| dc.description.abstract | Pigmentasi warna rambut merupakan salah satu sifat kualitatif yang memiliki peran penting pada produktivitas dan adaptabilitas terhadap lingkungan. Pada sapi bali (Bos javanicus) warna rambut normal jantan berwarna hitam dan pada betina berwarna merah bata, namun ditemukan adanya abnormalitas pada warna rambut sapi bali seperti white-spotted dan albino yang tidak sesuai dengan kriteria bibit sapi bali. Fenomena albino merupakan kelainan yang disebabkan oleh faktor genetik.
Gen TYR yang mengenkripsi enzim tyrosinase untuk mensintesis melanin telah digunakan untuk mengidentifikasi abnormalitas warna rambut yaitu albinisme pada hewan maupun ternak. Penanda genetik Gen TYR sangat penting digunakan untuk mengidentifikasi fenomena albinisme pada sapi bali albino. Sapi tersebut merupakan sapi yang mengalami kelainan secara genetik sehingga tidak sesuai dengan kriteria bibit sapi bali yang telah diatur pada Standar Nasional Indonesia (SNI). Penelitian terkait ekspresi dan keragaman gen tyrosinase (TYR) pada sapi bali albino belum pernah dilaporkan. Penelitian ini bertujuan untuk mengidentifikasi ekspresi dan keragaman gen tyrosinase pada sapi bali, di wilayah pengkodean ekson 1 gen TYR dan menganalisis keterkaitannya dengan abnormalitas warna rambut pada sapi bali.
Penelitian telah dilaksanakan pada bulan Juni sampai November 2023 di Laboratorium Genetika Molekuler, Divisi Pemuliaan dan Genetika Ternak, Fakultas Peternakan, IPB University. Pengambilan sampel darah sapi bali warna rambut normal dan albino dilakukan di Desa Taro dan Sentra Ternak Daerah Sobangan, Provinsi Bali. Penelitian menggunakan sebanyak 189 sampel darah yang meliputi: sapi bali warna rambut normal (n=53); bali tutul (n=11); bali albino (n=17) dan sapi simmental (n=37); limousin (n=14); madura (n=21); peranakan ongole (PO) (n=36) sebagai pembanding.
Analisis transkriptomik menggunakan ekstraksi RNA dengan Protokol Geneaid™. Reverse Transcriptase cDNA dilakukan dengan menggunakan protokol kit cDNA synthesis (Toyobo) dan kuantifikasi ekspresi gen TYR menggunakan quantitative real time PCR (qRT-PCR). Analisis genomik, keragaman gen TYR menggunakan metode PCR-Direct sequencing, genotiping (PCR-RFLP). Ekspresi gen dianalisis menggunakan uji-T dengan bantuan software SPSS versi 29. Keragaman gen TYR dianalisis menggunakan program Finct TV, BioEdit, MEGA, dan POPGENE Versi 1.32.
Hasil analisis ekspresi gen TYR pada sapi bali normal dan sapi bali albino menunjukkan signifikan (P<0,05). Analisis keragaman menunjukkan bahwa terdapat dua mutasi gen TYR (SNP g. 939A>G dan SNP g. 887C>T) pada sapi bali. SNP tersebut tidak dapat digunakan sebagai penanda genetik untuk warna rambut pada sapi bali, namun, SNP g. 939A>G merupakan SNP baru yang hanya ditemukan pada sapi bali dan tidak ditemukan pada jenis sapi lain. SNP g. 939A>G bersifat polimorfik pada sapi bali sedangkan pada sapi madura, simmental, limousin, dan peranakan ongole (PO) bersifat monomorfik. Simpulan bahwa gen TYR ekson 1 pada sapi bali tidak dapat dijadikan penanda genetik untuk warna rambut albino. | id |
| dc.description.abstract | Coat color pigmentation is a qualitative trait that plays a crucial role in productivity and adaptability to the environment. In Bali cattle (Bos javanicus), the normal coat color for males is black, and for females, it is brick red. However, abnormalities in coat color, such as white-spotted and albino, have been found in bali cattle, which do not conform to the criteria of bali cattle seedlings. The albino phenomenon is a genetic disorder.
The TYR gene, which encodes the enzyme tyrosinase for melanin synthesis, has been used to identify abnormalities in coat color, such as albinism, in animals and livestock. The genetic marker TYR gene is crucial for identifying albinism phenomena in albino bali cattle. These cattle experience genetic abnormalities that do not conform to the criteria of bali cattle seedlings as regulated by the Indonesian National Standard (SNI). Research on the expression and diversity of the tyrosinase (TYR) gene in albino bali cattle has yet to be reported. This study aims to identify the expression and diversity of the tyrosinase gene in bali cattle, specifically in the coding region of exon 1 of the TYR gene, and to analyze its correlation with coat color abnormalities in bali cattle.
The study was conducted from June to November 2023 at the Molecular Genetics Laboratory, Animal Breeding and Genetics Division, Faculty of Animal Husbandry, IPB University. Blood samples from regular and albino bali cattle were collected from Taro Village and the Livestock Center in Sobangan District, Bali Province. The study used a total of 189 blood samples, including normal-coated bali cattle (n=53), spotted bali cattle (n=11), albino bali cattle (n=17); simmental cattle (n=37); limousin cattle (n=14); madura cattle (n=21); and ongole crossbred cattle (PO) (n=36) as a comparison.
Transcriptomic analysis was performed using RNA extraction with the Geneaid™ protocol. Reverse Transcriptase cDNA was synthesized using the cDNA synthesis kit protocol (Toyobo), and the expression of the TYR gene was quantified using quantitative real-time PCR (qRT-PCR). Genomic analysis and TYR gene diversity were analyzed using the PCR-Direct sequencing method, genotyping (PCR-RFLP). Gene expression was analyzed using t-tests with SPSS software version 29. TYR gene diversity was analyzed using Finct TV, BioEdit, MEGA, and POPGENE Version 1.32.
TYR gene expression analysis results in regular and albino bali cattle showed significance (P<0.05). Diversity analysis revealed two TYR gene mutations (SNP g. 939A>G and SNP g. 887C>T) in bali cattle. However, these SNPs could not be used as genetic markers for coat color in bali cattle—SNP g. 939A>G is a novel SNP found only in bali cattle, not other breeds. SNP g. 939A>G was polymorphic in bali cattle, whereas in madura, simmental, limousin, and ongole crossbred cattle (PO), it was monomorphic. The conclusion was that the TYR exon 1 gene in Bali cattle cannot be used as a genetic marker for albino hair color | id |
