Nucleotide sequence and exact localization of the neomycin phosphotransferase gene from transposon Tn5

The nucleotide sequence of 1200 bp from the unique region of transposon Tn5 containing the neomycin phosphotransferase gene (neo) was determined, and the location of the neo gene was identified by deletion mutants in a translational reading frame of 792 bp. The derived gene product, an aminoglycoside 3′-phosphotransferase (APH) II, consists of 264 amino acid residues and has a calculated M_r of 29053. Its amino acid sequence shows sequence homologies to the APH type I enzyme coded for by transposon Tn903 (Oka et al., 1981).     

Multiorgan autoimmunity in a Turner syndrome patient with partial monosomy 2q and trisomy 10p

Turner syndrome is a condition caused by numeric and structural abnormalities of the X chromosome, and is characterized by a series of clinical features, the most common being short stature and gonadal dysgenesis. An increased frequency of autoimmune diseases as well as an elevated incidence of autoantibodies has been observed in Turner patients.     

论实轴型中柱皱纹珊瑚的分类

具实轴型中柱的皱纹珊瑚的分类位置至今尚未取得统一。这类珊瑚的轴部由纤状组织构成,它不同于复中柱或皱形复中柱,它的形成与主隔壁,对隔壁或一级隔壁内端没有关系,是皱纹珊瑚中一类独立发育的轴部构造。具实轴型中柱的珊瑚可以独立建立新目,称Ｃｙａｔｈａｘｏｎｉｉｄａ ｏｒｄ．ｎｏｖ．。按照组成实轴的纤状组织类型和实轴形态,可以划分为３科,即Ｃｙａｔｈａｘ－ｏｎｉｉｄａｅ ｅｄｗａｒｄｓ ｅｔ Ｈａｉｍｅ,１     

A plasmid cloning system utilizing replication and packaging functions of the filamentous bacteriophage fd

DNA cloning vectors were developed which utilize the replication origin (ori) of bacteriophage fd for their propagation. These vectors depend on the expression of viral gene 2 that was inserted into phage lambda, which in turn was integrated into the host genome. The constitutive expression of gene 2 in the host cells is sufficient for the propagation of at least 100 pfd plasmids per cell. In addition to the fd ori, the pfd vectors carry various antibiotic-resistance genes and unique restriction sites. Some of these vectors have no homologies to commonly used pBR plasmids or to lambda DNA. The nucleotide sequence of the vectors can be deduced from published sequences. Large DNA inserts can be stably propagated in pfd vectors; these are more stable than similar DNA fragments cloned in intact genomes of filamentous bacteriophage. Inclusion of phage sequences required for efficient phage packaging and infection with a helper phage resulted in formation of phage particles containing single-stranded plasmid genomes. Growth at 42 degrees C without selective pressure results in loss of pfd plasmids.     

Replication of the cauliflower mosaic virus: role and stability of the cloned delta 3 discontinuity sequence

A fragment of cauliflower mosaic virus (CaMV) DNA, containing delta 3, one of the three discontinuity sequences, was cloned in various ways into CaMV DNA deleted for the delta 3 sequence. The series of constructions was monitored for the appearance of the typical single-strand (ss) discontinuity after hybrid CaMV replication in plants. The delta 3 discontinuity was observed only if the orientation of inserted DNA sequence was the same as in the wild-type virus. Long polylinker sequences used for insertion of the fragment into cloned viral DNA, affected the stability of the insert in progeny viral DNA in plants by acting as recombination targets.