Kanithaporn Vangnai

Chicken (Gallus gallus domesticus) domestication, likely associated with dry-rice farming in central Thailand, has led to substantial loss of ancestral immune-related genetic diversity in commercial chicken lineages. This study addresses allelic loss by providing the first comprehensive analysis of the highly polymorphic BG1 gene, an MHC-linked marker across the wild–domestic interface in Thailand and Vietnam, using high-depth Illumina amplicon sequencing. Genomic DNA from 47 Thai and Vietnamese chicken populations was extracted using a salting-out protocol following ethical sampling. Allelic variation was examined by targeting the BG1 intron 15–exon 16 region using triplicate PCR and Salus Pro NGS sequencing. Evolutionary dynamics and selection pressures were analyzed using AmpliSAS, MrBayes, and Datamonkey, while AlphaFold 3 was used to predict and validate 3D protein structures. We identified 98 novel alleles and 172 polymorphic sites within the BG1 intron 15–exon 16 region encoding an Ig-like domain. Extensive allele sharing between indigenous chickens and red junglefowl indicated strong balancing selection and trans-species polymorphism. Selection analyses showed that purifying selection conserved structural integrity at codons 9, 13, and 18, while variation at other sites enhanced immune recognition. AlphaFold 3 modeling confirmed conservation of the β-sandwich fold across variants, maintaining stability of the Immunoreceptor Tyrosine-based Inhibition Motif (ITIM). Thus, despite the regional gene flow, geographic isolation has shaped distinct signatures, as evidenced by the presence of 38 unique Thai and 9 unique Vietnamese alleles in addition to breed-specific private markers in the Betong (BG1*TH88), Decoy (BG1*TH91), and Tre (BG1*VN54) populations. A notable adaptive outlier under positive selection (ω = 1.357) was detected in the Dong Tao population, suggesting a recent selective sweep. These findings support the mission of the Siam Chicken Bioresource Project (SCBP) to utilize indigenous breeds as genetic reservoirs and provide a molecular basis for restoring resilience traits in domestic poultry to enhance global food security.

Objective: The objective is to investigate the genetic variation and linkages of Korean native chickens (KNCs), which are regarded as a significant genetic resource due to their distinctive features, however remain inadequately studied in these aspects. In this study, we investigated the genetic variation within five KNC varieties: Korean commercial chicken (KOR-C/M), Silkie (KOR-KS), Leghorn (KOR-LH)—all imported and adapted varieties—and two pureline KNCs: Korean traditional Gray Brown (KOR-KGB) and Korean traditional Yellow Brown (KOR-KYB).Methods: The relationship of KNCs with chicken breeds from Thailand was evaluated using microsatellite genotyping.Results: High genetic diversity was observed among the KNC breeds, with KOR-KYB showing the highest heterozygosity, whereas KOR-C/M exhibited the lowest heterozygosity and signs of inbreeding. The loci MCW0016, ADL0268, MCW0081, MCW0067, MCW0248, MCW0165, ADL0278, and MCW0330 were identified as being under directional selection. Genetic clustering analyses indicated four distinct clusters, with KOR-C/M differing from other KNC breeds. Distinct gene pools were observed between KNC breeds and indigenous and local chicken populations, as well as red junglefowl in Thailand, suggesting that they have evolved separately. However, connections may exist due to shared ancestry and crossbreeding.Conclusion: Clustering analysis revealed that KNC breeds formed a separate group from indigenous and local chickens and red junglefowl in Thailand. The distinct genetic patterns suggest independent evolution of the KNC and local Thai breeds, although shared ancestry and crossbreeding may have introduced some connections. These findings bear significant implications for the conservation and sustainable management of KNC populations.

Objective: Indigenous and local breeds, such as Phuphan chickens, are vital due to their adaptability and nutritional value. However, the precise origin, historical records, and genetic diversity of Phuphan chickens remain unclear. This study aimed to evaluate origin and genetic diversity of four Phuphan chicken groups from the Phuphan Royal Development Study Centre.Methods: This study assesses four groups of Phuphan chicken: Phuphan black 1 (SK-B1), Phuphan black 2 (KU-BM/F), Phuphan white (KU-WM/F), and Phuphan color (KU-VM/F) using 28 microsatellite markers and comparing them with those of other Thai chicken breeds within “The Siam Chicken Bioresource Project” database.Results: The results highlighted significant genetic diversity among these groups (mean expected heterozygosity [He] = 0.623±0.014; Allelic richness [AR] = 4.594±0.124), indicating effective management through the breeding program of the Phuphan Royal Development Study Centre. Population structure analyses revealed distinct gene pools, emphasizing the genetic uniqueness of SK-B1 relative to the other three groups. Bayesian inference validated historical genetic exchanges, primarily among KU-BM/F, KU-WM/F, and KU-VM/F, with limited exchanges involving SK-B1. This suggests that the Phuphan chicken groups share a common lineage, primarily distinguished by variations in plumage color, resulting from residual selection processes. Microsatellite markers pinpointed the loci LEI0234, MCW206, MCW0016, MCW0222, MCW0098, MCW0165, and ADL0278 as potentially subject to directional selection and associated with plumage color variation among the Phuphan chicken groups. Comparative evaluations with other Thai indigenous local chickens and red junglefowl revealed a closer affinity of SK-B1 to existing Thai chicken breeds, suggesting it may represent a variant of these breeds. Alternatively, KU-BM/F, KU-WM/F, and KU-VM/F, which exhibited comparable external characteristics, may constitute a novel breed of Phuphan chicken.Conclusion: The findings may enhance understanding on genetic architecture of Phuphan chicken groups and contribute to Thailand's economic growth while preserving the genetic diversity of the indigenous chickens.

The potential of rice starch types was explored to mimic the fat and improve the stability of chicken sausage during multiple freeze-thaw (F-T) cycles. This study investigated the effect of partial fat replacement with non-waxy and waxy rice starch on the physical properties of chicken sausage during multiple F-T cycles. Sausages were manufactured using eight different formulas (standard fat, reduced-fat, and reduced-fat with both starches at addition levels of 3%, 6%, and 9%). Emulsion stability, cooking loss, color, and texture profile were analyzed as initial qualities. Sausages were stored at -18 oC for seven days and thawed at 4 oC for 17 h for each of three F-T cycles, then thawing loss and texture were evaluated. The result showed that the incorporation of non-waxy and waxy rice starch up to 9% increased the emulsion stability, lightness (L*), and the value of hardness, gumminess, and chewiness of chicken sausage (p<0.05). Multiple F-T cycles lead to mechanical damage and quality deterioration, including water-holding capacity loss and textural change. The thawing loss value of all treatments significantly increased during the F-T cycle. Utilization of waxy rice starch 3% in low-fat chicken sausage exhibited optimum physical properties and minimum thawing loss and texture change during multiple F-T cycles.

Objective: The remarkable adaptability to the environment, high growth rate, meat with good taste and aroma, and ornamental appearance of the Pradu Hang Dam (PDH) and Samae Dam (SD) chickens make them valuable for improvement of poultry production to enhance food security. However, despite their close phenotypic similarity, distinct classification of PDH and SD chickens remains controversial. Thus, this study aimed to clarify genetic origins and variation between PDH and SD chickens, genetic diversity and structures of PDH and SD chickens.Methods: This study analyzed 5 populations of PDH and 2 populations of SD chickens using 28 microsatellite markers and compared with those of other indigenous and local chicken breeds using Thailand's "The Siam Chicken Bioresource Project" database.Results: Considerably high genetic variability was observed within PDH (370 total alleles; 4.086±0.312 alleles/locus) and SD chickens (179 total alleles; 3.607±0.349 alleles/locus). A partial overlap of gene pools was observed between SD chickens from the Department of Livestock, Uthai Thani (SD1) and PDH chickens, suggesting a potentially close relationship between the two chicken breeds. A gene pool that partially overlapped with that of the red junglefowl was observed in the SD chicken population from the Sanhawat Farm Uthai Thani population (SD2). Distinct subclusters were observed within SD chickens, indicating the possibility that genetic differentiation occurred early in the process of establishment of SD chickens.Conclusion: These findings could offer valuable insights into genetic verification of Thai local chicken breeds and their sustainable conservation and utilization.

The relationship between the chemical structures of six flavonoids and their abilities to inhibit the formation of polycyclic aromatic hydrocarbons (PAHs) in a heated meat model system was investigated. The PAH8 forming in samples was analyzed by using QuEChERS coupled GC-MS. Inhibitory effects of PAHs were myricetin (72.1%) > morin (55.7%) > quercetin (57.3%) > kaempferol (49.9%) > rutin (32.7%) > taxifolin (30.2%). The antioxidant activities of these flavonoids, assessed through (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity assay (DPPH), [2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)] free radical scavenging activity assay (ABTS) and ferric ion reducing antioxidant power assay (FRAP) assays, exhibited a significant negative correlation with PAH reduction. Notably, myricetin that contained three hydroxyl groups on the B-ring, along with a 2,3-double bond in conjugation with a 4-keto moiety on the C-ring, demonstrated strong antioxidant properties and free radical scavenging abilities, which significantly contributed to their ability to inhibit PAH formation. However, rutin and taxifolin, substituted at the C-3 position of the C-ring, decreased the PAH inhibitory activity. The ABTS assay proved the most effective in demonstrating the correlation between flavonoid antioxidant properties and their capacity to inhibit PAH formation in heated meat model systems. Thus, the inhibition of PAHs can be achieved by dietary flavonoids according to their chemical structures.