The polymorphism of the bovine β-casein gene (CSN2) is of increasing interest due to its relevance for A2 milk production. This study genotyped 2773 Holstein-Friesian cows for five CSN2 alleles (A1, A2, A3, B, I) using both conventional DNA-based PCR and a newly evaluated direct PCR protocol. Eleven genotypes were detected, with A2/A2 (33.9%) and A1/A2 (30.3%) being the most common, resulting in an A2 allele frequency of 59.0%. Genetic diversity indices indicated moderate polymorphism and a significant deviation from Hardy–Weinberg equilibrium, consistent with ongoing selection for the A2 allele. Associations between CSN2 genotype and milk traits (305-day milk, fat, and protein yield; fat% and protein%) were evaluated using linear mixed-effects models including lactation number, age at calving, and calving year as covariates, and cow ID as a random intercept. Several genotype effects reached statistical significance (p < 0.05); however, all effect sizes were very small (partial η2 < 0.01), indicating that any influence of CSN2 on production traits is negligible within this population and management context. These findings suggest that A2-oriented selection is unlikely to compromise productivity. The direct PCR genotyping method achieved 96–100% success and enabled substantially faster and more cost-efficient processing (approximately 80–90% reduction in reagent costs), providing a rapid and scalable approach for large herds.
This study investigated the presence and levels of five key mycotoxins—aflatoxins (AFs), deoxynivalenol (DON), fumonisin B1 (FB1), ochratoxin-A (OTA), and zearalenone (ZEN) and its metabolite alpha-zearalenol (α-ZOL)—in liver samples from 19 golden jackals (Canis aureus) in southern Hungary. Golden jackals, as apex predators with a diverse diet encompassing both plant and animal matter, can serve as valuable bioindicators of environmental mycotoxin contamination. Genetic analysis confirmed the canid samples as coming from golden jackals, excluding the possibility of domestic dogs or hybrid individuals. All samples tested positive for at least three mycotoxins, with multiple mycotoxins frequently co-occurring. DON was detected in 95% of the samples, followed by FB1 (79%) and ZEN (42%). ZOL, AFs, and OTA were present in all samples. Significant differences in mycotoxin concentrations were observed between age groups and sexes for some mycotoxins. Specifically, adult males exhibited higher ZEN concentrations, adult females had higher OTA levels, and females generally showed significantly higher DON concentrations than males. For all investigated individuals, we found significantly higher concentrations of ZEN, alpha-ZOL, and OTA in adult samples. Malondialdehyde (MDA), an indicator of oxidative stress, was also measured and correlated with mycotoxin levels. Pareto analysis suggested a correlation between MDA and OTA/ZEN. These findings highlight the exposure of golden jackals to a range of mycotoxins in their natural environments, potentially through both plant and animal food sources, and underscore the potential of these canids as sentinels for mycotoxin contamination in ecosystems.
The European rabbit exists in the wild and has several highly bred domesticated forms. There are well-separated wild European rabbit populations, and intensive breeding has resulted in various forms and utilizations. In this work, we aimed to carry out an extended WGS-based population genomics study on several wild European rabbit populations and selected breeds. Utilizing multiple methods, we showed that although domestic and wild populations were clearly separated, there was evidence of admixture between them in France and Hungary. The populations showed various levels of inbreeding, with one of the Hungarian subpopulations having excess runs of homozygosity. We identified numerous variants fixed in either domestic or wild animals, two of which were found to be fixed at different alleles in the two populations. Some putatively selected regions did not overlap with any known genes in the rabbit genome, suggesting some importance to these intergenic sites. The enrichment of selected regions in certain types of transcription factor binding sites suggests a possible role for these regulatory elements during domestication. In addition, the new high-coverage rabbit whole-genome sequences may provide helpful material for further population genetics analyses.
The CSN2 gene encoding β-casein has gained increasing attention in dairy cattle breeding due to the global adoption of A2-oriented selection strategies. However, robust large-scale evidence assessing potential unintended effects on functional traits, particularly fertility, under intensive commercial conditions remains limited. This study evaluated whether selection for the CSN2 A2 β-casein variant is associated with biologically relevant differences in fertility traits in Holstein cows. Reproductive and genomic data from 7826 lactation records of 2773 Holstein cows collected between 2022 and 2025 in a large commercial dairy herd were analyzed. Fertility indicators included days open, number of services per conception, calving interval, first-service conception rate, and pregnancy by 100 days in milk. Mixed-effects models accounting for repeated lactations and cow- and sire-level clustering were applied, and predefined equivalence margins were used to distinguish statistical non-significance from biological irrelevance. Across all evaluated fertility traits, differences among CSN2 genotypes (A1A1, A1A2, and A2A2) were consistently small, biologically negligible, and well within predefined equivalence margins. Differences in days open were within ±2 days, and effect sizes for count and binary traits were close to unity. Parity and calving year significantly influenced reproductive performance, whereas no CSN2 genotype × parity interactions were detected. These findings indicate that selection for the CSN2 A2 β-casein variant does not compromise reproductive performance under intensive commercial management conditions. From a breeding and industry perspective, the results support the implementation of A2-oriented selection strategies without biologically meaningful adverse effects on fertility.
Until the end of the 20th century, the populations of European large carnivores were declining due to loss and fragmentation of habitats, but nowadays their numbers are increasing again. Large carnivores can directly affect ungulate populations and indirectly influence their behaviour. Predators may impact their prey through indirect, non-lethal effects, described by the „landscape of fear” concept. The aim of this study was to investigate available information about the landscape of fear caused by the presence of three main large carnivores in Europe (the brown bear Ursus arctos, the Eurasian lynx Lynx lynx and the grey wolf Canis lupus). A systematic literature review was performed to collect data on the species, habitats and techniques involved in published research and the effects of the „landscape of fear”. 67.86% of prey species in these publications were cervids (e.g. red deer, roe deer) and 32.14% were other ungulates (e.g. wild boar, bison). Our study confirms that European large carnivores have detectable non-lethal effects on their prey species. The „landscape of fear” was revealed in 71.43% of the studies reviewed. The majority (75%) of those results showed changes in habitat use, 15% of studies found altered vigilance and 10% of studies detected differences in vegetation renewal. Perceived predation risk may affect habitat use or foraging patterns of herbivores, and this behavioural change may have cascading local or landscape- scale effects on vegetation and faunal assemblages. Thus, complete protection or sustainable management of these European large predators can also affect landscape-scale wildlife and vegetation patterns.
Allele-specific expression (ASE) reflects the unequal expression of the parental alleles and can imply functional variants in cis-regulatory elements. The conventional ASE detection methods often depend on the presence of heterozygous variants in transcripts or sequencing a large number of individuals, both of which are often limited. In this study, we present a family-based strategy for detecting ASE and potential cis-regulatory elements utilizing both RNA-seq and whole-genome sequencing (WGS) from a pedigree. Using a rabbit family consisting of two divergent parents and their eight offspring, we identified 913 ASE genes by analyzing inheritance patterns of gene expression levels. Expression was classified into three levels—high, medium, and low—and used to define seven distinct expression groups across the family (e.g., H_L: high in the mother, low in the father, and intermediate in the offspring). Many ASE genes lacked heterozygous exonic variants, and inference was achieved via RNA read count patterns. We also pinpointed conserved transcription factor binding sites (TFBS) with sequence variants showing similar inherited genotypic patterns (e.g., AAxBB), suggesting their regulatory roles as eQTLs. Differential gene expression (DEG) analysis between the parents highlighted some candidate genes related to meat production and quality traits. Our findings show that the family-based method using RNA-seq and WGS data is promising for exploring ASE and mapping possible eQTLs.