The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Tim D Spector - One of the best experts on this subject based on the ideXlab platform.
-
genetic control of the circulating concentration of transforming growth factor type β1
Human Molecular Genetics, 1999Co-Authors: David J Grainger, Kirsten Heathcote, Mathias Chiano, Harold Snieder, Paul R Kemp, James C Metcalfe, N D Carter, Tim D SpectorAbstract:The concentration of transforming growth factor β (TGF-β) in plasma has been correlated with the development of several diseases, including atherosclerosis and certain forms of cancer. However, the mechanisms that control the concentration of TGF-β in plasma are poorly understood. In a study of 170 pairs of female twins (average age 57.7 years) we show that the concentration of active plus acid-activatable latent TGF-β1 [(a+l) TGF-β∴ is predominantly under genetic control (Heritability Estimate 0.54). Single strand conformation polymorphism (SSCP) mapping of the TGF-β1 gene promoter has identified two single base substitution polymorphisms. The two polymorphisms (GA at position ‐800 bp and CT at position ‐509 bp) are in linkage disequilibrium (correlation coefficient Δ = 0.215, P < 0.01). The C‐509T polymorphism is significantly associated with the plasma concentration of (a+l) TGF-β1, explaining 8.2% of the additive genetic variance of (a+l) TGF-β1 concentration. It is therefore possible that predisposition to atherosclerosis, bone diseases or various forms of cancer may be correlated with the presence of particular alleles at the TGFB1 locus.
-
genetic control of the circulating concentration of transforming growth factor type β1
Human Molecular Genetics, 1999Co-Authors: David J Grainger, Kirsten Heathcote, Mathias Chiano, Harold Snieder, Paul R Kemp, James C Metcalfe, N D Carter, Tim D SpectorAbstract:The concentration of transforming growth factor beta (TGF-beta) in plasma has been correlated with the development of several diseases, including atherosclerosis and certain forms of cancer. However, the mechanisms that control the concentration of TGF-beta in plasma are poorly understood. In a study of 170 pairs of female twins (average age 57.7 years) we show that the concentration of active plus acid-activatable latent TGF-beta1 [(a+l) TGF-beta therefore is predominantly under genetic control (Heritability Estimate 0.54). Single strand conformation polymorphism (SSCP) mapping of the TGF-beta1 gene promoter has identified two single base substitution polymorphisms. The two polymorphisms (G-->A at position -800 bp and C-->T at position -509 bp) are in linkage disequilibrium (correlation coefficient Delta = 0.215, P < 0.01). The C-509T polymorphism is significantly associated with the plasma concentration of (a+l) TGF-beta1, explaining 8.2% of the additive genetic variance of (a+l) TGF-beta1 concentration. It is therefore possible that predisposition to atherosclerosis, bone diseases or various forms of cancer may be correlated with the presence of particular alleles at the TGFB1 locus.
Erin E. Connor - One of the best experts on this subject based on the ideXlab platform.
-
Heterogeneity in genetic and nongenetic variation and energy sink relationships for residual feed intake across research stations and countries.
Journal of dairy science, 2015Co-Authors: Robert J. Tempelman, D.m. Spurlock, Mike Coffey, Roel F. Veerkamp, Louis E. Armentano, Kent A. Weigel, Y. De Haas, C.r. Staples, Erin E. ConnorAbstract:Our long-term objective is to develop breeding strategies for improving feed efficiency in dairy cattle. In this study, phenotypic data were pooled across multiple research stations to facilitate investigation of the genetic and nongenetic components of feed efficiency in Holstein cattle. Specifically, the Heritability of residual feed intake (RFI) was Estimated and heterogeneous relationships between RFI and traits relating to energy utilization were characterized across research stations. Milk, fat, protein, and lactose production converted to megacalories (milk energy; MilkE), dry matter intakes (DMI), and body weights (BW) were collected on 6,824 lactations from 4,893 Holstein cows from research stations in Scotland, the Netherlands, and the United States. Weekly DMI, recorded between 50 to 200 d in milk, was fitted as a linear function of MilkE, BW0.75, and change in BW (ΔBW), along with parity, a fifth-order polynomial on days in milk (DIM), and the interaction between this polynomial and parity in a first-stage model. The residuals from this analysis were considered to be a phenotypic measure of RFI. Estimated partial regression coefficients of DMI on MilkE and on BW0.75 ranged from 0.29 to 0.47 kg/Mcal for MilkE across research stations, whereas Estimated partial regression coefficients on BW0.75 ranged from 0.06 to 0.16 kg/kg0.75. Estimated partial regression coefficients on ΔBW ranged from 0.06 to 0.39 across stations. Heritabilities for country-specific RFI were based on fitting second-stage random regression models and ranged from 0.06 to 0.24 depending on DIM. The overall Heritability Estimate across all research stations and all DIM was 0.15±0.02, whereas an alternative analysis based on combining the first- and second-stage model as 1 model led to an overall Heritability Estimate of 0.18±0.02. Hence future genomic selection programs on feed efficiency appear to be promising; nevertheless, care should be taken to allow for potentially heterogeneous variance components and partial relationships between DMI and other energy sink traits across environments when determining RFI.
Lingfeng Kong - One of the best experts on this subject based on the ideXlab platform.
-
Heritability Estimate for mantle edge pigmentation and correlation with shell pigmentation in the white shell strain of pacific oyster crassostrea gigas
Aquaculture, 2018Co-Authors: De Xing, Lingfeng KongAbstract:Abstract The pacific oyster ( Crassostrea gigas ) is one of the most widely farmed aquatic animal species and of great economic importance. Mantle edge color in C . gigas is highly variable and considered as a new potential trait for a better commercial value. In this study, Heritability for mantle edge pigmentation and its correlation with shell pigmentation were explored in the white-shell strain of C . gigas with mixed-family method. A total of 460 offspring raised under communal conditions were successfully assigned to their parents using four multiplex PCR protocols based on 11 microsatellite loci. Mantle edge pigmentation was measured through assay of melanin content using spectrophotometric analysis. Animal model Heritability Estimate were 0.215 ± 0.092 for mantle edge pigmentation. The genetic and phenotypic correlations between two pigment traits were 0.980 ± 0.094 and 0.423 ± 0.042, respectively. Pearson analyses for average mantle edge and shell pigmentation of family also showed strong and significant correlation ( r = 0.729, P = 0.000, n = 29). Chi-square analyses showed that mantle edge pigmentation of family 7 segregated into “lighter” and “darker” groups in a 3:1 ratio ( P = 0.833), suggesting that a major locus might control mantle edge pigment trait. The results obtained in this study will benefit selective breeding of C . gigas with desired mantle and shell pigmentation.
-
selection response and realized Heritability for growth in three stocks of the pacific oyster crassostrea gigas
Fisheries Science, 2011Co-Authors: Qingzhi Wang, Shikai Liu, Lingfeng KongAbstract:To Estimate response to selection and realized Heritability for shell height, a one-generation selection was performed in the Pacific oyster Crassostrea gigas using three stocks from China (stock C), Japan (stock J), and Korea (stock K). Applying about the same intensity of selection in the upward direction, three selected and three control lines were created, which were reared under the same environmental conditions at larvae, spat, and grow-out stages. Stock C and stock J showed significantly higher response to selection and realized Heritability than stock K at spat and grow-out stages (P < 0.05). At harvest on day 360, the selected lines of stocks C, J, and K were 12.2, 12.2, and 7.9% larger than their control lines, respectively, for shell height. When averaged across the grow-out period, the genetic gain for stocks C, J, and K was 13.2 ± 1.2, 13.2 ± 1.0, and 7.2 ± 0.7%, respectively, and realized Heritability was 0.334 ± 0.028, 0.402 ± 0.024 and 0.149 ± 0.027, respectively. The relatively high realized Heritability Estimate obtained for stock C and stock J indicates that there is genetic variation in the two stocks and that selective breeding by mass selection is very promising.
Montira Thavornyutikarn - One of the best experts on this subject based on the ideXlab platform.
-
realized Heritability estimation on growth rate of oyster saccostrea cucullata born 1778
Aquaculture, 1995Co-Authors: Padermsak Jarayabhand, Montira ThavornyutikarnAbstract:Abstract A selective breeding programme for commercially important oyster species i.e. S. cucullata, Crassostrea belcheri , and C. lugubris , was initiated in October 1990 in Thailand. A base population of S. cucullata was produced in an oyster hatchery at Chulalongkorn University. They were reared at an oyster demonstration farm, Klong Prong, Angsila for almost 2 years. At 15 months the base population was separated into three groups (i.e. fast, medium and slow) based on their whole weights. They were used as broodstock to produce F 2 . In November 1993, most of the F 2 reached market size. Means (± S.D.) of the whole weight of offspring produced from each group are significantly different with the values of 28.4 ± 7.84 (n = 112), 23.8 ± 8.46 (n = 83), and 20.3 ± 7.94 (n = 91) g, for fast, medium, and slow groups, respectively. This suggests that growth rate in this oyster species is heritable. In addition, survival rate of the fast group was relatively higher than but not significantly different from the other two groups. The realized Heritability Estimate for growth rate from this experiment was 0.277 ± 0.006, which means that mass selection, to increase S. cucullata production is very promising.
Anna Hedman - One of the best experts on this subject based on the ideXlab platform.
-
A population-based Heritability Estimate of bipolar disorder - In a Swedish twin sample.
Psychiatry research, 2019Co-Authors: Viktoria Johansson, Ralf Kuja-halkola, Tyrone D. Cannon, Christina M. Hultman, Anna HedmanAbstract:Abstract Twin- and family studies have shown variations in the Heritability Estimates of bipolar disorder (BPD). The current study uses an updated statistical methodology for Heritability estimation in BPD by taking available time of follow-up into account while controlling for co-variates. We identified monozygotic and dizygotic same and different sex twins with BPD ( n = 804) or unaffected from BPD ( n = 91,604) from the Swedish Twin Register and the National Patient Register. We applied structural equational modeling with inversed probability weighting to Estimate the Heritability, taking into account censoring and truncation of data. Sex-limitation models were constructed to analyze qualitative or quantitative sex-differences in BPD. Heritability for BPD was 60.4% (95% Confidence Interval: 50.3–70.5) after age, sex, left-hand truncation and censoring of the data was taken into account. A larger proportion of females were affected from BPD (females 62.2%; males 37.8%, p