The androgen-dependent mouse seminal vesicle secretory protein IV: characterization and complementary deoxyribonucleic acid cloning

Seminal vesicle secretory protein IV of a mouse has been isolated, and the cDNA coding for its mRNA has been cloned and sequenced. The 556-nucleotides encode 16 amino acid signal peptides and 92 residues of mature protein. Considerable homology between mouse and rat SVS IV cDNA was found. In the leader peptide and 3'-noncoding region there is 92% and 85% homology, respectively. The other regional homologies are 86% for the first 12, 68.5% for the last 35, and 40% for the middle 44 amino acids. The expression of mouse SVS IV mRNA is under the control of androgen. Administration of testosterone to castrated mice resulted in induction of the mRNA level to 50% of the mature male in 96 h of hormone treatment. Secretion of the protein after testosterone injection follows a similar pattern.     

质粒YRP7的基本特性鉴定

质粒YRP7用氯霉素法扩增,碱变性裂解法提取,酸酚法及核糖核酸酶纯化后,得到了高产量(5.6mg/L培养液),高纯度(A260:A280=2.0)的质粒制品,经转化实验及酶切分析确定YRP7具有下列特征:大小为5.41±0.10kb,可赋予宿主细胞AmP~r、Tet~r的表型,对大肠杆菌C600的转化频率为10~(-6)、转化效率为1.5×10~6转化子/mgDNA。限制性内切酶BamH Ⅰ、ECoRⅠ、Hind Ⅲ及PstⅠ在其分子上的切点数分别为1、2、2、2,并确定了各酶切片段的分子大小,对BanHⅠ的单切点,经插入失活法证实其位于Tet~r的基因上。由上述特征可确定,质粒YRP7是一个比较理想的克隆载体。     

Ontogenetic patterns of volatiles identified in Dufour's gland extracts from queens and workers of the primitively eusocial halictine bee,Lasioglossum malachmum (Hymenoptera: Halictidae)

Summary Ontogenetic patterns of volatile compounds identified in Dufour's gland extracts from queens and workers of the primitively eusocial sweat beeLasioglossum malachurum (K.) were compared. Only young unmated queens showed high proportions of isopentenyl esters, while macrocyclic lactones were dominant in old breeding queens, spring queens, and workers. In young queens the relative and absolute amounts of volatiles changed one day after mating. A discriminant analysis revealed significant differences in odor patterns of unmated and mated young queens. The fat body was the largest in young females, while eggs could be recorded only in breeding queens. Possible functions of different odor components in the investigated female groups are discussed.     

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of 2-substituted 3-chloro-1,4-naphthoquinone derivatives

A series of 2-substituted 3-chloro-1,4-naphthoquinones was synthesized, and the antiplatelet, antiinflammatory, and antiallergic activities of these compounds were evaluated. The structure-activity relationships in this series were also examined. Most of the 2-alkyl/arylcarboxamido derivatives of 3-chloro-1,4-naphthoquinone showed potent activities with similar trends in each of the activities evaluated.     

Studies on sex-organ development. Oestrogenic effect on ornithine decarboxylase activity in the differentiating Müllerian ducts and other organs of the chick embryo.

The activity of ornithine decarboxylase in the differentiating left and right Müllerian ducts was assayed and compared with that in other embryonic organs, i.e. the liver and the brain throughout the stages of development. In general the enzyme activity was high in the early stages and decreased extensively in the late stages of development. Specifically, in the left and righ Müllerian ducts, the enzyme activity was high from day 8 to day 9 of incubation. In the right duct the enzyme activity started to decline on day 9 and then continuously decreased to an almost undetectable value on day 18 of incubation. In the left duct the enzyme activity also decreased slightly from day 9 to day 12; however, it increased from day 13 to day 15 and finally decreased to a constant value from day 18 until hatching. The alteration in enzyme activity in the Müllerian duct as assayed in vitro during development is not due to the effect of the size of the endogenous ornithine pool. When the enzyme activity was subjected to oestrogen stimulation, an increase of 5--10-fold for the left duct and of 5--3-fold for the right duct was observed during the course of development. No such stimulation was observed with the treatment of progesterone. Testosterone consistently caused a 25--30% inhibition of the enzyme activity in the Müllerian duct. Oestrogen slightly stimulated the enzyme activity in the developing liver but inhibited that of the brain. The concentration of the three polyamines measured in the Müllerian duct corresponds to the activity of the enzyme determined.     

Studies on sex-organ development. Changes in nuclear and chromatin composition and genomic activity during spermatogenesis in the maturing rooster testis.

We developed a technique to separate nuclei of rooster testis by centrifugation through a discontinuous sucrose density gradient and by sedimentation at unit gravity. Four different major fractions obtained from testicular nuclei and one from the vas deferens were characterized according to their velocity of sedimentation, morphology and DNA content. The ratios (w/w) of basic proteins, non-histone proteins and RNA to DNA decreased during spermiogenesis both in nuclei and chromatin. Changes in the electrophoretic patterns of histones and non-histone proteins were detected especially in the elongated spermatids. The lack of uptake of [3H]uridine in elongating and elongated spermatids and in spermatozoa was demonstrated by radioautography and by the detection of labelled RNA extracted from different fractions of nuclei. Template activity for RNA synthesis and the binding of actinomycin D by testicular nuclei reached a peak in the elongated spermatid stage, when the histones are replaced by the protamine.     

Mechanism of action of the antiplatelet peptide, arietin, from Bitis arietans venom

Arietin, an Arg-Gly-Asp containing peptide from venom of Bitis arietans, inhibited aggregation of platelets stimulated by a variety of agonists with a similar IC50, 1.3-2.7.10(-7) M. It blocked aggregation through the interference of fibrinogen binding to fibrinogen receptors on platelet surface. In this paper, we further demonstrated that arietin had no significant effect on the intracellular mobilization of Ca2+ in Quin2-AM-loaded platelets stimulated by thrombin. It inhibited 125I-fibrinogen binding to ADP-stimulated platelets in a competitive manner (IC50, 1.1.10(-7) M). 125I-arietin bound to unstimulated, ADP-stimulated and elastase-treated platelets in a saturable manner and its Kd values were estimated to be 3.4.10(-7), 3.4.10(-8) and 6.5.10(-8) M, respectively, while the corresponding binding sites were 46,904, 48,958 and 34,817 per platelet, respectively. Arg-Gly-Asp-Ser (RGDS) inhibited 125I-arietin binding to ADP-stimulated platelets in a competitive manner. RGD-containing peptides, including trigramin and rhodostomin, EDTA and monoclonal antibody, 7E3, raised against glycoprotein IIb-IIIa complex, inhibited 125I-arietin binding to ADP-stimulated platelets, indicating that the binding sites of arietin appear to be located at or near glycoprotein IIb-IIIa complex. In conclusion, arietin and other RGD-containing trigramin-like peptides preferentially bind to the fibrinogen receptors associated with glycoprotein IIb-IIIa complex of the activated platelets, thus leading to the blockade of fibrinogen binding to its receptors and subsequent aggregation. The presence of RGD of arietin is essential for the expression of its biological activity. Its binding sites are overlapped with those of trigramin, rhodostomin and the monoclonal antibody, 7E3.