Structural organization of the beta-globin locus of B-haplotype sheep

Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta C2), at birth and produce this hemoglobin exclusively during severe anemia. Sheep that synthesize this juvenile hemoglobin are of the A haplotype. Other sheep, belonging to a separate group, the B haplotype, do not synthesize hemoglobin C and during anemia continue to produce their adult hemoglobin. To understand the basis for this difference we have determined the structural organization of the beta- globin locus of B-type sheep by constructing and isolating overlapping genomic clones. These clones have allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype. Thus, B sheep lack four genes, including the BC gene, and have only eight genes, compared with the 12 found in the goat globin locus. The goat beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta Y-beta F3'. Southern blot analysis of A-type sheep reveals that these animals have a beta- globin locus similar to that of goat, i.e., 12 globin genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of cows and may have retained the duplicated locus of the ancestor of cows and sheep. Alternatively, the B-sheep locus arrangement may be the result of a deletion of a four-gene set from the triplicated locus.      

The innervation of the pyloric region of the crab,Cancer borealis: Homologous muscles in decapod species are differently innervated

Summary The muscles of the pyloric region of the stomach of the crab,Cancer borealis, are innervated by motorneurons found in the stomatogastric ganglion (STG). Electrophysiological recording and stimulating techniques were used to study the detailed pattern of innervation of the pyloric region muscles. Although there are two Pyloric Dilator (PD) motorneurons in lobsters, previous work reported four PD motorneurons in the crab STG (Dando et al. 1974; Hermann 1979a, b). We now find that only two of the crab PD neurons innervate muscles homologous to those innervated by the PD neurons in the lobster,Panulirus interrruptus. The remaining two PD neurons innervate muscles that are innervated by pyloric (PY) neurons inP. interruptus. The innervation patterns of the Lateral Pyloric (LP), Ventricular Dilator (VD), Inferior Cardiac (IC), and PY neurons were also determined and compared with those previously reported in lobsters. Responses of the muscles of the pyloric region to the neurotransmitters, acetylcholine (ACh) and glutamate, were determined by application of exogenous cholinergic agonists and glutamate. The effect of the cholinergic antagonist, curare, on the amplitude of the excitatory junctional potentials (EJPs) evoked by stimulation of the pyloric motor nerves was measured. These experiments suggest that the differences in innervation pattern of the pyloric muscles seen in crab and lobsters are also associated with a change in the neurotransmitter active on these muscles. Possible implications of these findings for phylogenetic relations of decapod crustaceans and for the evolution of neural circuits are discussed.Abbreviations ACh acetylcholine - Carb carbamylcholine - cpv muscles of the cardio-pyloric valve - cpv7n nerve innervating muscle cpv7 - cv muscles of the ventral cardiac ossicles - cv1n nerve innervating muscle cvl - cv2n nerve innervating muscle cv2 - EJP excitatory junctional potential - IC inferior cardiac neuron - IV inferior ventricular neuron - IVN inferior ventricular nerve - LP lateral pyloric neuron - LPG lateral posterior gastric neuron - lvn lateral ventricular nerve - mvn medial ventricular nerve - p muscles of the pylorus - PD pyloric dilator neuron - PD _in intrinsic PD neuron - PD _ex extrinsic PD neuron - pdn pyloric dilator nerve - PY pyloric neuron - pyn pyloric nerve - STG stomatogastric ganglion - VD ventricular dilator neuron     

Selective inhibition of prostaglandin biosynthesis by gold salts and phenylbutazone

Gold salts and phenylbutazone selectively inhibit the synthesis of PGF_2α and PGE₂ respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE₂ and PGF_2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function.     

Two silicone nontoxic fouling release coatings: Hydrosilation cured PDMS and CaCO3 filled,ethoxysiloxane cured RTV11

Two silicone coatings have been evaluated for barnacle adhesion. One coating is an unfilled hydrosilation cured polydimethylsiloxane (PDMS) network, while the other is a room temperature vulcanized (RTV), filled, ethoxysiloxane cured PDMS elastomer, RTV11^?. The adhesion strength of one species of barnacle, Balanus eburneus, to the hydrosilation coatings is in the range of 0.37–0.60 kg cm^‐2 while the corresponding range for RTV11 is 0.64–0.90 kg cm^‐2. The easier release of B. eburneus from the hydrosilation cured network compared to RTV11 is discussed in relationship to differences in bulk and surface properties. Preliminary results suggest bulk modulus may be the most important parameter in determining barnacle adhesion strength. In light or mechanical property analysis, a re‐evaluation of surface properties and chemical stability is presented.     

Identification of Immunodominant Responses to the Plasmodium falciparum Antigens PfUIS3, PfLSA1 and PfLSAP2 in Multiple Strains of Mice

Malaria, caused by the Plasmodium parasite, remains a serious global public health concern. A vaccine could have a substantial impact on eliminating this disease, alongside other preventative measures. We recently described the development of three novel, viral vectored vaccines expressing either of the antigens PfUIS3, PfLSA1 and PfLSAP2. Each vaccination regimen provided high levels of protection against chimeric parasite challenge in a mouse model, largely dependent on CD8⁺ T cells. In this study we aimed to further characterize the induced cellular immune response to these vaccines. We utilized both the IFNγ enzyme-linked immunosorbent spot assay and intracellular cytokine staining to achieve this aim. We identified immunodominant peptide responses for CD4⁺ and CD8⁺ T cells for each of the antigens in BALB/c, C57BL/6 and HLA-A2 transgenic mice, creating a useful tool for researchers for subsequent study of these antigens. We also compared these immunodominant peptides with those generated from epitope prediction software, and found that only a small proportion of the large number of epitopes predicted by the software were identifiable experimentally. Furthermore, we characterized the polyfunctionality of the induced CD8⁺ T cell responses. These findings contribute to our understanding of the immunological mechanisms underlying these protective vaccines, and provide a useful basis for the assessment of these and related vaccines as clinical constructs.     

Natural selection and neoteny

Summary Even today, a century after the publication of the Origin of Species, current zoological literature often reveals an insufficient grasp of the implications of the now generally accepted view that it is natural selection that confers direction on the evolutionary process.This is, in part, due to a reaction against oversimplified teleology and against Lamarckism. In rejecting Lamarck's thesis that the activities of an animal directly affect its hereditary characters it is frequently assumed that this implies that such activities are irrelevant to the study of evolution. This is a non-sequitur, for activities may affect evolution not directly, through heredity, but indirectly, by influencing the direction of the selective forces impinging on the organism. Reasons are given for concluding that changes in habits and behaviour frequently precede structural change and, in fact, determine the direction of the latter.As an example of a concept which deserves a more evolutionary treatment than it commonly receives, the subject of neoteny is considered. It appears that failure to think in terms of the selective forces involved has frequently led to error. An analysis in functional terms is made of the theory that the chordates represent secondarily glorified sea-squirts and it is concluded that this idea is unlikely to be correct. The characteristics of man that are commonly considered to be neotenous are also discussed. It is concluded that a facile and unanalytical application of the label neoteny to many of the evolutionary changes involved has tended to obscure rather than to clarify their significance: the neotenous features of man are not those that have been of primary importance in human evolution, but are secondary to the acquisition of new characters which are not to be found in either the adult or the young stages of any other primate.

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Zusammenfassung Sogar heutzutage, ein Jahrhundert nach dem Erscheinen der Origin of Species, zeigt die jetzige zoologische Literatur oft eine unzulängliche Einsicht in die Folgerungen, zu denen die jetzt allgemein akzeptierte Annahme leitet, dass die natürliche Selektion die Richtung des Evolutionsprozesses bedingt.Dies ist teilweise zu sehen als eine Reaktion gegen eine einseitige Teleologie und gegen das Lamarckismus. Bei der Ablehnung der TheseLamarck's, dass die Aktivitäten eines Tieres einen direkten Einfluss ausüben auf seine erbliche Konstitution, nimmt man oft an, dass dies bedeutet, dass derartige Aktivitäten demnach nichts zur Sache tun bei dem Studium der Evolution. Zu einer derartigen Konklusion ist man jedoch nicht berechtigt, denn, obwohl die Aktivitäten die Evolution nicht direkt beeinflussen können mittels der Erblichkeit, so können sie dies jedoch indirekt, weil sie die Richtung der selektiven Kräfte, welche auf das Organismus einwirken, bestimmen. Es werden Argumente gegeben, welche die Konklusion rechtfertigten, dass Änderungen in Gewohnheit und Verhalten oft Strukturänderungen vorhergehen und tatsächlich die Richtung dieser letztgenannten bestimmen. Die Neotenie wirdt als ein Beispiel eines Begriff betrachtet, welcher eine mehr evolutionäre Behandlung verdient als bisher geschehen ist. Es ergibt sich dass man viele Irrtümer hat gemacht, indem man den betreffenden selektiven Kräften keine Rechnung getragen hat. Eine Analyse der Theorie, welche die Chordaten als neotenische Ascidien betrachtet, wird von einem funktionellen Gesichtspunkt aus durchgeführt. Daraus scheint der Schluss berechtigt, dass diese Theorie falsch ist. Auch werden die menschlichen Kennzeichen, welche gewöhnlich als neotenische betrachtet werden, besprochen. Die Konklusion lautet, dass, wenn man leichtfertig und ohne genügende Analyse den Zettel Neotenie für mancherlei evolutive Änderungen anwendet, man die richtige Bedeutung dieser Erscheinung vielmehr verdunkelt als aufklärt: nicht die neotenische Kennzeichen des Menschen sind am wichtigsten in seiner Evolution; in Gegenteil sie erscheinen nur sekundär, nachdem die neuen Kennzeichen, welche sich weder in den Erwachsenen noch in den jüngeren Stadien von den anderen Primaten finden lassen, erschienen sind.

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Résumé Aujourd'hui, un siècle après l'apparition de l'Originedes Espèces, la conviction est presque générale que la sélection naturelle dirige le procès de l'évolution. Néanmoins, les publications zoologiques actuelles révèlent souvent une compréhension insuffisante de ce qui en résulte.Ceci doit en partie être considéré comme réaction contre une téléologie simpliste et contre le Lamarckisme. En rejetant la thèse de Lamarck, que les activités d'un animal ont une influence directe sur ses caractéristiques héréditaires, on admet fréquemment que de pareilles activités n'ont rien à voir avec l'étude le l'évolution. Cependant, une telle conclusion n'est pas justifiée, car les activités peuvent influer sur l'évolution non pas directement, par la voie de l'hérédité, mais indirectement en agissant sur la direction des forces sélectives que l'organisme rencontre. Des raisons ont été données qui mènent à conclure que des changements dans les habitudes et dans le comportement précèdent maintes fois le changement structural et même déterminent la direction de celui-ci.Comme exemple d'un concept qui mérite un traitement plus évolutionniste qu'il ne reçoive en général, la néoténie a été examinée. Il paraît que l'on a fait beaucoup d'erreurs en ne tenant pas compte des forces sélectives engagées. Une analyse au pointde-vue de la fonction a été appliquée à la théorie que les chordées ne sont que des ascidies néoténiques transfigurées par après, et il s'ensuit que cette idée n'est probablement pas correcte. Aussi les caractéristiques de l'homme généralement regardées comme neoténiques ont été discutées. Il en résulte que, en désignant légèrement et sans analyse plusieurs changements évolutionnaires comme néoténie, on a plutôt obsurci qu'éclairci leur signification. Ce ne sont pas les traits néoteniques de l'homme qui ont joué le rôle principal dans l'évolution humaine; au contraire, ils n'apparaissent qu'après l'acquisition de quelques nouvelles caractéristiques qui ne se trouvent ni dans l'adulte ni dans les phases plus jeunes des autres primates.

     

Spatial and Temporal Analysis of Contact Rates in Female White-Tailed Deer

Abstract: White-tailed deer (Odocoileus virginianus) are important game mammals and potential reservoirs of diseases of domestic livestock; thus, diseases of deer are of great concern to wildlife managers. Contact, either direct or indirect, is necessary for disease transmission, but we know little about the ecological contexts that promote intrasexual contact among deer. Using pair-wise direct contacts estimated from Global Positioning System collar locations and joint utilization distributions (JUDs), we assessed habitats in which contacts occur to test whether direct contact rates among female white-tailed deer in different social groups differs among land-cover types. We also tested whether contact rates differed among seasons, lunar phases, and times of day. We obtained locations from 27 female deer for periods of 0.5–17 months during 2002–2006. We designated any simultaneous pair of locations for 2 deer <25 m apart as a direct contact. For each season, we used compositional analysis to compare land-cover types where 2 deer had contact to available land-cover weighted by their JUD. We used mixed-model logistic regression to test for effects of season, lunar phase, and time of day on contact rates. Contact rates during the gestation season were greater than expected from random use in forest and grassland cover, whereas contact rates during the fawning period were greater in agricultural fields than in other land-cover types. Contact rates were greatest during the rut and lowest in summer. Diel patterns of contact rates varied with season, and contact rates were elevated during full moon compared to other lunar periods. Both spatial and temporal analyses suggest that contact between female deer in different social groups occurs mainly during feeding, which highlights the potential impact of food distribution and habitat on contact rates among deer. By using methods to associate contacts and land-cover, we have created beneficial tools for more elaborate and detailed studies of disease transmission. Our methods can offer information necessary to develop spatially realistic models of disease transmission in deer.     

Invariant association of ecdysis with increases in cyclic 3′,5′-guanosine monophosphate immunoreactivity in a small network of peptidergic neurons in the hornworm, Manduca sexta

At the end of each molt insects shed their old cuticle by performing the stereotyped behavior of ecdysis. In the moth, Manduca sexta, this behavior is triggered by the neuropeptide eclosion hormone (EH). Insights into the mechanism of action of EH have come from the identification of a small network of peptidergic neurons that shows increased cyclic 3′,5′-guanosine monophosphate (cGMP) immunoreactivity at ecdysis in insects from many different orders. Here we present further evidence that strengthens the association between ecdysis and the occurrence of this cGMP response in Manduca. We found that the cGMP increases occurred at every ecdysis, although some of the neurons that showed a response at larval ecdysis did not participate at pupal and adult ecdysis. Both ecdysis and the cGMP increases only required an intact connection with the brain for the first 30 min after EH injection. Interestingly, ecdysis in debrained animals only occurred if the cGMP response had been initiated, suggesting that the onset of this response marks the time at which the central nervous system is first able to drive ecdysis. Finally, we found that the appearance of sensitivity to EH for triggering the cGMP response coincided with the time at which EH first triggers ecdysis. Accepted: 6 May 1997