Architectural specialization of the intrinsic thoracic limb musculature of the American badger (Taxidea taxus)

Evaluation of the relationships between muscle structure and digging function in fossorial species is limited. Badgers and other fossorial specialists are expected to have massive forelimb muscles with long fascicles capable of substantial shortening for high power and applying high out‐force to the substrate. To explore this hypothesis, we quantified muscle architecture in the thoracic limb of the American badger (Taxidea taxus) and estimated the force, power, and joint torque of its intrinsic musculature in relation to the use of scratch‐digging behavior. Architectural properties measured were muscle mass, belly length, fascicle length, pennation angle, and physiological cross‐sectional area. Badgers possess hypertrophied shoulder flexors/humeral retractors, elbow extensors, and digital flexors. The triceps brachii is particularly massive and has long fascicles with little pennation, muscle architecture consistent with substantial shortening capability, and high power. A unique feature of badgers is that, in addition to elbow joint extension, two biarticular heads (long and medial) of the triceps are capable of applying high torques to the shoulder joint to facilitate retraction of the forelimb throughout the power stroke. The massive and complex digital flexors show relatively greater pennation and shorter fascicle lengths than the triceps brachii, as well as compartmentalization of muscle heads to accentuate both force production and range of shortening during flexion of the carpus and digits. Muscles of most functional groups exhibit some degree of specialization for high force production and are important for stabilizing the shoulder, elbow, and carpal joints against high limb forces generated during powerful digging motions. Overall, our findings support the hypothesis and indicate that forelimb muscle architecture is consistent with specializations for scratch‐digging. Quantified muscle properties in the American badger serve as a comparator to evaluate the range of diversity in muscle structure and contractile function that exists in mammals specialized for fossorial habits. J. Morphol. 2013. © 2012 Wiley Periodicals, Inc.     

PHYLOGENY AND SYSTEMATICS OF THE MARINE ALGAL FAMILY GRACILARIACEAE (GRACILARIALES,RHODOPHYTA) BASED ON SMALL SUBUNIT rDNA AND ITS SEQUENCES OF ATLANTIC AND PACIFIC SPECIES1

We sequenced the small subunit rDNA and internal transcribed spacer region of Gracilariaceae from the tropical Atlantic and Pacific, with emphasis on flattened or compressed species. Sequence comparisons confirmed three main lineages of Gracilariaceae: Curdiea/Melanthalia, Gracilariopsis/Gracilariophila, and Gracilaria. The Curdiea/Melanthalia diverged early in the family. Gracilariopsis was paraphyletic, because at least one Gracilariophila species evolved from it. The Atlantic Gracilariopsis were monophyletic and separated from the Pacific lineages. The Gracilaria included all species referable to its own species and to Hydropuntia, which was paraphyletic, formed by distantly related lineages. The new combination Gracilaria pauciramosa (N. Rodríguez Ríos) Bellorin, M. C. Oliveira et E. C. Oliveira is proposed for Polycavernosa pauciramosa N. Rodríguez Ríos. Recognition of subgenera within Gracilaria, based on spermatangial arrangement, was not supported. Instead, infrageneric groups were delineated by geographic origins and combinations of reproductive characters. Most Pacific species with either “textorii” or “verrucosa” type spermatangia were deeply separated from Atlantic species. Within the Atlantic Gracilaria, a lineage encompassing mostly tropical cylindrical species with “henriquesiana” type spermatangia and distinctive cystocarp anatomy was recognized. A lineage was also retrieved for cold water stringy species with verrucosa type spermatangia. Several species from the western Atlantic are closely related to Gracilaria tikvahiae McLachlan with nearly identical morphology. On the other hand, most flattened species from the tropical Atlantic were closely related despite their diverse morphologies. The interpretation of our data in addition to the literature indicates that more populations from the Indo‐Pacific must be studied before a general picture of Gracilariaceae evolution can be framed.     

The electrochemical proton potential generated by the sulphur respiration of Wolinella succinogenes

Wolinella succinogenes grown on formate and elemental sulphur was found to use the polysulphide derivatives 2,2-tetrathiobispropionate (R₂S₄) or pentathionate (S₅O ₆ ⁼ ) as acceptors for formate oxidation. The specific activities of formate oxidation with these acceptors were similar to those with elemental sulphur. The main reaction products of R₂S₄ reduction were 2,2-dithiobispropionate (R₂S₂) and sulphide. Pentathionate was converted to thiosulphate and some elemental sulphur. The electrochemical proton potential across the cytoplasmic membrane of the bacterium was measured in the steady state of electron transport from formate to R₂S₄. The electrical proportion () of the determined through the distribution of labeled tetraphenylphosphonium cation was obtained as 0.17 Volt. The was zero, when a protonophore was present. The pH-difference across the membrane was negligible. Thus the generated by sulphur respiration is close to that measured earlier with fumarate as the terminal acceptor of electron transport.Abbreviations DMO 5,5-dimethyloxazolidine-2,4-dione - R₂S_n (n=2–5) 2,2-polythiobispropionate - TTFB 4,5,6,7-tetrachloro-2-trifluoromethylbenzimidazol - TPP tetraphenylphosphonium cation     

Preface

Goldman Festschrift

Preface     

Brutbiologie des Turmfalken (Falco tinnunculus): 16j?hrige Untersuchungen in Westfalen

Zusammenfassung Anhand einer 16jährigen Untersuchung im Raum Ostwestfalen/Bielefeld wird der Bruterfolg des Turmfalken anhand von 439 Gelegen und 2256 Eiern beschrieben. Drei Brutplatztypen können unterschieden werden: A. Baumbruten in Nestern; B₁. Baumbruten in Nistkästen; B₂. Gebäudebruten in Nischen oder Nistkästen. Zwischen Baumbruten (A) und Nistkastenbruten (B_1/2) werden signifikante Unterschiede beschrieben, die für Nistkästen größere Gelege (ca. ein Ei mehr) und größeren Ausfliegeerfolg belegen. Zwischen Nistkästen in Bäumen (B₁) oder an Gebäuden (B₂) konnten keine signifikanten Unterschiede festgestellt werden. Weiterhin werden Lege- und Schlupftermine, Legerhythmus und oologische Daten aus dem Untersuchungsgebiet angegeben.

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Breeding biology of Kestrels (Falco tinnunculus) in Eastern Westfalia 1972–1987

Summary The 16 years of study gave 439 clutches with 2,256 eggs. We separated three types of breeding sites: the use of (a) stick nests, mostly built by corvids (cf. Tab., Fig. 3), (b₁) nest boxes attached to trees or telegraph poles (Fig. 2) and (b₂) nest boxes or cavities at or in buildings (Fig. 1). Within these different types of breeding places we found some significant differences. Stick nests had less eggs and though less breeding success, which was possibly caused by predation of corvids, especially magpies. Within the two types of places with nest boxes no significant differences could be established. We concluded, that stick nests were marginal in Kestrels and nest boxes were optimal despite of their placement in trees, at poles or in buildings. Furthermore, the timing of breeding cycle was described (Fig. 4) and laying interval was determind to an average value of approximately two days (Fig. 5). Mean egg size was and average volume 21.2 cm². Two daily controlled clutches lost 15.5% and 16.1% of mass (Fig. 6) pressumably mostly due to water losses.

     

Ion Effects on the H+-Translocating Adenosine Triphosphatase and Pyrophosphatase Associated with the Tonoplast of Chora corallina

H⁺-translocating ATPase and pyrophosphatase (PPase) associatedwith the tonoplast of Chara corallina were isolated with theaid of a perfusion technique, and the effects of ions on theiractivities were studied. All the alkali metal cations testedstimulated the ATPase and ATPdependent H⁺ pumping activitiesonly by 10 to 40%. Anions, on the other hand, strongly affectedthe activities. Potassium salts of Cl^- and Br^- stimulated them,while F^- and NO₃^- inhibited them. By contrast, the H⁺-translocatingPPase was insensitive to anions but sensitive to cations. Theorder of cation stimulation was Rb⁺=K⁺>Cs⁺>Na⁺=Li⁺>choline⁺.NO₃^- (50 mil), thought to be a specific inhibitor of the tonoplast-typeH⁺-ATPase, inhibited the ATPdependent H⁺ pumping almost completelybut the ATPase activity by only about 50%. Na⁺ inhibited thePP₁-dependent H⁺ pumping (I_5O=5OmM) in the presence of 50 mMKCl but not the ATP-dependent one. The PPase was more sensitiveto F^- (I₅₀=400µM) than the ATPase. Both the H⁺-ATPaseand the H⁺-PPase required Mg²⁺ for their activities, althoughan excess was inhibitory to both. The different sensitivitiesof the PP₁-dependent and the ATP-dependent H⁺- pumping enzymesto ions correspond to the tonoplast enzymes of higher plantsand may be used as "markers" to distinguish between these enzymesin characean cells (Received October 2, 1987; Accepted May 18, 1988)     

Ferritin enhances production of DNA strand breaks by 6-hydroxydopamine,ascorbic acid and H2O2 in CCC PM2 bacteriophage DNA

Damage of CCC PM2 DNA by 6-hydroxydopamine (6-OHDA) and ascorbic acid (AA), compounds that are both able to release iron from ferritin, was significantly enhanced in the presence of ferritin. H₂O₂, a product of 6-OHDA autoxidation, did not induce DNA strand breaks in the absence of ferritin and only to a minor extent in the presence of ferritin. DNA damage by 6-OHDA and AA could be reduced by the hydroxyl radical scavenger mannitol, the iron chelator desferrioxamine, and, partly, by a combination of superoxide dismutase and catalase. These inhibitory effects were clearly less pronounced in the presence of ferritin. Ferritin obviously played an important role as a source of iron in the pro-oxidative processes of 6-OHDA and AA. These features might be of importance in cancer therapy since many tumor cells contain elevated ferritin levels.     

Growth of Wolinella succinogenes with polysulphide as terminal acceptor of phosphorylative electron transport

Polysulphide was formed according to reaction (1), when tetrathionate was (1) $${\text{S}}_4 {\text{O}}_6^{2 - } + {\text{HS}}^ - \to 2{\text{S}}_2 {\text{O}}_3^{2 - } + {\text{S(O)}} + {\text{H}}^ + $$ added to an anaerobic buffer (pH 8.5) containing excess sulphide. S(O) denotes the zero oxidation state sulphur in the polysulphide mixture S _infn ^sup2- . The addition of formate to the polysulphide solution in the presence of Wolinella succinogenes caused the reduction of polysulphide according to reaction (2). The bacteria grew in a medium containing formate and sulphide, (2) $${\text{HCO}}_2^ - + {\text{S(O)}} + {\text{H}}2{\text{O}} \to {\text{HCO}}_3^ - + {\text{HS}}^ - + {\text{H}}^ + $$ when tetrathionate was continuously added. The cell density increased proportional to reaction (3) which represents the sum of reactions (1) and (3) $${\text{HCO}}_2^ - + {\text{S}}_{\text{4}} {\text{O}}_6^{2 - } + {\text{H}}2{\text{O}} \to {\text{HCO}}_3^ - + 2{\text{S}}_{\text{2}} {\text{O}}_3^{2 - } + 2{\text{H}}^ + $$ (2). The cell yield per mol formate was nearly the same as during growth on formate and elemental sulphur, while the velocity of growth was greater. The specific activities of polysulphide reduction by formate measured with bacteria grown with tetrathionate or with elemental sulphur were consistent with the growth parameters. The results suggest that W. succinogenes grow at the expense of formate oxidation by polysulphide and that polysulphide is an intermediate during growth on formate and elemental sulphur.     

Acetic acid esters and permeable weak acids induce active proton extrusion and extension growth of coleoptile segments by lowering the cytoplasmic pH

In Avena coleoptile segments a decrease of cytoplasmic pH activates energy-dependent H⁺ extrusion into the apoplast, thereby triggering extension growth. This sequence of events cannot be inhibited by cycloheximide and is induced by the following conditions and compounds. (i) A short anaerobic treatment of coleoptile segments results in the formation of lactic acid and an intracellular decrease of pH. For a period of 20 min after transfer to normal air, the growth rate is up to six times higher than the rate before anaerobiosis. (ii) Similarly, incubation of segments with CN^– (0.1 mM) in the presence of oxygen causes and accumulation of lactic acid and a fall in cell-sap pH. After removing CN^– a growth burst occurs. (iii) Higher concentrations of permeable acids (10 mM in buffer pH 5.8) induce extension growth. This growth is O₂-dependent and therefore differs from the acid growth, which can be triggered under anaerobic conditions by acid buffers of pH5 via the direct increase of cell-wall plasticity. (iv) A short application of CO₂-saturated buffer (pH 5.8) causes CO₂-induced elongation growth; after a 3-min pulse the growth rate is enhanced for about 15 min. (v) Lipophilic esters of acetic acid or propionic acid, such as naphthylacetate, naphthylpropionate, phenylacetate, benzylacetate induce elongation growth. These compounds, when taken up into the cell, are hydrolized by esterases; the acids released lower the cytoplasmic pH (shown by the pH indicator, fluorescein). The highest esterase activity was found in a microsomal membrane fraction of coleoptiles. While the carboxyester-induced extension growth is completely inhibited under anoxia, the initial acidification of the bathing solution can still be observed. This decrease in external pH is obviously the result of ester hydrolysis, caused by damaged cells, and is not the result of pH changes within the cell-wall compartment. It is suggested that a fast uptake of carboxyesters and the shift in equilibrium caused by their internal hydrolysis leads to a continuous formation of acids which lowers the cytoplasmic pH and activates the ATP-dependent H⁺ extrusion. In most experiments fusicoccin (a diacetic acid ester) acts similarly to naphthylacetate and the other carboxyesters, although quantitative differences exist. Therefore, it is possible that fusicoccin is effective partly on the basis of its ester characteristic. The effects observed are discussed with regard to the very narrow pH optimum of plasma-membrane H⁺-ATPases exhibiting their highest levels of activity at pH 6.5 (Hager and Biber 1984, Z. Naturforsch. C 39, 927–937).Abbreviations CHM cycloheximide - DMO dimethadione (5.5-dimethyl-2,4-oxazolidinedione) - FC fusicoccin - IAA indole-3-acetic acid - Mes 2-(N-morpholino)ethanesulfonic acid - NA (or )-naphthylacetate (acetic acid-1(or-2-)naphthylester) - NAA (or )-naphthaleneacetic acid - PA phenylacetate (acetic acid phenylester)