproductive to relinquish reproductive opportunities to achieve a détente with the host immune response. However, a small fraction of latent infections reactivate to the disease state. Thus, latency has been argued to provide a safe harbour for future infections which optimizes the persistence of M. tuberculosis in human populations. Yet, if a pathogen begins interactions with humans as an active disease without latency, how could it begin to evolve latency properties without incurring an immediate reproductive disadvantage? We address this question with a mathematical model. Results suggest that the emergence of tuberculosis latency may have been enabled by a mechanism akin to cryptic genetic variation in that detrimental latency properties were hidden from natural selection until their expression became evolutionarily favoured.

scholarly journals Libertad, igualdad, competitividad: En torno a la transfiguración de los valores europeos tras la era de la modernización

2019 ◽  
pp. 131
Author(s):  
Teresa López Ruiz
Keyword(s):  
Natural Selection ◽  
Social Order ◽  
Production System ◽  
Economic Indicator ◽  
Cultural Dimensions ◽  
The Other ◽  
Innovation Development ◽  
Other Hand ◽  
Cultural Terms

Competitividad es una expresión polisémica que, en términos económicos,implica el grado de integración de la sociedad en un modelo productivobasado en la investigación, la innovación y las altas tecnologías. Pero, a su vez, entérminos ideológicos no deja de hundir sus raíces en la idea darwinista de la luchapor la supervivencia y la selección natural. Por ello, aun cuando la competitividadse invoca en términos pretendidamente objetivos como los económicos, conscienteo inconscientemente se refuerza a la vez el relato de un determinado orden social;un relato que divide el mundo entre ganadores y perdedores y que determinaquiénes merecerán perder o ganar. Y en términos culturales ello es probablementelo único que se hace, en tanto que mayores dosis de cultura competitiva no implicannecesariamente la mejora de ningún indicador real. El artículo confronta algunosde los principales indicadores económicos y sociales en el entorno UE28, conlos índices culturales de cada sociedad, encontrando que son otros los conjuntos devalores que inciden en la productividad, el empleo, la riqueza, el bienestar o ladesigualdad.Competitiveness is a polysemic word that, first of all, makes referenceto a production system based on innovation, development and high technologies.But, on the other hand, in ideological terms it refers us to the darwinist ideasof the natural selection and the fight for survive. So, when we appeal to competitivenesseven in economic, impartial terms, at the same time -and conscious orunconsciously- we reinforce the narrative of a social order that divides our societybetween winners and losers, and defines who of all will deserve to be at one sideor at the other. And in cultural terms it probably is the only thing we do, becausehigher doses of competitive culture do not necessarily increase the improvement ofany social or economic indicator. This work confronts some of these indicatorswith the cultural dimensions of the UE28 countries, finding that are others thevalues that affect the results on wealth, productivity, employment, welfare or inequality.

Frank Bridge and The Land Without Music

Tempo ◽  
1977 ◽  
pp. 7-11
Author(s):  
Hugh Wood
Keyword(s):  
Natural Selection ◽  
The Other ◽  
Musical Evolution ◽  
Survival Of The Fittest

Why the work of one composer survives and another doesn't remains a little mysterious. I myself incline on the whole to a Darwinian view of musical posterity: it is quality that chiefly determines the survival of the fittest, and some process of natural selection upon this criterion that ensures that the best are sorted out in the end. (If one throws in the other bit of evolutionist jargon—adaptation to one's environment—the limits to pursuing this metaphor become obvious). But temperamentally I distrust the endless discovery of Unjustly Neglected Composers. When the writer Mr. X is spoken of as ‘the persuasive advocate for’ composer Mr. Y, the phrase itself suggests the lawyer doing too good a job, and that the client so skilfully defended is in fact guilty—of lack of distinction anyway, if not lack of talent. There are so many Justly Neglected Composers. Every now and then, though, you make a discovery that upsets the comfortable applecart of this non-revisionist view of musical evolution.

Sign in / Sign up

Export Citation Format

Share Document