Prioritizacija kandidatnih genetskih označevalcev za poletni ekcem pri konjih

Pevc, Špela (avtor), Potočnik, Klemen (mentor), Šimon, Martin (komentor)

Poletni ekcem oziroma preobčutljivost na pike insektov (IBH) je alergijska kožna bolezen pri konjih, ki jo povzročijo antigeni v slini mušic Culicoides spp. Povzroča srbečico, kar posledično privede do brezdlačnih mest po grivi, vihru, repu in trebuhu, odebelitev kože ter prhljaj. Na prizadetih mestih lahko pride tudi do sekundarnih okužb. Namen naše raziskave je bil določiti nove potencialne kandidatne označevalce in gene, povezane z IBH. Za odkrivanje novih potencialnih označevalcev smo primerjali genotipe obolelega žrebca Arkana in zdrave kobile Miše ter upoštevali tiste, ki so se pri Arkanu pojavljali v manj kot 10 %, pri Miši pa pogosteje kot v 10 % v populaciji 432 konj. Odkrili smo 66 označevalcev za 65 SNP-jev, za katere smo nato poiskali dodatne SNP-je v vezavnem ravnovesju (Animal-SNPAtlas), kar nam je omogočilo pridobitev še 129 SNP-jev. SNP-je smo prioritizirali glede na prehodno povezavo z IBH, ali imajo GERP oceno 2 ali več, ali ležijo v ohranjeni regiji, imajo regulatorno ortologno regijo pri prašiču, človeku in/ali miši, ali se nahajajo v CpG otoku, vplivajo na poliadenilacijo, ali pa vplivajo na vezavo miRNA. Poleg tega pa smo prioritizirali tudi en SNP, ki se nahaja v 5'UTR regiji. Skupno smo tako določili 26 prioritiziranih označevalcev na 23 genih ter treh medgenskih regijah. Ostalih 40 potencialnih kandidatov ima vpliv na 23 genov. Analizirali smo tudi genotipa dveh obolelih posavskih konj, ki sta imela z Arkanom določene skupne genetske označevalce, vendar nobenega, ki bi bil skupen vsem trem. Prav tako smo v raziskavo vključili potomca Arkana in Miše, Amorja in Megi, ki sta na določenih označevalcih podedovala očetov genotip, zato ju bo potrebno v prihodnje podrobneje spremljati. Naše ugotovitve tako potrjujejo ugotovitve na drugih populacijah konj, da na razvoj IBH ne vpliva samo en označevalec ali gen, temveč verjetno poleg kombinacije le teh tudi stanje imunskega sistema konja in okoljski dejavniki. Za boljše razumevanje genetskega ozadja te bolezni so potrebne nadaljnje raziskave ter večje število vzorcev obolelih konj.

• Jezik: Slovenski jezik
• Ključne besede: konji, alergije, piki insektov, preobčutljivost, poletni ekcem, genetika
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: BF - Biotehniška fakulteta
• Leto izida: 2025
• PID: 20.500.12556/RUL-167592
• COBISS.SI-ID: 227779075
• Datum objave v RUL: 02.03.2025

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Prioritization of candidate genetic markers for sweet itch in horses

Izvleček

Sweet itch or insect bite hypersensitivity (IBH) is an allergic skin disease in horses caused by antigens in the saliva of mosquitoes of the genus Culicoides spp. It leads to itching, bald patches on the mane, withers, tail, and belly, as well as skin thickening and scaling. Secondary infections can also occur in the affected areas. The aim of our study was to identify new potential candidate markers and genes associated with IBH. To identify new potential markers, we compared the genotypes of the affected stallion, Arkan, and the healthy mare, Miša, considering those that appeared in less than 10% of Arkan’s genotype but in more than 10% of Miša’s genotype within a population of 432 horses. We identified 66 markers for 65 SNPs, which we then used to search for linked SNPs in linkage disequilibrium (LD) (Animal-SNPAtlas), which led to the identification of an additional 129 SNPs. The SNPs were prioritized based on their previous association with IBH, whether they had a GERP score of 2 or higher, whether they were located in a conserved region, overlap with a regulatory orthologous region in pigs, humans, and/or mice, were located within a CpG island, influenced polyadenylation, or affected miRNA binding. Additionally, we prioritized one SNP located in the 5'UTR region. In total, we prioritized 26 markers in 23 genes and three intergenic regions. The remaining 40 potential candidates affect 23 genes. We also analyzed genotypes of two affected Posavec horses that shared certain genetic markers with Arkan, but none that were common to all three. We also included in the study the offspring of Arkan and Miša, Amor and Megi, who inherited the paternal genotype on certain markers, so they will need to be monitored in more detail in the future. Our findings thus confirm the results observed in other horse populations, indicating that the development of IBH is not influenced by a single marker or gene alone, but rather by their combination, along with the horse's immune system status and environmental factors. Further studies with larger cohort of affected horses are needed to better understand the genetic background of this disease.

• Ključne besede: horses, allergy, insect bite hypersensitivity, sweet itch, genetics