Epistasis in maize (Zea mays L.)

Summary Three flint and three dent maize (Zea mays L.) inbred lines, their possible F₁ crosses, F₂ and backcross progenies, and all possible three-way crosses were evaluated in a three-year experiment for yield, ear moisture, and plant height. The purpose was to estimate genetic parameters in European breeding materials from (i) generation means analysis, (ii) diallel analysis of generation means, and (iii) analysis of F₁ and three-way cross hybrids. Method (i) was based on the F-metric model and methods (ii) and (iii) on the Eberhart-Gardner (1966) genetic model; both models extended for heterotic maternal effects.Differences among generation means for yield and plant height were mainly attributable to dominance effects. Epistatic effects were significantly different from zero in a few crosses and considerably reduced heterosis in both traits. Additive x additive and domiance x dominance effects for yield were consistently positive and negative, respectively. Significant maternal effects were established to the advantage of generations with a heterozygous seed parent. In the diallel analysis, mean squares for dominance effects were greater than for additive effects for yield and plant height but smaller for ear moisture. Though significant for yield and plant height, epistatic variation was small compared to additive and dominance variation. Estimates of additive x additive epistasis for yield were significantly negative in 11 of 15 crosses, suggesting that advantageous gene combinations in the lines had been disrupted by recombination in the segregating generations. The analysis of hybrids supported the above findings regarding the analysis of variance. However, the estimates of additive x additive epistasis for yield were considerably smaller and only minimally correlated with those from the diallel analysis. Use of noninbred materials as opposed to materials with different levels of inbreeding is considered the main reason for the discrepancies in the results.     

Biological activity in vivo of insulin analogues modified in the N-terminal region of the B-chain

[AlaB5]Insulin as well as a hybrid analogue of insulin and "insulin-like growth factor" (IGF-I), in which the N-terminal amino-acid sequence H-Phe-Val-Asn-Gln- of the B-chain has been replaced by the tripeptide H-Gly-Pro-Glu-of IGF-I, have been prepared by the partial-synthetic route. Their biological activity in vivo has been compared with that of other analogues in rabbits, mice and rats as far as data are available. These rodents respond differently, rats being less sensitive to modifications than rabbits and mice. The results explain unexpected discrepancies discussed in previous papers.     

Antigenic interrelationship between the 40-kilodalton cytokeratin polypeptide and desmoplakins

We describe here antigenic cross-reactivity between the human 40-kilodalton cytokeratin polypeptide [Moll et al] and components of bovine desmosomal plaque, namely desmoplakins I and II. This relationship was revealed by an antibody (KM 4.62), raised against cytoskeletal preparation of cultured human breast adenocarcinoma cells (MCF-7) and selected by immunoblotting and immunofluorescent labeling. In cultured human cells that contain the 40-kD cytokeratin, antibody KM 4.62 labeled arrays of filaments throughout the cytoplasm. This antibody labeled the basal layer of nonkeratinizing squamous epithelia as well as various simple (normal and malignant) epithelia and epithelial elements of the thymus. In liver tissue, labeling was obtained only in bile ducts and canaliculi but not in the hepatocytes. In bovine cells and tissues, on the other hand, immunofluorescent labeling with antibody KM 4.62 was strictly confined to desmosomes. This was verified by double immunolabeling with both antibody KM 4.62 and specific cytokeratin or desmosomal antibodies. Immunoblotting analysis indicated that the former antibody reacts specifically with the high molecular weight components of the bovine desmosomal plaque, namely desmoplakins I and II. These immunochemical results suggest that bovine desmoplakins share same structural relationship with the human acidic, 40-kD cytokeratin.     

Human tissue kallikrein. I. Isolation and characterization of human pancreatic kallikrein from duodenal juice

Human pancreatic kallikrein was purified from duodenal juice by ion exchange chromatography on DEAE-Sepharose and immunoaffinity chromatography. Thus, an enzyme preparation with a specific activity (using Ac-Phe-Arg-OEt as substrate) of 1 000 U/mg protein was obtained. A specific biological activity of 1310 KE/mg protein was measured in the dog blood pressure assay and of 0.361 HMW kininogen-U/mg, corresponding to the liberation of 383 micrograms bradykinin-equivalents per mg enzyme per min from HMW kininogen in the rat uterus assay. In dodecyl sulfate gel electrophoresis one protein band corresponding to a molecular mass of 27 kDa was obtained. Using gel filtration on Ultrogel AcA-44 a molecular mass of 40 kDa was measured. The amino-acid composition was determined and isoleucine and alanine were identified as the only N-terminal amino-acid residues. On isoelectric focusing four protein bands with isoelectric points of 5.60, 5.65, 5.70 and 5.85 were separated. The bimolecular velocity constant for the inhibition by diisopropyl fluoro phosphate was determined as 10.5 l x mol-1 x min-1. The dissociation constant Ki of the human pancreatic kallikrein-aprotinin complex was calculated to be 1.5 x 10(-10)M. The kinetic constants for the kallikrein-catalysed hydrolysis of Ac-Phe-Arg-OEt and D Val-Leu-Arg-Nan were determined. Immunological studies showed a close relationship between the human pancreatic kallikrein and other human tissue kallikreins, especially with human urinary kallikrein. Detergents such as Triton X-100, Tween 20 and lysolecithin, as well as human serum albumin, activated the human pancreatic kallikrein preparation.     

Sources of sucrose translocated from illuminated sugar beet source leaves

A search for source leaf sucrose pools that differed in their relation to export was carried out in photosynthesizing leaves of Beta vulgaris L. The time course of depletion of [¹⁴C]sucrose in a leaf in unlabeled CO₂ following steady state labeling provided evidence for two distinct sucrose pools. After the start of the light period, leaf blade sucrose remained constant although it exchanged between the two pools. Newly synthesized sucrose destined for export passed through one pool more rapidly than through the other. All of the leaf blade sucrose appeared to exchange with export sucrose. Modeling and regression analysis of [¹⁴C]sucrose data provided a means for estimating the size of the two pools. From 20 to 40% of the sucrose was calculated to be present in the pool that provided the less direct path to export; this was likely vacuolar sucrose. The remainder of the sucrose in the blade was probably in the cytoplasm and veins. Added amounts of leaf blade sucrose, produced in response to elevated CO₂, appeared to be stored mainly in the vacuolar compartment.     

De novo synthesis and specific assembly of keratin filaments in nonepithelial cells after microinjection of mRNA for epidermal keratin

Poly(A)+ RNA isolated from bovine muzzle epidermis was microinjected into nonepithelial cells containing only intermediate-sized filaments of the vimentin type. In recipient cells keratin polypeptides are synthesized and assemble into intermediate-sized filaments at multiple dispersed sites. We describe the time course and the pattern of de novo assembly of keratin filaments within living cells. These filaments were indistinguishable, by immunofluorescence and immunoelectron microscopic criteria, from keratin filament arrays present in true epithelial cells. The presence of extended keratin fibril meshworks in these injected cells is compatible with cell growth and mitosis. Double immunolabeling revealed that newly assembled keratin was not codistributed with microfilament bundles, microtubules or vimentin filaments. We suggest that assembly mechanisms exist which in vivo sort out newly synthesized cytokeratin polypeptides from vimentin.     

Ergebnisse ornithologischer Beobachtungen auf Sardinien im Winter 1961/62

Zusammenfassung Das Vogelleben der Mittelmeerländer ist in der Zeit der Winterregen bisher kaum untersucht worden. Verf. teilt deshalb Beobachtungsergebnisse von der Insel Sardinien mit, die er vom 15. X. 1961–15. III. 1962 während eines Studienaufenthaltes machen konnte. Der genannte Zeitraum umfaßt Beginn und Ende der sardischen Regenzeit und wird als Winter bezeichnet.Insgesamt wurden 125 Vogelarten beobachtet, von denen 65 Jahresvögel, 56 Gastvögel und 4 Sommervögel Sardiniens sind.Bei den Jahresvögeln interessierte vor allem die Vertikalverbreitung. Im Vergleich mit der Vertikalverbreitung zur Brutzeit ergeben sich teilweise beträchtliche Verschiebungen der Höhengrenzen. Für 10 Jahresvögel wird auch die horizontale Verbreitung mit Punktkarten dargestellt. Weitere Kapitel behandeln Biotope, Schwarmbildung und Vergesellschaftung sowie den Gesang im Winter.Die Gastvögel werden nach ihrer Herkunft untersucht, wobei über 260 Ringfunde ausgewertet werden. Auch über Ankunft und Abzug, Massenschlafplätze und Wasservogelleben der Gastvögel wird berichtet.In einer tabellarischen Übersicht sind wichtige Daten aller beobachteten Jahres- und Gastvögel zusammengefaßt.Abschließend werden Aufgaben der weiteren ornithologischen Erforschung Sardiniens genannt, die vor allem in der Erkundung abgelegener Gebirgsteile und weiterer Beobachtertätigkeit in den Winter- und Sommermonaten bestehen.

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Summary The bird life of the Mediterranean countries has hardly been studied during the period of the winter rains. Therefore the author records of observations results made on Sardinia from the 15^th of October, 1961 to the 15^th of March, 1962 while studying. The period mentioned above comprises the beginning and end of the Sardinian rain period, which is termed winter.Alltogether 125 bird species have been observed, 65 of which were resident, 56 visitors and 4 Sardinian summer birds.Above all the elevation distribution of residents was of interest. Comparing the vertical distribution during the breeding period with that during the winter period considerable displacements in the elevation limits were shown. For 10 residents the horizontal distribution is also described by means of dotted maps. Further chapters deal with the environment, flock formation, socialization and the winter song.The breeding regions of the visitors has been studied from the records of more than 260 ringed birds. Reports of the visitors' arrival and departure, mass sleeping places and aquatic life was also given.In a tabulated survey important facts are summarized of all residents and visitors.Finally, problems of further ornithological studies on Sardinia are mentioned which are exploration of remote mountain parts and further observation during the winter and summer periods.

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Riassunto La vita degli uccelli del bacino mediterraneo è stata fino ad oggi poco esaminata durante la stagione delle piogge.Perciò l'autore comunica i risultati delle sue osservazioni, fatte nell'isola di Sardegna durante un soggiorno di studio dal 15. X. 1961 al 15. III. 1962.Questo periodo comprende l'inizio e la fine della stagione sarda delle piogge ed è chiamato inverno.In tutto furono osservate 125 specie, delle quali 65 sono stazionarie, 56 ospiti e 4 uccelli d'estate di Sardegna.La distribuzione verticale degli uccelli stazionari risulta di particolare interesse.Si riscontrano considerevoli spostamenti dei limiti d'altezza, confrontando la distribuzione verticale d'inverno e d'estate.Cartelli di punti mostrano la distribuzione orizzontale per 10 uccelli stazionari.Altri capitoli trattano di biotopi, formazioni di stormi, socializzazioni e canto d'inverno.La provenienza degli ospiti è studiata secondo la valorizzazione di più di 260 ritrovamenti di uccelli inanellati.Vengono trattati anche l'arrivo e la partenza degli ospiti, i posti per dormire in massa e la vita degli uccelli acquatici.Dati importanti su tutti gli uccelli, sia stazionari che ospiti, sono raccolti in un quadro sinottico.Infine si fa cenno ad altri problemi degli studi ornitologici in Sardegna, che consistono soprattutto nella esplorazione delle montagne remote ed in ulteriori osservazioni, sia nella stagione invernale che in quella estiva.

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Für seine ständige, wertvolle Hilfe und Beratung bei meiner ornithologischen Tätigkeit auf Sardinien danke ich Herrn Prof. Dr.G. Niethammer, für die Ermöglichung meines Studienaufenthalts Herrn Prof. Dr. Dr.R. Lehmensick sehr herzlich. Dank abstatten möchte ich auch den Universitäten Bonn und Cagliari sowie vielen sardischen Freunden, die mir auf vielfältige Weise behilflich waren. HerrnH. E. Wolters danke ich für die Durchsicht des Manuskripts.     

Kurze Mitteilungen

Zusammenfassung Ein Paar Türkentauben brütete vom 29. 1. bis 15. 2. 1966 auf einem Straßenbaum in Berlin-Tempelhof. Es wurde nur ein Ei gelegt. Nach 17 Tagen schlüpfte das gelbbedaunte Junge. Es ist dann kurz danach, wahrscheinlich beim Umherkriechen auf dem Nestrand, erfroren. Die Umstände, unter denen die Brut erfolgte, waren äußerst ungünstig. Die Temperatur lag seit dem 7. 2. 1966 dauernd unter Null (–9 und –13 Grad). Die brütende Taube hatte von Anfang an auf dem Nestrand brüten müssen, da die Mulde schon vor der Eiablage völlig mit Schnee bedeckt war. Der brütende Vogel war mehrere Tage und Nächte von einem hohen Schneewall umgeben, der sich auf dem Nest gebildet hatte. Dieses Nest wurde von Mai 1964 an viermal von einem Türkentaubenpaar zum Brüten benutzt. Es wird vermutet, daß zum mindesten der eine Partner, der Tauber, während der ganzen Zeit derselbe geblieben ist.