Tchurikov N A, Ilyin Y V, Ananiev E V, Georgiev G P
Nucleic Acids Res. 1978 Jun;5(6):2169-87. doi: 10.1093/nar/5.6.2169.
The properties of Dm 225 DNA, a fragment of D.melanogaster genome 2.9 kb in length excised by EcoRI endonuclease and cloned in the lambda gt phage or pMB9 plasmid, are described. The DNA hybridizes to a significant portion (0.8%) of total polysomal poly(A)(+)RNA (mRNA). The size of the hybridizing mRNA is about 2.3 kb (19S); it is present in the fraction of heavy polysomes. Dm 225 DNA fragments obtained with the aid of Hae III endonuclease have been mapped. mRNA hybridizes with all the fragments. In one of the end fragments, the 3'-end of mRNA has been localized and thus the direction of transcription determined. About 250 copies of the gene Dm 225 are present in the haploid genome of D.melanogaster, and all of them have the same size upon restriction with EcoRI endonuclease. On the other hand, the sequences of the genome adjacent to Dm 225 DNA are different and may vary from one cell line to another as evidenced by experiments in which the D.melanogaster DNA was restricted by Hind III endonuclease. In combination with in situ hybridization data /1,2/ the results obtained in this paper demonstrate that the structural gene present in Dm 225 DNA is a representative of a multiple gene family dispersed throughout the whole genome of D.melanogaster.Images
本文描述了Dm 225 DNA的特性，它是一段2.9 kb长的黑腹果蝇基因组片段，由EcoRI内切酶切割后克隆于λgt噬菌体或pMB9质粒中。该DNA与多核糖体多聚腺苷酸（+）RNA（mRNA）总量的很大一部分（0.8%）杂交。杂交mRNA的大小约为2.3 kb（19S）；它存在于重多核糖体部分。借助Hae III内切酶获得的Dm 225 DNA片段已被定位。mRNA与所有片段杂交。在其中一个末端片段中，已定位了mRNA的3'末端，从而确定了转录方向。在黑腹果蝇的单倍体基因组中约有250个Dm 225基因拷贝，用EcoRI内切酶切割后它们的大小都相同。另一方面，与Dm 225 DNA相邻的基因组序列不同，并且从一个细胞系到另一个细胞系可能会有所变化，这在黑腹果蝇DNA用Hind III内切酶切割的实验中得到了证明。结合原位杂交数据/1,2/，本文获得的结果表明，Dm 225 DNA中存在的结构基因是一个分散在黑腹果蝇整个基因组中的多基因家族的代表。图片
