scholarly journals Genetische Analyse der Population des Vorderwälder Rindes

2004 ◽  
Vol 47 (2) ◽  
pp. 141-153 ◽  
Author(s):  
G. Biedermann ◽  
B. Ott ◽  
K. Rübesam ◽  
F. Maus
Keyword(s):  
Genetic Analysis ◽  
Generation Interval ◽  
Genetische Analyse ◽  
Gene Contribution ◽  
The Mean ◽  
Coefficient Of Inbreeding

Abstract. Title of the paper: Genetic analysis of the population of Vorderwald cattle The actual population of Vorderwald cattle, comprising 5452 animals has been analysed concerning the gene contribution, the generation interval and the degree of relationship and inbreeding with regard of five generations of ancestors. About 84 % of the genes are originating from Vorderwald cattle. The genetic portions of other breeds have been contributed by Red Holsteins, Montbéliards and Ayrshires. The average generation interval parents–current animals is about 4.5 years. The mean relationship has been found out with 5.5 % within the bulls and 3.4 % within the cows. Accordingly the mean coefficient of inbreeding is higher within the bulls (2,7 %) than within the cows (2,4 %). Only 28.6 % of the bulls and 36.6 % of the cows are not inbred. With 0.9 % the increase of inbreeding in the last generation is of alarming proportions; that’s why a carefully directed program of mating has to be recommended.

scholarly journals Genetische Analyse der Population des Hinterwälder Rindes

2003 ◽  
Vol 46 (4) ◽  
pp. 307-319
Author(s):  
G. Biedermann ◽  
S. Waldmann ◽  
F. Maus
Keyword(s):  
Genetic Analysis ◽  
Dairy Cows ◽  
Genetic Contribution ◽  
Average Percentage ◽  
Generation Interval ◽  
Current Population ◽  
Genetische Analyse ◽  
Average Coefficient ◽  
The Mean ◽  
Coefficient Of Relationship

Abstract. Title of the paper: Genetic analysis of the population of Hinterwald cattle Since 1994 the Hinterwald population is devided into one of dairy cows and one of suckling cows. The bulls are available to both subpopulations. By means of herdbook records of the year of 2002 there were gained 79 bulls, 698 dairy cows and 517 suckling cows. Considering five generations of ancestors the subpopulations have been investigated with regard to genetic contribution, generation intervals, and circumstances of relationship and inbreeding. The average percentage of Hinterwald blood in the current population amounts to 97 %. The genetic portions of other breeds are low and mostly originating from Vorderwald cattle. The mean generation interval (parents–current animals) is about 5 years. Between the sires and current animals it is shorter (about 4 years) than between the dams and the current animals (about 7 years). The average coefficient of relationship among the bulls is the highest (3.7 %) compared to the dairy cows (2.2 %) and the suckling cows (0.9 %). The mean degree of inbreeding is 1.2 up to 1.3 %, and 37 % of the bulls, 57 % of the dairy cows and 74 % of the suckling cows are not inbred. The increase of inbreeding is rather low and doesn’t surmount 0.7 % in all subpopulations. Therefore it can be assumed that the Hinterwald cattle at present is not subjected to any danger of inbreeding.

scholarly journals A genetic method for dating ancient genomes provides a direct estimate of human generation interval in the last 45,000 years

2016 ◽  
Vol 113 (20) ◽  
pp. 5652-5657 ◽  
Author(s):  
Priya Moorjani ◽  
Sriram Sankararaman ◽  
Qiaomei Fu ◽  
Molly Przeworski ◽  
Nick Patterson ◽  
...  
Keyword(s):  
Upper Paleolithic ◽  
Direct Estimate ◽  
Radiocarbon Dates ◽  
Genetic Method ◽  
Generation Interval ◽  
Neanderthal Admixture ◽  
The Common ◽  
The Mean ◽  
The Difference ◽  
Age Estimates

The study of human evolution has been revolutionized by inferences from ancient DNA analyses. Key to these studies is the reliable estimation of the age of ancient specimens. High-resolution age estimates can often be obtained using radiocarbon dating, and, while precise and powerful, this method has some biases, making it of interest to directly use genetic data to infer a date for samples that have been sequenced. Here, we report a genetic method that uses the recombination clock. The idea is that an ancient genome has evolved less than the genomes of present-day individuals and thus has experienced fewer recombination events since the common ancestor. To implement this idea, we take advantage of the insight that all non-Africans have a common heritage of Neanderthal gene flow into their ancestors. Thus, we can estimate the date since Neanderthal admixture for present-day and ancient samples simultaneously and use the difference as a direct estimate of the ancient specimen’s age. We apply our method to date five Upper Paleolithic Eurasian genomes with radiocarbon dates between 12,000 and 45,000 y ago and show an excellent correlation of the genetic and 14C dates. By considering the slope of the correlation between the genetic dates, which are in units of generations, and the 14C dates, which are in units of years, we infer that the mean generation interval in humans over this period has been 26–30 y. Extensions of this methodology that use older shared events may be applicable for dating beyond the radiocarbon frontier.

scholarly journals Consanguinité, Isonymie et Age Précoce au Mariage dans les deux Provinces de Tétouan et M’diq-fnideq (Maroc)

2018 ◽  
Vol 14 (25) ◽  
pp. 63
Author(s):  
Mohamed Hajjaji ◽  
Abd Errazzak Khadmaoui ◽  
Abd El-Majid Soulaymani ◽  
Younes Azzouzi
Keyword(s):  
Marital Status ◽  
Significant Positive Correlation ◽  
Strong Association ◽  
Current Generation ◽  
Positive Correlation ◽  
Age At Marriage ◽  
Consanguineous Marriages ◽  
The Mean ◽  
Intergenerational Comparison ◽  
Coefficient Of Inbreeding

The purpose of this work is to contribute to the description of marital practices in Northern Morocco, to follow the evolution of these practices, and to determine the motives for marriages between relatives. Thus our results show a highly significant positive correlation between the age of the two spouses (r = 0.619, p <0.001), with the mean age of the mothers being 49.03 ± 6.56 years, while for the fathers it is 56,02 ± 6,16 years with a difference of 7 years between the two spouses in the current generation. For consanguineous marriages, we identified 51 relatives, namely a frequency of 25.4% for the generation of studied couples GCE, 13.3% for the generation of paternal grandparents GGPP, and 17.5% for the generation of maternal grandparents GGPM. The intergenerational comparison reveals a highly significant increase in the percentage of consanguinity, ranging from the generation of grandparents (15.4%) to that of the studied couples (25.4%), with a difference of 10% (p˂0.001). These results also show that there is a strong association between the prevalence of consanguineous marriages and the group of women under 19 years old (p = 0.002), whereas for husbands it is noted that There is no association between marital status and age at marriage. The coefficient of consanguinity estimated by isonymy is almost twice as large as the coefficient of inbreeding estimated by genealogy.

DEVELOPMENT OF THE ROMNELET SHEEP

1961 ◽  
Vol 41 (1) ◽  
pp. 102-108 ◽  
Author(s):  
H. F. Peters ◽  
S. B. Slen ◽  
H. J. Hargrave
Keyword(s):  
Inbreeding Coefficient ◽  
Department Of Agriculture ◽  
Generation Interval ◽  
Canada Department ◽  
Performance Traits ◽  
White Face ◽  
The Mean ◽  
Standard Deviations ◽  
Skin Wrinkles ◽  
Foundation Stock

In 1935 the Canada Department of Agriculture undertook the development of a new breed of sheep at the Experimental Farm, Manyberries, Alberta. The foundation stock consisted of 15 Romney Marsh rams and 520 Rambouillet ewes, with introductions of 1 Targhee ram in 1942 and 6 Romeldale rams in 1944. Two of the Romeldale rams were used again in 1945. The flock has been closed to outside introductions since 1945 and the breed which resulted has been named "Romnelet".Following the first cross, the F1 animals were inter-mated and no back-crosses were made. A genealogical study up to, and including, 1955 showed the average annual size of the breeding flock to be 10 rams and 338 ewes and the average generation interval 3.5 years. On the average, there were 13 rams and 301 ewes selected per generation. The mean inbreeding coefficient of the 1955 lambs was 8 per cent.Romnelets are polled, open-faced, free from skin wrinkles, with white face and legs and a fleece of [Formula: see text] or [Formula: see text] staple wool. Means and standard deviations of performance traits in the new breed under range conditions are reported.

Microsatellite marker-based estimation of the genetic diversity of cattle in Chongqing

2018 ◽  
Author(s):  
Weiwei Ni ◽  
An Jiang ◽  
Jian Zhang ◽  
Guangxin E ◽  
Yongfu Huang
Keyword(s):  
Genetic Diversity ◽  
Microsatellite Markers ◽  
Microsatellite Marker ◽  
Weinberg Equilibrium ◽  
The Future ◽  
Hardy Weinberg Equilibrium ◽  
The Mean ◽  
Coefficient Of Inbreeding

Cattle are the main source of meat in Chongqing. This study investigated the genetic diversity of cattle native to Chongqing and 4 introduced breeds. A total of 96 individuals from 5 breeds were genotyped using six microsatellite markers. Five markers were highly polymorphic within the breed populations, and one marker had moderate levels of polymorphism. Heterozygosity ranged from 0.5379±0.0434 in Simmental to 0.6667±0.0559 in Charolais. The heterozygosity deficit was significant in all populations analyzed compared with the expected level of heterozygosity. In addition, two microsatellite markers (TGLA53 and OarFCB20) deviated from Hardy-Weinberg equilibrium across populations (except in cattle native to Chongqing). The mean number of alleles ranged from 6.00±2.37 in Angus to 7.17±2.14 in Droughtmaster across six markers. The coefficient of inbreeding ranged from 0.0017 in Simmental and Droughtmaster to 0.0367 in Angus. Pairwise difference analyses revealed that Simmental and Droughtmaster were the most differentiated (FST= 0.06861) from each other, whereas cattle native to Chongqing and Charolais were the least differentiated (FST= 0.00557). In summary, this study showed that cattle native to Chongqing and 4 introduced breeds were genetically well protected in Chongqing, and information from this study would be helpful for guiding hybridization and genetic improvements in the future.

MIGRATION AS A DETERMINANT OF MARRIAGE PATTERN: PRELIMINARY REPORT ON CONSANGUINITY AMONG AFGHANS

2005 ◽  
Vol 38 (3) ◽  
pp. 315-325 ◽  
Author(s):  
ABDUL WAHAB ◽  
MAHMUD AHMAD ◽  
SYED AKRAM SHAH
Keyword(s):  
Preliminary Report ◽  
Marriage Pattern ◽  
Cousin Marriage ◽  
Dominant Type ◽  
Resident Population ◽  
Refugee Population ◽  
Consanguineous Marriages ◽  
Significant Difference ◽  
The Mean ◽  
Coefficient Of Inbreeding

Two sample populations, one refugee and one resident, were studied. The frequencies of consanguineous marriages came out to be 49·8% and 55·4%, respectively, for the refugees and the residents. Caste endogamy was dominant both in the residents and the refugees. The mean coefficient of inbreeding was calculated to be 0·0303 for the refugee population and 0·0332 for the resident population samples. First cousin marriage was the dominant type of marriage in both samples; father’s brother’s daughter (FBD) marriage was more frequent among the refugees while mother’s brother’s daughter (MBD) marriage was more frequent among the residents. Education has no decreasing effect on the incidence of consanguineous marriages. A significant difference in the pattern of marriages in the refugees is observed after the Saur Revolution of 1979.

A note on selection differential and generation length when generations overlap

1977 ◽  
Vol 24 (1) ◽  
pp. 109-112 ◽  
Author(s):  
J. W. James
Keyword(s):  
Age Groups ◽  
Parental Age ◽  
Selection Differential ◽  
Generation Interval ◽  
Generation Length ◽  
The Mean ◽  
Selection Differentials ◽  
Selection Of

SUMMARYThe generation interval may be defined as the mean age of parents of all progeny born, or as the mean age of parents of only those progeny destined to be selected as replacements. If the mean age of parents of replacements is used, selection differentials must be calculated within parental age groups. If the mean age of parents of all progeny born is used, the selection differential contains a component due to disproportionate selection of replacements from different parental age groups.

scholarly journals On realized serial and generation intervals given control measures: The COVID-19 pandemic case

2021 ◽  
Vol 17 (3) ◽  
pp. e1008892
Author(s):  
Andrea Torneri ◽  
Pieter Libin ◽  
Gianpaolo Scalia Tomba ◽  
Christel Faes ◽  
James G. Wood ◽  
...  
Keyword(s):  
Reproduction Number ◽  
Transmission Probability ◽  
Theoretical Explanation ◽  
Control Measures ◽  
Strong Impact ◽  
Generation Interval ◽  
Incidence Data ◽  
Intervention Measures ◽  
Serial Interval ◽  
The Mean

The SARS-CoV-2 pathogen is currently spreading worldwide and its propensity for presymptomatic and asymptomatic transmission makes it difficult to control. The control measures adopted in several countries aim at isolating individuals once diagnosed, limiting their social interactions and consequently their transmission probability. These interventions, which have a strong impact on the disease dynamics, can affect the inference of the epidemiological quantities. We first present a theoretical explanation of the effect caused by non-pharmaceutical intervention measures on the mean serial and generation intervals. Then, in a simulation study, we vary the assumed efficacy of control measures and quantify the effect on the mean and variance of realized generation and serial intervals. The simulation results show that the realized serial and generation intervals both depend on control measures and their values contract according to the efficacy of the intervention strategies. Interestingly, the mean serial interval differs from the mean generation interval. The deviation between these two values depends on two factors. First, the number of undiagnosed infectious individuals. Second, the relationship between infectiousness, symptom onset and timing of isolation. Similarly, the standard deviations of realized serial and generation intervals do not coincide, with the former shorter than the latter on average. The findings of this study are directly relevant to estimates performed for the current COVID-19 pandemic. In particular, the effective reproduction number is often inferred using both daily incidence data and the generation interval. Failing to account for either contraction or mis-specification by using the serial interval could lead to biased estimates of the effective reproduction number. Consequently, this might affect the choices made by decision makers when deciding which control measures to apply based on the value of the quantity thereof.

scholarly journals A genetic model for control of hypertriglyceridemia and apolipoprotein B levels in the Johns Hopkins colony of St. Thomas Hospital rabbits.

Genetics ◽  
1992 ◽  
Vol 132 (4) ◽  
pp. 1095-1104 ◽  
Author(s):  
T H Beaty ◽  
V L Prenger ◽  
D G Virgil ◽  
B Lewis ◽  
P O Kwiterovich ◽  
...  
Keyword(s):  
Genetic Analysis ◽  
Apolipoprotein B ◽  
Segregation Analysis ◽  
Genetic Model ◽  
Mendelian Segregation ◽  
Accelerated Atherosclerosis ◽  
Genetic Mechanisms ◽  
The Mean ◽  
Parsimonious Model

Abstract The St. Thomas Hospital (STH) rabbit has been previously shown to have a Mendelian form of hypertriglyceridemia, accompanied by accelerated atherosclerosis, and these animals may serve as a useful model for human dyslipoproteinemia syndromes. Here we describe the establishment of a new colony of these STH animals, and present genetic analysis of triglyceride (TG) and apolipoprotein B (apoB) levels. Segregation analysis of TG in 39 STH animals and 24 controls gave evidence of Mendelian segregation for an allele leading to both elevated TG levels and increased variability in these levels. Predicted means from the most parsimonious model for the Johns Hopkins STH colony were quite similar to that seen in the original London colony, and this model accounted for 80% of the variation in TG seen in the sample. This hypertriglyceridemia locus indirectly influenced the mean apoB levels in these rabbits, and segregation analysis of mean apoB levels suggested a second locus controlling apoB levels. Analysis of residual apoB levels (adjusted for predicted effects of the hypertriglyceridemia locus) revealed clearer evidence for a second locus controlling mean apoB levels in this colony. Arguments for two distinct genetic mechanisms operating in these STH animals are presented.

scholarly journals Selection intensity for milk yield in 1970—1977 in the Finnish Ayrshire

1978 ◽  
Vol 50 (6) ◽  
pp. 445-454
Author(s):  
U. B. Lindström
Keyword(s):  
Milk Yield ◽  
Genetic Gain ◽  
Genetic Change ◽  
Selection Intensity ◽  
Genetic Progress ◽  
Generation Interval ◽  
Ayrshire Breed ◽  
The Mean ◽  
Selection Differentials

Selection differentials for sires and dams of bulls taken into AI use in 1970—1977, as well as for sires used in AI, were combined with an estimate of the quality of dams of female replacements to calculate the (predicted) genetic change in milk yield in the Ayrshire breed. In the period the average annual genetic gain was 0.97 % of the mean yield, in the last three years it was c. 1.1 %. The average generation interval was 6.8 years; 8.7 years for the bull sires, 7.4 years for the bull dams and 6.4 years for the cow sires. The bull sires accounted for 42 %, the bull dams for 37 % and the cow sires for only 12% of the total genetic gain. A more rational use of progeny tested and young bulls, combined with a reduction of the generation interval of 15 %, could easily have increased the genetic progress by 20 %.

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