초파리의 v. pr, sp 그리고 sable 돌연변이주에서 그 기능을 회복시키는 억제유전자인 $su(s)^2$ 유전자를 gypsy-transposable element tagging 방법으로 cloning하였다. 우선 8-11 kb 크기의 DNA sequence를 $su(s)^2$, $pr^{bw}cn$ 초파리로부터 준비하여 pUC9 vector의 Hind III site에 삽입시켜 genomic library를 제조하였다. 재조합 plasmid를 $^{32}p$로 label시킨 gypsy probe를 사용하여 posi ti ve clone을 찾아내고 제한효소로 분석하여 다시 골라내었다. 이 중에서 $su(s)^2$ sequence를 가지는 clone은 최종적으로 Oregon-R $su(s)^2$; $pr^{bw}cn$, $pr^{bw}cn$ 초파리들의 거대염색체에 in situ hybridization시켜 확인하였다. pYDS 2라고 명명된 이 $su(s)^2$ clone의 restriction map을 작성한 결과 $su(s)^+$와는 달리 약 1.5 kb의 또다른 DNA sequence가 들어가 있음이 확인되었다.
The suppressor of sable mutant allele [$su(s)^2$] of Drosophila melanogaster was cloned by the use of gypsy-transposable element tagging technique. The $su(s)^2$; $pr^{bw}cn$ genomic library of 8-11 kb size-range was prepared into the Hind III site of pUC 9 vector. The recombinant plasmids were screened with $^{32}P$-labeled gypsy probe and the positive clones were rescreened by restriction endonuclease analysis. The presence of $su(s)^2$ sequence was confirmed by in situ hybridization of the biotinylated probe to the polytene chromosomes of $su(s)^2$; $pr^{bw}cn$, $pr^{bw}cn$ and Oregon-R strains. The restriction map of the $su(s)^2$ clone (named pYDS 2) was shown to be different from that of $su(s)^+$. The pYDS 2 contained another DNA sequence, 1.5 kb in length, besides the gypsy insertion.
