scholarly journals EFFECT OF SELECTION ON HERITABILITY AND GENETIC CORRELATION OF TWO QUANTITATIVE TRAITS IN MICE

1974 ◽  
Vol 16 (3) ◽  
pp. 599-609 ◽  
Author(s):  
T. K. Cheung ◽  
R. J. Parker
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Quantitative Traits ◽  
Random Mating ◽  
Tail Length ◽  
Control Group ◽  
Mass Selection ◽  
Initial Population ◽  
Significant Difference ◽  
Selection For

The effects of different intensities of single trait directional selection on the heritability and genetic correlation of two quantitative traits in random mating populations of mice were observed during 14 generations. The initial population was divided at random into five groups (A, B, C, D and E). Group A and Group B were under 30% and 60% mass selection for large 6-week body weight, respectively. Group C and Group D were under 30% and 60% mass selection for long 6-week tail length, respectively. Group E acted as control group with no selection applied. In all groups, the parent population consisted of 15 males and 30 females each generation, mated at random.Direct selection had no apparent effect on the heritability of either the trait under selection or the correlated trait over the 14 generations. Heritability of 6-wk tail length was higher than the heritability of 6-wk body weight. Estimates of heritability of 6-wk tail length ranged from 0.15 ± 0.22 to 0.68 ± 0.24, while estimates of heritability of 6-wk body weight ranged from 0.05 ± 0.17 to 0.33 ± 0.09. There was no significant difference among the estimates of genetic correlation between the two traits in the five selection groups. Estimates of realized genetic correlation between 6-wk body weight and 6-wk tail length seemed to indicate that more intense selection led to some decrease in genetic correlation between the two traits.

scholarly journals SELECTION FOR HIGH ADULT BODY WEIGHT IN DROSOPHILA POPULATIONS WITH DIFFERENT STRUCTURES

Genetics ◽  
1975 ◽  
Vol 81 (1) ◽  
pp. 163-175
Author(s):  
A J Katz ◽  
S S Y Young
Keyword(s):  
Body Weight ◽  
Random Mating ◽  
Large Mass ◽  
Mass Selection ◽  
Adult Body ◽  
Large Populations ◽  
Subdivided Populations ◽  
Adult Body Weight ◽  
Selection For ◽  
Selection Intensities

ABSTRACT Selection for high adult body weight in Drosophila melanogaster was practiced for 18 generations in three selection lines. These lines were genetically similar and of equal size but different in population structure. One line represented a large mass-selected, random-mating population, while the other two lines simulated large populations that had been subdivided into partial isolates or demes. Mass selection and random mating occurred within each deme. These two subdivided lines were different only in the rate of effective migration among the demes (5% and 10%). Selection intensities of approximately 20% were applied to these populations. A fourth line served as a random mating control. Heritability of adult body weight in the base population was estimated to be 0.58± 0.22. The results indicate that significantly greater responses were achieved in the subdivided lines than in the large mass-selected line, in spite of the fact that larger selection differentials were applied to the latter. No significant differences in response were observed between the two subdivided lines. Wright (1930, 1931) postulated that selection would be most efficient in subdivided populations with limited interdeme migration. The present findings appear to support this theory.

scholarly journals Regression of gestational diabetes induced cardiomegaly in offspring of diabetic rat

2009 ◽  
Vol 24 (4) ◽  
pp. 251-255 ◽  
Author(s):  
Honório Sampaio Menezes ◽  
Cláudio Galeano Zettler ◽  
Alice Calone ◽  
Jackson Borges Corrêa ◽  
Carla Bartuscheck ◽  
...  
Keyword(s):  
Body Weight ◽  
Wistar Rats ◽  
Weight Ratio ◽  
Diabetic Rats ◽  
Heart Weight ◽  
Diabetic Rat ◽  
Control Group ◽  
Computer Assisted ◽  
Significant Difference ◽  
Levene Test

PURPOSE: To compare body weight and length, heart weight and length, heart-to-body weight ratio, glycemia, and morphometric cellular data of offspring of diabetic rats (ODR) and of normal rats (control). METHODS: Diabetes was induced in 3 pregnant Wistar rats, bearing 30 rats, on the 11th day after conception by intraperitoneal injection of 50 mg/kg of streptozotocin. Six normal pregnant Wistar rats, bearing 50 rats, made up the control group. Morphometric data were obtained using a scale for the weight, length, heart and body measurements. Morphometric cellular data were obtained by a computer assisted method applied to the measurements of myocytes. Statistical analysis utilized Student's t-test, ANOVA and Levene test. RESULTS: Control offspring had greater mean body weight and length than offspring of diabetic rats (p < 0.001). Heart weight and length and heart-to-body ratios of newborn rats differed between groups at birth (p < 0.001), but showed no difference at 21 days. Mean nuclei area and perimetric value of the myocytes decrees throughout the first 21 days of life (p < 0.01) in the diabetic group. CONCLUSIONS: Heart hypertrophy on the offspring of diabetic rats at birth was demonstrated by the significant difference between the groups. After the eleventh day, no difference was found, which confirmed regression of cardiomegaly. The significant difference between the first and the 21th day of life, for nuclei area feature, demonstrate regression of cardiac hypertrophy in the offspring of diabetic rats.

A study on the safety evaluation of buphrenorphine administered through an autoinjector compared with manual injection using haematological and biochemical variables in rats

2016 ◽  
Vol 36 (9) ◽  
pp. 901-909 ◽  
Author(s):  
D Sheela ◽  
R Vijayaraghavan ◽  
S Senthilkumar
Keyword(s):  
Body Weight ◽  
Research Work ◽  
Safety Evaluation ◽  
Weight Ratio ◽  
The Body ◽  
Control Group ◽  
Body Weight Ratio ◽  
Significant Difference ◽  
Manual Group ◽  
Significant Change

Buprenorphine drug cartridge was made for autoinjector device for use in emergency and critical situations to reduce the morbidity and mortality. Water-filled cartridges were prepared and buprenorphine was injected aseptically in the cartridge, to make 0.05 and 0.10 mg/mL. Rats were injected intraperitoneally, buprenorphine (0.3 and 0.6 mg/kg), repeatedly with the autoinjector and compared with manual injection (7 days and 14 days) using various haematological and biochemical parameters. No significant change was observed in the body weight, organ to body weight ratio and haematological variables in any of the experimental groups compared with the control group. Except serum urea and aspartate aminotransferase, no significant change was observed in glucose, cholesterol, triglycerides, bilirubin, protein, albumin, creatinine, uric acid, alanine aminotransferase, gamma glutamyltransferase and alkaline phosphatase. The autoinjectors deliver the drugs with spray effect and force for faster absorption. In the present study, the autoinjector meant for intramuscular injection was injected intraperitoneally in rats, and the drug was delivered with force on the vital organs. No significant difference was observed in the autoinjector group compared to the manual group showing tolerability and safety of the buphrenorphine autoinjector. This study shows that buprenorphine autoinjector can be considered for further research work.

scholarly journals EFFECTS OF ANCESTRAL X IRRADIATION FOLLOWED BY RANDOM MATING ON BODY WEIGHT OF RATS

Genetics ◽  
1977 ◽  
Vol 86 (4) ◽  
pp. 849-860
Author(s):  
Daniel Gianola ◽  
A B Chapman ◽  
J J Rutledge
Keyword(s):  
Body Weight ◽  
Random Mating ◽  
Rapid Response ◽  
Response To Selection ◽  
Previous Evidence ◽  
Selection Responses ◽  
Inbred Rats ◽  
X Irradiation ◽  
Selection For ◽  
Variance Estimates

ABSTRACT Effects of nine generations of 450r per generation of ancestral spermatogonial X irradiation of inbred rats on body weight were examined. After six generations of random mating (avoiding inbreeding) following the termination of irradiation, descendants of irradiated males (R) were significantly lighter than their controls (C) at 3 and 6 weeks, but not at 10 weeks of age. However, differences in growth between R and C populations were small. Among-litter and within-litter variance estimates were generally larger in the R lines than in the C lines, suggesting that selection responses would be greater in R than in C lines. In conjunction with previous evidence—obtained during the irradiation phase of the experiment—this suggested that more rapid response to selection for 6-week body weight, in particular, might accrue in the R lines.

scholarly journals PSVIII-38 Late-Breaking Abstract: Estimating genetic parameters of feed efficiency traits in American mink

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 347-347
Author(s):  
Pourya Davoudi ◽  
Duy Ngoc Do ◽  
Guoyu Hu ◽  
Siavash Salek Ardestani ◽  
Younes Miar
Keyword(s):  
Body Weight ◽  
Genetic Correlation ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
American Mink ◽  
Genetic Correlations ◽  
Final Body Weight ◽  
Selection For

Abstract Feed cost is the major input cost in the mink industry and thus improvement of feed efficiency through selection for high feed efficient mink is necessary for the mink farmers. The objective of this study was to estimate the heritability, phenotypic and genetic correlations for different feed efficiency measures, including final body weight (FBW), daily feed intake (DFI), average daily gain (ADG), feed conversion ratio (FCR) and residual feed intake (RFI). For this purpose, 1,088 American mink from the Canadian Center for Fur Animal Research at Dalhousie Faculty of Agriculture were recorded for daily feed intake and body weight from August 1 to November 14 in 2018 and 2019. The univariate models were used to test the significance of sex, birth year and color as fixed effects, and dam as a random effect. Genetic parameters were estimated via bivariate models using ASReml-R version 4. Estimates of heritabilities (±SE) were 0.41±0.10, 0.37±0.11, 0.33±0.14, 0.24±0.09 and 0.22±0.09 for FBW, DFI, ADG, FCR and RFI, respectively. The genetic correlation (±SE) was moderate to high between FCR and RFI (0.68±0.15) and between FCR and ADG (-0.86±0.06). In addition, RFI had low non-significant (P &gt; 0.05) genetic correlations with ADG (0.04 ± 0.26) and BW (0.16 ± 0.24) but significant (P &lt; 0.05) high genetic correlation with DFI (0.74 ± 0.11) indicating that selection for lower RFI will reduce feed intake without adverse effects on the animal size and growth rate. The results suggested that RFI can be implemented in genetic/genomic selection programs to reduce feed intake in the mink production system.

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 A 90-Day Oral Toxicity of Hydroethanolic Root Extract of Carissa spinarum in Wistar Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Komlan M. Dossou-Yovo ◽  
Aboudoulatif Diallo ◽  
Povi Lawson-Evi ◽  
Yendubé T. Kantati ◽  
Tchin Darré ◽  
...  
Keyword(s):  
Body Weight ◽  
Biochemical Parameters ◽  
Wistar Rats ◽  
Hematological Parameters ◽  
Relative Weight ◽  
Control Group ◽  
Root Extract ◽  
Weight Changes ◽  
Oral Toxicity ◽  
Significant Difference

Background. Herbal medication is a worldwide and ancient practice, mostly in developing countries, where a large part of the population is involved in this practice. Hence, studies must be conducted to evaluate their safety and efficiency to avoid or prevent toxicological risks due to their usage. In Togo, Carissa spinarum is a medicinal plant belonging to Apocynaceae family, used as an aphrodisiac or to heal some ailments including malaria, sickle cell anemia, hypertension, pain, and asthma. Notwithstanding its several ethnomedicinal benefits, just a few toxicological data associated with its chronic use are available. Objective. Therefore, this study aims to assess the toxicity of an ethanolic root extract of Carissa spinarum in Wistar rats. Methods. The 90-day oral toxicity process following OECD TG 408 guidelines is used. Male Wistar rats received Carissa spinarum root hydroethanolic extract at 500 and 1000 mg/kg for 90 days by oral gavage. Body weight changes, hematological and blood biochemical parameters, organ weight changes, malondialdehyde as a lipoperoxidation marker expressed according to tissue proteins, and histopathology of vital organs were assessed. Results. No signs of toxicity or mortality were observed during the 90 days experiment. Hematological parameters have not shown any treatment-related abnormalities. According to biochemical parameters, an increase in the chloride ion level was observed at 1000 mg/kg p < 0.01 . There was no significant difference between the treated groups and the control group concerning the malondialdehyde concentration, body weight, and organ relative weight. No changes in necropsy and histopathology of vital organs associated with extract treatment were observed. Conclusion. The results indicated that an ethanolic root extract of Carissa spinarum does not cause adverse effects, which can lead to Wistar rats’ death after 90-day oral administration at 500 and 1000 mg.

RESPONSE TO SELECTION FOR BODY WEIGHT OR FEED EFFICIENCY IN MICE TESTED ON CORN, RYE AND WHEAT DIETS

1986 ◽  
Vol 66 (2) ◽  
pp. 389-397
Author(s):  
R. I. McKAY ◽  
R. J. PARKER ◽  
W. GUENTER
Keyword(s):  
Body Weight ◽  
Feed Efficiency ◽  
Mass Selection ◽  
Response To Selection ◽  
Initial Weight ◽  
Commercial Diet ◽  
Final Weight ◽  
Dc Line ◽  
Selection For ◽  
Seven Generations

Mass selection for adjusted feed efficiency (AFE, g gain/g feed) and adjusted body weight (ABW, g) of male mice was practiced for seven generations on each of three diets: corn, rye and wheat. The three experimental diets, fed between 21 and 35 d, were isocaloric (approximately 16.5 MJ GE kg−1) and isonitrogenous (CP approximately 13%). A common commerical diet (PC) was fed at all other times. With each diet two control lines, randomly mated, were tested on either the experimental diets (DC) or a commercial diet (PC). Selection was based upon linear adjustment to a common initial weight (10 g) for either final weight (ABW) or feed efficiency (AFE) measured between 21 and 35 d of age. Response was determined as a deviation from the appropriate DC line. All animals were placed in specially designed individual cages during the test period. Half-sib estimates of heritability in the PC line were 0.13(± 0.11) for ABW and 0.19(± 0.10) for AFE. Half-sib estimates pooled across lines and diets were 0.16(± 0.07) for ABW and 0.28(± 0.07) for AFE. Realized heritabilities for ABW were 0.24(± 0.06), 0.06(± 0.07) and 0.14(± 0.06) for the corn, rye and wheat diets, respectively. Response to selection for AFE was poor with the highest heritability obtained on the wheat diet (h2 = 0.13 ± 0.02). Key words: Selection, mice, body weight, feed efficiency, diets

Mass selection for 70-day body weight in rabbits.

1996 ◽  
Vol 74 (7) ◽  
pp. 1481 ◽  
Author(s):  
S D Lukefahr ◽  
H B Odi ◽  
J K Atakora
Keyword(s):  
Body Weight ◽  
Mass Selection ◽  
Selection For
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