Heritability Estimates Research Articles

Genetic Variation in Yield and Fruit Weight Among Strawberry (Fragaria ×ananassa) Cultivars and the Interaction With Year and Location Effect

ABSTRACTStrawberry (Fragaria ×ananassa) is an important crop in the United States. In this study, we analysed strawberry trials established across 7 years and two locations. Our objective was to estimate genetic parameters and predict breeding values for yield. Linear mixed models were used for unbalanced data across years and locations and study the genotype by year and location interactions. The results suggested significant differences between cultivars for fruit weight but not for total and marketable yield. Fruit weight was controlled by genetic factors, shown by the high heritability of cultivar means (0.93), whereas marketable yield and total yield showed lower heritability estimates (0.48 and 0.63, respectively), indicating a substantial environmental influence. For fruit weight, cultivars exhibited stability across years and locations, supported by the high additive genetic correlations observed for cultivar‐by‐year (r = 0.90) and cultivar‐by‐location interactions (r = 0.98). Fruit weight and total yield were genetically independent as suggested near zero additive genetic correlation (−0.06 ± 0.416) between two traits, and they should be considered for an index selection in the strawberry breeding strategy.

Estimates of microbiome heritability across hosts.

Microbiomes contribute to variation in many plant and animal traits, suggesting that microbiome-mediated traits could evolve through selection on the host. However, for such evolution to occur, microbiomes must exhibit sufficient heritability to contribute to host adaptation. Previous work has attempted to estimate the heritability of a variety of microbiome attributes. Here we show that most published estimates are limited to vertebrate and plant hosts, but significant heritability of microbiome attributes has been frequently reported. This indicates that microbiomes could evolve in response to host-level selection, but studies across a wider range of hosts are necessary before general conclusions can be made. We suggest future studies focus on standardizing heritability measurements for the purpose of meta-analyses and investigate the role of the environment in contributing to heritable microbiome variation. This could have important implications for the use of microbiomes in conservation, agriculture and medicine.

Pangenome Reveals Gene Content Variations and Structural Variants Contributing to Pig Characteristics.

Pigs are among the most essential sources of high-quality protein in human diets. Structural variants (SVs) are a major source of genetic variants associated with diverse traits and evolutionary events. However, the current linear reference genome of pigs limits the presentation of position information for SVs. In this study, we generated a pangenome of pigs and a genome variation map of 599 deep-sequenced genomes across Eurasia. Moreover, a section-wide gene repertoire was constructed, which indicated that core genes were more evolutionarily conserved than variable genes. Subsequently, we identified 546,137 SVs, their enrichment regions, and relationships with genomic features and found significant divergence across Eurasian pigs. More importantly, the pangenome-detected SVs could complement heritability estimates and genome-wide association studies based only on single nucleotide polymorphisms. Among the SVs shaped by selection, we identified an insertion in the promoter region of the TBX19 gene, which may be related to the development, growth, and timidity traits of Asian pigs and may affect the gene expression. Our constructed pig pangenome and the identified SVs provide rich resources for future functional genomic research on pigs.

Genetic Characterisation of Feeding Patterns in Lactating Holstein Cows and Their Association With Feed Efficiency Traits.

Feeding behaviour traits, such as number, duration or intake per feeder visit, have been associated with feed efficiency in dairy cattle. Those traits, however, do not fully capture cows' feeding patterns throughout the day. The goal of this study was to propose a new phenotype for characterising within-day feeding patterns and estimate its heritability and genetic correlations with dry matter intake (DMI), secreted milk energy, metabolic body weight and residual feed intake. Feeding patterns were evaluated using 4.8 million bunk visits from 1684 midlactation Holstein cows collected from 2009 to 2023 with an Insentec system. Feed efficiency traits were available from 6099 lactating Holstein cows at six research stations across the United States. Daily bunk visits were ordered, with Time 0 designated as the time of first feed delivery. Intake proportions were calculated by visit for each cow by dividing feed intake per visit by the total intake of the cow for that day. Feeding patterns were characterised by the area under the curve of cumulative feed intake proportions for each cow throughout the day. The feeding pattern phenotype per cow was defined as the average of areas under the curve across days, whereas consistency of feeding pattern was calculated as the natural logarithm of variance of daily area under the curve values. Estimates of heritability and genetic correlations were performed using Bayesian inference with an animal model, considering lactation, days in milk and cohort (trial-treatment) as fixed effects and animal as a random effect. Heritability estimates for average area under the curve and variance of daily area under the curve were 0.35 ± 0.05 and 0.16 ± 0.05, respectively. The genetic correlation between average area under the curve and secreted milk energy was -0.30 ± 0.14. Genetic correlations between average area under the curve and DMI, metabolic body weight and residual feed intake were not statistically significant. Variance of daily area under the curve was genetically correlated with DMI (0.47 ± 0.15), secreted milk energy (0.40 ± 0.17) and metabolic body weight (0.28 ± 0.13). The genetic correlation between variance of daily area under the curve and residual feed intake was not significant. Overall, we provided a reliable method to truly characterise feeding patterns in midlactation dairy cows. Feeding pattern and its consistency were heritable, indicating that a significant proportion of phenotypic variation is explained by additive genetic effects. Genetic correlation estimates indicate that cows with more consistent daily feeding patterns have lower DMI, lower secreted milk energy and lower metabolic body weight.

Genomic evaluation of residual feed intake in US Holstein cows: insights into lifetime feed efficiency

Residual feed intake (RFI) is an important trait of feed efficiency that has been increasingly considered in the breeding objectives for dairy cattle. The objectives of this study were to estimate the genetic parameters of RFI and its component traits, namely, dry-matter intake (DMI), body weight (BW), and energy-corrected milk (ECM), in lactating Holstein cows; we thus developed a system for genomic evaluation of RFI in lactating Holstein cows and explored the associations of the RFI of heifers and cows. The RFI values were calculated from 2,538 first (n = 2,118) and second (n = 420) lactation Holsteins cows between 2020 and 2024 as part of the STgenetics EcoFeed® program. Of the animals, 1,516 were heifers from the same research station with previously established RFI values . After quality control, 61,283 single-nucleotide polymorphisms were used for the analyses. Univariate analyses were performed to estimate the heritabilities of RFI and its components in lactating cows; bivariate analyses were then performed to estimate the genetic correlations between the RFI of heifers and lactating cows using the genomic best unbiased linear prediction method. Animals with phenotypes and genotypes were used as the training population, and animals with only genotypes were considered the prediction population. The reliability of breeding values was obtained by approximation based on partitioning a function of the accuracy of the training population’s genomic estimated breeding values (GEBVs) and magnitudes of genomic relationships between the individuals in the training and prediction populations. The heritability estimates (mean ± SE) of the RFI, DMI, ECM, and BW were 0.43 ± 0.07, 0.44 ± 0.04, 0.40 ± 0.05, and 0.46 ± 0.04, respectively. The average reliability of the GEBVs for RFI from the training and prediction populations were 44% and 30%, respectively. The genetic correlations for the RFI were 0.42 ± 0.08 between heifers and first lactation cows and 0.34 ± 0.06 between heifers and first and second lactation cows. Our results show that the genetic components of RFI are not fully carried over from heifers to cows and that there is re-ranking of the individuals at different life stages. Selection of animals for feed efficiency on a lifetime basis thus requires accounting for the efficiencies during animal growth and milk production as a lactating cow.

Assessment of genetic biodiversity and association of micronutrients and agronomic traits using microsatellites and staining methods which accelerates high-micronutrients variety selections within different wheat groups

Evaluation of genetic biodiversity for micronutrients is crucial for breeding high-quality crops and addressing the negative impacts of mineral deficiencies. The objectives of this research were to assess genetic variation and the relationship between grain Fe and Zn levels and agronomic traits in a diverse collection of wheat varieties. Additionally, the study aimed to determine the correlation between microsatellite markers (SSR) and micronutrient quantities. A total of 42 genotypes (Iranian commercial cultivars, landraces, and Afghan and Swiss varieties) were evaluated over a two-year period. Fe and Zn levels were measured using two semi quantitative staining assays and atomic absorption spectrophotometry (AAS) facility. Semi-quantitative staining methods and AAS showed high correlations for micronutrient contents. Landraces exhibited higher Fe (63.79 mg/kg) and Zn (44.76 mg/kg) but lower grain yield compared with commercial cultivars. Heritability estimates ranged 53%-79.43%, suggesting that genetic variance played a higher contribution in the phenotypic variation of traits than environmental factors. Notably, Fe content displayed significant correlations with days to maturity. Canonical correlation analysis (CCA) revealed that Zn content was correlated with four agronomic traits. Evaluation of genetic diversity using SSR markers demonstrated high genetic variation among the genotypes tested. The analysis of polymorphism information content (PIC) indicated that SSR primers had an average PIC of 0.75, with the Xgwm192 primer exhibiting higher PIC than others. Several SSR markers revealed association with micronutrient content that can be used in marker-assisted selection (MAS) programs aimed at selection of high micronutrient genotypes. In conclusion, the findings underscored the substantial genetic diversity present in micronutrient levels among global wheat genotypes, the potential of landraces for micronutrients biofortification of wheat cultivars through cross hybridization, the utility of staining methods for screening high/low micronutrient genotypes, and use of microsatellite markers for marker-assisted breeding aiming to micronutrient improvement in breeding programs.

Estimation of dominance genetic effects on pre-weaning efficiency-related traits in Baluchi sheep

Abstract This study was conducted to estimate the relative contribution of dominance genetic effects to efficiency-related traits including Kleiber ratio (KR), efficiency of growth (EF) and relative growth rate (RGR) in Baluchi sheep. To this end, each trait was analysed with a series of 12 animal models which were identical for fixed and additive genetic effects but differed for combinations of dominance genetic and maternal effects. The Akaike's information criterion (AIC) was used to rank models. (Co)variances between traits were estimated using bivariate analyses. For all traits studied, according to AIC values, models containing the dominance genetic effects provided a better data fit than otherwise identical models. By including dominance genetic effects in the model, additive genetic variance did not change, but a significant decrease was observed in the residual variance (24, 19 and 25% for KR, EF and RGR, respectively). Estimates of dominance heritability $( {\boldsymbol h}_{\boldsymbol d}^ 2 )$ were 0.20 ± 0.05, 0.17 ± 0.05 and 0.19 ± 0.07 for KR, EF and RGR, respectively, more than corresponding estimates of additive heritability ${\bf ( }{\boldsymbol h}_{\boldsymbol a}^{\bf 2} {\bf ) }$ as 0.14 ± 0.02, 0.09 ± 0.03 and 0.13 ± 0.02, respectively. Dominance genetic correlations between traits were 0.89 ± 0.17 (KR-EF), 0.86 ± 0.20 (KR-RGR) and 0.93 ± 0.21 (EF-RGR). Additive genetic correlations between traits were 0.84 ± 0.05 (KR-EF), 0.78 ± 0.04 (KR-RGR) and 0.83 ± 0.04 (EF-RGR). The Spearman correlation between additive breeding values including and excluding dominance genetic effects were close to unity either for all animals or top ranked animals. Since presence of dominance genetic effects increased the model power to fit the data, inclusion of these effects in the genetic evaluation models for Baluchi sheep was recommended.

Estimation of genetic variability parameters and trait association in cherry tomato (Solanum lycopersicum L. var. cerasiforme)

Cherry tomatoes are the smaller version of classic tomatoes but are valued for their sweet taste and captivating colors. They are highly favored by the urban elite and the chefs catering to high-profile restaurants. To formulate selection criteria for utilization in breeding programs, variability parameters, an association between different characters, and direct and indirect effects of component traits of 29 cherry tomato genotypes were assessed under polyhouse conditions. Sufficient genetic variability was found for the morphological and yield traits studied, as revealed by the variance analysis. Plant height, primary branches per plant, days to 50 percent flowering, flower clusters per plant, flowers per cluster, fruits per cluster, days to first harvest, fruits per plant, fruit length, fruit girth, fruit weight, locules per fruit, pericarp thickness, days to final harvest, yield per plant, total soluble solids, lycopene, ascorbic acid, reducing sugars and non-reducing sugars showed high estimates of heritability and genetic advance as percent of the mean. Correlation analysis demonstrated a significant positive relationship between fruit yield per plant and pericarp thickness (0.727), fruit length (0.685), fruit girth (0.536), fruit weight (0.530), and the number of fruits per cluster (0.386). Principal component analysis identified the primary component (PC1) as the main contributor to variance. Path analysis revealed that fruit length, pericarp thickness, number of fruits per plant, flowers per cluster, and fruit weight had the highest direct effect on yield. These traits were the key factors influencing fruit yield per plant in cherry tomatoes.

Unravelling genetic variability for yield and contributing characteristics in green gram [vigna radiata (L.) wilczek] germplasm

Mungbean [Vigna radiata (L.) Wilczek] is an essential crop for food, feed, and income generation in rice-based farming systems across Southeast Asia and other regions. Its popularity stems from its good taste, high nutritional value, and ease of digestion, making it a promising crop for enhancing livelihoods. However, despite its significance, mungbean productivity remains low, primarily due to environmental stresses and a lack of sufficient genetic variability. This study examines the variability, heritability, phenotypic and genotypic coefficient of variation, and genetic advance among yield-contributing traits in green gram germplasm. A total of 450 germplasm lines were evaluated alongside check varieties, revealing significant variation, with the analysis of variance showing notable differences across nearly all traits. The mean sum of squares for the germplasm was highly significant for all phenotypic traits. Several traits exhibited high estimates of heritability and genetic advance, viz., the number of branches/ plants, number of clusters/ plants, number of pods/ clusters, pod length, test weight, and seed yield/plant, indicating their potential for direct selection in breeding programs. These findings suggest that additive gene effects play a dominant role in controlling these traits, with minimal environmental influence, making simple phenotypic selection an effective approach. The results provide valuable insights for advancing green gram breeding programs focused on improving yield and quality through targeted hybridization and trait selection.

Shared environmental similarity between relatives influences heritability of reproductive timing in wild great tits.

Intraspecific variation is necessary for evolutionary change and population resilience, but the extent to which it contributes to either depends on the causes of this variation. Understanding the causes of individual variation in traits involved with reproductive timing is important in the face of environmental change, especially in systems where reproduction must coincide with seasonal resource availability. However, separating the genetic and environmental causes of variation is not straightforward, and there has been limited consideration of how small-scale environmental effects might lead to similarity between individuals that occupy similar environments, potentially biasing estimates of genetic heritability. In ecological systems, environments are often complex in spatial structure, and it may therefore be important to account for similarities in the environments experienced by individuals within a population beyond considering spatial distances alone. Here, we construct multi-matrix quantitative genetic animal models using over 11,000 breeding records (spanning 35 generations) of individually-marked great tits (Parus major) and information about breeding proximity and habitat characteristics to quantify the drivers of variability in two key seasonal reproductive timing traits. We show that the environment experienced by related individuals explains around a fifth of the variation seen in reproductive timing, and accounting for this leads to decreased estimates of heritability. Our results thus demonstrate that environmental sharing between relatives can strongly affect estimates of heritability and therefore alter our expectations of the evolutionary response to selection.

Genetic improvement of indigenous cattle breeds in Ethiopia: A systematic review of the Fogera cattle open nucleus breeding scheme

Fogera cattle are one of the valuable indigenous milk-type local breeds of Ethiopia, widely adapted to the area around Lake Tana in the Amhara region. The objective of this systematic review was to evaluate the performance of the Fogera cattle breed under an open nucleus breeding scheme. The review was done systematically by collecting published and unpublished data sources on the breed. The overall milk yield of the nucleus Fogera cattle herd was 2.26±0.794L/day. From the total herd, the top 10% and 25% of them produced daily milk yields of 3.31 and 2.87L, respectively, and some elite cows gave an average of 5.45±0.73L/day with a maximum yield of 8L/day. The predicted 305-day milk yield for the top 10% and 25% of the total herd was 883.64 and 772.83L, respectively. The average lactation milk yield and lactation length were reported to be 489±184L and 243±72.79 days, respectively. The respective heritability estimates for the aforementioned traits were 0.20±0.23 and 0.27±0.001. The birth and weaning weights (at 8 months of age) of village Fogera cattle born from community-based breeding programmes (CBBP) were 23.77±.21 and 85.89±1.07kg, respectively. The average weaning age for the CBBP herds was reduced to 8 months. The overall calf mortality in the nucleus herd was 3%. The CBBP demonstrated that it could act as a significant entry point for ensuring the conservation and restocking efforts of this breed as a country asset.

Genetic variation in surface temperature measured using infra-red thermography and genetic associations with production traits in grazing dairy cattle

ABSTRACT Increasing global temperatures and the incidence of extreme weather conditions will result in heat stress becoming a greater issue in production animals. Genetic selection and breeding for heat-tolerant animals have been promoted as a possible mitigation strategy in dairy cattle. The objectives of this study were to obtain in-field skin temperature measurements of the eye, muzzle and udder using infra-red thermography to examine the genetic variation in skin temperature within cows of a dairy herd and to estimate the genetic correlations between skin temperature and production traits. Thermal images and herd test records were obtained for the dairy herd at Massey University’s dairy farm 1. Estimates of (co)variances were obtained using the JWAS program with univariate and bivariate animal models. The heritability estimates for the eye, muzzle and udder temperature were low to moderate at 0.20, 0.24 and 0.39, respectively. All genetic correlations between production and temperature traits were positive except for eye temperature with milk yield and protein yield which was negative and weak. These results indicate that it may be possible to select for a greater skin temperature, however, these results need to be validated using a larger sample size.

Genetic characterization and mapping of the shell-strength trait in peanut.

Shell strength is an important trait in peanuts that impacts shell breakage and yield. Despite its significance, the genetic basis of shell strength in peanuts remains largely unknown, and the current methods for rating this trait are qualitative and subjective. This study aimed to investigate the genetics of shell strength using a segregating recombinant-inbred-line (RIL) population derived from the hard-shelled cultivar 'Hanoch' and the soft-shelled cultivar 'Harari'. Initially, a quantitative method was developed using a texture analyzer, focusing on the proximal part of isolated shells with a P/5 punching probe. This method revealed significant differences between Hanoch and Harari. Shell strength was then measured in 235 RILs across two distinct environments, revealing a normal distribution with some RILs exhibiting shell strength values beyond those of the parental lines, indicating transgressive segregation. Analysis of variance indicated significant effects for the RILs, with no effects of block or year, and a broad-sense heritability estimate of 0.675, indicating a substantial genetic component. Using an existing genetic map, we identified three QTLs for shell strength, with one major QTL (qSSB02) explaining 18.7% of the phenotypic variation. The allelic status of qSSB02 corresponded significantly with cultivar designation for in-shell or shelled types over four decades of Israeli peanut breeding. Physical and compositional analyses revealed that Hanoch has a higher shell density than Harari, rather than any difference in shell thickness, and is associated with increased levels of lignin, cellulose, and crude fiber. These findings provide valuable insights into the genetic and compositional factors that influence shell strength in peanut, laying a foundation for marker-assisted selection in breeding programs focused on improving pod hardness in peanuts.

Genetic Evaluation of Monthly Test-Day Milk Yields of Jersey Crossbred Cattle Under Farmers' Production System in Tamil Nadu, India.

Tamil Nadu, a state in southern India, is bereft of any native dairy or dual-purpose cattle breeds, and the state depends chiefly on crossbred cattle for milk production. Jersey crossbred cattle account for 90% of the state's milk production. This genetic evaluation study aimed to assess milk production traits, including test-day milk yields (TDMYs), total lactation milk yield (TMY), and 305-day milk yield (305MY), in these cattle reared under farmers' conditions. Data on monthly TDMYs (TDMY1 to TDMY10) of Jersey crossbred cows (n = 75,627) reared by the farmers over 11 years (2012-2022) were collected for evaluation. The influence of non-genetic factors viz., location (agroclimatic zones), period and season of calving, and parity on TDMYs, TMY and 305MY were assessed, and the variance and covariance components for genetic parameters (heritability and genetic correlation) of the traits were estimated by the method of restricted maximum likelihood (REML) under a multivariate animal model and by a random regression model (RRM). The overall means of various TDMYs ranged from 4.98 (TDMY10) to 9.95 kg (TDMY2), and for TMY and 305MY, the means were 2480.33 and 2393.71 kg, respectively. The heritabilities estimated by the multivariate animal model for TDMYs were moderate and ranged from 0.26 ± 0.02 to 0.37 ± 0.02 and the estimates were less variable throughout lactation, while the estimates obtained by RRM were medium to high and ranged between 0.29 ± 0.01 and 0.67 ± 0.02 for milk yield on day 5 to 305 (DIM 5-DIM 305). The heritabilities estimated for TMY and 305MY were 0.43 ± 0.02 and 0.43 ± 0.02, respectively. The estimates of heritability for mid-lactation yields were comparatively less than those at the beginning and the end of lactation. The moderate to high estimates of heritabilities for TDMYs, TMY, and 305MY obtained in the present study offer ample scope for improving milk production through selective breeding. Genetic correlations between TDMYs estimated by the multivariate animal model were positive and high, with a range between 0.75 ± 0.03 and 0.99 ± 0.00. Considerably higher estimates (0.98-0.99) were observed between adjacent TDMYs showing strong genetic associations. By RRM, genetic correlations estimated between DIMs were positive (except for DIM 5 with DIM 125 to DIM 185 and DIM 125 with DIM 305), and the magnitude of genetic correlation decreased with an increase in the interval between the DIMs. The high genetic correlation observed between the TDMYs (in the early stage of lactation) and total lactation milk yield suggested that these test-day yields could be used favorably for the early selection of cows for milk production, which facilitates reduction in the generation interval and consequently increases the annual genetic gain for the milk production traits.

English

Coffee breeding programs aim at developing superior genotypes, which entail exploring the genetic variability existing in conilon/robusta coffee. This study aimed at examining the variability and estimate genetic param of physical and physiological nature in Coffea canephora seeds in order to provide bases for the selection of genotypes for superior seeds quality. Forty-three C. canephora genotypes were evaluated for 11 physical and physiological seed traits. Estimates of genetic param, environmental variance, phenotypic variance, genotypic variance, broad-sense heritability, variation index and Pearson's correlation were obtained. The Dissimilarity between genotypes was obtained by generalized Mahalanobis distance. The dendrogram was constructed using unweighted pair group method with arithmetic mean (UPGMA). C. canephora genotypes presented high germination potential and exhibited genetic diversity for all seed traits, with estimates of genetic variance greater than environmental variance. Heritability reached values above 96.0% and all genetic variation indices found were higher than unity. The UPGMA hierarchical method grouped the genotypes in three groups. The physical traits (circumference, area and roundness) were those that contributed the most to explaining the dissimilarity between genotypes. Genotypes Alecrim, AP, Bamburral, Z39 and Tardio C were the most divergent. The results revealed the presence of genetic variability between C. canephora genotypes and greater genetic than environmental influence on the characters of seeds, indicating that selection for the studied traits showed favorable conditions in terms of immediate gain.

Host genetic regulation of specific functional groups in the rumen microbiome of dairy cows: Implications for lactation trait

IntroductionRuminants play a pivotal role in our society by transforming non-consumable substances from industrial by-products and plant fibers into valuable resources such as meat and milk. This remarkable conversion ability is primarily attributed to the rumen microbiota, which is influenced by various factors, including diet, climate, and geographical location. In recent years, increasing research has shown that host factors (breed, genetic variation, etc.) also play vital roles in shaping rumen microbial composition and function in cattle. ObjectiveThis study aims to provide a theoretical basis and an opportunity for further investigating the regulation of lactation traits in dairy cows through host genetics and the interaction with the rumen microbiota. MethodTo investigate the interactions between host genotype, rumen microbiota, and animal phenotype, we curated and analyzed the dairy herd improvement (DHI) data, single nucleotide polymorphisms (SNPs) genotypes, and 16S rumen microbiota data from 1,169 Holstein dairy cows. Heritability and microbiability estimation, along with genome-wide association studies (GWAS) were performed to identify candidate microorganisms and host genetic loci. ResultWe identified thirty-one heritable taxa, whose functions were predominantly enriched in carbohydrate metabolism and energy metabolism. The genome-wide association study revealed that nine heritable bacteria were significantly associated with forty-three SNPs. Functional genes located within or near these SNPs were primarily associated with rumen epithelial development. Additionally, these nine heritable bacteria were primarily annotated as complex polysaccharide degraders and butyrate producers, such as Fibrobacter sp900143055 and Pseudoruminococcus massiliensis, which showed significant associations with milk yield and milk fat percentage. Compared to previous studies, we newly discovered the existence of a high heritability of Olsenella umbonate, Butyrivibrio hungatei, among others.

Bayesian Evaluation of Growth Rates and Kleiber's Ratios in Harnali Sheep: Dissecting Maternal and Additive Genetic Contributions.

Understanding the genetic basis of growth and metabolic traits in sheep is crucial for improving production efficiency and sustainability. The current study aimed to estimate the genetic influences, both direct and maternal, on growth rate and Kleiber's ratio traits in Harnali sheep using pedigree data under Bayesian inference. The data pertained to 2404 animals spanned over 24 years (1998-2021). Fixed factors such as birth period, lamb sex and dam's weight at lambing were considered. The traits studied included average daily gains (ADGs) categorised into ADG1 (birth to weaning age), ADG2 (weaning to 6 months of age) and ADG3 (6-12 months of age), as well as corresponding Kleiber's ratios (KR1, KR2 and KR3). Six single-trait animal models were employed to estimate covariance components and heritabilities, integrating direct additive and maternal effects alongside significant fixed factors using THRGIBBS1F90 and POSTGIBBSF90 programmes. Direct heritability estimates were obtained for ADG1 (0.11 ± 0.05), ADG2 (0.06 ± 0.03), ADG3 (0.03 ± 0.03), KR1 (0.07 ± 0.03), KR2 (0.06 ± 0.03) and KR3 (0.05 ± 0.03). Maternal genetic effects have contributed significant particularly to pre-weaning traits. The study identified an antagonistic relationship between direct additive and maternal genetic effects. Positive genetic and phenotypic correlations emphasised the intricate relationship between growth and metabolic efficiency in Harnali sheep. The current study offers critical insights into the genetic basis of growth and metabolic traits in Harnali sheep, ultimately contributing to more efficient and sustainable sheep production systems.

Genetic parameters and genome-wide association analyses for lifetime productivity in Chinese Holstein cattle

Lifetime productivity is a trait of great importance to dairy cattle populations, as it combines information from production and longevity variables. Therefore, we investigated the genetic background of lifetime productivity in high-producing dairy cattle by integrating genomics and transcriptomics datasets. A total of 3,365,612 test-day milk yield records from 134,029 Chinese Holstein cows were used to define 6 lifetime productivity traits, including lifetime milk yield covering full lifespan and 5 cumulative milk yield traits covering partial lifespan. Genetic parameters were estimated based on univariate and bivariate linear animal models and the restricted maximum likelihood method. Genome-wide association studies and weighted gene co-expression network analyses (WGCNA) were performed to identify candidate genes associated with lifetime productivity based on genomic data from 3,424 cows and peripheral blood RNA-sequencing data from 23 cows, respectively. Lifetime milk yield averaged 24,800.8 ± 14,396.6 kg (mean ± SD) across an average of 2.4 parities in Chinese Holstein population. The heritability estimates for lifetime productivity traits ranged from 0.05 (±0.01 for SE) to 0.10 (±0.02 for SE). The estimate of genetic correlation between lifetime milk yield and productive life is 0.88 (±0.3 for SE), whereas the genetic correlation with 305-d milk yield in the first lactation was 0.49 (±0.08 for SE). Absolute values for most genetic correlation estimates between lifetime productivity and type traits were lower than 0.30. Moderate genetic correlations were found between udder related traits and lifetime productivity, such as with udder depth (0.33), rear udder attachment height (0.33), and udder system (0.34). Some single nucleotide polymorphisms and gene co-expression modules significantly associated with lifetime milk yield were identified based on GWAS and WGCNA analyses, respectively. Functional enrichment analyses of the candidate genes identified revealed important pathways related to immune system, longevity, energy utilization, and metabolism, and FoxO signaling. The genes NTMT1, FNBP1, and S1PR1 were considered to be the most important candidate genes influencing lifetime productivity in Holstein cows. Overall, our findings indicate that lifetime productivity is heritable in Chinese Holstein cattle, and important candidate genes were identified by integrating genomic and transcriptomic datasets.

Genetic and environmental contributions to adult attachment styles: Evidence from the Minnesota Twin Registry.

Attachment theory, as originally outlined by Bowlby (1973, 1980, 1969/1982), suggests that the ways people think, feel, and behave in close relationships are shaped by the dynamic interplay between their genes and their social environment. Research on adult attachment, however, has largely focused on the latter, providing only a partial picture of how attachment styles emerge and develop throughout life. The present research leveraged data from the Minnesota Twin Registry, a large sample of older adult twins (N = 1,377 twins; 678 pairs; Mage = 70.40 years, SD = 5.42), to examine the relative contributions of genetic and environmental factors to adult attachment styles. Participants reported on both their general attachment styles and relationship-specific attachments to their mothers, fathers, partners, and best friends. The results suggest that attachment styles are partly heritable (∼36%) and partly attributable to environmental factors that are not shared between twins (∼64%). Heritability estimates were somewhat higher for parent-specific attachment styles (∼51%), whereas nonshared environmental factors accounted for larger proportions of the variance in partner- and best friend-specific attachment styles. Using multivariate biometric models, we also examined the genetic and environmental factors underlying the covariation among people's relationship-specific attachment styles. The findings indicate that the similarities among people's avoidant tendencies in different relationships can be explained by a single, higher order latent factor (e.g., global avoidance). In contrast, the genetic and environmental factors underlying attachment anxiety appear to be more differentiated across specific close relationships. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Assessment of Genetic Variability in Groundnut (Arachis hypogaea L.)

The present study was carried out with thirty advanced breeding lines of groundnut for estimation of genetic variability, heritability and genetic advance. Analysis of variance revealed highly significant differences among genotypes for all the studied characters indicating that there is substantial variability among the genotypes for these traits. High estimates of GCV and PCV was observed for pod yield per plant, kernel yield per plant, dry haulm yield per plant and number of mature pods per plant. High heritability coupled with high genetic advance as per cent of mean were recorded for number of mature pods per plant, pod yield per plant, kernel yield per plant, dry haulm yield per plant, number of immature pods per plant, plant height, harvest index and hundred kernel weight indicating the preponderance of additive gene action in expression of these traits and hence simple phenotypic selection would be effective for improvement of these characters.