Scientists Prefer them Blind: The History of Hypogean Fish Research

The history of hypogean fish research has been strongly influenced by neo-Lamarckism (including orthogenesis) and typological thinking. Only in the last few decades neo-Darwinism has made any inroads in the research approach to this subject. The majority of the most distinguished and productive hypogean fish researchers have used their research subjects to confirm their own views on evolution rather than to use those subjects as a spring of knowledge to enrich mainstream biological thought. Of these views, I found that the most perversive of all is the notion of evolutionary progress that has led many researchers to envision hypogean fishes as prime examples of regressive evolution. I propose that the utilization of hypogean fishes for the study of convergent evolution should catapult these subjects of research into prime objects of evolutionary ideas.     

Endogenous abscisic acid and 2-trans-abscisic acid in alternate bearing ‘Wilking’ mandarin trees

The relationship of abscisic acid (ABA) and 2-trans-abscisic acid (t-ABA) to alternate bearing has been examined in Wilking mandarin (Citrus reticulata Blanco) trees. Leaves, stems and buds of trees loaded with fruit (on trees) had 4.3, 6.0 and 2.2 fold higher ABA levels than the corresponding organs from off trees. Leaves had higher ABA levels than stems and buds in both on and off trees. t-ABA was non-detectable in Wilking leaf, stem and bud tissue. Amounts of t-ABA not exceeding 40% of the ABA content, were found in Shamouti and Valencia orange buds and in Wilking fruit peel.The elevated levels of ABA in on tree organs may reflect a stress imposed by the fruit overload.     

Analysis of primary food sources and trophic relationships of aquatic animals in a mangrove-fringed estuary,Khung Krabaen Bay (Thailand) using dual stable isotope techniques

Stable carbon (¹³C) and nitrogen (¹⁵N) isotopes were used to elucidate primary food sources and trophic relationships of organisms in Khung Krabaen Bay and adjacent offshore waters. The three separate sampling sites were mangroves, inner bay and offshore. The ¹³C values of mangrove leaves were –28.2 to –29.4, seagrass –10.5, macroalgae –14.9 to –18.2, plankton –20.0 to –21.8, benthic detritus –15.1 to –26.3, invertebrates –16.5 to –26.0, and fishes –13.4 to –26.3. The ¹⁵N values of mangrove leaves were 4.3 to 5.7, seagrass 4.3, macroalgae 2.2 to 4.4, plankton 5.7 to 6.4 , benthic detritus 5.1 to 5.3, invertebrates 7.2 to 12.2 , and fishes 6.3 to 15.9. The primary producers had distinct ¹³C values. The ¹³C values of animals collected from mangroves were more negative than those of animals collected far from shore. The primary carbon sources that support food webs clearly depended on location. The contribution of mangroves to food webs was confined only to mangroves, but a mixture of macroalgae and plankton was a major carbon source for organisms in the inner bay area. Offshore organisms clearly derived their carbon through the planktonic food web. The ¹⁵N values of consumers were enriched by 3–4 relative to their diets. The ¹⁵N data suggests that some of aquatic animals had capacity to change their feeding habits according to places and availability of foods and as a result, individuals of the same species could be assigned to different trophic levels at different places.     

High-level Expression of Maize <Emphasis Type="Italic">γ</Emphasis>-zein Protein in Transgenic Soybean (<Emphasis Type="Italic">Glycine max</Emphasis>)

Primers were developed for 118 microsatellites isolated from grape (Vitis vinifera) genomic libraries enriched for (AC)n repeats. Only one microsatellite sequence matched other grape SSR-sequences in the GeneBank database. Genotyping was carried out in the parental lines and four offspring of two pseudo-test-cross populations, Cabernet Sauvignon x Seyval and Chardonnay x Bianca, and a further six other grape genotypes (V. vinifera Sultanina, Merlot, Syrah, Müller-Thurgau, Vitis Regent and V. riparia Gloire de Montpellier). A total of 108 microsatellites showed easily scorable alleles and 100 of them segregated according to a configuration suitable for mapping in either cross. A further 8 SSRs, although unsuitable for mapping in those crosses, showed polymorphism in the other genotypes tested. This set of markers was used, along with 75 microsatellites of other repeat-types, to fingerprint 46 offspring of the cross Chardonnay x Bianca. For each full-sib, individual heterozygosity and distance in repeat units between pairs of alleles at each locus (mean d²) were calculated as a tool for predicting highly outbred recombinant individuals. Six microsatellites with segregation ratios significantly distorted towards the lack of homozygous sibs were identified and mapped to linkage groups LG 3 and LG 5. Estimation of heterozygosity at genome-wide level and genotyping at loci for which homozygous sibs are discriminated against are discussed for marker-assisted background selection in outcrossing grapevines.     

Occurrence of pppApp-synthesizing activity in actinomycetes and isolation of purine nucleotide pyrophosphotransferase

The occurrence of adenosine 5-triphosphate-3-diphosphate-synthesizing activity was detected in five strains of actinomycetes; Streptomyces morookaensis, Streptomyces aspergilloides, Streptomyces hachijoensis, Actinomyces violascens and Streptoverticillium septatum, out of 825 strains of actinomycetes, bacteria, fungi and imperfecti. Purine nucleotide pyrophosphotransferase were extracellularly excreted associating with the cell growth, and were purified partially or to apparent homogeniety from the culture filtrate. The enzymes are a monomeric protein with a molecular weight of 18000–26000 and synthesize adenosine, guanosine and inosine 5-phosphate (mono, di or tri)-3-diphosphate such as pApp, ppApp, pppApp, pGpp, ppGpp, pppGpp and pppIpp by transferring a pyrophosphoryl group from the 5-position of ATP, dATP and pppApp to the 3-position of purine nucleotides in the presence of a divalent cation and in alkaline state.Abbreviations pppApp adenosine 5-triphosphate 3-diphosphate - ppApp adenosine 5-diphosphate 3-diphosphate - pApp adenosine 5-monophosphate 3-diphosphate - pppGpp guanosine 5-triphosphate 3-diphosphate     

Modulation of Adenosine 5′-Monophosphate Adsorption Onto Aqueous Resident Pyrite: Potential Mechanisms for Prebiotic Reactions

The adsorption of adenosine 5-monophosphate (5-AMP) ontopyrite (FeS₂) and its modulation by acetate, an organic precursor of complex metabolic pathways, was studied in aqueousmedia that simulate primitive environments. 5-AMP adsorptionrequires divalent cations, indicating that a cationic bridge mediates its attachment to negatively charged sites of the mineral surface. The isotherm of 5-AMP adsorption exhibits a strong cooperative effect at low nucleotide concentrations inacetate-rich medium, whereas high levels of adsorption were only found at high nucleotide concentrations in a model of primitive seawater (acetate free). The modulating role of acetate is also evidenced in the presence of high dipolar moment molecules: dimethyl sulfoxide (Me₂SO) and dimethylformamide (DMF) strongly inhibit 5-AMP adsorption in acetate-rich media, whereas no effect of DMF was found in artificial seawater. The observation that exogenous divalentcations are not needed for acetate attachment onto FeS₂ reveals that organic acids can interact with the Fe²⁺ atoms in the mineral surface. All considered, the results showthat complex and flexible iron-sulfide/biomonomers interactionscan be modulated by molecules that accumulate in the interfacelayer.     

α-Thalassemia and the production of different α chain variants in heterozygotes

The production of five chain variants (Hb G-Georgia, Hb St. Luke's, Hb Lloyd, Hb Montgomery, and Hb G-Philadelphia) in heterozygotes was evaluated through hematological observations, hemoglobin quantification, and biosynthetic studies. All heterozygotes for Hb St. Luke's and Hb Lloyd and most heterozygotes with Hb G-Georgia and Hb Montgomery had normal hematology and average / values of about 1.1. They were assigned a normal genotype (^G/), although the proportions of Hb St. Luke's and Hb G-Georgia were low (10 to 13%) and those of Hb Lloyd and Hb Montgomery twice as high (20%). Data from short-term incubations confirmed this genotype for some of these heterozygotes. Isolated Hb St. Luke's and Hb G-Georgia gave low ^G/ values (0.2 and 0.3) indicating that these Hb variants were defective at the level of Hb assembly. Isolated Hb Montgomery and Hb G-Philadelphia, however, gave higher ^G/ values of 0.6 and 0.8, respectively. A second type of variability existed among Hb G-Georgia (20 vs. 13%), Hb Montgomery (28 vs. 20%), and Hb G-Philadelphia (47 vs. 34%) heterozygotes, in whom the levels of Hb G differed. The occurrence of higher levels of these three chain heterozygosities was associated with hematological or biosynthetic evidence of a mild or moderate chain deficiency due to an -thalassemia-2 heterozygosity (^G/⁰ or ^0G/) or a homozygosity (^0G/⁰), respectively.This study was supported in part by USPHS Research Grants HLB-05168 and HLB-15158.     

Endothermy in fishes: a phylogenetic analysis of constraints,predispositions, and selection pressures

Synopsis Endothermy, the ability to raise body temperature by internal heat production, is unusual in teleost fishes and has only been documented within one suborder, the Scombroidei. Two separate modes of endothermy have evolved in the scombroidei; tunas warm their muscles, brain and viscera using heat exchangers in the circulation to these metabolically active tissues while billfishes and one primitive mackerel have a thermogenic organ situated beneath the brain. Both modes of endothermy emphasize common themes. Large body size coupled with heat exchangers are necessary to reduce convective and conductive heat exchange. A tissue with a high oxidative capacity is required for heat generation. Studies based upon morphology and mitochondrial DNA analyses indicate that endothermy has evolved independently at least three times within the scombroid lineage. Mapping of-morphological and physiological traits on a molecular phylogeny for scombroids provides evidence of selective pressures favoring evolution of diverse endothermic styles. The new results suggest anatomical constraints prevent most fish from using the tuna form of endothermy and indicate a possible linkage between endothermy and locomotory style (thunniform or sub-carangiform).Paper from the International Union of Biological Societies symposium The biology of tunas and billfishes: an examination of life on the knife edge, organized by Richard W. Brill and Kim N. Holland.     

Transformation of 16-dehydroprogesterone and 17α-hydroxyprogesterone by Mucor piriformis

Mucor piriformis was used to study the mode of transformation of 16-dehydroprogesterone (I, pregna-4, 16-diene-3, 20-dione) and 17-hydroxyprogesterone (II, 17-hydroxypregn-4-ene-3, 20-dione). Biotransformation products formed from I were 14-hydroxypregna-4, 16-diene-3, 20-dione (Ia), 7, 14-dihydroxypregna-4, 16-diene-3, 20-dione (Ib), 3, 7, 14-trihydroxy-5-pregn-16-en-20-one (Ic), and 3, 7, 14-trihydroxy-5-pregn-16-en-20-one (Id). Metabolites Ic and Id appear to be hitherto unknown. Time-course studies suggested that the transformation is initiated by hydroxylation at the 14-position (Ia) followed by hydroxylation at the 7-position (Ib). Microsomes (105,000 g sediment) prepared from 16-dehydroprogesterone-induced cells hydroxylate I to its 14-hydroxy derivative (Ia) in the presence of NADPH. Incubation of Ia with the organism resulted in the formation of Ib, Ic and Id. Biotransformation products formed from compound II were 17, 20-dihydroxypregn-4-en-3-one (IIa), 7, 17-dihydroxypregn-4-ene-3, 20-dione (IIb), 6, 17, 20-trihydroxypregn-4-en-3-one (IIc) and 11, 17, 20-trihydroxypregn-4-en-3-one (IId). Time-course studies indicated that IIa is the initial product formed, which is further hydroxylated either at the 6 or 11 position. Incubation of IIa with the organism resulted in the formation of IIc and IId. Reduction of the 4-en-3-one system and 20-keto group has not been observed before in organisms of the order Mucorales. In addition, M. piriformis has been shown to carry out hydroxylation at the C-6, C-7, C-11 and C-14 positions in the steroid molecules tested.     

Tetramethyl Rhodamine Methyl Ester (TMRM) is Suitable for Cytofluorometric Measurements of Mitochondrial Membrane Potential in Cells Treated with Digitonin

A new method for cytofluorometric analysis of mitochondrial membrane potential has been developed by using TMRM as a cationic, mitochondrial selective probe. The method is based on limited treatment of cultured cells with digitonin which permeabilises the plasma membrane and leaves mitochondria intact. The resulting signal of TMRM-stained cells thus represents only the probe accumulated in mitochondria. Fibroblasts and cybrids were used as a model cell systems and optimal conditions for digitonin treatment and staining by TMRM were described. The TMRM signal collapsed by valinomycin, KCN and antimycin A and FCCP titration was used to gradually lower and characterise the stability of . The method is suitable for sensitive measurement of in different types of cultured cells.     

Plant regeneration from Citrus protoplasts: Variability in methodological requirements among cultivars and species

Summary Nucellar callus lines were established from two orange cultivars (Nucellar Shamouti, Shamouti Landau), three mandarin cultivars (Murcott, Dancy, Ponkan) one grapefruit cultivar (Duncan) and sour orange (Citrus aurantium). These callus lines were initiated from in vitro cultured ovules of young fruits and maintained an embryogenic capacity. The plating efficiencies of protoplasts derived from these calli, as well as those of protoplasts from lemon (cv. Villafranca) nucellar callus were differentially affected by the maceration enzymes and by the sugars used as osmotic stabilizers. Plants with normal morphological features were regenerated from cultured protoplasts derived from each of the nucellar callus lines. The establishment of eight new protoplast systems in Citrus paves the way for cell genetics studies and for novel breeding approaches in these economically important orchard trees.Contribution from the Agricultural Research Organization, The Volcani Center, Bet Dagan, Israel. No. E-290, 1981 series     

Coexistence of coral reef fishes — a lottery for living space

Synopsis Data are summarised from studies of two reef fish communities — pomacentrids territorial on rubble patches, and fishes resident in small isolated colonies of coral. In each case there is evidence that availability of living sites limits numbers of fishes, and that similar species of fish use the same kinds of spaces. Priority of arrival as recruits, rather than subtle differences in requirements or competitive abilities of adults, appears to determine which species holds each site. Faced with a limited and patchy supply of living space, most reef fishes are sedentary as adults, and produce frequent clutches of pelagic larvae over extended breeding seasons In this way they maximise their chances of getting offspring into suitable living sites as such sites appear. It is argued that by adopting this strategy, reef fishes are preadapted for forming inter-specific lotteries for living space if several species with similar requirements occur together. Such lotteries among similar species may be a feature common to many reef fish communities, and may explain the typically high within-site diversity found in them.This paper forms part of the proceedings of a mini-symposium convened at Cornell University, Ithaca, N.Y., 18–19 May 1976, entitled Patterns of Community Structure in Fishes (G. S. Helfman, ed.).     

Peptide modification by incorporation ofα-trifluoromethyl substituted amino acids

Summary Metabolic stabilization of pharmacologically active peptides can be achieved by incorporation of sterically hindered non-natural amino acids, e.g. C ^, -disubstituted amino acids.-Trifluoromethyl substituted amino acids, a subclass of C ^, -disubstituted amino acids, also fulfil this requirement while featuring additional properties based on the electronic influence of the fluorine substituents.This review summarizes the results concerning the stability of peptides containing-TFM amino acids towards proteolysis by-chymotrypsin. Furthermore, configurational effects of-TFMAla on the proteolytic stability of peptides are explained using empirical force field calculations. The influence of-TFMAla incorporation on the secondary structure of selected tripeptide amides is compared to the effects exerted by its fluorine-free analogue, aminoisobutyric acid.Finally, results on metabolic stabilization and biological activity of modified thyrotropin releasing hormone are interpreted.     

Degradation of the diarylpropane lignin model compound 1-(3′,4′-diethoxyphenyl)-1,3-dihydroxy-2-(4′'-methoxyphenyl)-propane and derivatives by the basidiomycete Phanerochaete chrysosporium

The white rot basidiomycete Phanerochaete chrysosporium metabolized 1-(3,4-diethoxyphenyl)-1,3(dihydroxy)-2-(4'-methoxyphenyl)-propane (XII) in low nitrogen stationary cultures, conditions under which the ligninolytic enzyme system is expressed. 3,4-Diethoxybenzyl alcohol (IV), 1,2(dihydroxy)-1-(4-methoxyphenyl)ethane (XX) and anisyl alcohol were isolated as metabolic products indicating an initial , bond cleavage of this dimer. Exogenously added XX was rapidly converted to anisyl alcohol, indicating that XX is an intermediate in the metabolism of XII. Fungal cleavage of the , bond of 1-(3-4-diethoxyphenyl)-1-(hydroxy)-2-(4'-methoxyphenyl)ethane (XI) also occurred, indicating that a hydroxymethyl group is not a prerequisite for this reaction. P. chrysosporium also metabolized 1-(4-ethoxy-3-methoxyphenyl)-2,2(dihydroxy)-2-(4'-methoxyphenyl)propane-1-ol (XIII). The major products of the degradation of this triol included 4-ethoxy-3-methoxybenzyl alcohol (III) and 2-hydroxy-1-(4-methoxyphenyl)-1-oxoethane (XXI). The nature of the products formed indicates that this triol is also cleaved directly at the , bond. The significant difference in the nature of the products formed from the diaryl propane (XII) and the triol (XIII), however, suggests that XIII is not an intermediate in the major pathway for the degradation of XII. Metabolites were identified after comparison with chemically synthesized standards by GLC-mass spectrometry.Abbreviations GLC Gas liquid chromatography - TMSi trimethylsilyl - TLC thin layer chromatography - MS mass spectrometry     

Identification of two RAPD markers tightly linked with the Nicotiana debneyi gene for resistance to black root rot of tobacco

Linkage of randomly amplified polymorphic DNA (RAPD) markers with a single dominant gene for resistance to black root rot (Chalara elegans Nag Raj and Kendrick; Syn. Thielaviopsis basicola [Berk. and Broome] Ferraris) of tobacco (Nicotiana tabacum L.), which was transferred from N. debneyi Domin, was investigated in this study. There were 2594 repeatable RAPD fragments generated by 441 primers on DNAs of Delgold tobacco, a BC₅F₈ near isogenic line (NIL) carrying the resistance gene in a Delgold background, and PB19, the donor parent of the resistance gene. Only 7 of these primers produced eight RAPD markers polymorphic between Delgold and PB19, indicating there are few RAPD polymorphisms between them despite relatively dissimilar pedigrees. Five of the eight RAPD markers were not polymorphic between Delgold and the NIL. All of these markers proved to be unlinked with the resistance gene in F₂ linkage tests. Of the remaining three RAPD markers polymorphic between Delgold and the NIL, two were shown to be strongly linked with the resistance gene; one in coupling and the other in repulsion. Application of the two RAPDs in the elimination of linkage drag associated with the N. debneyi resistance gene and marker-assisted selection for the breeding of new tobacco cultivars with the resistance gene is discussed.     

γδ T-cell receptor repertoire in human peripheral blood and thymus

T-cell clones expressing the T-cell receptor (Tcr) were generated from peripheral blood lymphocytes (PBLs) and from a thymus sample. In the panel of ten thymus-derived clones, four Tcr phenotypes [as defined by the reaction of monoclonal antibodies (mAbs) directed against known V and V regions] were identified. All the clones lacked expression of the V3 V region, while seven clones were V1+ . V1 was found in combination with V9 or with undefined VVregions. In addition, two other Tcr phenotypes were identified on these clones: V9⁺ V1^– V3^– and V9^– V1^– V3^– One of the clones expressed CD4 and another was CD8positive. The remaining clones were CD4^– CD8^–. In the panel of 76 PBL-derived, Tcr-bearing clones, five Tcr phenotypes could be identified. In contrast to the thymus-derived clones, 30% of the clones were V3⁺ whereas V1 was expressed by a minority of the clones only. One clone was CD4-positive and approximately 30% of the clones were CD8-positive. Four of the five mAb-defined Tcr phenotypes could be identified on both thymus and PBL-derived T-cell clones. However, biochemical analysis of the Tcrs demonstrates differences in the usage of Ct- and C2-encoded y chains by T cells derived from the thymus and PBLs. The results therefore indicate that, at the clonal level, similarities and differences exist between the Tcr repertoires expressed in the thymus and by PBLs. Furthermore, they indicate that combinatorial Tcr heterogeneity is larger than has so far been described. The receptor diversity, combined with the potential of Tcr+ cells to express CD4 or CD8, indicates that these cells are a heterogeneous population that might mediate a number of immune functions.     

Alterations in protein kinase C isoenzyme expression and autophosphorylation during the progression of pressure overload-induced left ventricular hypertrophy

Cardiomyocytes express several isoenzymes of protein kinase C (PKC), which as a group have been implicated in the induction of left ventricular hypertrophy (LVH) and its transition to heart failure. Individual PKC isoenzymes also require transphosphorylation and autophosphorylation for enzymatic activity. To determine whether PKC isoenzyme expression and autophosphorylation are altered during LVH progression in vivo, suprarenal abdominal aortic coarctation was performed Sprague-Dawley rats. Quantitative Western blotting was performed on LV tissue 1, 8 and 24 weeks after aortic banding, using antibodies specific for total PKC, PKC and PKC, and their C-terminal autophosphorylation sites. Aortic banding produced sustained hypertension and gradually developing LVH that progressed to diastolic heart failure over time. PKC levels and autophosphorylation were not significantly different from sham-operated controls during any stage of LVH progression. PKC expression levels were also unaffected during the induction of LVH, but increased 3.2 ± 0.8 fold during the transition to heart failure. In addition, there was a high degree of correlation between PKC levels and the degree of LVH in 24 week banded animals. However, autophosphorylated PKC was not increased at any time point. In contrast, PKC autophosphorylation was increased prior to the development of LVH, and also during the transition to heart failure. The increased PKC autophosphorylation in 1 week banded rats was not accompanied by an increase in total PKC, whereas total PKC levels were markedly increased (6.0 ± 1.7 fold) in 24 week banded animals. Furthermore, both phosphorylated and total PKC levels were highly correlated with the degree of LVH in 24 week banded rats. In summary, we provide indirect evidence to indicate that PKC may be involved in the induction of pressure overload LVH, whereas both PKC and PKC may be involved in the transition to heart failure.     

The effect of some macronutrients on adventitious root development on scion apple cultivars in vitro

The influence of some macronutrients, especially NH₄NO₃ and KNO₃, on root development of microcuttings from 3 apple scion cultivars is discussed. A reduction of the level of NH₄NO₃ in the medium from full strength to 1/4 strength significantly increased the percentage rooting of Gala and Royal Gala, but not Jonagold. Further reduction of NH₄NO₃ level from 1/4 strength to zero significantly reduced the percentage of rooting in Gala but not Royal Gala. Jonagold rooted best at zero concentration NH₄NO₃. Without NH₄NO₃, rooting percentages were as high as 100% for all 3 cultivars when KNO₃ was provided at full strength. The results show that adventitious roots can be induced on apple scion cultivars by media manipulation.     

Neutral changes during divergent evolution of hemoglobins

Summary A comparison of the mRNAs for rabbit and human-hemoglobins shows that synonymous changes in codons have accumulated three times as rapidly as nucleotide replacements that produced changes in amino acids. This agrees with predictions based on the so-called neutral theory. In addition, seven codon changes that appear to be single-base changes (according to maximum parsimony) are actually two-base changes. This indicates that the construction of primordial sequences is of limited significance when based on inferences that assume minimum base changes for amino acid replacements.     

The effect of humidity and light on cellular water relations and diffusion conductance of leaves ofTradescantia virginiana L.

Turgor (_p) and osmotic potential (_s) in epidermal and mesophyll cells, in-situ xylem water potential (-xyl) and gas exchange were measured during changes of air humidity and light in leaves ofTradescantia virginiana L., Turgor of single cells was determined using the pressure probe. Sap of individual cells was collected with the probe for measuring the freezing-point depression in a nanoliter osmometer. Turgor pressure was by 0.2 to 0.4 MPa larger in mesophyll cells than in epidermal cells. A water-potential gradient, which was dependent on the rate of transpiration, was found between epidermis and mesophyll and between tip and base of the test leaf. Step changes of humidity or light resulted in changes of epidermal and mesophyll turgor (_p-epi, _p-mes) and could be correlated with the transpiration rate. Osmotic potential was not affected by a step change of humidity or light. For the humidity-step experiments, stomatal conductance (g) increased with increasing epidermal turgor.g/_p-epi appeared to be constant over a wide range of epidermal turgor pressures. In light-step experiments this type of response was not found and stomatal conductance could increase while epidermal turgor decreased.Symbols E transpiration - g leaf conductance - w leaf/air vapour concentration difference - -epi water potential of epidermal cells - -mes water potential of mesophyll cells - -xyl water potential of xylem - _p-epi turgor pressure of epidermal cells - _p-mes turgor pressure of mesophyll cells - _s-epi osmotic potential of epidermal cells - _s-mes osmotic potential of mesophyll cells