Testing quantitative genetic selection theory with the mouse: A review

2005 ◽  
Vol 2005 ◽  
pp. 238-238
Author(s):  
E. J. Eisen
Keyword(s):  
Genetic Selection ◽  
Selection Response ◽  
Farm Animals ◽  
Base Population ◽  
Selection Theory ◽  
Quantitative Genetic ◽  
Selection Experiments ◽  
Downward Bias ◽  
Dynamic Population ◽  
Good Agreement

The theory of quantitative genetics is used to predict certain outcomes in a dynamic population undergoing selection. The goal of this review is to demonstrate the value of the mouse as a model to test quantitative genetic selection theory.Heritablity estimates in a base population are used to predict selection response. How good is this prediction? Sheridan (1988) reported discrepancies between predicted and realized heritabilities in selection experiments with laboratory and farm animals. An updated summary of single-trait selection experiments for different traits in mice indicates good agreement between predicted and realized heritabilities (r = 0.81, P < 0.01), with no suggestion of upward or downward bias in the base estimates (Eisen, 2005).

Long-term animal research in genetic improvement of livestock and poultry

1996 ◽  
Vol 76 (4) ◽  
pp. 581-585
Author(s):  
E. B. Burnside
Keyword(s):  
Animal Species ◽  
Genetic Variance ◽  
Genetic Selection ◽  
Selection Response ◽  
Animal Experimentation ◽  
Private Industry ◽  
Animal Products ◽  
Selection Experiments ◽  
Long Term Studies

In animal experimentation, long-term studies have contributed substantially to our knowledge of genetics in particular, and of nutrition, physiology, and reproduction, to lesser extents. Long-term genetic selection experiments have yielded information on selection limits, dissipation of genetic variance over time, and created unique lines which may be utilized as consumer demands shift. Costs of long-term experimentation are not inordinately high in comparison to other experimentation, if economic animal species are used and returns from animal products are recovered to help finance the experiment. Government finance is, however, required for long-term experimentation, as private industry has little motivation for this work. The paper outlines recent significant contributions of long-term experimentation, and provides guidelines for planning experiments. Key words: Selection response, animal genetics, long-term experimentation, experimental design

scholarly journals The Nature of Quantitative Genetic Variation in Drosophila. II* Average Dominance of Abdominal Bristle Polygenes

1974 ◽  
Vol 27 (6) ◽  
pp. 683 ◽  
Author(s):  
R Frankham
Keyword(s):  
Genetic Variation ◽  
Selection Response ◽  
Base Population ◽  
Quantitative Genetic

A comparison of 13 abdominal bristle selection lines with their base population and with reciprocal Fls between the selection lines and the base population was carried out. There was no significant directional contribution of maternally inherited factors to selection response.

ESTIMASI NILAI HERITABILITAS BOBOT IKAN MAS VARIETAS PUNTEN DALAM PROGRAM SELEKSI INDIVIDU

2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi
Keyword(s):  
Body Weight ◽  
Selection Response ◽  
Base Population ◽  
Breeding Programs ◽  
Male And Female ◽  
Body Weight Trait ◽  
Population Selection ◽  
Selection For ◽  
Weight Trait ◽  
Selection Of

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).

scholarly journals UNEQUAL CROSSING OVER AT THE rRNA TANDON AS A SOURCE OF QUANTITATIVE GENETIC VARIATION IN DROSOPHILA

Genetics ◽  
1980 ◽  
Vol 95 (3) ◽  
pp. 727-742 ◽  
Author(s):  
R Frankham ◽  
D A Briscoe ◽  
R K Nurthen
Keyword(s):  
Genetic Variation ◽  
Selection Response ◽  
Crossing Over ◽  
Wild Type ◽  
X Chromosomes ◽  
Unequal Crossing Over ◽  
Quantitative Genetic ◽  
Y Chromosomes ◽  
Homozygous Line ◽  
Minimum Estimate

ABSTRACT Abdominal bristle selection lines (three high and three low) and controls were founded from a marked homozygous line to measure the contribution of sex-linked "mutations" to selection response. Two of the low lines exhibited a period of rapid response to selection in females, but not in males. There were corresponding changes in female variance, in heritabilities in females, in the sex ratio (a deficiency of females) and in fitness, as well as the appearance of a mutant phenotype in females of one line. All of these changes were due to bb alleles (partial deficiencies for the rRNA tandon) in the X chromosomes of these lines, while the Y chromosomes remained wild-type bb+. We argue that the bb alleles arose by unequal crossing over in the rRNA tandon.—A prediction of this hypothesis is that further changes can occur in the rRNA tandon as selection is continued. This has now been shown to occur.—Our minimum estimate of the rate of occurrence of changes at the rRNA tandon is 3 × 10-4. As this is substantially higher than conventional mutation rates, the questions of the mechanisms and rates of origin of new quantitative genetic variation require careful re-examination.

scholarly journals Corrigendum to: Consequences of genetic selection for environmental impact traits on economically important traits in dairy cows

2018 ◽  
Vol 58 (10) ◽  
pp. 1966
Author(s):  
Purna Kandel ◽  
Sylvie Vanderick ◽  
Marie-Laure Vanrobays ◽  
Hélène Soyeurt ◽  
Nicolas Gengler
Keyword(s):  
Dairy Cows ◽  
Body Condition Score ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Selection Response ◽  
Direct Selection ◽  
Correlated Response ◽  
Production Traits ◽  
Ch4 Emissions ◽  
Natural Logarithm

Methane (CH4) emission is an important environmental trait in dairy cows. Breeding aiming to mitigate CH4 emissions require the estimation of genetic correlations with other economically important traits and the prediction of their selection response. In this study, test-day CH4 emissions were predicted from milk mid-infrared spectra of Holstein cows. Predicted CH4 emissions (PME) and log-transformed CH4 intensity (LMI) computed as the natural logarithm of PME divided by milk yield (MY). Genetic correlations of PME and LMI with traits used currently were approximated from correlations between estimated breeding values of sires. Values were for PME with MY 0.06, fat yield (FY) 0.09, protein yield (PY) 0.13, fertility 0.17; body condition score (BCS) –0.02; udder health (UDH) 0.22; and longevity 0.22. As expected by its definition, values were negative for LMI with production traits (MY –0.61; FY –0.15 and PY –0.40) and positive with fertility (0.36); BCS (0.20); UDH (0.08) and longevity (0.06). The genetic correlations of 33 type traits with PME ranged from –0.12 to 0.25 and for LMI ranged from –0.22 to 0.18. Without selecting PME and LMI (status quo) the relative genetic change through correlated responses of other traits were in PME by 2% and in LMI by –15%, but only due to the correlated response to MY. Results showed for PME that direct selection of this environmental trait would reduce milk carbon foot print but would also affect negatively fertility. Therefore, more profound changes in current indexes will be required than simply adding environmental traits as these traits also affect the expected progress of other traits.

scholarly journals Comparative behaviour of local and exotic chickens in tests of fearfulness, anxiety and cognition

2021 ◽  
Vol 41 (1) ◽  
pp. 4-15
Author(s):  
T. B. Raji ◽  
A. A. Toye
Keyword(s):  
Production System ◽  
Genetic Selection ◽  
Test Results ◽  
Extensive Management ◽  
Quantitative Genetic ◽  
Voluntary Approach ◽  
Ongoing Effort ◽  
Poultry Birds ◽  
Distress Calls ◽  
Two Phases

Behaviour affects performance and productivity of poultry birds especially chickens, some behavioural traits are advantageous in a particular production system and may be of disadvantage in another production system. The present study compared behavioural of Nigeria Local Chicken, NLC (two separate samples of 11 Yoruba Ecotype) and its Exotic counterparts (11 Broilers and 11 Pullets) by use of the Open Field (OFT), T-Maze, Forced Approach, and Voluntary Approach Tests (FAT and VAT respectively) during two phases of Growth (0-4 Weeks, and 4-8 weeks age respectively). The former group (NLC) is better adapted to extensive management in the Nigerian Guinea savannah than the latter Results showed that Yoruba NLC issued a significantly (p<0.05) higher number of distress calls than the Exotic genotypes in the OFT at age 7 and 48 days, and the NLC issued significantly more calls at 7 days age. Broilers exhibited significantly lower OFT Latency at 7 and 48 days, and Broilers traversed fewer squares and spent less time ambulating than other genotypes at 48 days age. Ina T-maze, Broilers showed significantly (p<0.05) lower exploratory behaviour than other groups (higher latency to leave the start box). In the FAT, NLC showed lower Latency to flight (p<0.05) than the Exotic genotypes. Ethological test results indicate differences in the behavioural characters exhibited by Yoruba NLC and Exotic Chickens and such differences could embody the basis of anecdotal differences in the rates of survival under extensive management conditions, and may be subjected to quantitative genetic selection in the ongoing effort to produce improved chickens that incorporate a combination of desirable traits from both Local and Exotic chickens.

scholarly journals A SIMULATION STUDY OF TRUNCATION SELECTION FOR A QUANTITATIVE TRAIT OPPOSED BY NATURAL SELECTION

Genetics ◽  
1980 ◽  
Vol 94 (4) ◽  
pp. 989-1000
Author(s):  
Francis Minvielle
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Random Mating ◽  
Selection Response ◽  
Quantitative Character ◽  
Mass Selection ◽  
Frequency Selection ◽  
Selection Experiments ◽  
Selection For ◽  
Selective Process

ABSTRACT A quantitative character controlled at one locus with two alleles was submitted to artificial (mass) selection and to three modes of opposing natural selection (directional selection, overdominance and underdominance) in a large random-mating population. The selection response and the limits of the selective process were studied by deterministic simulation. The lifetime of the process was generally between 20 and 100 generations and did not appear to depend on the mode of natural selection. However, depending on the values of the parameters (initial gene frequency, selection intensity, ratio of the effect of the gene to the environmental standard deviation, fitness values) the following outcomes of selection were observed: fixation of the allele favored by artificial selection, stable nontrivial equilibrium, unstable equilibrium and loss of the allele favored by artificial selection. Finally, the results of the simulation were compared to the results of selection experiments.

scholarly journals An integrative genomic analysis of the Longshanks selection experiment for longer limbs in mice

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
João PL Castro ◽  
Michelle N Yancoskie ◽  
Marta Marchini ◽  
Stefanie Belohlavy ◽  
Layla Hiramatsu ◽  
...  
Keyword(s):  
Bone Growth ◽  
Rapid Evolution ◽  
Genomic Analysis ◽  
Selection Response ◽  
Major Effect ◽  
Selection Experiment ◽  
Genomic Analyses ◽  
Selection Experiments ◽  
Polygenic Adaptation ◽  
History Of

Evolutionary studies are often limited by missing data that are critical to understanding the history of selection. Selection experiments, which reproduce rapid evolution under controlled conditions, are excellent tools to study how genomes evolve under selection. Here we present a genomic dissection of the Longshanks selection experiment, in which mice were selectively bred over 20 generations for longer tibiae relative to body mass, resulting in 13% longer tibiae in two replicates. We synthesized evolutionary theory, genome sequences and molecular genetics to understand the selection response and found that it involved both polygenic adaptation and discrete loci of major effect, with the strongest loci tending to be selected in parallel between replicates. We show that selection may favor de-repression of bone growth through inactivating two limb enhancers of an inhibitor, Nkx3-2. Our integrative genomic analyses thus show that it is possible to connect individual base-pair changes to the overall selection response.

Rates of inbreeding using DNA fingerprinting in aquaculture breeding programs at various broodstock fitness levels — a simulation study

2005 ◽  
Vol 45 (8) ◽  
pp. 893 ◽  
Author(s):  
M. Macbeth
Keyword(s):  
Dna Fingerprinting ◽  
Simulation Study ◽  
Intraclass Correlation ◽  
Genetic Selection ◽  
Selection Response ◽  
Phenotypic Variance ◽  
Selection Intensity ◽  
Breeding Programs ◽  
Inbreeding Rate ◽  
Number Of Individuals

A simulation study was used to examine the potential use of DNA fingerprinting (DNA tagging) as a tool to avoid excessive inbreeding by identifying suitable candidate breeders in genetic selection programs. ‘Broodstock fitness’ (the ability of broodstock to survive from harvest and reproduce) needs to be considered in designing breeding programs using DNA tagging. In this study, reduced broodstock fitness increased inbreeding exponentially. The level of inbreeding was also dependent on the intraclass correlation (t), selection intensity, number of individuals DNA tagged (NDNA), number of families maintained (Nf) and the number of candidate breeders retained per sex/family at harvest (C). With a broodstock fitness of 0.90, DNA tagging could theoretically achieve a selection intensity, in terms of the total phenotypic variance, of 2.90 standard deviations with 800 000 graded at harvest, while maintaining an inbreeding rate of 1.0% per generation (NDNA = 800, Nf = 30, C = 4, t = 0.3). In practice, the numbers required could be achieved by growing families in individual facilities (e.g. sea cages for barramundi or ponds for prawns). When mechanical grading is not possible, the selection pool may be limited to a level where physical tagging is feasible. In this case, there was no advantage in selection response using DNA tagging compared with physical tags. DNA tagging as a selection tool may be more feasible when broodstock fitness is above 0.6, and may fill a niche where industry infrastructure is not large enough to support separate rearing of families or where physical tagging is not economically viable or suitable. DNA tagging may also be useful as a means of recovering families in backup facilities where families have been pooled to reduce infrastructure costs. Due to the random nature of DNA sampling, not all families may be recovered and a reduction in selection pressure may facilitate family recovery.

Sign in / Sign up

Export Citation Format

Share Document