Mean Heritability Research Articles

Valuation of the Economic Benefits from Using Genetically Improved Forest Reproductive Materials in Afforestation

The research objective was to demonstrate the economic impact of using, in afforestation, forest reproductive materials (FRMs) obtained from seed trees selected in the most valuable Norway spruce populations of the FGRs’ (forest genetic resources’) category. The values obtained for the main growth traits (diameter at breast height (Dbh), tree height (Th), and tree volume (Tv)), both in the FGR and in the closest population (with the same age and growth in similar environmental conditions), were compared. Three comparative trials were analyzed, each belonging to different breeding levels: Open-pollinated (Breţcu, 40 years old), half-sib (Măneciu, 25 years), and full-sib (Comandău, 23 years). The difference in volume/hectare between the FGR and an unimproved neighbor population was economically quantified (€), based on the average price per cubic meter (m3) of spruce wood in Romania; the profit at the end of the rotation period (110 years) was projected taking into account the genetic gain that will result from the use of FRM collected from the FGRs. The average FGR growth results were superior to the unimproved neighbor populations, with 8%–13%, 14%–25%, and 26%–79% for Dbh, Th, and volume/ha, respectively, and the differences increased if the best 10% seed trees of the trials were used. For Th, a five times higher family mean heritability was registered for the pendula trees (compared to pyramidalis) in the half-sib trial, while in the full-sib experiment, the pendula trees (both full and half pendula) again registered higher heritability, but for Dbh, which recommends the pendula selection for different traits in the two trials. These results have led to a rate of profitability between 540 and 3366 €/ha, a value that is predicted to increase until the end of the rotation period, when the genetic gain could generate a profit of 7560 €/ha.

Testing Hungarian oak (Quercus frainetto Ten.) provenances in Romania

Abstract: In this study ten Hungarian oak provenances from Southern Romania were tested in two comparative trials 10 years after planting. The diameter at breast height (dbh) and tree height (Th) were measured in family progenies and the survival rate was determined. In both trials, the local provenances (Bals and Seaca 2) revealed superior fitness in terms of growth and adaptability traits, confirming the recommendation of using local provenances with priority in afforestation activities. Based on the measured traits, families which ranked in the first ten positions at age 3 and age 10 years were identified in both trials. The analysis of variance revealed statistically significant differences in growth traits between provenances and families in both comparative trials. Duncan’s test for 5% transgression probability revealed different results for dbh and Th in terms of provenance homogeneity in the two test sites, with a superior homogeneity in the Aramadia trial for dbh and in the Bals trial for Th. Growth performances of the Hungarian oak provenances were significantly influenced by the experimental location and by the interactions between provenance, family and locality, suggesting that maximum precaution must be taken in the choice of forest reproductive materials to be planted in different environmental conditions. The family mean heritability (h2f) was significantly lower than the individual heritability (h2i), suggesting the possible adoption of an individual selection strategy in the next stage of the current breeding programme. The juvenile-adult correlations will be made at the age of 40 years and will take advantage of the results of this study to shorten the testing period for the selection of genetically improved material in Hungarian oak.

Patterns of heritability across the human diphyodont dental complex: Crown morphology of Australian twins and families.

This study generates a series of narrow-sense heritability estimates for crown morphology of the deciduous and permanent dentition with two overarching aims. The first is to test the hypothesis that deciduous teeth provide a more faithful reflection of genetic information than their permanent successors. The second is to use quantitative genetic methods to evaluate assumptions underlying common data collection and analysis practices in biodistance research. Dental morphology data were collected from longitudinal dental casts representing Australian twins and families using Arizona State Dental Anthropology System standards. Polygenic models and estimates of narrow-sense heritability were generated using SOLAR v.8.1.1. Each model considered age, sex, and age/sex interaction as covariates. Heritability estimates significantly differed from zero for the majority of morphological crown characters. Most estimates fell within the 0.4-0.8 range typically observed for crown morphology. Mean heritability was stable across the dental complex, but for paired homologues, permanent traits often yielded higher estimates than their deciduous counterparts. Results indicate directional asymmetry in environmental influence for crown morphology and inform biodistance "best practices" related to data collection and treatment. Overall, results for this sample support the use of crown morphology as a proxy for genetic variation in evolutionary research. This includes the deciduous dentition, which justifies the expansion of efforts to incorporate subadults into reconstructions of past microevolutionary processes. Results do not indicate that deciduous phenotypes more closely approximate underlying genotype, at least for deciduous/permanent homologues.

Genetic evaluation of heat tolerance in Holstein cows in Japan.

We used test‐day records and daily records from provincial weather stations in Japan to evaluate heat tolerance (HT) in Holstein cows according to a random regression test‐day model. Data were a total of 1,641,952 test‐day records for heritability estimates and 17,245,694 test‐day records for genetic evaluation of HT by using milk yield and somatic cell score (SCS) in Holstein cows that had calved for the first time in 2000 through 2015. Temperature–humidity index (THI) values were estimated by using average daily temperature and average daily relative humidity records from 60 provincial Japanese weather stations. The model contained herd–test‐day, with lactation curves on days in milk within month–age group as a fixed effect. General additive genetic effect and HT of additive genetic effect were included as random effects. The threshold value of THI was set to 60. For milk yield, estimated mean heritabilities were lower during heat stress (THI = 78; 0.20 and 0.28) than when below the heat stress threshold (THI ≤ 60; 0.26 and 0.31). For SCS, heritability estimates (range 0.08–0.10) were similar under all heat stress conditions. Genetic trends of HT indicated that EBVs of HT are changing in an undesirable direction.

PSVIII-29 Analysis of genotype by environment interaction across time for Nile tilapia reared in different production systems

Abstract Nile tilapia is the second most important freshwater fish for human consumption worldwide and it is produced under many different conditions. Even though genotype by environment interaction (GEI) can arise due to many factors, most studies with tilapia have focused on water quality on pond and cage systems. Therefore, the objective of the current work was to evaluate GEI on body weight (BW) of Nile tilapia raised in biofloc technology (BFT), Cage, and recirculation aquaculture systems (RAS) from 100 to 350 days of age. A Bayesian multi-trait random regression model (MTRRM) with age as random regression covariable was employed to evaluate the temporal trend of GEI. Estimated genetic correlations between BFT and RAS were above 0.7 for almost any combination of ages evaluated (Figure 1). However, genetic correlations between Cage at ages below 150 days with either BFT or RAS at any other age were positive but below 0.5. The posterior means of heritability for BW were found to reach peaks of 0.40, 0.38 and 0.29 around 230 days for RAS, BFT, and Cage respectively (Figure 2). Conversely, the ratio between common family environment and phenotypic variances presented an overall decreasing trend with minimums around 0.22, 0.15 and 0.10 at 230 days for Cage, RAS, and BFT, respectively. The MTRRM has shown to be a powerful statistical tool to assess changes across time for genetic parameters of interest. In conclusion, GEI was found to be dynamic across time, with stronger effects between Cage and both BFT and RAS if selection is promoted prior to 150 days. However, GEI is negligible for most of the situations considered if selection is performed after 200 days of age in either BTF or RAS, with the possibility of achieving better indirect selection results if selection is performed around 230 days.

Pedigree analysis of atrial fibrillation in Irish wolfhounds supports a high heritability with a dominant mode of inheritance

BackgroundAtrial fibrillation (AF) is the most common arrhythmia in dogs. The Irish Wolfhound breed has a high prevalence of AF making them an ideal breed to investigate possible genetic contributions to this disease. The aim of this study was to perform a heritability analysis in North American Irish Wolfhounds using phenotype data from cardiac screenings performed between 2000 and 2019 in order to determine how much of this disease can be attributed to genetics compared to environmental causes. The second aim was to determine the disease mode of inheritance to help inform prevention and breeding practices.ResultsThere were 327 Irish Wolfhounds diagnosed with AF and 136 Irish Wolfhounds over 8 years of age without AF. The estimated mean (95% confidence interval) heritability of AF in Irish Wolfhounds was 0.69 (0.50–0.86). The pedigree was consistent with a dominant mode of inheritance.ConclusionResults of this study indicate a strong genetic contribution to AF in Irish Wolfhounds and suggest that future research to identify causative genetic mutations is warranted.

Large-scale GWAS reveals genetic architecture of brain white matter microstructure and genetic overlap with cognitive and mental health traits (n = 17,706)

Individual variations of white matter (WM) tracts are known to be associated with various cognitive and neuropsychiatric traits. Diffusion tensor imaging (DTI) and genome-wide single-nucleotide polymorphism (SNP) data from 17,706 UK Biobank participants offer the opportunity to identify novel genetic variants of WM tracts and explore the genetic overlap with other brain-related complex traits. We analyzed the genetic architecture of 110 tract-based DTI parameters, carried out genome-wide association studies (GWAS), and performed post-GWAS analyses, including association lookups, gene-based association analysis, functional gene mapping, and genetic correlation estimation. We found that DTI parameters are substantially heritable for all WM tracts (mean heritability 48.7%). We observed a highly polygenic architecture of genetic influence across the genome (p-value=1.67*10−05) as well as the enrichment of genetic effects for active SNPs annotated by central nervous system cells (p-value=8.95*10−12). GWAS identified 213 independent significant SNPs associated with 90 DTI parameters (696 SNP-level and 205 locus-level associations; p-value<4.5*10−10, adjusted for testing multiple phenotypes). Gene-based association study prioritized 112 significant genes, most of which are novel. More importantly, association lookups found that many of the novel SNPs and genes of DTI parameters have previously been implicated with cognitive and mental health traits. In conclusion, the present study identifies many new genetic variants at SNP, locus and gene levels for integrity of brain WM tracts and provides the overview of pleiotropy with cognitive and mental health traits.

Genetic parameters for litter traits at different parities in purebred Landrace and Yorkshire pigs.

Comparison of the multi-trait animal model and the traditional repeatability model was carried out using data obtained from 6,424 Landrace and 20,835 Yorkshire sows farrowed from January 2000 to April 2018 in order to estimate genetic parameters for litter traits at different parities. Specifically, records of the total number born (TNB), number born alive (NBA), total number of mortality (MORT), number of stillborn (NSB) and number of mummified pigs (MUM) were used. Although results showed the heterogeneity of heritability for litter traits at different parities, the mean heritability estimates from the multi-trait model were found to be higher than those of the repeatability model for all traits in both pig breeds. In terms of genetic correlation between parities, a slight difference in genetic control in the first parity was noted for TNB and NBA in Landrace and Yorkshire pigs. The correlation between the first parity and later parities ranged from 0.48 to 0.74 for TNB and NBA in both breeds. Moreover, genetic correlation between parities for MORT and NSB was observed to be high for parities higher than 2 in Yorkshire pigs. For MUM, genetic correlation between the first and other parities was generally low in both breeds, indicating that culling pigs on the basis of MUM at the first parity could probably be unreasonable. Overall, the results of this study suggest that the multi-trait approach for litter size traits is useful for the accurate estimation of genetic parameters.

Growth and survival of Siberian larch in Alberta at the species, population, and family levels

Survival and growth of Siberian larch (SL, Larix sibirica Ledeb.) were compared with those of three conifer species native to Alberta, Canada: lodgepole pine (LP; Pinus contorta var. latifolia Engelm. ex S. Watson), white spruce (WS, Picea glauca (Moench) Voss), and jack pine (JP, Pinus banksiana Lamb.) at 12, 10, and 3 trial locations, respectively. The average data age was 18 years (range: 3 to 27 years). Survival of SL averaged 4.2% and 6.5% worse than LP and WS, respectively, while it was 5% better than JP. SL grew 25%, 94%, and 23% taller than LP, WS, and JP, respectively. Stem forking rates were similar between SL and LP, WS, and JP. The best seed sources for Alberta were mature trees established in Alberta and Saskatchewan of unknown initial provenances. The Russian Altai Mountain source grew well at high elevations, while the Finnish Raivola performed well in the northern, low-elevation area. Open-pollinated progeny tests of 58 families planted in five diverse locations yielded individual-tree narrow-sense heritabilities and family mean heritabilities for height at age 15 of 0.15 and 0.59, respectively. The type B between-site genetic correlation was 0.44, indicating a strong genotype × environment interaction. SL has performed well in Alberta, and its growth can be further improved by selection and breeding from appropriate seed sources.

66 A genome-wide association study for gestation length in swine

Abstract The objective of the current study was to conduct a genome-wide association on gestation length (GL) in different parities in swine. Sows (n = 831) belonging to the University of Nebraska – Lincoln resource population (Landrace X Nebraska Index Line) were utilized. GL was defined as the number of days between the final insemination and farrowing. Four traits, GL at parity 1, 2, 3 and 4 (GL1, GL2, GL3 and GL4, respectively) were investigated. Animals which were induced 24h prior to a farrowing event were removed from the analysis. Sows were genotyped with the Illumina SNP60 BeadArray. A Bayes C model with π=0.995 was implemented with fixed effects of contemporary group, development pen, diet, linear and quadratic terms for age at puberty (GL1; P &lt; 0.01), and linear and quadratic terms for farrowing age (GL2; P &lt; 0.01). Results are posterior means of 55,000 samples.Single marker association analysis (SMA) was performed in R utilizing a linear model on SNP from 1-Mb windows (n = 10) which explained the largest proportion of genetic variation in GL1. Top 10 (0.5% of all windows) 1-Mb windows accounted for a limited proportion of genetic variance, 7.75, 4.66, 3.45 and 2.05% in GL1, GL2, GL3 and GL4, respectively. Posterior mean heritability estimates (posterior SD) for GL1, GL2, GL3 and GL4 were 0.33 (0.06), 0.34 (0.07), 0.32 (0.08) and 0.20 (0.08), respectively. The top SNP (ASGA0017859, SSC4, 7.8 Mb) located in one of the two top common genomic regions associated with GL1, GL2 and GL3 displayed a difference of 1.1d in GL1 between alternate homozygotes (P &lt; 0.01). The top SNP from nine of the ten regions were significant (P &lt; 0.05) in the SMA. Two of these regions were in common with GL2 and GL3 where SNP with potential functional effects were found in ZFAT, MAML2 and CCDC82. Results suggest GL is a largely polygenic trait.

Genotypic variation in the basic density, dynamic modulus of elasticity and tracheid traits of Pinus elliottii in three progeny trials in southern China

Abstract A firm understanding of the genetic relationships among wood properties is a prerequisite for breeding for higher wood quality in Pinus elliottii families. To examine and deal with such relationships, increment cores were sampled at breast height from 1260 trees in 42 open-pollinated families in three 27-year-old Slash pine progeny trials in southern China, and genetic variation, genotype-by-environment (G × E) interaction, genetic correlation and correlated response were investigated. The basic density (BD), dynamic modulus of elasticity (MOED) and tracheid traits were found to be under moderate to strong genetic control for the three locations combined, with individual narrow-sense and family mean heritability ranging from 0.28 to 0.44 and 0.52 to 0.69, respectively. Type B genetic correlation estimates indicated that the G × E interaction had a small-level influence on wood properties. Strong genetic correlations (rg) were found between BD and MOED at the three sites (rg = 0.46–0.85), and BD or MOED showed moderate to strong correlations with most tracheid traits at specific localities. In tree breeding programs, one possible strategy would be to improve pulpwood quality and the strength of structural wood through selection for different wood quality traits.

A genome-wide association study for gestation length in swine.

Selection for increased litter size in swine has potentially resulted in a correlated increase in preweaning mortality. Additional selection criteria should be considered when selecting for increased litter size to account for associated decreases in piglet quality, specifically piglet survival, initial weight and growth. Traits such as gestation length (GL), which have been associated with piglet performance, could be utilized to improve piglet development and survivability. The objective of this study was to conduct a genome-wide association study to identify genomic regions associated with GL in differing parities in swine (n=831) from the University of Nebraska-Lincoln reproductive longevity project. Gestation length was calculated as the number of days between last insemination administered and farrowing. Sows were genotyped with the Illumina SNP60 BeadArray, and the data were analyzed using Bayesian mixture models for GL at parity 1, 2, 3 and 4 (GL1, GL2, GL3 and GL4 respectively). Means (SD) forGL1-GL4 were 113 (1.4), 114 (1.2), 114 (1.3) and 115 (1.2) respectively. Posterior mean heritability estimates (PSD) for GL1, GL2, GL3 and GL4 were 0.33 (0.06), 0.34 (0.07), 0.32 (0.08) and 0.20 (0.08) respectively. Rank correlations between genomic estimated breeding values between GL1 and GL2, GL3 and GL4 respectively were moderate: 0.67, 0.65 and 0.60. The top SNP (ASGA0017859, SSC4, 7.8Mb), located in the top common genomic region associated with GL1, GL2 and GL3, was associated with a difference of 1.1days in GL1 between homozygote genotypes (P<0.0001). The results of this study suggest that GL is a largely polygenic trait with relatively minor contributions from multiple genomic regions.

Estimation of genetic, heritability, and phenotypic trends for weight and wool traits in Rambouillet sheep

Genetic and phenotypic trends give an indication of the progress of a breed over the years and help in understanding the effectiveness of selection. Therefore, a study was planned to estimate genetic, heritability and phenotypic trends for Rambouillet breed of sheep. Trends were estimated for birth weight, weaning weight, fibre diameter, greasy fleece weight at clip one and staple length on data collected from 1998 to 2008. Two yearly mean phenotypic values, heritability values, and mean breeding values for birth weight, weaning weight, fibre diameter, greasy fleece weight at clip one and staple length were estimated. These trends were determined as a linear regression coefficient of mean breeding values using BLUP (best linear unbiased prediction) for the animal’s year of birth and a trend line was generated separately for each trait. Trends for phenotypic values were positive for birth weight, staple length and greasy fleece weight whereas for weaning weight and fibre diameter, the trends were negative. The slopes for birth weight and weaning were found to be 0.040 ± 0.0525 and −0.07 ± 0.241 respectively. Slopes for fibre diameter, staple length and greasy fleece weight for first clip were -0.011 ± 0.01, 0.146 ± 0.041 and 0.052 ± 0.029 respectively. The slopes all traits were found to be insignificant except staple length. For heritability, the slopes of birth weight, weaning, fibre diameter, staple length and greasy fleece weight for first clip were 0.0005 ± 0.0048, 0.009 ± 0.0048 0.0058 ± 0.011, 0.0041 ± 0.003, and 0.0061 ± 0.0039 respectively. Trends obtained for breeding values were positive for birthweight, staple length and greasy fleece weight for first clip and negative for weaning weight and fibre diameter. All traits had an insignificant slope for breeding values. The slopes for breeding values for birth weight and weaning were 0.001 ± 0.0004 and −0.0025 ± 0.001 respectively. Slopes for fibre diameter, staple length and greasy fleece weight for first clip were −0.0002 ± 0.0002, 0.0002 ± 0.0001, 0.0001 ± 0.0002 respectively. It is concluded that an optimal selection strategy that considers both genetic merits and coancestry of mates (in order to avoid close breeding and inbreeding depression) should be adopted to sustain the sheep breeding programs in the State.

Assessment of energy production in full-sibling families of elephant grass by mixed models

The search for alternative energy sources has grown recently. Surely, elephant grass (Pennisetum purpureum Schum.) is a tropical grass of increased efficiency in the use of light and presents a high production of biomass, being cost-effective for direct combustion and charcoal obtainment. This study aimed to select the best families and individuals in full-sibling families of elephant grass by estimation of genetic parameters and prediction of genetic values by methods of restricted maximum likelihood (REML) and best linear unbiased prediction (BLUP), respectively, as an alternative of energy easy for Brazil. One hundred twenty progenies of full-siblings from bi-parental crossings were assessed in two harvests and one environment. The experimental design was a randomized block design with five-plant per plots and three replications. The assessed traits were dry matter production, tiller number, plant height, stem diameter, and neutral detergent fiber. For all traits, accuracy showed values above 90% and heritability of family means between 0.81 and 0.92%. Families 3, 1, and 2 were the best ranked, being the most indicated for selection. The REML/BLUP method proved to be suitable for selecting individuals of elephant grass for energetic purposes.

Genetic parameter estimates and GxE interaction in a large cloned population of Pinus taeda L.

Cloned progeny tests in forest tree breeding provide the ability to assess the same genotypes across multiple environments and partition observed phenotypic variance into additive and non-additive genetic effects. In this study, 2362 clones from 53 crosses of loblolly pine (Pinus taeda L.) were tested across eight locations in the Southern US. Alpha cyclic incomplete row-column design was used to accommodate a large number of clones in a replication. Tree stem volume (cubic decimeter) was assessed at age 6 using various variance-covariance structures of mixed models. Models with factor analytic additive genetic structures and spatially correlated residuals or polynomial fixed row and column effects efficiently captured heterogeneity in the data. The narrow-sense clone mean heritability estimate for stem volume was 0.41 for the simple compound symmetry additive genetic structure. The estimates were higher for more complex models, ranging from 0.56 to 0.61. Non-additive genetic variance for stem volume was about a fraction of the additive genetic variance, suggesting that the trait is mainly controlled by large number of genes each with small effect. The results suggested that for forest trees genetic field tests with large number of genetic entries, breeders should consider incomplete row-column designs to model micro-site heterogeneity in two directions. These designs allow spatial modeling using row and column information, which can efficiently account for heterogeneity in the environment, resulting in higher heritability estimates and more reliable ranking of varieties for selection.

Time class for racing performance of the Quarter Horse: Genetic parameters and trends using Bayesian and multivariate threshold models

The aim of this study was to evaluate racing performance in the Quarter Horse breed in Brazil using genetic parameter estimates, breeding values, and genetic trends for a differentiated trait, time class (TC), at four different distances. The speed records comprising races that occurred between 1981 and 2011 were obtained from hippodromes in the states of São Paulo, Ceará, Brasília, and Mato Grosso do Sul. The final archive analysed contained 4263 horses born to 431 stallions and 1716 dams. These animals participated in 3904 races, providing 17,342 records of final racing time. The four TC traits were defined by 5 scores based on the final times (in seconds) of each animal in each race. The scores for formation of the classes were attributed within each race based on the percent difference from winner's time. Time class was evaluated at distances of 301, 320, 365 and 402 m, generating four phenotypic measures: TC301, TC320, TC365 and TC402, respectively. The genetic parameters were estimated by Bayesian inference in multivariate analysis using a threshold animal model. The model included the fixed effects of race, sex and age class of animal in the race, in addition to additive genetic, animal permanent environmental and residual random effects. The mean heritability estimates were of high magnitude and ranged from 0.45 ± 0.06 (TC402) to 0.56 ± 0.04 (TC365). Repeatability estimates ranged from 0.78 ± 0.06 (TC402) to 0.97 ± 0.01 (TC320). The additive genetic and animal permanent environmental correlations were positive, with mean correlations ranging from 0.33 ± 0.06 between TC301 and TC320 to 0.62 ± 0.06 between TC365 and TC402 and from 0.44 ± 0.08 between TC301 and TC320 to 0.58 ± 0.06 between TC365 and TC402, respectively. The mean breeding values transformed by the cumulative distribution function of the standard normal distribution ranged from 54.6 ± 25.3 (TC365) to 57.8 ± 28.5 (TC320) in the group of animals included in the pedigree and born after 1980. The genetic trends observed indicated that TC301 (301 m) exhibited the greatest evolution between 1981 and 2008. The results suggest the possible use of TC traits as selection criteria since they respond positively to selection, permitting genetic gains in breeding programs of racehorses.

Mean performance and heritability studies of some ridge gourd (Luffa acutangula L.) genotypes

In the present investigation, 29 genotypes of ridge gourd were grown during 2016-2017 at the experimental field of Regional Horticulture Research Station, Patuakhali, Bangladesh. The experiment was laid out in randomized complete block design with three replications. The mean sum of squares is due to various sources of variance for different characters of ridge gourd genotypes. The results indicated highly significant variation among the genotypes for the 11 characters studied viz., such as fruit length, fruit diameter, single fruit weight, number of fruits per plant, yield of fruit per plant. The genotype BD2975 showed the highest performance in fruit length (42.05cm) and weight of fruits (258.90g). While the genotype PK3 showed the highest performance in number of fruits per plant (28.67), respectively. Of eleven traits, eight showed high heritability (over 80%). The highest genotypic and phenotypic coefficients were recorded in the parameter fruit yield per plant (39.59% and 40.96%).&#x0D; Res. Agric., Livest. Fish.6(1): 45-55, April 2019

Potential exists to change, through breeding, the yield of individual primal carcass cuts in cattle without increasing overall carcass weight1.

The ability to alter the morphology of cattle towards greater yields of higher value primal cuts has the potential to increase the value of animals at slaughter. Using weight records of 14 primal cuts from 31,827 cattle, the objective of the present study was to quantify the extent of genetic variability in these primal cuts; also of interest was the degree of genetic variability in the primal cuts adjusted to a common carcass weight. Variance components were estimated for each primal cut using animal linear mixed models. The coefficient of genetic variation in the different primal cuts ranged from 0.05 (bavette) to 0.10 (eye of round) with a mean coefficient of genetic variation of 0.07. When phenotypically adjusted to a common carcass weight, the coefficient of genetic variation of the primal cuts was lesser ranging from 0.02 to 0.07 with a mean of 0.04. The heritability of the 14 primal cuts ranged from 0.14 (bavette) to 0.75 (topside) with a mean heritability across all cuts of 0.48; the heritability estimates reduced, and ranged from 0.12 (bavette) to 0.56 (topside), when differences in carcass weight were accounted for in the statistical model. Genetic correlations between each primal cut and carcass weight were all ≥0.77; genetic correlations between each primal cut and carcass conformation score were, on average, 0.59 but when adjusted to a common carcass weight, the correlations weakened to, on average, 0.27. The genetic correlations among all 14 primal cut weights was, on average, strong (mean correlation of 0.72 with all correlations being ≥0.37); when adjusted to a common carcass weight, the mean of the genetic correlations among all primal cuts was 0.10. The ability of estimated breeding values for a selection of primal cuts to stratify animals phenotypically on the respective cut weight was demonstrated; the weight of the rump, striploin, and fillet of animals estimated to be in the top 25% genetically for the respective cut, were 10 to 24%, 12 to 24%, and 7 to 17% heavier than the weight of cuts from animals predicted to be in the worst 25% genetically for that cut. Significant exploitable genetic variability in primal carcass cuts was clearly evident even when adjusted to a common carcass weight. The high heritability of many of the primal cuts infers that large datasets are not actually required to achieve high accuracy of selection once the structure of the data and the number of progeny per sire is adequate.

Born for fairness: evidence of genetic contribution to a neural basis of fairness intuition.

Human beings often curb self-interest to develop and enforce social norms, such as fairness, as exemplified in the ultimatum game (UG). Inspired by the dual-system account for the responder’s choice during the UG, we investigated whether the neural basis of psychological process induced by fairness is under genetic control using a twin fMRI study (62 monozygotic, 48 dizygotic; mean age: 19.32 ± 1.38 years). We found a moderate genetic contribution to the rejection rate of unfair proposals (24%–35%), independent of stake size or proposer type, during the UG. Using a voxel-level analysis, we found that genetic factors moderately contributed to unfairness-evoked activation in the bilateral anterior insula (AI), regions representing the intuition of fairness norm violations (mean heritability: left 37%, right 40%). No genetic contributions were found in regions related to deliberate, controlled processes in the UG. This study provides the first evidence that evoked brain activity by unfairness in the bilateral AI is influenced by genes and sheds light on the genetic basis of brain processes underlying costly punishment.

Genetic variation in resistance to Uromycladium acaciae fungus, growth, gummosis, and stem form in Acacia mearnsii populations

A new epidemic disease caused by the rust fungus Uromycladium acaciae emerged in 2013/2014 causing defoliation, branch, and stem deformations in plantations of Acacia mearnsii (black wattle) in South Africa. This study investigated the level of genetic resistance to the rust fungus Uromycladium acaciae in six progeny tests from two different trial series. A total of 269 open pollinated families of different levels of improvement, ranging from wild selections to fourth cycle generations were included in the study. Families originated from land race subpopulations of South Africa and from Australian provenances. Rust severity was assessed across all the trials at 6 months of age. In the rust screening trials, different measures of rust incidence were assessed at 6, 12, and 17 months, as well as tree height and mirid damage at 12 months. In the progeny trial series, tree height, stem defects, and gummosis were measured at 36 months. Results suggested that rust incidence is under moderate genetic control at the family level. The coefficient of additive genetic variation was large (59.4%) for the disease incidence. The family mean heritability for rust disease was $$ {h}_{fm}^2=0.48\pm 0.16 $$ in the progeny trial series, whereas it was $$ {h}_{fm}^2=0.33\pm 0.06 $$ in the rust screening trials. Among the rust assessment methods, 6-month rust incidence (yes/no) assessment produced higher heritability estimates. With some exceptions, Australian provenances from low altitude sites along the eastern coast of Victoria and the south east coast of New South Wales showed high tolerance to rust, better growth, low gummosis incidence but poor stem form. All the South African sources showed high rust susceptibility and had average or below average growth, gummosis incidence, and stem form. For rust disease improvement, the South African material should be avoided and the best existing Australian families should be used for further breeding. In addition, new seed sources from Australia should be infused to the breeding program in order to increase the genetic diversity while increasing genetic gain for the rust, gummosis, and growth.