Molecular cloning of the gene coding for the human T cell differentiation antigen CD7

The CD7 molecule is a differentiation antigen found on the surface of T lymphocytes and also on a very minor fraction of acute nonlymphocytic leukemia (ANLL). To study the genomic structure of the CD7 gene, two clones (SY4 and SY22) were isolated by screening a genomic library with a CD7 cDNA probe. Restriction mapping of these two phage clones showed that both overlapped each other, covering a total length of 23 kilobases (kb). Transfection of mouse L cells demonstrated that SY22 contains the gene expressing the CD7 antigen reactive with monoclonal CD7 antibody (Tp40), while SY4 does not. Subcloning of a 10.5 kb fragment from a 14.4 kb insert of SY22 contained the structural gene for the CD7 antigen. Detailed restriction mapping and partial sequence analysis revealed the CD7 gene to consist of four exons. By RNase protection assay, multiple initiation sites — 122 base pairs (bp) to — 38 bp from ATG translation initiation site were demonstrated. The promoter region had high G+C content and contained two SP1 binding sites (CCGCCC) and an AP2 binding site (CCCCAGGC), but lacked CAAT and TATA motifs.     

Copulatory behavior unaccompanied by ovulation in the Japanese monkey (Macaca fuscata)

Copulatory behavior unrelated to conception is sometimes observed in some non-human primates including the Japanese monkey. In the present study, the authors examined whether a mature follicle or a newly formed fresh corpus luteum was observed in the ovaries of female Japanese monkeys which displayed the copulatory behavior unrelated to conception. Post-conception copulatory behaviors were observed in three out of four females usually kept in individual cages in an air-conditioned room, and in two out of three females without infants kept in an outdoor group cage. However, neither a mature Graafian follicle nor a fresh corpus luteum formed newly after conception was observed in any of these females by laparoscopic examinations conducted immediately after termination of the copulatory behavior. In females with infants born in the preceding birth season, copulatory behaviors were observed in three out of four females kept in the outdoor group cage, and in two out of four females in a free-ranging troop. Ovulation was confirmed in one case out of the three kept in the outdoor group cage, but neither a mature follicle nor a newly formed corpus luteum was observed in the remaining four females. These findings suggest that copulatory behavior in the Japanese monkey is not always controlled by the development of a follicle or ovulation in the ovary.     

Sperm motility initiation factor is a minor component of the Pacific herring egg chorion

Polyclonal antibodies were generated to the 105 kDa herring sperm motility initiation factor (SMIF) and used to explore the role of SMIF in sperm-egg interaction. Using sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting with SMIF antibodies, it was demonstrated that SMIF is present as a minor (4–7% of total chorion protein) component of the chorion. The major polypeptides in the chorion migrated at 117 kDa and in a grouping between 48–54 kDa, with other minor bands above and below. The only detectable glycosylated component was the 105 kDa band, which was resolved at two isoelectric points (8.22 and 8.31) after isoelectric focusing gel electrophoresis. Using antibodies to SMIF, fertilization was blocked, sperm motility was inhibited in vitro in the presence of solubilized SMIF and SMIF binding sites on sperm were localized. Lastly, SMIF was localized to the region of the herring egg that encircles the micropyle.     

Factor in urinary extracts from pregnant women that inhibit mouse oocyte maturation in vitro

Mouse oocyte maturation inhibitory factors, on the basis of inhibitory activity of spontaneous germinal vesicle breakdown (GVBD) of denuded mouse oocytes in culture, were extracted and partially purified by reversed-phase resin adsorption and Sephadex G-100 and G-50 column chromatographies from the urine of pregnant women. Denuded oocytes obtained from ovaries of ICR mice underwent spontaneous GVBD by cultivation for 3 h in modified Krebs–Ringer's buffered solution, while this spontaneous GVBD was found to be inhibited by adding the final preparation (U-D-4) of urine. The inhibition was dose dependent, ranging from 0.6 to 10 μg protein/ml medium. Oocytes treated with U-D-4 and resuspended in control medium resumed GVBD. The molecular mass of U-D-4 was estimated to be less than 2,000 Da with gel filtration. Ether treatment failed to extract inhibitory factor(s) from U-D-4 and pepsin treatment inactivated U-D-4, indicating that inhibitory factor(s) in U-D-4 are peptide-like substances. The inhibitory effect of U-D-4 on spontaneous GVBD was partially reversed in the presence of naloxone, a potent opioid antagonist. U-D-4s obtained from urine samples of pregnant women, nonpregnant women, and men showed the inhibitory effect on spontaneous GVBD; however, the activity of U-D-4 obtained from pregnancy urine was significantly more potent than those of the other urine samples. © 1993 Wiley-Liss, Inc.     

In vitro neurotoxicity of amyloid β-peptide cross-linked by transglutaminase

Transglutaminase catalyzes the intermolecular cross-linking of peptides between Gln and Lys residues, forming an -(-glutamyl) lysine bond. Amyloid -peptide, a major constituent of the deposits in Alzheimer disease, contains Lys16, Lys28, and Gln15 which may act as substrates of transglutaminase. Transglutaminase treatment of amyloid -peptide (1–28) and amyloid -peptide (1–40) yielded cross-linked oligomers. Transglutaminase-treated A retarded neurite extension of PC12 cells, and rat cultured neurons of hippocampus and septum, brain areas severely affected by Alzheimer disease, and subsequently caused cell death, whereas the transglutaminase-untreated counterparts did not show harmful effects. The transglutaminase-catalyzed oligomers of amyloid -peptide and their neurotoxicity may be involved in two characteristics in Alzheimer disease, neuronal degeneration and formation of the insoluble deposits.Abbreviations: AD – Alzheimer disease, A – amyloid -peptide, DMEM – Dulbecco's modified Eagle's medium, DMEM/F–12–1:1 mixture of DMEM and Ham's F–12 medium, FCS – fetal calf serum, HS – horse serum, PAGE – polyacrylamide gel electrophoresis, MTT – 3-(4,5-dimethylthiazol–2-yl)–2,5-diphenyltetrazolium bromide, NGF – nerve growth factor, TGase – transglutaminase.     

Photomicrobial sensors for selective determination of phosphate

A photomicrobial sensor consisting of immobilized Chlorella vulgaris and an oxygen electrode has been developed for selective determination of phosphate. When 40 mM phosphate was added to the sensor system, the photocurrent increased to a maximum under light irradiation with a response time of 1 min. The current increased with increasing phosphate concentration in the range 8–70 mM. Selectivity of the sensor was satisfactory. Good agreement was obtained between the phosphate concentrations in lake water determined by the photomicrobial sensor and by conventional colorimetry (correlation coefficient 0.96).     

Photomicrobial electrode for selective determination of sulphide

Summary A photomicrobial electrode, which uses the photosynthetic bacteria Chromatium sp. in conjunction with a hydrogen electrode, was developed for the determination of sulphide. The response time of the photomicrobial electrode was 5–10 min. A linear relationship was obtained between the current of the electrode and the sodium sulphide concentration below 3.5 mM. The minimum detectable concentration of sodium sulphide was 0.4 mM. Selectivity of the sensor is satisfactory. A good agreement was obtained between the photomicrobial electrode and the ethylene blue method (correlation coefficient: 0.90).     

Development of the axon cap neuropil of the Mauthner cell in the goldfish

Summary Development of the axon cap neuropil of the Mauthner neuron in post-hatching larval goldfish brains was observed electron-microscopically. The axonal initial segment of newly hatched (day-4) larvae is completely covered with synaptic terminals containing clear spherical synaptic vesicles. Profiles of thin terminal axons, the spiral fibers, containing similar synaptic vesicles, rapidly increase in number around the initial segment and form glomerular neuropil similar to the central core of the adult axon cap by day 7. Three types of synapses are formed in the core neuropil. Bouton-type synapses contacting the initial segment are most abundant in day-4 to-14 larvae; they decrease thereafter and are rare on the distal half of the initial segment of day-40 larvae. Asymmetric axo-axonic synapses are commonly observed between spiral fibers in the core neuropil of day-7 to -19 larvae, but become fewer by day 40. Unique symmetrical axo-axonic synapses showing accumulation of synaptic vesicles on either side of apposed membrane thickenings first appear in day-14 core neuropil, gradually increase in number, and become the predominant type in day-40 core neuropil. Thick myelinated axons, which lose their myelin sheaths in the glial cap cell layer, start to penetrate into the axon cap on day 10. They gradually increase in number and form the peripheral part of the axon cap together with the cap dendrites, which finally grow into the axon cap from the axon hillock region of the Mauthner cell by day 40.     

Primary structure of mitochondrial glutamic oxaloacetic transaminase from rat liver: Comparison with that of the pig heart isozyme

The complete amino acid sequence of the mitochondrial glutamic oxaloacetic transaminase isozyme from rat liver is presented. The sequence contained 401 amino acid residues, 10 of which are methionine. Cyanogen bromide cleavage of mitochondrial glutamic oxaloacetic transaminase produced 12 peptides, one of which contained an internal homoserine residue resulting from incomplete cleavage by cyanogen bromide. The calculated molecular weight was 44,358. The sequence showed 94% homology with that of the corresponding isozyme from pig heart. These findings support the conclusion that the rate of evolution of the mitochondrial isozymes is lower than that of their cytosolic isozymes.