Some correlates of cranial and cervical morphology with predatory modes in snakes

Dissection of the cervical and basicranial regions in three species of snakes indicates that compared to Crotalus viridis and Lichanura roseofusca, Masticophis flagellum possesses relatively high numbers of compound axial muscle insertions on the atlas-axis and vertebrae numbers 3-5. It is suggested that the condition in Masticophis facilitates its vertical-neck-horizontal-head foraging posture and has allowed axial muscles inserting on the dorsocaudal braincase in this snake to generate vertical and lateral head movements more effectively.     

Correlation of enzymatic activity, muscle myoglobin concentration and lung morphology with activity metabolism in snakes.

In vitro activity of the anaerobic enzymes phosphofructokinase and lactic dehydrogenase from axial muscle tissue of Coluber constrictor, Crotalus viridis and Lichanura roseofusca was shown to correlate with levels of lactate production during activity by these snakes. Additionally, gross and histological lung structure and axial muscle myoglobin concentration were investigated in these species. Coluber was shown to have the most complex lung structure and highest muscle myoglobin content. These are interpreted to be correlated with high aerobic scope in Coluber. Finally, the ophidian saccular lung is postulated to assist in maintenance of high tidal volume.     

Anaerobic metabolism during activity in lizards

Summary A new technique developed for the determination of total lactate production in small animals was used to evaluate the role of anaerobiosis during activity at different temperatures in lizards. Measurements on six species of small lizards indicate little interspecific variation or thermal effect in resting lactate levels (0.35 mg lactate/g body weight) or maximal lactate levels achieved at exhaustion (1.4 mg lactate/g). Normally activeAnolis in captivity had a lactate content of 0.5 mg lactate/g. Rates of lactate formation were most rapid during the first 30 sec of activity and had a low thermal dependence (Q₁₀=1.1–1.3 above 20 °C). The lactate formed during activity persists for long periods; e.g., for 30 to 60 min between 20 and 37 °C inAnolis carolinensis (Fig. 1). Recovery rate generally increases with temperature. Muscle lactate concentrations peak at the end of activity, but liver and blood lactate are not maximal until 10 and 30 min, respectively, after activity (Fig. 2). The decrease in the blood lactate is shown to be a poor estimator of total recovery. An estimated 80–90% of the total energy utilized during initial vigorous activity comes from anaerobic sources. Because of its low thermal dependence, anaerobiosis permits high levels of activity in lizards at all body temperatures without requiring high levels of aerobic resting metabolism.Support for this research was provided by a Miller Post-doctoral Research Felowship to AFB and NSF Grant GB 22642 to PL.     

The karyology of some neotropicalStyracaceae

Chromosome numbers and karyomorphological characters have been investigated inPamphilia andStyrax (Styracaceae). Counted for the first time in the genus, two species ofPamphilia were found to have 2n = 16. The twoStyrax spp. investigated share withPamphilia the same chromosome number, a peculiar condensation behaviour of the chromosomes (Fig. 1a–c) and the same type of semi-reticulate interphase nucleus, results which indicate a close relationship of the two genera. The base number inStyracaceae is probably x = 8 (2n = 2x = 16) with stabilized triploids inHalesia andPterostyrax (2n = 3x = 24). A preliminary comparison withSapotaceae andEbenaceae does not allow a general karyological characterisation of the orderEbenales.     

Mineralized Tissues and Exercise Physiology of Snakes

Previous studies indicate a tight correlation of predatory modes,morphology, and activity physiology in snakes. Active foragerslike the coachwhip (Masticophis flagellum) exhibit great staminaand high rates of aerobiosis and anaerobiosis during intenseexercise. The western rattlesnake (Crotalus viridis), a sit-and-waitpredator, is capable of bouts of intense activity for limitedperiods of time before exhaustion. During maximal activity therattlesnake has moderate powers of anaerobiosis and limitedpowers of aerobiosis. Superior blood buffering capacity in thecoachwhip seems at least partially responsible for its stamina.New evidence presented here indicates that low endurance inthe rattlesnake may be associated with exercise-related bonedissolution, resulting in hypercalcemia. Such hypercalcemiamay function to further debilitate the already poorly developedblood buffering capacity of the rattlesnake.     

The role of retinula cell types in fixation behaviour of walkingDrosophila melanogaster

Summary Fixation behaviour of free walking wild typeDrosophila and various retinal mutants was tested in a circular arena. Optomotor response was also measured as a test of the function of R1-6.ora andsev,ora do not fixate a narrow stripe (10° or 20°, Fig. 1) but are able to orient towards broad stripes (110° or 180°, Fig. 1). The behaviour ofsev is not different from wild type. Fixation behaviour ofw rdgB is similar toora (Figs. 5, 6). The mutantora has a maximum optomotor response at low contrast frequencies (Fig. 2), but the threshold for this response is at least one log unit higher than in wild type orsev (Fig. 8). The light intensity threshold at 550 nm of fixation to a broad stripe (110°) is 1–2 log units higher inora than in wildtype, and 4 log units higher insev,ora and the structural brain mutantVam (Fig. 7).The conclusions are that retinula cells R1-6 mediate fixation to a narrow stripe at high and low ambient light intensities, and to a broad stripe at low ambient light levels. R8, possibly in conjunction with R1-6, contributes to orientation towards broad stripes at high light intensities. This hypothesis is supported by evidence that blue-adapted white-eyed flies are able to orient towards a broad stripe at high blue light intensities (Figs. 9 and 12). Blue adaptation totally eliminates the optomotor response (Figs. 10, 11) and so the optomotor response observed inora at low contrast frequencies (Figs. 2 and 8) is most likely due to the small remnants of the rhabdomeres of R1-6 that remain.Abbreviations PDA prolonged depolarising afterpotential - ERG electroretinogram     

The effects of chemicals on the phenotypic expression of aVestigial mutant inDrosophila melanogaster

Several kinds of chemicals were tested to determine their effects on the wings of avestigial mutant inDrosophila melanogaster. Two isogenic strains were used, viz.vg-ms andB; vg-ms, both co-isogenic with the Oregon-isogenic strain. Ammonium lactate was found to have a conspicuous effect in enlarging thevestigial wings. At an appropriate concentration of this agent the wings of thevg-ms- andB;vg-ms-co-isogenic strains were restored almost to wild-type wing at 27°C. This fact indicates that the wings of thevg-ms mutant can be restored to wild type not only by temperature but also by certain chemicals. Ammonium lactate was effective conspicuously on bothBar andvestigial-ms mutants. However, there was found an interaction betweenBar andvestigial-ms when these genes were combined. The manifestation ofB is enhanced byvg-ms, especially under the the condition of feeding in medium containing the chemical, and the manifestation ofvg-ms is reduced byB.This work forms part of a thesis for the doctorate of Kyoto University.     

Hibernation patterns and energy expenditure in hedgehogs from semi-arid and temperate habitats

Summary Hibernation patterns, body temperature (T _b) and oxygen consumption ( ) were measured during hibernation in two hedgehog species, a desert speciesHemiechinus auritus (body mass 367 g) and a temperate habitat speciesErinaceus europaeus (body mass 598 g). A continuous ambient temperature of 11 °C was the only necessary condition for both species to enter hibernation outdoors and in the laboratory. At this temperature, hibernation could be induced at any time of the year. Hibernation bouts ofHemiechinus were regular and short (average 4.8 days), whereas those ofErinaceus lasted 5 to 27 days (average 9.3 days). The frequency of spontaneous arousals was 5.3 and 2.9 per month forHemiechinus andErinaceus, respectively. None of the hedgehogs took any food during arousal periods. Both species had the sameT _b during hibernation (12.5 °C) and during arousal (33 °C). of the hibernatingHemiechinus was twice the rate ofErinaceus (0.050 vs. 0.025 ml g^–1 h^–1), but during arousal it was the same for both. The monthly average energy expenditure for both species was 1,477 kJ per animal, which is 15% of the energy used by non-hibernating hedgehogs. The corresponding amount of fat catabolized was 37 g per month. This mass loss would limit the hibernation inHemiechinus to 3.9 months and inErinaceus to 6.5 months. Although hibernation inHemiechinus does not constitute a special adaptation to hot environments, it significantly improves the hedgehog's energy economy during the desert winter.     

Galactose-1-phosphate uridyltransferase of lemurs: A comparison of four species

Erythrocyte galactose-1-phosphate uridyltransferase (Gal-1-PUT) was studied in four species of lemurs. Electrophoretic phenotypes of Lemur fulvusand Lemur macacowere indistinguishable and different from the phenotypes of Lemur cattaand Lemur variegatus,which were different from each other. Enzymatic activity of hemolysates was species specific, with that of Lemur variegatusabout twice that of either Lemur fulvusor Lemur macacoand almost three times that of Lemur catta.Only minor interspecific differences were demonstrated in pH optima and k_m for galactose-1-phosphate; however, thermal stability varied considerably with phenotype. Antibody inhibition studies indicated that differences in enzyme activity of hemolysates from these species are probably due to differences in enzyme concentration.     

Action of griseofulvin on geophilic dermatophytes and related keratinophilic fungi

Summary Growth response to griseofulvin has been studied in 24 strains of 16 species of geophilic dermatophytes and related keratinophilic fungi. Based on their sensitivity to griseofulvin these fungi fall into three groups: (1) Resistant group includesKeratinomyces ajelloi, Trichophyton terrestre andTrichophyton evolceanui which can grow upto 40µg per ml concentration of griseofulvin. (2) Fairly resistant group comprisingMicrosporon cookei, Microsporon vanbreuseghemii, a strain ofMicrosporon gypseum andTrichophyton sp., with growth occurring upto 8–16µg per ml concentration. (3) Sensitive group includes species ofTrichophyton, Keratinophyton, Microsporon, Nannizzia, Chrysosporium andCtenomyces which are completely inhibited at 4–8µg or lower griseofulvin concentrations. Griseofulvin inhibited formation of cleistothecia inK. terreum, delayed pleomorphic growth inT. indicum andN. incurvata, and influenced pigment production in several strains.     

Glucose- and K+-induced acidification in different yeast species

The process of acidification of the external medium after addition of glucose and subsequently of KCl to a suspension of yeast cells varies substantially from species to species. After glucose it is most pronounced inSaccharomyces cerevisiae andSchizosaccharomyces pombe but is very much lower inLodderomyces elongisporus, Dipodascus magnusii andRhodotorula gracilis. Both the buffering capacity and the varied effects of vanadate, suloctidil and erythrosin B indicate that the acidification is by about one-half due to the activity of plasma membrane H⁺-ATPase and by about one-half to the extrusion of acidic metabolites from cells. This is supported by the finding that a respiratory quotient greater than one (in various strains ofS. cerevisiae and inS. pombe) is indicative of a greater buffering capacity and overall acidification of the medium. Taking into account the virtually negligible buffering capacity of the medium in the pH range where the effect of K⁺ is observed, the effect of K⁺ is generally of a similar magnitude as that of adding glucose. It is clearly dependent on (anaerobic) production of metabolic energy, quite distinct from the dependence of the H⁺-ATPase-caused acidification.     

Effects of long scotophase and cold acclimation on heat production in two diurnal rodents

Summary Heat production of two diurnal rodents,Rhabdomys pumilio andLemniscomys griselda was measured in long scotophase-LS (8L: 16D; 25°C) acclimated and long scotophase and cold — LSAC (8L: 16D; 6°C) acclimated animals and compared to a control group (12L: 12D; 25°C).LS increased in both species. Further acclimation of LSAC increased inR. pumilio and decreased inL. griselda. LS increased body temperature (T _b) inL. griselda only. LS increased overall thermal conductance in both species. LSAC caused a further increase in this parameter inR. pumilio.A singificant (P<0.001) increase in the magnitude of maximal nonshivering thermogenesis (NST) was observed in both species due to LS acclimation. LSAC did not change this maximal NST but increased its obligatory part (minimal , P<0.05, inL. griselda, andP<0.001, inR. pumilio).The results of this study show that winter acclimatization of heat production mechanisms, in both species, may be due to extension of scotophase.Abbreviations LS long scotophase - LSAC long scotophase and cold - NA noradrenaline - NST nonshivering thermogenesis - RMR resting metabolic rate     

The neotropical angiosperm familiesBrunelliaceae andCaryocaraceae: First karyosystematical data and affinities

Chromosome numbers are polyploid, 2n = 28 inBrunellia comocladiifolia andB. mexicana, and 2n = 46 inCaryocar brasiliense, C. microcarpum andC. villosum. The chromosome are small in both genera, with a length of ca. 1,6-0,4µm. Interphase nuclei correspond to the prochromosomal and the chromocentric type, respectively. This is in conformance with the systematic placement ofBrunelliaceae intoCunoniales, and ofCaryocaraceae intoTheales. Brunellia exhibits affinities to various other orders ofRosidae (andHamamelididae), and is suggested to be primarily apetalous. On a comparative basis, the chromosome numbers found in both families are interpreted as paleopolyploid (4 x and 6 x). This apparently is in correspondence with their rather primitive features, systematic isolation, relatively depauperate status, and evidently great age.     

Evaluation of some common aquatic macrophytes cultivated in enriched water as possible source of protein and biogas

The biomass production of three common aquatic macrophytes,viz. Azolla pinnata, Eichhornia crassipes andHydrilla verticillata, was high at the prevailing environmental conditions and by the enriched water of River Ganga. The biomass production ofAzolla andEichhornia was positively correlated with the orthophosphate phosphorus and nitrate-nitrogen concentrations of the enriched water. The biomass ofAzolla andHydrilla was positively correlated with the electrical conductivity of the water. The average yield of crude protein was highest in Azolla (8,520 kg.ha^–1.yr^–1), and somewhat lower inEichhornia (6,520 kg.ha^–1.yr^–1). The annual biogas production was highest inEichhornia (44,381 litres), and somewhat lower inAzolla (17,186 litres).     

Evolution of hybrid taxa inNasturtium R.Br. (Brassicaceae)

Nasturtium officinale (2n=4x=32),N. microphyllum (2n=8x=64) andN. ×sterile (2n=6x=48) have been investigated by isozyme analyses to study evolutionary processes withinNasturtium. Four additional species assumed to be involved in the formation of the octoploidN. microphyllum (Rorippa amphibia, R. sylvestris, R. palustris, andCardamine amara) were also examined. A total of 641 individuals were analyzed for six isozyme systems (alcohol dehydrogenase, aspartate aminotransferase, glutamate dehydrogenase, leucine aminopeptidase, malate dehydrogenase, and phosphoglucoisomerase). Eleven gene complexes coding for 43 allozymes were detected. Fifteen alleles were observed inN. officinale, twelve of them being fixed. All alleles fixed inN. officinale were also present and fixed inN. microphyllum. Seven additional fixed alleles were observed inN. microphyllum. The presence of these seven alleles inRorippa taxa provide evidence for an allopolyploid origin ofN. microphyllum withN. officinale and aRorippa taxon involved.C. amara is not a parent species ofN. microphyllum. N. ×sterile showed a fixed banding pattern which was identical to that ofN. microphyllum. It is argued thatN. ×sterile is a hybrid betweenN. officinale andN. microphyllum. Human impact has played a major role in the evolution ofN. ×sterile. The formation and persistence of the hybrid were influenced by introducingN. officinale into the natural distribution area ofN. microphyllum and by creating ditches and ponds where due to its vegetative capabilitiesN.×sterile could establish.     

Ultrastructural study of two rumen fungi:Piromonas communis andSphaeromonas communis

Two species of strictly anaerobic rumen fungi,Sphaeromonas communis andPiromonas communis, were examined by light and electron microscopy (scanning and transmission). Although morphologically different (vegetative body, number of flagella per zoospore), the ultrastructure of these two microorganisms was rather similar to that ofNeocallimastix frontalis andN. patriciarum. Two types of organelles were regularly found, i.e., isolated or associated ribosomes in the form of aggregates and hydrogenosome-like organelles with an amorphous content that may be involved in energy generation for these mitochondria-free strictly anaerobic fungi. UnlikeN. frontalis, the distribution of organelles was homogenous.     

Regulation of biosynthesis of thiolutin and aureothricin inStreptomyces kasugaensis

l-Methionine anddl-ethionine decreased production of thiolutin and aureothricin inStreptomyces kasugaensis. In the presence ofl-methionine the culture also produced 3-methylthioacrylic acid, 3-methylthiopropionic acid and 3,6-bis-(2-methylthioethyl)-2,5-dioxopiperazine. Production of the metabolites depended on the concentration ofl-methionine in the medium.     

Changes in body core temperatures and heat balance after an abrupt release of lower body negative pressure in humans

Changes in body core temperature (T _cor) and heat balance after an abrupt release of lower body negative pressure (LBNP) were investigated in 5 volunteers under the following conditions: (1) an ambient temperature (T _a) of 20 °C or (2) 35 °C, and (3)T _a of 25 °C with a leg skin temperature of 30°C or (4) 35°C. The leg skin temperature was controlled with water perfusion devices wound around the legs. Rectal (T _re), tympanic (T _ty) and esophageal (T _es) temperatures, skin temperatures (7 sites) and oxygen consumption were measured. The intensity of LBNP was adjusted so that the amount of blood pooled in the legs was the same under all conditions. When a thermal balance was attained during LBNP, application of LBNP was suddenly halted. The skin temperatures increased significantly after the release of LBNP under all conditions, while oxygen consumption hardly changed. The release of LBNP caused significant falls inT _cor s under conditions (1) and (3), but loweredT _cor s very slightly under conditions (2) and (4). The changes inT _es were always more rapid and greater than those ofT _ty andT _re. The falls inT _ty andT _re appeared to be explained by changes in heat balance, whereas the sharp drop ofT _es could not be explained especially during the first 8 min after the release of LBNP. The results suggest that a fall inT _cor after a release of LBNP is attributed to an increase in heat loss due to reflexive skin vasodilation and is dependent on the temperature of venous blood returning from the lower body. It is presumed thatT _es may not be an appropriate indicator forT _cor when venous return changes rapidly.     

Polyploidy and aneuploidy inOphrys,Orchis, andAnacamptis (Orchidaceae)

Studies on chromosome numbers and karyotypes in Orchid taxa from Apulia (Italy) revealed triploid complements inOphrys tenthredinifera andOrchis italica. InO. tenthredinifera there is no significant difference between the diploid and the triploid karyotypes. The tetraploid cytotype ofAnacamptis pyramidalis forms 36 bivalents during metaphase I in embryo sac mother cells. Aneuploidy was noticed inOphrys bertolonii ×O. tarentina with chromosome numbers n = 19 and 2n = 38. There were diploid (2n = 2x = 36), tetraploid (2n = 4x = 72), hexaploid (2n = 6x = 108) and octoploid (2n = 8x = 144) cells in the ovary wall of the diploid hybridOphrys apulica ×O. bombyliflora. Evolutionary trends inOphrys andOrchis chromosomes are discussed.     

DNA contents,giemsa banding,and systematics inScilla bifolia,S. drunensis,andS. vindobonensis (Liliaceae)

DNA contents have been determined cytophotometrically in the three Central European, relatedScilla speciesS. bifolia (2n = 18, 2 x, 1 C = 6.2 pg),S. drunensis (2n = 36, 4 x, 1 C = 12.8 pg), andS. vindobonensis (2n = 18, 2 x, 1 C = 9.4 pg). The tetraploid speciesS. drunensis contains twice as much DNA as the diploidS. bifolia. However, the diploid speciesS. vindobonensis differs in DNA content fromS. bifolia by a factor of about 1.5. This difference is largely due to euchromatic DNA, although the higher DNA content inS. vindobonensis is combined with higher heterochromatin content. The data indicate thatS. bifolia andS. drunensis on the one hand, andS. vindobonensis on the other hand are phyletically well separated. Previous taxonomic conclusions from morphology as well as C-banding are thus corroborated.Evolution ofScilla and Related Genera, V.