Association between MYLK4 gene polymorphism and growth traits at different age stages in Anatolian black cattle

Genomics and transcriptomics identify quantitative trait loci affecting growth-related traits in silver pomfret (Pampus argenteus)

Pampus argenteus, a species distributed throughout the Indo-West Pacific, plays a significant role in the yield of aquaculture species. However, cultured P. argenteus has always been characterised by unbalanced growth synchronisation among individuals, slow growth rate, and lack of excellent germplasm resources. Therefore, we conducted mass selection for fast-growing strain P. argenteus for several consecutive years. Various genetic improvement programs have modified its genome sequence through selective pressure, leaving nucleotide signals that can be detected at the genomic level. In the present study, we combined bulked segregant analysis and transcriptome sequencing to identify candidate single nucleotide polymorphisms (SNPs) and key genes for growth-related traits in P. argenteus. A total of 7,280,936 SNPs and 2,212,379 insertions/deletions were identified in the extreme phenotypes of the fast-growing and slow-growing groups. Based on the examination of SNP frequency differences and sliding-window analysis, 42 SNPs were identified as candidate markers. Moreover, 14 of the 42 SNPs linked to growth-related traits were confirmed to be credible SNPs, and eight growth-related genes were screened, namely myb-binding protein 1 A, insulin A/B chains, α-1B adrenoceptor, engulfment and cell motility protein 3, myosin light chain kinase family member 4, insulin receptor located, unconventional myosin-9b, and matrilin-1. An optimal three-factor model (SNP4&SNP12&SNP14) was constructed using the generalized multifactor dimensionality reduction method, and its accuracy was verified as 67.72 %. These results may benefit genetic studies and accelerate genetic improvement of fast-growing strains of P. argenteus.

Identification of novel genetic loci related to dromedary camel (Camelus dromedarius) morphometrics, biomechanics, and behavior by genome-wide association studies

In the realm of animal breeding for sustainability, domestic camels have traditionally been valued for their milk and meat production. However, key aspects such as zoometrics, biomechanics, and behavior have often been overlooked in terms of their genetic foundations. Recognizing this gap, the present study perfomed genome-wide association analyses to identify genetic markers associated with zoometrics-, biomechanics-, and behavior-related traits in dromedary camels (Camelus dromedarius). 16 and 108 genetic markers were significantly associated (q < 0.05) at genome and chromosome-wide levels of significance, respectively, with zoometrics- (width, length, and perimeter/girth), biomechanics- (acceleration, displacement, spatial position, and velocity), and behavior-related traits (general cognition, intelligence, and Intelligence Quotient (IQ)) in dromedaries. In most association loci, the nearest protein-coding genes are linkedto neurodevelopmental and sensory disorders. This suggests that genetic variations related to neural development and sensory perception play crucial roles in shaping a dromedary camel's physical characteristics and behavior. In summary, this research advances our understanding of the genomic basis of essential traits in dromedary camels. Identifying specific genetic markers associated with zoometrics, biomechanics, and behavior provides valuable insights into camel domestication. Moreover, the links between these traits and genes related to neurodevelopmental and sensory disorders highlight the broader implications of domestication and modern selection on the health and welfare of dromedary camels. This knowledge could guide future breeding strategies, fostering a more holistic approach to camel husbandry and ensuring the sustainability of these animals in diverse agricultural contexts.

Characterization of runs of homozygosity islands in American mink using whole-genome sequencing data

The genome-wide analysis of runs of homozygosity (ROH) islands can be an effective strategy for identifying shared variants within a population and uncovering important genomic regions related to complex traits. The current study performed ROH analysis to characterize the genome-wide patterns of homozygosity, identify ROH islands and annotated genes within these candidate regions using whole-genome sequencing data from 100 American mink (Neogale vison). After sequence processing, variants were called using GATK and Samtools pipelines. Subsequent to quality control, 8,373,854 bi-allelic variants identified by both pipelines remained for further analysis. A total of 34,652 ROH segments were identified in all individuals, among which shorter segments (0.3-1 Mb) were abundant throughout the genome, approximately accounting for 84.39% of all ROH. Within these segments, we identified 63 ROH islands housing 156 annotated genes. The genes located in ROH islands were associated with fur quality (EDNRA, FGF2, FOXA2 and SLC24A4), body size/weight (MYLK4, PRIM2, FABP2, EYS and PHF3), immune capacity (IL2, IL21, PTP4A1, SEMA4C, JAK2, CCNA2 and TNIP3) and reproduction (ADAD1, KHDRBS2, INSL6, PGRMC2 and HSPA4L). Furthermore, Gene Ontology and KEGG pathway enrichment analyses revealed 56 and 9 significant terms (FDR-corrected p-value < 0.05), respectively, among which cGMP-PKG signalling pathway, regulation of actin cytoskeleton, and calcium signalling pathway were highlighted due to their functional roles in growth and fur characteristics. This is the first study to present ROH islands in American mink. The candidate genes from ROH islands and functional enrichment analysis suggest possible signatures of selection in response to the mink breeding targets, such as increased body length, reproductive performance and fur quality. These findings contribute to our understanding of genetic characteristics, and provide complementary information to assist with implementation of breeding strategies for genetic improvement in American mink.

Potential status of A1 and A2 variants of bovine beta-casein gene in milk samples of Indian cattle breeds

This study aimed to determine the polymorphism in 7th exon of beta-casein gene (CSN2) gene in seven domestic (Kosali, Tharparkar, Gangatiri, Sahiwal, Gir, Khariar, Motu) and two exotic cattle breeds (Jersey and Holstein-Friesian). Genomic DNA was extracted from 1000 milk samples, and the C > A polymorphism in CSN2 was determined using the tetra-primer amplification refractory mutation system-polymerase chain reaction method. In all Indigenous cattle breeds, the mean frequency of A1A2 and A2A2 genotypes was 0.19 and 0.80, respectively. The A1A1 genotype was absent in all seven domestic cattle breeds. The frequency of the A2A2 genotype was highest in the Gir breed (0.93). However, the Sahiwal, Tharparkar, and Motu breeds also had a higher frequency of A2A2 genotype compared to other breeds. In contrast, Gangatiri breed of India showed lowest frequency of A2A2 genotype. The mean A1 and A2 allele frequency was 0.09 and 0.91, respectively. In exotic breeds, the mean frequencies of the A1A1, A1A2, and A2A2 genotypes were 0.42, 0.55, and 0.03, respectively. Similarly, the mean A1 and A2 allele frequency was 0.69 and 0.31, respectively. This study suggests the high potential of Gir, Sahiwal, Tharparkar, and Motu cattle for A2 milk production since they carry a favorable A2 genotype.

Analysis of Potential Genes and Economic Parameters Associated with Growth and Heat Tolerance in Sheep (Ovis aries)

This study explored the potential genes and economic factors that might be associated with growth and heat tolerance in two sheep breeds. Data on growth performance from the third month to six months of age were obtained based on records. In comparison to Aboudeleik lambs, Barki lambs developed considerably greater starting body weight, final body weight, final body weight gain, daily weight gain, and percentage increase in BW/month. Single nucleotide polymorphisms (SNPs) were found between lambs of the two breeds using PCR-DNA sequencing of CAST, LEP, MYLK4, MEF2B, STAT5A, TRPV1, HSP90AB1, HSPB6, HSF1, ST1P1, and ATP1A1 genes. Lambs from each breed were divided into groups based on detected SNPs in genes related to growth. The least squares means of the differentiated groups revealed a significant correlation of detected SNPs with growth and heat tolerance attributes (p ≤ 0.05). Barki lambs elicited greater total variable costs, total costs, total return, and net return values. The Barki sheep provided the best economic efficiency value when comparing the percentage difference between net profit and economic efficiency. Together with economic considerations, SNPs found may be used as proxies for marker-assisted selection of the best breed of sheep for traits related to growth and heat tolerance.

Estimation of the associations between GH and DGAT1 genes and growth traits by using decision tree in Awassi sheep

GH and DGAT1 are candidate genes associated with growth traits in sheep breeds. This study aims to determine the association between growth traits and GH and DGAT1 gene polymorphism using three statistical methods in Awassi sheep. The polymorphism was detected by the PCR-RFLP method. Three genotypes (AA, AB and BB) were observed for GH gene locus with allele and genotype frequency 0.70(A) and 0.30(B); 0.60(AA), 0.20(AB) and 0.20(BB). Three genotypes (CC, CT and TT) were found for DGAT1 gene locus with allele and genotype frequency 0.58(C) and 0.42(T); 0.47(CC), 0.23(CT) and 0.30(TT). The genes were in agreement with Hardy-Weinberg equilibrium (p > 0.05). CHAID, CRT and GLM were used to identify the association between growth traits and gene polymorphism. The results showed an association between GH locus and body weight and tail length. Also, found an association between DGAT1 locus and tail length. The three methods showed similar results in determining the association between genes and growth traits. Thus, the CHAID and CRT methods can evaluate the association between genes and growth traits.

Determination of the relationship between Anatolian black cattle growth properties and myostatin, GHR and Pit-1 gene

The aim of this study is to determine the relationship between some growth and development characteristics in Anatolian Black cattle from birth to twelve months of age with the Pit-1, GHR and Myostatin genes. PCR-RFLP method was used to detect the polymorphism. Genotype and allele frequencies were found to be AA/AB/BB: 0.096/0.519/0.385 and A/B: 0.356/0.644; AA/AG/GG: 0.346/0.385/0.269 and A/G: 0.538/0.462 in the Pit-1 and GHR genes respectively. Myostatin gene was found to be also monomorphic in all genotypes. Although the chi-square χ² test in the Pit-1 gene showed an agreement to Hardy-Weinberg equilibrium (p > 0.05), in the GHR gene did not showed an agreement (p < 0.05). The results of the statistical analysis indicated an association between Pit-1 and GHR genes polymorphism and growth traits at different stage ages in Anatolian Black cattle. But Pit-1/HinfI gene and GHR/Alul polymorphisms were not found statistically significant in the specified periods, at all characters. On the other hand, since the MSTN/BstF5I gene was found to be monomorphic, no association analysis was performed between the measured values and this gene. In conclusion, mutation of these genes is difficult to suggest as a potential marker in a herd selection regarding the growth and development characteristics.