Investigating the Polymorphism of TLR2 Gene and its Association with Somatic Cell Count in the Milk of Aleppo Goats Raised in Sanliurfa Province

Yıl 2025, Cilt: 18 Sayı: 2, 154 - 159, 31.12.2025

Sultan Göllü , Mehmet Batmaz , Mehmet Osman Atlı , Faruk Bozkaya

https://doi.org/10.47027/duvetfd.1739798

https://izlik.org/JA94BG75LU

Öz

Mastitis is an important problem in the dairy industry which reduces milk yield and quality as well as causes economic loses. Somatic cell count (SCC) in milk is strongly associated to intra-mammary infections, thus represents an indicator of mammary health and milk quality. Toll-like receptor 2 (TLR2) is a member of of the Toll-like receptor family which is responsible for recognition of pathogens causing mastitis. Studies have shown that a 739G>A polymorphism in TLR2 gene is associated with SCC in milk in goat. This study aimed to determine the in the TLR2 gene (Toll-Like-Receptor 2) in Aleppo goats in Sanliurfa and to investigate whether there is a relationship between this polymorphism and somatic cell count (SCC) in milk. Milk samples (50 ml) were collected twice at one-month intervals from 100 goats in five farms raising Aleppo goats in Sanliurfa. The milk samples were used for DNA isolation and determination of SCC. The 442 bp region of the target TLR2 gene was amplified by PCR, and the PCR products were digested with the VspI enzyme and subjected to 2% agarose gel electrophoresis. Three genotypes, GG, GA, and AA, were observed in the entire sample. Of the 100 genotyped samples, 95 were GG, four were GA, and one was AA. The frequency of allele G was calculated as 0.97, and the frequency of allele A was calculated as 0.03. Mean SCC determined in milk samples from individuals carrying the A allele was found to be significantly lower. In conclusion, the G/A polymorphism of the TLR2 gene has a significant effect on SCC and this polymorphism can be used as a marker for selection purposes in breeding programs aimed at improving SCC and mastitis resistance in Aleppo goats.

Anahtar Kelimeler

Goat , PCR , polymorphism , somatic cell count , TLR2

Destekleyen Kurum

This study was financially supported by Harran University Scientific Research Council (Grant No: 22067)

Proje Numarası

This study was financially supported by Harran University Scientific Research Council (Grant No: 22067)

Teşekkür

This study was financially supported by Harran University Scientific Research Council (Grant No: 22067)

Şanlıurfa İlinde Yetiştirilen Halep Keçilerinde TLR2 Genindeki Polimorfizm ve Sütteki Somatik Hücre Sayısı Arasındaki İlişkinin Araştırılması

https://izlik.org/JA94BG75LU

Öz

Mastitis, süt endüstrisinde süt verimini ve kalitesini düşüren ve ekonomik kayıplara neden olan önemli bir sorundur. Sütteki somatik hücre sayısı (SCC), meme içi enfeksiyonlarla güçlü bir şekilde ilişkilidir ve bu nedenle meme sağlığı ve süt kalitesinin bir göstergesidir. Toll-like reseptör 2 (TLR2), mastitise neden olan patojenlerin tanınmasından sorumlu olan Toll-like reseptör ailesinin bir üyesidir. Araştırmalar, TLR2 genindeki 739G>A polimorfizminin keçi sütünde SCC ile ilişkili olduğunu göstermiştir. Sunulan bu çalışmada Şanlıurfa’daki Halep keçilerinde TLR2 genindeki (Toll-Like-Receptor 2) 739G>A polimorfizminin belirlenmesi ve bu polimorfizm ile sütteki somatik hücre sayısı (SHS) arasında ilişki olup olmadığının araştırılması amaçlanmıştır. Şanlıurfa’da Halep keçisi yetiştiren 5 işletmedeki 100 keçiden birer aylık arayla iki kez 50 ml süt örneği alındı. Süt örnekleri DNA izolasyonu ve SHS’nin belirlenmesi amacıyla kullanıldı. Hedef TLR2 geninin 442 bç’lik kısmı PCR işlemi ile çoğaltıldı ve VspI enzimi ile kesilen PCR ürünleri %2’lik agaroz jel elektroforezine tabi tutuldu. Tüm örneklem içerisinde GG, GA ve AA şeklinde üç genotip gözlendi. Genotiplenen 100 örnekten 95’inin GG, dördünün GA ve birinin ise AA genotipinde olduğu gözlendi. Allel G’nin frekansı 0.97, allel’nın A frekansı ise 0.03 hesaplandı. A allelini taşıyan bireylerin süt örneklerinde belirlenen ortalama SHS'nin önemli ölçüde daha düşük olduğu bulunmuştur. Sonuç olarak, TLR2 geninin G/A polimorfizmi SHS üzerinde önemli bir etkiye sahiptir ve bu polimorfizm Halep keçilerinde SCC ve mastitis direncini iyileştirmeyi amaçlayan ıslah programlarında seçim amaçlı bir belirteç olarak kullanılabilir.

Anahtar Kelimeler

Keçi , PCR , polimorfizm , somatik hücre sayısı , TLR2

Proje Numarası

This study was financially supported by Harran University Scientific Research Council (Grant No: 22067)

Kaynakça

• Saikia D, Hassani MI, Walia A (2022). Goat milk and its nutraceutical properties. Int J Appl Res., 8(4):119-122.
• Ogorevc J, Simčič M, Zorc M, Škrjanc M, Dovč, P (2019). TLR2 polymorphism (rs650082970) is associated with somatic cell count in goat milk. Peer J., 7:e7340.
• Haenlein GFW (2002). Relationship of somatic cell counts in goat milk to mastitis and productivity. Small Ruminant Res., 45(2):163-178.
• Smistad M, Inglingstad RA, Vatne MK, Franklin FV, Hansen BG, Skeie S Porcellato D (2025). Somatic cell count in dairy goats II: udder health monitoring at goat and herd level. BMC Veterinary Res, 21(1):157.
• Rupp R, Clément,V, Piacere A, Robert-Granié C, Manfredi E (2011). Genetic parameters for milk somatic cell score and relationship with production and udder type traits in dairy Alpine and Saanen primiparous goats. J Dairy Sci, 94(7):3629-3634.
• Leitner G, Silanikove N, Merin U (2008). Estimate of milk and curd yield loss of sheep and goats with intrammamary infection and its relation to somatic cell count. Small Ruminant Res., 74(1-3):221-225.
• Silanikove N, Merin U, Leitner G (2014). On effects of subclinical mastitis and stage of lactation on milk quality in goats. Small Ruminant Res., 122(1-3):76-82.
• Gay NJ, Gangloff M (2007). Structure and function of Toll receptors and their ligands. Annu. Rev. Biochem. 76:141-165.
• Kaisho T, Akira S (2006). Toll-like receptor function and signalling. J. Allergy Clin. Immunol., 117:979-987.
• Krutzik SR, Ochoa MT, Siebling PA, Uematsu S, Ng YW, Legaspi A, Liu PT, Cole ST, Godowski PJ, Maeda Y, Sarno EN, Norgard MV, Brennan PJ, Akira S, Rea TH, Modlin RL (2003). Activation and regulation of Toll-likereceptors 2 and 1 in human leprosy. Nat. Med., 9:525–532.
• Świderek WP, Bhide MR, Gruszczyńska J, Soltis K, Witkowska D, Mikula I (2006). Toll-like receptor gene polymorphism and its relationship with somatic cell concentration and natural bacterial infections of the mammary gland in sheep. Folia Microbiol., 51(6):647-652.
• Sindhu P, Magotra A, Dhundwal K, Chaudhary P, Garg AR (2025). Association of toll like receptor-4 immune gene polymorphism with production, clinical mastitis and fertility disorders in Hardhenu (Bos taurus x Bos indicus) cattle. Nucleus, 1-14.
• Russell CD, Widdison S, Leigh JA, Coffey TJ (2012). Identification of single nucleotide polymorphisms in the bovine Toll-like receptor 1 gene and association with health traits in cattle. Vet. Res.,43:1-12.
• Soquila SS, de Guia ACM, Medina NP, Mingala, CN (2022). Molecular Characterization and Gene Expression of TLR4 Gene Associated with Mastitis in Goats. Indonesian J of Anim Vet Sci. 27(4):159-169.
• Ruiz-Rodriguez CT, Brandt JR, Oliverio R, Ishida Y, Guedj N, Garrett EF, Roca AL (2017). Polymorphisms of the toll-like receptor 2 of goats (Capra hircus) may be associated with somatic cell count in milk. Anim Biotech., 28(2):112-119.
• Barıtcı İ, Adıgüzel C (2017). Halep Damascus, Şam Keçisi Yetiştiriciliği. Dicle Üniv. Fen Bilimleri Enst. Derg, 6(1):39-42.
• Liu YF, Gao JL, Yang YF, Ku T, Zan LS (2014). Novel extraction method of genomic DNA suitable for long-fragment amplification from small amounts of milk. J Dairy Sci., 97(11):6804-6809.
• Sambrook J, Fritsch EF, Maniatis T (1989). Molecular Cloning-A Laboratory Manual, Second ed. Cold Spring Harbor Laboratory Press, NY.
• Cedden, F, Kor A, Keskin S (2002). Laktasyonun geç döneminde keçi sütünde somatik hücre sayımı; yaş, süt verimi ve bazı meme özellikleri ile olan ilişkileri. Yuzuncu Yıl Univ. J Agricultural Sci., 12(2):63-67.
• Eyduran E, Yilmaz, I, Kaygisiz A, Aktas, ZM (2013). An investigation on relationship between lactation milk yield, somatic cell count and uddert raits in first lactation Turkish Saanen Goat using different statistical techniques. J Anim. Plant Sci., 23(4):956-963.
• Patır B, Yıldız N, İncili AK Gürses M (2012). Keçi Sütünde Somatik Hücre Sayısı ile Toplam Mezofilik Aerob Bakteri Sayısı ve Bazı Yetiştiricilik Özellikleri Arasındaki İlişki. FÜ Sağ. Bil. Vet. Derg., 26(3):145-150.
• Orman A, Günay A, Balci F, Koyuncu M (2011). Monitoring of somatic cell count variations during lactation in primiparous and multiparous Turkish Saanen goats (Caprahircus). Turkish J Vet Anim Sci., 35(3):167-175.
• Can A, Yılmaz İ (2022). MilkYield, Fertility, Udder Characteristics, and Raw Milk Somatic Cell Count of the Damascus Goats Reared in Iğdır Conditions. Uluslararası Tarım ve Yaban Hayatı Bilimleri Dergisi, 8(2):358-367.
• Safari D, Evrig N., Seyed Sharifi R, Shakouri MD, Vahedi V, Evrigh RK (2021). Identification of single nucleotide polymorphism in exon 3 of TLR4 gene and its association with somatic cell count in dairy cattle. Journal of Animal Environment, 13(1):47-52.
• Wang H, Yu G, Yu H, Gu M, Roldan-Montes V, Cardoso DF, Hurtado-Lugo N A, do Nascimento AV, Santos DJDA, Scalez DCB, Tonhati H (2020). Polymorphisms in TLR4 gene associated with somatic cell score in Water buffaloes (Bubalus bubalis). Frontiers in Veterinary Science 7:568249.
• Bishnoi S, Jyotsana B, Kumar V, Prakash V, Ranjan R, Narnaware SD, Pannu U (2024). Toll like receptor 4 (TLR4) gene polymorphism and its association with somatic cell score and milk production traits in Indian dromedary camels. Animal Biotechnology, 35(1):2331642.
• Zhang J, Meng X, Li J (2015). Characterization of TLR2, NOD2, and related cytokines in mammary glands infected by Staphylococcus aureus in a rat model. Acta Veterinaria Scandinavica, 57(1):25.
• Zhang X, Wang L, Chen W, Song X, Wang M, Ma X, Wang, C (2025). Staphylococcus aureus Mastitis: A Time-Course Transcriptome of Immune Activation in Small-Tailed Han Sheep. Pathogens,14(11):1133.
• El-Sayed A, Elshopakey G, Ateya A (2025). Evaluating gene expression and biomarkers for mastitis resistance in Barki sheep. Scientific Reports, 15(1):20127.