Varietas ikan mas tumbuh cepat dan tahan infeksi virus Koiherpes: produksi keturunan kedua

Abstract

Penelitian ini dilakukan untuk menghasilkan ikan mas transgenik generasi kedua (F2) yang tumbuh cepat dan tahan infeksi KHV. Ikan transgenik F2 diproduksi dengan cara mengawinkan antara ikan mas betina non-transgenik (B) yang mempunyai marka molekuler ketahanan terhadap KHV dan ikan mas jantan (Jg) transgenik generasi pertama (F1) yang mengekspresikan gen hormon pertumbuhan. Hasil penelitian menunjukkan bahwa dari enam persilangan, peningkatan bobot tubuh, sintasan di kolam, dan biomassa tertinggi diperoleh pada persilangan B1xJg2, yaitu berturut-turut sekitar 31%, 70%, dan 123% dibandingkan dengan kontrol non-transgenik. Analisis PCR dan uji tantang dengan virus KHV menunjukkan keterkaitan yang kuat antara keberadaan marka molekuler dengan sintasan ikan. Selanjutnya, ikan transgenik F2 juga diproduksi dengan cara menyilangkan antar ikan transgenik F1 yang mempunyai marka molekuler (BgxJg). Hasil penelitian menunjukkan bahwa rerata bobot populasi (RBP) ikan dari sembilan persilangan BgxJg adalah sekitar 47% lebih tinggi daripada RBP ikan non-transgenik, sedangkan sintasannya relatif sama kecuali persilangan B2xJ1 dengan sintasan sangat rendah. Analisis PCR menunjukkan bahwa ikan yang berukuran minimal 4 kali lebih tinggi daripada RBP semua transgenik, sekitar 80% ikan dengan bobot sekitar 2 kali lebih tinggi daripada RBP adalah transgenik, sedangkan yang berukuran jauh lebih kecil dari RBP semua bukan transgenik. Selanjutnya, persentase keturunan BgxJg transgenik dan membawa marka adalah sekitar 42%, dan ikan ini akan diidentifikasi lebih lanjut untuk memperoleh ikan transgenik homosigot. Sebagai kesimpulan bahwa ikan transgenik F2 tumbuh cepat dan tahan KHV telah berhasil diproduksi.

This research was performed to produce common carp transgenic second generation (F2) that fast growth and resistant to KHV. Transgenic F2 fish was produced by crossing between female non-transgenic common carp (B) having a molecular marker for resistant to KHV infection and male transgenic F1 expressing growth hormone gene (Jg). The results showed that of the six crosses, the highest increased body weight, pond survival, and biomass was obtained in B1xJg2, i.e. 31%, 70%, and 123% compared with control non-transgenic fish, respectively. The PCR analysis and KHV challenge test showed strong linkage between the present of molecular marker and survival of fish. Furthermore, F2 transgenic fish were also produced by crossing between F1 transgenic fish that have molecular markers (BgxJg). The results showed that average body weight of population (ABWP) from nine crosses BgxJg was about 47% higher than the ABWP of nontransgenic progenies, while their survival was similar except for B2xJ1 progenies that have lower survival. The result of PCR analysis showed that all the fish which the average body weight (ABW) of at least 4 times higher than the AWBP was carrying the transgene, approximately 80% of the fish with ABW of about 2 times higher than the ABWP was carrying the transgene, while all smaller fish than the ABWP did not carry the transgene. In addition, percentage of BgxJg progenies as transgenic fish and have the molecular marker was about 42%, and those fish will be indentified further to obtain a homozygous transgenic fish which is very useful in mass production of transgenic fish. As conclusion that the fast-growing transgenic F2 and KHV-resistant common carp has successfully been obtained.