Keragaan Gen Pituitary-Specipik Transcription Factor-1 Locus Pit-1-Hinf1 dan Pengaruhnya terhadap Bobot Tumbuh Induk, dan Produksi Susu Pada Domba Lokal

Abstract

ABSTRACT SUMANTRI, C., D. HERDIANA, A. FARAJALLAH and D. RAHMAT. 2009. Polymorphism of Pituitary-Specific Transcription Factor-1 (Pit-1) Gene at Locus (Pit-1-Hinf1) and its effects on dam body weight and milk production of local sheeps. JITV 14(3): 222-229. Pituitary-Specific Transcription Factor-1 (Pit-1) is a transcription factor with critical role in the transcriptional regulation of multiple genes in the pituitary. The objective of this research was to identify polymorphism of Pituitary-Specific Transcription Factor-1 (Pit-1) gene at Locus (Pit-1-Hinf1) and to investigate any possible associations of Pit-1 genotypes on dam body weight, milk production and milk quality in local sheep at the Jonggol Animal Science Teaching and Research Unit (JASTRU), Fact. Anim. Sci. Bogor. Agric. Univ. A total number of 161 blood samples were collected from 3 local sheep, namely Garut from Wanaraja (55 hd), Garut from Margawati (23 hd) and lactating ewes (83 hd) from JASTRU farm in Bogor. Genomic DNAs were extracted by a standard phenol-chloroform protocol and amplified by a polymerase chain reaction (PCR) techniques, then PCR products were digested with a Hinf1 enzyme restriction. Fragments of Pit-1gene at locus Pit-1-Hinf1 was detected by a silver-staining method. A length of 637 base pairs (bps) of the Pit-1 gene of local sheep was successfully amplified. The Hinf1 restriction enzyme cut the PCR product into three different length of fragments succesively at 345, 137, and 115 bps designated as A allele; whilst B allele had four fragments at 283, 137, 115, and 62 bps respectively. The locus of Pit-1-Hinf1 was polymorphic in local sheep from Jonggol, however it was monomorfic in Garut sheep. The frequencies of A and B alleles were 0,806 and 0,194 respectively. Pit-1 genotypes had no significant effect on dam body weight and milk production. This result is indicating that the use of single locus Pit-1-Hinf1 in Pit-1 gen is less effective to be used as a candidate in selecting dam body weight and milk production in these three local sheep

ABSTRAK SUMANTRI, C., D. HERDIANA, A. FARAJALLAH dan D. RAHMAT. 2009. Keragaman Gen Pituitary-Specific Transcription Factor-1 Lokus Pit-1-Hinf1 dan pengaruhnya terhadap bobot tubuh induk dan produksi susu pada domba lokal. JITV 14(3): 222-229. Gen pituitary-Spesific Transcription Factor-1 (Pit-1) adalah faktor transkripsi khusus untuk ekspresi gen penyandi hormon pertumbuhan dan hormon prolaktin dan faktor transkripsi dibutuhkan untuk penempelan enzim RNA polymerase pada bagian promotor suatu gen. Penelititian ini bertujuan mengidentifikasi polimorfisme gen Pituitary-specfic Transcription Factor-1/Pit-1 (lokus Pit-1-Hinf1) dan menganalisis hubungan antara genotipe Pit-1 dari lokus Pit-1-HinfI dengan bobot tubuh induk dan produksi susu pada domba lokal di Unit Pendidikan dan Penelitian Peternakan Jonggol (UP3J). Sebanyak 161 sampel darah dikoleksi dari tiga domba lokal, yaitu Garut dari Wanaraja (55 ekor), Garut dari Margawati (23 ekor) dan domba lokal dari Jonggol (83 ekor). Genom DNA diekstrak menggunakan protokol phenol-khloroform dan diamplifikasi dengan teknik polymerase chain reaction (PCR), kemudian PCR produk dipotong dengan enzim. Potongan fragmen dari gen Pit-1 lokus Pit1-HinfI dideteksi dengan metoda pewarnaan perak. Suatu basa dengan panjang 637 pb (PB) dari gen Pit-1 berhasil diamplifikasi dari domba lokal. Enzim pemotong Hinf1 memotong produk PCR kedalam tiga fragmen berbeda berurutan pada 345, 137dan 115 dan dinyatakan sebagai alel A; sedangkan alel B mempunyai empat potongan fragmen masing-masing pada 283, 137, 115, dan 62. Lokus Pit-1-HinfI polimorfik pada domba lokal dari Jonggol, tetapi monomorfik pada domba Garut. Frekuensi dari alel A dan B masing-masing 0,806 dan 0,194. Genotipe Pit-1-Hnf1 tidak berpengaruh nyata terhadap bobot tubuh dan produksi susu dari domba induk pengamatan. Ini mengindikasikan penggunaan lokus tunggal Pit-1-Hnf1 dari gen Pit-1 tidak begitu efektif kuat untuk dipakai sebagai satu kandidat dalam seleksi bobot tubuh induk dan produksi susu dari ketiga grup domba lokal pengamatan.