Bridging the gap between chemistry, physiology, and evolution: quantifying the functionality of sperm whale myoglobin mutants

This work merges a large set of previously reported thermochemical data for myoglobin (Mb) mutants with a physiological model of O₂-transport and -storage. The model allows a quantification of the functional proficiency of myoglobin (Mb) mutants under various physiological conditions, i.e. O₂-consumption rate resembling workload, O₂ partial pressure resembling hypoxic stress, muscle cell size, and Mb concentration, resembling different organism-specific and compensatory variables. We find that O₂-storage and -transport are distinct functions that rank mutants and wild type differently depending on O₂ partial pressure. Specifically, the wild type is near-optimal for storage at all conditions, but for transport only at severely hypoxic conditions. At normoxic conditions, low-affinity mutants are in fact better O₂-transporters because they still have empty sites for O₂, giving rise to a larger [MbO₂] gradient (more varying saturation curve). The distributions of functionality reveal that many mutants are near-neutral with respect to function, whereas only a few are strongly affected, and the variation in functionality increases dramatically at lower O₂ pressure. These results together show that conserved residues in wild type (WT) Mb were fixated under a selection pressure of low P_O2.     

Proteome comparison of hypopharyngeal gland development between Italian and royal jelly producing worker honeybees (Apis mellifera L.)

The hypopharyngeal gland (HG) of the honeybee (Apis mellifera L.) produces royal jelly (RJ) that is essential to feed and raise broods and queens. A strain of bees (high royal jelly producing bee, RJb) has been selected for its high RJ production, but the mechanisms of its higher yield are not understood. In this study, we compared HG acini size, RJ production, and protein differential expressions between the RJb and nonselected honeybee (Italian bee, ITb) using proteomics in combination with an electron microscopy, Western blot, and quantitative real-time PCR (qRT-PCR). Generally, the HG of both bees showed age-dependent changes in acini sizes and protein expression as worker behaviors changed from brood nursing to nectar ripening, foraging, and storage activities. The electron microscopic analysis revealed that the HG acini diameter of the RJb strain was large and produced 5 times more RJ than the ITb, demonstrating a positive correlation between the yield and HG acini size. In addition, the proteomic analysis showed that RJb significantly upregulated a large group of proteins involved in carbohydrate metabolism and energy production, those involved in protein biosynthesis, development, amino acid metabolism, nucleotide and fatty acid, transporter, protein folding, cytoskeleton, and antioxidation, which coincides with the fact that the HGs of the RJb strain produce more RJ than the ITb strain that is owing to selection pressure. We also observed age-dependent major royal jelly proteins (MRJPs) changing both in form and expressional intensity concurrent with task-switching. In addition to MRJPs, the RJb overexpressed proteins such as enolase and transitional endoplasmic reticulum ATPase, protein biosynthesis, and development proteins compared to the ITb strain to support its large HG growth and RJ secretion. Because of selection pressure, RJb pursued a different strategy of increased RJ production by involving additional proteins compared to its original counterpart ITb. To our knowledge, this morphological and proteomic comparison study on the HG of the two strains of worker honeybees associated with their age-dependent division of labor is the first of its kind. The study provided not only the quantity and quality differences in the HG from the RJb and the ITb, but also addressed the cellular and behavioral biology development question of how the RJb strain can produce RJ more efficiently than its wild type strain (ITb).     

Lipid peroxidation in buffalo (Bubalus bubalis L.) spermatozoa: effect of added vitamin C and glucose

Addition of 2.5 mM vitamin C or 40 mM of glucose to washed buffalo spermatozoan suspensions in Ca2(+)-free Kreb's Ringer Hanseliet saline buffer (pH 7.0) resulted in significant lower malonaldehyde concentration and higher spermatozoan motility and liver spermatozoa compared to control levels after 45 min of aerobic incubation at 37 degrees C or pre-incubation levels.     

The spermatodesm of Cloeon dipterum (L.): fine structure and sperm movement

Sperm bundles of the ephemeropteran Cloeon dipterum (L.) were found in the seminal vesicle. They are apically protected by cyst cells and sperm anterior regions are embedded in a secretion produced by these cells. Cyst cells further degenerate making sperm cells free. The sperm bundles are able to perform a forward progression only when sperm are stick together with their tail posterior tips. On the contrary, when sperm have their tail ends free, they beat but are unable to progress. The functional significance of the sperm bundles is discussed.     

Discrete charge calculations of potentiometric titrations for globular proteins: sperm whale myoglobin, hemoglobin alpha chain, cytochrome c.

The modified Tanford-Kirkwood theory of Shire et al. for intramolecular electrostatic interactions has been applied to hydrogen ion equilibria of sperm whale ferrimyoglobin, human hemoglobin α-chain and horse cytochrome c. The model employs two sets of parameters derived from the crystalline protein structures, first, the atomic coordinates of charged amino acid residues and, second, static accessibility factors to reflect their solvent exposure. In addition, a consistent set of intrinsic pK values (pK_int) for the individual groups is employed. The theoretical pK values at half-titration for individual groups in each protein correspond to the available observed pK values, and the theoretical titration curves compare closely with experimental potentiometric curves.     

A comparison of ventilation rates and haemoglobin concentrations between two species of loach,Noemacheilus barbatulus (L.) and Cobitis taenia (L.)

The mean haemoglobin concentration of Noemacheilus barbatulus was found to be significantly higher than that of Cobitis taenia. Under conditions of reduced oxygen saturation, both species achieved maximum rates of ventilation at 10% 0₂. An alteration in opercular beat pattern accounted for the increased ventilation rates between 20% and 30%. A slightly higher tolerance for lowered oxygen concentrations was demonstrated by Cobitis taenia with disorientation and aerial respiration occurring at lower oxygen tensions than in Noemacheilus barbatulus.     

Cryopreservation of common carp (Cyprinus carpio L.) sperm I. The importance of oxygen supply

Experiments were carried out on the cryopreservation of common carp ( Cyprinus carpio L.) sperm. The effects of pre-freezing oxygen supply on post-thaw motility and the efficacy of different extenders were studied. Sperm diluents contained DMSO as a cryoprotectant in 10% final concentration. The dilution rate was 1:9 (sperm:diluent). Sperm was diluted and equilibrated (10 min) at 0°C. Sperm was then frozen in plastic straws (0.5 ml) at the following rate: 0°C–4°C: 4°C min⁻¹−4°C–80°C: 11°C min⁻¹ from −80°C, straws were plunged directly into liquid nitrogen (−196°C) for further storage. Frozen samples were thawed in a water bath at 40°C.
The freezability of common carp sperm showing reduced motility (due to suboptimal oxygen supply) after transportation could be restored when 30 min of oxygenation was applied prior to freezing. Highest post-thaw motility (57%, percent of control) was achieved when sperm was diluted with modified Kurokura's 'Extender 2'.     

Fragmentation of condensed chromatin in nuclei of a plant sperm,pteridium aquilinum (L.) Kuhn

Nuclei of pteridium sperm have been dispersed by turbulence in natural or slightly alkaline buffer after stripping off the cytoplasm with nonionic detergent. The nuclei tended to break up into fragments arranged in a linear order. These fragments fluoresced brightly with acridine orange as did intact nuclei. Grounds are given for identifying the smaller fragments with chromosomes. It is proposed that the sperm nucleus of British Pteridium, possibly an autotetrapolid, consists of a sequence of paired homologues.     

The genomic relationship between cultivated sorghum [Sorghum bicolor (L.) Moench] and Johnsongrass [S. halepense (L.) Pers.]: a re-evaluation

Summary The genomic relationship between cultivated sorghum [Sorghum bicolar (L.) Moench, race bicolor, De Wet, 2n=20] and Johnsongrass [S. halepense (L.) Pers., 2n=40] has been a subject of extensive studies. Nevertheless, there is no general consensus concerning the ploidy level and the number of genomes present in the two species. This research tested the validity of four major genomic models that have been proposed previously for the two species by studying chromosome behaviors in the parental species, 30-chromosome hybrids [sorghum, (2n=20) x Johnsongrass, (2n=40)], 40-chromosome hybrids [sorghum, (2n=40) x Johnsongrass, (2n=40)] and 60-chromosome amphiploids. Chromosome pairings of amphiploids are reported for the first time. Chromosomes of cultivated sorghums paired exclusively as 10 bivalents, whereas Johnsongrass had a maximum configuration of 5 ring quadrivalents with occasional hexavalents and octovalents. In contrast, 40-chromosome cultivated sorghum had up to 9 ring quadrivalents and 1 hexavalent. Pairing in the 30-chromosome hybrids showed a maximum of 10 trivalents, and that in the 40-chromosome hybrids exhibited 8 quadrivalents, 5 of which were rings, together with a few hexavalents. Amphiploid plants showed up to 3 ring hexavalents, 1 chain hexavalent and a chain of 12 chromosomes. The data suggest that cultivated sorghum is a tetraploid species with the genomic formula AAB1B1, and Johnsongrass is a segmental auto-allo-octoploid, AAAA B1B1B2B2. The model is further substantiated by chromosome pairing in amphiploid plants whose proposed genomic formula is AAAAAA B1B1B1B1 B2B2.Contribution no. 87-391-J from the Kansas Agriculatural Experiment Station     

Heterogeneity in blood proteins and egg albumen proteins of the eiderduck,Somateria M. mollissima (L.)

• 1.1. The heterogeneity of blood proteins (including haemoglobin) of adult and subadult male and female Eiderducks, and the egg albumen proteins was studied, in relation with some behavioural properties, as nest-site preference and being migratory or sedentary.
• 2.2. The blood proteins demonstrate a high degree of multiplicity, with two different patterns in the pH range of 5.3–5.7; half the number of blood samples showed two “single” bands. The other half two “double” bands.
• 3.3. The egg albumen proteins show three different patterns, indicating three phenotypes (aa, ab and bb), occurring in four habitat types.
• 4.4. No relation exists between blood protein or egg albumen protein patterns and behavioural aspects of habitat preference for nesting sites.
• 5.5. The Eiderducks of the Vlieland colony are residents, with a high frequency of b-allele, compared to the b-frequency of the Forvie colony birds.

     

The effect of methanol on photosynthetic parameters of bean (Phaseolus vulgaris L.) under water deficit

Water availability is the main factor limiting crop growth and productivity in dry regions. This study was carried out in order to determine the effect of spraying methanol solution on the photosynthetic characteristics of bean plants. The main aim of our experiment was to improve plant performance under stress caused by water shortage. Two factors were involved: water-deficit stress, such as severe stress (25% of field capacity), mild stress (75% of field capacity), and no stress (100% of field capacity), and application of methanol solution spray at four concentrations: control (without spraying), 10, 20, and 30%. Methanol was applied three times at different growth stages (seedling, flowering, and podding stage) in 10-d intervals. The treatment with 20% methanol at the seedling stage resulted in increased net photosynthesis (P_N), intercellular CO₂ concentration (C_i), and decreased transpiration rate (E) under no stress and mild stress conditions. Under severe stress, 10 and 20%-methanol treatments resulted in increased C_i, maximal quantum yield of PSII photochemistry, and decreased E. At the flowering stage, methanol treatments resulted in decreased E and increased C_i under mild and severe stress. At the podding stage, 10 and 20%-methanol treatments resulted in increased P_N, C_i, and total chlorophyll content under mild stress. In conclusion, we suggested that foliar application of methanol had a positive role in enhancing photosynthetic performance.     

Genetic diversity of Asian water buffalo (Bubalus bubalis): microsatellite variation and a comparison with protein-coding loci

Twenty-one microsatellite loci in 11 populations of Asian water buffalo (eight swamp, three river type) were analysed and, within and among populations, genetic variability was compared with results from 25 polymorphic protein-coding loci. Within-population mean heterozygosity ranged from 0·380–0·615, approximately twice that estimated from the protein-coding loci (0·184– 0·346). Only eight significant departures from Hardy–Weinberg equilibrium (involving four loci) were detected; global tests showed significant heterozygote deficiencies for these four loci. Non-amplifying alleles are likely to be segregating in some or all populations for one of these loci, and probably for the other three. There was significant differentiation between the swamp and river types of water buffalo, and among populations within each buffalo type. Estimates of θ (measure of population differentiation) for each locus for the eight swamp populations were all highly significant (mean θ = 0·168 ± 0·018). Mean θ for protein-coding loci was not significantly different (0·182 ± 0·041). The variance among protein-coding loci was significantly higher than among microsatellite loci, suggesting balancing selection affecting allele frequencies at some protein-coding loci. Genetic distances show clear separation of the swamp and river types, which were estimated to have diverged at least 10 000–15 000 years ago. The topology of the swamp populations’ microsatellite tree is consistent with their geographical distribution and their presumed spread through south-east Asia. By contrast, the tree based on the protein-coding loci distances is quite different, being clearly distorted by a bottleneck effect in one population, and possibly in at least two others. As many domestic livestock breeds are possibly descended from small numbers of founders, microsatellite-based trees are to be preferred in assessing breed genetic relationships.     

Killer sperm whale: a new basal physeteroid (Mammalia, Cetacea) from the Late Miocene of Italy

Zygophyseter varolai , a new genus and species of Physeteroidea (Cetacea, Odontoceti), is based on an almost complete skeleton from the Late Miocene (Tortonian) in southern Italy. The extreme elongation of the zygomatic process of the squamosal and the circular supracranial basin (probably for housing the spermaceti organ) delimited by a peculiar anterior projection of the supraorbital process of the right maxilla are the most distinctive features of this bizarre sperm whale. Large body size, large teeth present in both lower and upper jaw, and anteroposteriorly elongated temporal fossa and zygomatic process of the squamosal indicate that this cetacean (for which we suggest the English common name killer sperm whale) was an active predator adapted to feeding on large prey, similarly to the extant killer whale ( Orcinus orca ). A phylogenetic analysis reveals that Zygophyseter belongs to a Middle–Late Miocene clade of basal physeteroids, together with Naganocetus (new genus for the type of ' Scaldicetus ' shigensis ). Moreover, the phylogenetic analysis shows evidence of a wide physeteroid radiation during the Miocene and that the extant Physeter and Kogia belong to two distinct families that form a clade representing the crown-group Physeteroidea.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 103–131.     

The life cycles of Leptophlebia vespertina (L.) and L. marginata (L.) (Ephemeroptera) in Llyn Dinas, North Wales

Data is presented on the life cycles of Leptopblehia vespertina (L.) and L. marginata (L.) in Llyn Dinas, an oligotrophic North Wales lake. Both species are univoltine and growth continues throughout the winter although somewhat retarded. Except during July and August there is a clear size separation of the two species, L. marginata being larger and emerging earlier. The egg incubation period was determined directly from laboratory studies. The results are discussed in relation to previous research in the English Lake District.     

Oschmarinella albamarina (Treshchev, 1968) n. comb., a liver fluke from the killer whale Orcinus orca (L.) off the British coast

Oschmarinella albamarina n. comb. is described from the bile-ducts of a killer whale Orcinus orca stranded on the British coast. The systematic position of the species is discussed in relation to the genera Campula Cobbold, 1858, Orthosplanchnus Odhner, 1905 and Oschmarinella Skrjabin, 1947, and the species is transferred from Orthosplanchnus to Oschmarinella. Campula rochebruni (Poirrier, 1886) is transferred to Oschmarinella, as O. rochebruni n. comb., and Oschmarinella mascomai Raga, 1986 is considered its synonym.