Search Results (273)

Heat stress is a critical constraint to poultry production in tropical regions, where the temperature–humidity index (THI) frequently exceeds thermoneutral thresholds. Despite growing interest in climate-resilient livestock, limited research has explored the genetic sensitivity of local chicken breeds to increasing THI levels. This study aimed to evaluate the genetic effects of increasing THI on growth performance traits in two tropical chicken breeds. The data included body weight (BW), average daily gain (ADG), and absolute growth rate (AGR) from 4,745 black-boned and 3,001 Thai native synthetic chickens across five generations. Growth data were collected from hatching to 12 weeks of age, whereas temperature and humidity were continuously recorded to calculate daily THI values. A reaction norm model was used to estimate genetic parameters and rate of decline of BW, ADG, and AGR traits under varying THI thresholds (THI70 to THI80). Results indicated that the onset of heat stress occurred at THI72 for black-boned chickens and at THI76 for Thai native synthetic chickens. Heritability estimates for BW, ADG, and AGR decreased as the THI increased in both chicken breeds. However, the Thai native synthetic chickens consistently exhibited higher genetic potential across all THI levels (average heritability: BW = 0.28, ADG = 0.25, AGR = 0.36) compared to the black-boned chickens (average heritability: BW = 0.21, ADG = 0.15, AGR = 0.23). Under mild heat stress (THI72), black-boned chickens showed sharp declines in all traits (average reduction in BW = −10.9 g, ADG = −0.87 g/day, AGR = −3.20 g/week), whereas Thai native synthetic chickens maintained stable performance. At THI76, both breeds experienced significant reductions, particularly in males. Estimated breeding values (EBVs) for AGR decreased linearly with THI, though Thai native synthetic chickens showed greater individual variability, with some birds maintaining stable or positive EBVs up to THI80—suggesting the presence of heat-resilient genotypes. In conclusion, Thai native synthetic chickens demonstrated superior thermotolerance and genetic robustness under increasing THI conditions. The identification of breed-specific THI thresholds and resilient individuals provides novel insights for climate-smart poultry breeding. These findings offer valuable tools for genetic selection, environmental management, and long-term adaptation strategies in response to global climate change. Full article

Stevia rebaudiana Bertoni, a semi-perennial herb from the Asteraceae family, is native to the Paraguay–Brazil border region. The growing industrial interest in this species is due to its natural sweetening properties, such as steviol and its derivatives, which offer sweetness without adding calories. Morphological traits are crucial for assessing genetic variability and ensuring distinctness, homogeneity, and stability (DHS) for cultivar protection. This study characterized 19 elite Stevia genotypes from Embrapa Cerrados’ Active Germplasm Bank (BAG) using 21 morphological descriptors from Brazil’s Ministry of Agriculture, Livestock, and Supply (MAPA). Genetic distances were calculated using the simple coincidence index complement method, and clustering was performed via the Unweighted Pair-Group Method with Arithmetic Mean (UPGMA). The results showed that 17 of the 21 descriptors (>80%) effectively differentiated the genotypes, revealing significant genetic variability. Dendrogram analysis identified at least four major similarity groups, highlighting the potential of these genotypes for Stevia breeding programs. These findings underscore the suitability of these elite genotypes for developing superior varieties adapted to Cerrado conditions, supporting future cultivation and genetic improvement efforts. Full article

Prenatal and postnatal skeletal muscle development in ruminants is coordinated by interactions between genetic, nutritional, epigenetic, and endocrine factors. This review focuses on the influence of maternal nutrition during gestation on fetal myogenesis, satellite cell dynamics, and myogenic regulatory factors expression, including MYF5, MYOD1, and MYOG. Studies in sheep and cattle indicate that nutrient restriction or overnutrition alters muscle fiber number, the cross-sectional area, and the transcriptional regulation of myogenic genes in offspring. Postnatally, muscle hypertrophy is primarily mediated by satellite cells, which are activated via PAX7, MYOD, and MYF5, and regulated through mechanisms such as CARM1-induced chromatin remodeling and miR-31-mediated mRNA expression. Hormonal signaling via the GH–IGF1 axis and thyroid hormones further modulate satellite cell proliferation and protein accretion. Genetic variants, such as myostatin mutations in Texel sheep and Belgian Blue cattle, enhance muscle mass but may compromise reproductive efficiency. Nutritional interventions, including the plane of nutrition, supplementation strategies, and environmental stressors such as heat and stocking density, significantly influence muscle fiber composition and carcass traits. This review provides a comprehensive overview of skeletal muscle programming in ruminants, tracing the developmental trajectory from progenitor cell differentiation to postnatal growth and maturation. These insights underscore the need for integrated approaches combining maternal diet optimization, molecular breeding, and precision livestock management to enhance muscle growth, meat quality, and production sustainability in ruminant systems. Full article

Meiotic recombination is a key evolutionary process that generates novel allele combinations during prophase I of meiosis, promoting genetic diversity and enabling the selection of desirable traits in livestock breeding. Although its molecular mechanisms are well-characterised in model organisms such as humans and mice, studies in African indigenous cattle, particularly South African breeds, remain scarce. Key regulators of recombination, including PRDM9, SPO11, and DMC1, play essential roles in crossover formation and genome stability, with mutations in these genes often linked to fertility defects. Despite the Bonsmara and Nguni breeds’ exceptional adaptability to arid and resource-limited environments, little is known about how recombination contributes to their unique genetic architecture and adaptive traits. This review synthesises the current knowledge on the molecular basis of meiotic recombination, with a focus on prophase I events and associated structural proteins and enzymes. It also highlights the utility of genome-wide tools, particularly high-density single nucleotide polymorphism (SNP) markers for recombination mapping. By focusing on the underexplored recombination landscape in South African beef cattle, this review identifies key knowledge gaps. It outlines how recombination studies can inform breeding strategies aimed at enhancing genetic improvement, conservation, and the long-term sustainability of local beef production systems. Full article

Meat quality is a critical determinant of consumer preference and economic value in the livestock industry. However, the relationship between carcass performance and meat quality remains poorly understood. In our study, we conducted an integrative analysis of transcriptomics and metabolomics to investigate the molecular mechanisms underlying meat quality differences in Hu sheep with high (HHS, n = 10) and low (LHS, n = 10) carcass performance. Phenotypic analysis revealed that the HHS group exhibited superior meat quality traits, including higher intramuscular fat (IMF) content (reflected in elevated marbling scores), along with lower shear force, drip loss, and cooking loss, compared to the LHS group. Transcriptomic analysis identified 376 differentially expressed genes (DEGs) enriched in pathways linked to lipid metabolism, such as the PPAR signaling pathway and long-chain fatty acid metabolic process. Weighted gene co-expression network analysis (WGCNA) revealed important modules and key genes (e.g., ELOVL6, PLIN1, and ARHGEF2) associated with meat quality traits. Metabolomic profiling identified 132 differentially accumulated metabolites (DAMs), with significant enrichment in amino acid metabolism pathways, including D-amino acid metabolism, arginine biosynthesis, and glycine, serine, and threonine metabolism. Integrative analysis of transcriptomic and metabolomic data highlighted six co-enriched pathways, such as the mTOR signaling pathway and amino acid metabolism, underscoring their role in regulating meat quality. These findings provide valuable insights into the genetic and metabolic networks driving meat quality variation and offer potential biomarkers for genetic selection and nutritional strategies to enhance both carcass yield and eating quality in Hu sheep. This research enhances knowledge of the molecular basis of meat quality and supports precision breeding in livestock production. Full article

Heat stress (HS) in dairy cattle triggers systemic physiological disruptions, including milk yield decline, immune suppression, and reproductive dysfunction, jeopardizing sustainable livestock production. While conventional single-omics or phenotypic studies have provided fragmented insights, they fail to decipher the multi-layered regulatory networks and gene–environment interactions underlying HS. This review integrates current knowledge on HS-induced physiological responses and molecular adaptations in dairy cattle from a multi-omics perspective, highlighting integrative approaches that combine IoT-enabled monitoring and AI-driven genetic improvement strategies. However, key challenges persist, such as complexities in bioinformatic data integration, CRISPR off-target effects, and ethical controversies. Future directions will emphasize the development and application of AI-aided predictive models to enable precision breeding, thereby advancing climate-resilient genetic improvement in dairy cattle. Full article

Skeletal muscle is the largest heterogeneous organ in the body, and multiple factors in intrinsic genetic and epigenetic regulation influence its growth. The N⁶-methyladenosine ed(m⁶A) modification is a conserved and most prevalent RNA modification, whose function is dependent on m⁶A writers, erasers, and m⁶A readers, such as the YTH protein family. YTHDC1 is the only member of the YTH protein family member that exists in the cell nucleus, which plays an important role in mRNA alternative polyadenylation and alternative splicing processes. However, the function of YTHDC1 in regulating myoblast proliferation, differentiation, and in vivo skeletal muscle development remains unclear. Therefore, in this study, we studied the function of YTHDC1 in C2C12 cell line and mouse. Our results showed that YTHDC1 significantly promoted myogenic differentiation while inhibiting myoblast proliferation in C2C12 cells, and the results of our in vivo experiment showed that interfering with YTHDC1 led to a significant enhancement of muscle growth in mice. Furthermore, the transcriptome sequencing analysis revealed that YTHDC1 might modulate skeletal muscle development by regulating alternative splicing of genes, including Akap13, Smarca2, Tnnt3, and Neb. Our study shed light on understanding the function and molecular mechanisms of YTHDC1 in regulating skeletal muscle development, highlighting the critical contribution of m⁶A-mediated RNA splicing in muscle growth. These results indicated that YTHDC1 could be a potential breeding target gene to enhance meat quality in livestock. Full article

The transforming growth factor-beta (TGF-β) superfamily plays a crucial role in regulating female reproductive traits, particularly litter size, in small ruminants, such as sheep and goats. This review comprehensively examines the molecular mechanisms through which TGF-β superfamily members—including bone morphogenetic proteins (BMPs), growth differentiation factor 9 (GDF9), inhibin (INHA and INHB), and associated signaling genes—influence ovarian follicular development, ovulation rate, and ultimately, litter size. We synthesize recent findings on polymorphisms in key genes, such as BMPR1B, BMP15, GDF9, inhibins and SMADs family genes, across diverse sheep and goat breeds worldwide. The manuscript highlights how specific mutations in these genes create an intricate signaling network that modulates granulosa cell proliferation, follicular sensitivity to FSH, and the prevention of dominant follicle selection. These molecular interactions result in increased ovulation rates and larger litter sizes in prolific breeds. The gene dosage effects observed in heterozygous versus homozygous mutation carriers further illuminate the complex nature of these reproductive regulations. This improved the understanding of the genetic basis for prolificacy provides valuable insights for marker-assisted selection strategies aimed at enhancing reproductive efficiency in small ruminant breeding programs, with significant implications for improving livestock productivity and economic outcomes. Full article

Soybean [Glycine max (L.) Merr.] is a globally significant crop that provides essential meal protein and vegetable oil for human consumption. The protein content in soybean seeds is a critical factor that affects nutrition regarding human dietary needs as well as livestock feed. Therefore, identifying the key genes that affect the soybean seed protein content is one of the major goals in soybean research. To identify candidate genes and related pathways involved in soybean seed storage protein during seed development, an RNA-seq analysis was conducted in two soybean varieties that differ in protein content. A series of pathways related to seed protein metabolism, including “Photosynthesis”, “TCA cycle”, and “Starch and sucrose metabolism” pathways, were identified through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Seven candidate genes exhibiting two different gene regulation patterns were identified, six of which are directly related to the seed storage protein pathway, and one of which is related to the carbon binding pathway. An integrated analysis of transcriptomic and candidate gene expression trend suggested that 40 days after flowering (DAF) might be a crucial period for seed protein accumulation in soybean. Through a Weighted Gene Co-expression Network Analysis (WGCNA), two modules and two novel hub genes were found, which may be highly correlated with seed protein development. These findings might be valuable for a complete understanding of the genetic basis of seed protein content and lay a theoretical foundation for future gene functional identification and breeding efforts in soybean. Full article

The local goat breeds of Chongqing represent the typical goat populations of Southwestern China and play a significant role in global goat research. However, studies on these goats remain limited. Chongqing goats exhibit diverse coat colors, a crucial economic trait essential for individual and breed identification. In this study, we performed genome-wide association analysis (GWAS) of Chongqing goats to identify candidate genes associated with coat color. The results of the GWAS revealed that the ASIP, AHCY, and ITCH genes on chromosome 13 are significantly associated with coat color variation in Chongqing goats. Furthermore, haplotype analysis, gene function annotation, and pathway analysis enrichment further confirmed that a significant region on chromosome 13 is associated with coat color in local Chongqing goats, and that ASIP and AHCY are related to black coat color, whereas ITCH is potentially associated with white coat expression. Additionally, we also identified TPK1 as being associated with coat color in goats, which has hardly been reported. The newly identified genes expand our understanding of the complex genetic architecture underlying pigmentation traits in livestock. Our study identifies the genes related to coat color in local goats, which enriches the genetic resource pool of goats and contributes to a deeper understanding of the genetic mechanisms underlying coat color in these breeds. Full article

Understanding the genetic and phenotypic basis of economically important traits is essential for designing effective breeding programs in livestock. This study aimed to evaluate the phenotypic performance and estimate genetic parameters for one reproductive trait—litter size at birth (LSB)—and three pre-weaning growth traits—birth weight (BW), weaning weight (WW), and average daily gain (ADG)—in a population of 1888 Zaraibi kids born between 2018 and 2023. Genetic parameters were estimated using animal models implemented in the MTDFREML software. The overall least squares means (±standard error) for LSB, BW, WW, and ADG were 2.22 ± 0.02, 2.03 ± 0.01 kg, 10.22 ± 0.05 kg, and 90.00 ± 0.50 g/day, respectively. Statistical analyses indicated that month of birth, year of birth, and type of birth had significant (p < 0.05) effects on all traits, while the sex of the kids had no significant effect (p > 0.05) on LSB. Direct heritability estimates (h²_d) derived from Model 1 (including additive genetic, permanent environmental, and residual effects) were 0.13 ± 0.01 for LSB, 0.30 ± 0.04 for BW, 0.38 ± 0.01 for WW, and 0.30 ± 0.10 for ADG. Under Model 2 (which incorporated maternal genetic effects and their covariance with direct genetic effects), maternal heritability (h²_m) estimates for LSB, BW, WW, and ADG were 0.05 ± 0.01, 0.15 ± 0.01, 0.12 ± 0.01, and 0.14 ± 0.01, respectively. Overall, the results emphasize the importance of maternal genetic effects in influencing pre-weaning growth traits. Therefore, maternal genetic components should be explicitly considered in genetic evaluation and selection strategies aimed at improving early growth performance in Zaraibi goats. Full article

The once mysterious “dark matter of nutrition”, comprising countless plant-derived secondary compounds, also known as phytochemicals, is now understood to have significant and wide-ranging effects on consumers, including myriad health benefits in humans and livestock. The selective consumption of phytochemically rich and diverse plants, in appropriate doses, by ruminants represents an adaptive means of therapeutic and prophylactic self-medication. Due to their chemical structure, phytochemicals have long been recognized as antioxidants. However, the mechanisms that underlie numerous additional phytochemical-based health benefits are generally less understood. These effects (i.e., anti-inflammatory, immunomodulatory, and anticarcinogenic effects) are likely related to epigenetic processes. Evidence in humans and rodent models, as well as emerging ruminant data, has shown that phytochemicals can modulate gene expression by inhibiting or enhancing the activity of chromatin modifiers. The implication of adaptations with epigenetic mechanisms is significant as they are potentially heritable. We argue that heritable epigenetic changes, including “fetal programming”, are commonplace in ruminants under nutritional interventions. We also argue that these phenomena are significant for an industry that relies upon the efficient breeding and growth of offspring. We highlight emerging yet limited evidence and offer direction for future research. We explore interactions between the fields of plant secondary chemistry, ruminant nutrition, and molecular (epi)genetics and aim to familiarize researchers with the scope and foundational concepts of these emerging interactions. Full article

The Andalusian Black Cattle (Negra Andaluza) represents a genetic lineage linked to the ancient Eurasian aurochs, shaped by domestication events in the Near East and later introgressions from Italian and North African wild cattle. This study investigates the breed’s anthropological and historical origins, geographical distribution, and genetic structure. Key influences include historical use as draft animals, regional breeding preferences, and gene flow via transhumant routes. The genetic analysis reveals that Córdoba is the principal nucleus, accounting for 448 identified ancestors, compared to 252 in Huelva and 193 in Seville. In Córdoba, contributions of nodal ancestors through inbreeding loops reached a maximum of 0.0447, while mean inbreeding ($\overline{\mathrm{F}}$) was 0.000949 and mean coancestry ($\overline{\mathrm{C}}$) was 0.000475, indicating moderate but geographically structured genetic drift. In contrast, areas with better connectivity showed higher heterogeneity and lower inbreeding contributions. Canonical discriminant analysis (CDA) revealed that the first discriminant function (F1) explained 79.72% of the variation among groups, primarily driven by nodal ancestors and inbreeding loops. Despite these signs of inbreeding, historical transhumance has helped preserve overall genetic diversity. These findings offer essential insights for conservation programs aimed at maintaining both the genetic integrity and adaptive potential of this historically and culturally important breed. Full article

Vertebrate molecular genetic research methods typically employ single genetic loci (monolocus markers) and those involving a variable number of loci (multilocus markers). The former often employ microsatellites that ensure accuracy in establishing inbreeding, tracking pan-generational dynamics of genetic parameters, assessing genetic purity, and facilitating genotype/phenotype correlations. They also enable the determination and identification of unique alleles by studying and managing marker-assisted breeding regimes to control the artificial selection of agriculturally important traits. Microsatellites consist of 2–6 nucleotides that repeat numerous times and are widely distributed throughout genomes. Their main advantages lie in their ease of use for PCR amplification, their known genome localization, and their incredible polymorphism (variability) levels. Robust lab-based molecular technologies are supplemented by high-quality statistics and bioinformatics and have been widely employed, especially in those instances when more costly, high throughput techniques are not available. Here, we consider that human and livestock microsatellite studies have been a “roadmap” for the genetics, breeding, and conservation of wildlife and rare animal breeds. In this context, we examine humans and other primates, cattle and other artiodactyls, chickens and other birds, carnivores (cats and dogs), elephants, reptiles, amphibians, and fish. Studies originally designed for mass animal production have thus been adapted to save less abundant species, highlighting the need for molecular scientists to consider where research may be applied in different disciplines. Full article