Expression of myelin basic protein gene in the developing rat brain as revealed by in situ hybridization

The developmental program controlling the expression of myelin basic protein (MBP) gene was studied in the rat using the technique of in situ hybridization. A 35S-labeled cDNA clone of mouse MBP encoding an amino acid sequence present in all four of the major forms of rodent MBP was used. The probe hybridized to the tracts of white matter with different intensities, depending on the age of the animal and the region of the brain examined. In the medulla oblongata, maximal hybridization was found in 5- and 7-day-old rats and was confined to the tectospinal tracts, fibers of the seventh cranial nerve, and the spinocerebellar tracts. By 12 days the amount of MBP mRNA had decreased in these areas. In the cerebrum, the greatest amount of MBP mRNA was observed in 17-day-old rats in the radiations of the corpus callosum. Thereafter, the levels decreased but could still be observed in the adult animals. Thus, using this technique, we have been able to demonstrate that the level of MBP-specific mRNA correlates closely with the development of myelin in different regions of the brain.     

Cytogenetic relationship ofAegilops longissima chromosomes with common wheat chromosomes

The relationships of three wheat-Aegilops longissima chromosome addition lines A, C, and D with homoeologous wheat chromosomes were studied in PMC meiosis. Substitutions of alien chromosome A for wheat chromosome 6 B, chromosome C for 1 B and chromosome D for 4 B were obtained. The production of 4 BS/C and 7 BS/D chromosome translocations indicated cytogenetic relationships of C partially to homoeologous wheat chromosomes of group 1 and 4, and D partially to homoeologous wheat chromosomes of group 4 and 7.     

Identification of Erwinia amylovora, the Fireblight Pathogen, by Colony Hybridization with DNA from Plasmid pEA29

All strains of Erwinia amylovora characterized carry a medium-size plasmid of 29 kilobases (pEA29). We mapped this plasmid with various restriction enzymes, cloned the whole DNA into an Escherichia coli plasmid, and subcloned restriction fragments. These DNA species were used for identification of E. amylovora after handling of strains in the laboratory and also in field isolates. About 70 strains of E. amylovora and 24 strains from nine other species, mainly found in plant habitats, were checked in a colony hybridization test. Virulent and avirulent E. amylovora strains reacted positively, whereas the other species were negative. Apart from the hybridization assay, the positive strains were additionally tested for ooze production on rich agar with 5% sucrose and on immature-pear slices. Unspecific background hybridization of non-E. amylovora strains found for hybridization with the whole E. amylovora plasmid was almost eliminated when a 5-kilobase SalI fragment from pEA29 was used as a probe and when the washes after the hybridization procedure were done with high stringency. Under these conditions, E. amylovora could be readily identified from field isolates.     

Territorial expression of three different trans-genes in early sea urchin embryos detected by a whole-mount fluorescence procedure.

We have developed a new procedure for detection of the protein product of chloramphenicol acetyltransferase (CAT) reporter genes in whole mounted sea urchin embryos. The position of a commercially available anti-CAT antibody is visualized by video or confocal microscopy, and thus the spatial domains of exogenous reporter gene expression can be determined with regard to the intact three-dimensional structures of the embryo. We show that in pluteus stage embryos CAT protein expression patterns for SM50 . CAT or CyIIIa . CAT reporter genes are similar to those previously obtained by in situ hybridizations with radioactive probes. Taking advantage of the superior resolution of cellular CAT expression patterns using the antibody visualization method, we found for the first time that, in addition to the expression in aboral ectoderm, some cells in the ciliated band of the pluteus express CyIIIa . CAT. The expression of a new fusion construct, CyIIa . CAT, was also examined. As expected from the localization of endogenous CyIIa mRNA, CAT protein was expressed under control of the CyIIa promoter in gut and skeletogenic mesenchyme cells.     

Cytological analysis on the distribution and origin of the alien chromosome pair conferring blue aleurone color in several European common wheat (Triticum aestivum L.) strains

Summary Meiotic chromosome pairing and Giemsa C-banding analyses in crosses of several European blue-grained wheat strains with Chinese Spring double ditelosomic and other aneuploid lines showed that Triticum aestivum Blaukorn strains Berlin, Probstdorf, Tschermak, and Weihenstephan are chromosome substitutions, in which the complete wheat chromosome 4A pair is replaced, whereas the strains Brünn and Moskau are 4B substitutions. The alien chromosome pair in all of these strains is an A genome chromosome (4A) from diploid Triticum monococcum or T. boeoticum not present in common tetraploid and hexaploid cultivated wheats. The Blaukorn strain Weihenstephan W 70a86 possesses, in addition to a rye chromosome pair 5R compensating for the loss of part of chromosome 5D, a 4A/5DL translocation replacing chromosome pair 4B of wheat.     

Cardiogel: A biosynthetic extracellular matrix for cardiomyocyte culture

Summary Tissue-cultured neonatal cardiomyocytes can be successfully maintained in culture on a variety of extracellular matrix components such as laminin, fibronectin, and interstitial collagens (Types I and III).In vivo, however, cardiomyocytes (as well as many other cells) exist in a highly complex extracellular matrix environment composed of, in addition to the above three components, other proteins, proteoglycans, and growth factors. We have developed a procedure for culturing cardiomyocytes on a naturally occurring complete extracellular matrix, Cardiogel. This substrate, synthesized by cardiac fibroblasts, contains laminin, fibronectin, Types I and III collagen, and proteoglycans. When compared to cardiomyocytes grown on laminin alone or fibronectin alone, Cardiogel-supported cardiomyocytes adhere more rapidly after plating, exhibit spontaneous contractility earlier, undergo cytoskeletal and myofibrillar differentiation earlier, and grow larger than their counterparts. We suggest that their superior growth characteristics reflect the synergistic effect of numerous extracellular matrix components’ signals in Cardiogel transduced by the cardiomyocyte cytoskeletal elements.     

How many fish populations in Finland are affected by acid precipitation?

Synopsis The number of fish populations affected or lost from small lakes in southern and central Finland due to acid precipitation is estimated. Tolerance limits (pH and labile aluminum) of common fish species were obtained from a fish status survey of 80 lakes. These tolerance values were used to estimate the proportion of affected lakes from the water chemistry data of 783 statistically selected lakes. The proportion of anthropogenically acidified lakes was estimated by calculating pre-acidification pH and aluminum concentrations of the lakes, using a steady-state model based on water chemistry. The number of fish populations for which acidification has affected growth or population structure was estimated at between 2200 and 4400. Out of these, the number of fish populations that have disappeared due to acid precipitation would be about 1000–2000. Almost 60% of the affected or lost populations are roach, Rutilus rutilus, the most sensitive of the common fish species in small lakes in southern and central Finland. Less than 15% of the damaged population is European perch, Perca fluviatilis, the most common species. This is due to the substantially higher tolerance of perch to acidified water in comparison with roach.     

Zur Cytochemie der Lysosomen in der Rattenniere unter normalen und experimentellen Bedingungen

Zusammenfassung Es wird das Vorkommen der sauren Phosphatase (sP) und der -Glucu-ronidase (-Glu) in den Lysosomen von Rattennieren vom 16. Embryonaltag (ET) bis 33. Lebenstag (LT) sowie von erwachsenen unbehandelten, kastrierten und nach der Kastration mit gleich- bzw. gegengeschlechtlichen Hormonen behandelten Tieren untersucht. Bis zur Geburt entwickelt sich die lysosomale sP und -Glu in den einzelnen Nephronabschnitten und Sammelrohren annähernd parallel. Am 1. LT nimmt in den S₁-Segmenten der iuxtamedullären Nephrone Zahl, Durchmesser und Aktivität der sP positiven Lysosomen sprunghaft zu, um zwischen 5. und 9. LT wieder schnell abzunehmen. Die Aktivität der -Glu steigt dagegen kontinuierlich an. Zwischen 24. und 25. LT nimmt die Aktivität der -Glu in den Lysosomen der S₁- und S₃-Segmente ab, die der sP deutlich zu. Geschlechtsunterschiede treten bei der sP zum ersten Mal am 18. LT in den S₃-Segmenten, bei der -Glu am 25. LT in den S₁-Segmenten auf. Das ausdifferenzierte Enzymmuster für sP und -Glu kann erst bei erwachsenen Tieren nachgewiesen werden. Dann fallen bei beiden Geschlechtern unter den Lysosomen der S₁-Segmente zwei Größenklassen besonders auf: a. große Lysosomen (beim Weibchen 7 m, beim Männchen 5 m) und b. kleinere Lysosomen (bei beiden Geschlechtern 2–3 m). Die großen Lysosomen sind bei Weibchen zahlreicher und sP aktiver als bei Männchen. In den S₂-Segmenten (Durchmesser der Lysosomen 1,5–2,5 m) ist die -Glu in den Lysosomen der Männchen aktiver als bei den Weibchen; jedoch sind die Geschlechtsunterschiede in S₂ geringer als in S₁ In den S₃-Segmenten sind sP und -Glu in den Lysosomen weiblicher Nieren aktiver als in denen männlicher Tiere. — In den übrigen Abschnitten des Nephrons und in den Sammelrohren bestehen keine Geschlechtsunterschiede. — Die Lysosomen der Sammelrohre haben eine höhere Aktivität für -Glu als für sP.Durch Kastration werden die Geschlechtsunterschiede geringer, bleiben aber grundsätzlich erhalten; in den S₁-Segmenten können jedoch Lysosomen über 2,5 m nicht mehr nachgewiesen werden. Nach Testosteronbehandlung männlicher Kastrate nimmt die Aktivität der sP und -Glu gegenüber unbehandelten Kastraten ab. Bei kastrierten weiblichen Tieren treten nach Testosteronbehandlung wieder große Lysosomen auf, das Enzymmuster unbehandelter Tiere wird jedoch nicht erreicht. Östradiolbehandlung kastrierter Tiere führt bei beiden Geschlechtern in etwa zu einer Restitution der normalen Enzymverteilung, insbesondere bei den Männchen. Bei den Weibchen sind die Lysosomen größer und reagieren intensiver als bei Normaltieren, die Anzahl der Lysosomen scheint aber geringer zu sein.Insgesamt ergibt sich, daß die Lysosomen und die lysosomalen Enzyme unter dem Einfluß der Geschlechtshormone stehen.

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On the cytochemistry of lysosomes in the rat kidney under normal and experimental conditions

Summary Acid phosphatase (ap) and -glucuronidase (-glu) have been investigated in the lysosomes of the rat kidney between the 16th embryonic and 33th postnatal day. Furthermore these enzymes were demonstrated in the kidney of adult normal as well as of orchiectomized or ovarectomized rats following treatment with homosexual and heterosexual hormones. — Up till birth, the development of ap and -glu runs nearly parallel to one another in the nephron and in the collecting tubules. At the first day of life an irregular increase with respect to number, diameter, and activity of lysosomes containing ap can be observed in the S₁ segments of the iuxtamedullary nephrons; a decrease occurs between the 5th and 9th postnatal day. On the contrary the -glu activity increases continously. Between the 24th and 25th day of life its activity decreases in the lysosomes of the S₁ and S₂ segments; the ap activity, however, increases. For the first time sex-specific differences concerning the distribution pattern of ap can be revealed around the 18th day of life in the S₃ segments; in the case of -glu ca one week later in the S₁ segments. The final ap and -glu pattern only exists in the kidney of adult animals. Here, in the male and female kidney two classes of lysosomes exhibit striking peculiarities in the S₁ segments: a. big lysosomes (in male 5 m, in female 7 m in diameter) b. small lysosomes (in both sexes 2–3 m in diameter). The big lysosomes are more numerous. Moreover their ap activity is higher in female rats in comparison with the male kidney. In the S₂ segments (lysosomal diameter 1.5–2.5 m) the -glu activity of male rats surpasses that of females. However sex differences in the S₂ are as obvious as in the S₁ segments. In S₃ the strongest ap and -glu reaction appear in female kidneys. — In the other parts of the nephron and in the collecting tubules sexspecific differences have never been observed. — In the lysosomes of the collecting tubules more -glu than ap activity can be detected.Castration induces only a decrease of sex differences, but they do not disappear completely; in the S₁ segments lysosomes being bigger than 2.5 m are absent. In male castrates treated with testosterone the activity of ap and -glu is lowered in comparison with unsubstituted animals. Following application of testosterone the big lysosomes reappear in overectomized rats; but the enzyme pattern of untreated animals will never be obtained. In both sexes treatment of castrated animals with estradiol is accompanied by restitution of the normal ap and -glu pattern especially in males. In the female kidney lysosomes are bigger and more active in comparison with the controls; the number of lysosomes seems to be reduced. Summarizing strong evidence occurs that in the rat kidney lysosomes and lysosomal enzymes are controlled by sex hormones.

     

Die Lipide von Endomycopsis vernalis bei verschiedener Stickstoff-Ernährung

1. Endomycopsis vernalis was cultivated on media with different N supply: series A 1%, series B 0,125% asparagine. Sonified cells were extracted and yielded 14.3% (A) and 65.3 (B) total lipids/non lipid dry matter respectively.
2. Neutral and complex lipids were separated by rubber membrane dialysis. There is no difference in the percentage of complex lipids of both series. The increase of lipids in cells grown on low N level is due to a higher content of neutral lipids.
3. Components of the neutral lipids, analysed by DC, were diglycerides, triglycerides, free and esterified ergosterol. Their percentage is influenced by the nutritional conditions. There is a significant increase of triglycerides and of sterol esters in the high lipid cells of series B.
4. Methyl esters of component fatty acids of glycerides and sterol esters were analyzed by GLC. Saturated acids C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, monoenic acids C₁₆ and C₁₈, linoleic and linolenic acids were found to be present. Major acids were in all cases 18:1 (17–57%), 18:2 (18–50%) and 16:0 (10–18%). Linolenic acid is higher in di-and triglycerides of low lipid cells of series A than in high lipid cells of series B. Both qualitative and quantitative differences of fatty acids were found in sterol esters of series A and B respectively.
5. The major components of complex lipids, identified by DC and isolated by CC, in both series, were phosphatidyl choline (A:36.5, B:41.0%) and phosphatidyl ethanolamine (A:24.9, B:20.5%) in addition to small amounts of lysophosphatidyl choline, lysophosphatidyl ethanolamine, phosphatidyl serine, monophosphoinositide, diphosphatidyl glycerol and, possibly cerebroside like substances.
6. Methyl esters of the fatty acids of phosphatidyl choline and ethanolamine from both series were determined by GLC. In all samples 16:0, 18:0, 18:1, 18:2 and 18:3 acids were present besides of traces of 16:1 and 17:0. In contrast to neutral lipids the major acid of phospholipids is linoleic (53–58%), followed by oleic (8–24%) and linolenic acid (1–18%). The percentages of palmitic (4–8%) and stearic acids (tr.-1%) are small. Low lipid cells of series A differ from high lipid cells of series B by an increase of linolenic, and a decrease of linoleic acids, both in phosphatidyl choline and phosphatidyl ethanolamine.