Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Abstracted in Dissertation abstracts, v. 16 (1956) no. 2, p. 413. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 65-69).

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2005. / Includes bibliographical references.

Thesis (Ph. D.)--Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2005. / Includes bibliographical references.

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Made available in DSpace on 2014-08-13T14:50:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-06-21Bitstream added on 2014-08-13T18:01:08Z : No. of bitstreams: 1 000738502_20150619.pdf: 168048 bytes, checksum: 67974831ca78b6d925c01cebfef1a94c (MD5) Bitstreams deleted on 2015-06-22T12:53:50Z: 000738502_20150619.pdf,. Added 1 bitstream(s) on 2015-06-22T12:54:45Z : No. of bitstreams: 1 000738502.pdf: 1467766 bytes, checksum: 7c0de265290f7067173746101d9a2b71 (MD5) / Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle / Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control

Phenotypic plasticity, the ability of a single genotype to be expressed as a range of phenotypes in response to environmental variation, is a widespread phenomenon. Documented increasingly among the larval stages of marine organisms, phenotypic plasticity in the veliger larvae of the marine snail Littorina scutulata was investigated in response to predatory, nutritional, and gravitational stimuli. Veligers developed rounder shells, smaller apertures, and reinforced aperture margins in response to water-borne cues from predatory crab larvae. The nature and degree of the induced-morphologies depended on cue composition and conferred decreased vulnerability to predation. Food-limited veligers developed larger feeding and swimming structures (vela) with longer cilia relative to shell size compared to larvae raised with high food. This inducible offense corresponded with a decrease in vertical swimming speed, an unexpected result possibly reflecting behavioral manipulation of individual velar components. A cell proliferation assay indicated that growth of the larger structure was achieved partially by a steady rate of cell division over a longer period of time; an initially higher level of cell proliferation in veligers raised on high food dropped off sharply. Velar lobe asymmetry, where one lobe is larger than the other, may exist to offset an asymmetry in weight distribution due to how the larval shell is carried. The larger velar lobe overlies the protruding spire of the larval shell. Bi- and multi-lobed vela get bigger with shell size but follow different rules with regards to the relationship between velar asymmetry and shell asymmetry. Experimental alternations of mass distribution of the larval shell caused changes in the ratio of area between each side of the velum and total velar growth for larvae of L. scutulata. Following settlement and metamorphosis, juveniles of intertidal marine invertebrates are subject to additional stressors that can manifest as phenotypic variation. Color differences between juvenile and adult Strongylocentrotus purpuratus were shown to be caused by variation in light exposure. Green juveniles raised in sunlight turned purple (due to more pigment) and showed decreased susceptibility to artificial UVR than urchins kept in the dark, which remained green (due to less pigment). This dissertation includes previously unpublished co-authored material.

Larval development of Penaeus monodon from protozoea (PZ1) to postlarval stages is described on natural and commercially available artificial larval diets under controlled laboratory feed trials. Five species of live microalgae (Tetraselmis chuii, Chaetoceros calcitrans, Skeletonema costatum, Rhodomonas baltica and Pavlova lutheri) were evaluated in feed trials at seven (5-60 cells gl1) cell concentrations with protozoeal larval stages. Performance of five animal diets (rotifers, Mytilus eggs, Artemia nauplii, barnacle nauplii and crab eggs) were examined in feed trials from Mysis (Ml) to postlarvae (PL1). Best results for protozoeal stages were obtained on a combination diet T. chuii + R. baltica at 40 cells µl-', while results from mysis to postlarvae were best achieved on Artemia nauplii. Natural feeds are expensive, difficult to maintain in mass culture and often vary in nutritional value. Larval performance on ten leading brands of artificial larval diet marketed using different process technologies were evaluated in replicated feed trials, together with factors causing variability in larval growth and survival of P. monodon. It was found that nutrient leach loss from unstable artificial feeds in culture conditions increases levels of ammonia and nitrite beyond safe limits. Live microalgal species at 1000 cells µl1 added to culture water reduces these toxic levels. The role of microalgae in larval culture is also examined. To further improve larval growth and survival on artificial diets, proteins from different sources, lipid, vitamin and mineral levels were incorporated in microencapsulated feeds. As a result improvement in larval development to postlarval stage was achieved with feeds containing 60% soya + mussel protein, 5% lipid and 13.9% vitamin and mineral mix. Algal homogenates supplemented to encapsulated feeds produced larval growth and survival comparable to live feed controls. P. monodon larvae were grown to the juvenile prawn stage solely on Frippak feeds. Larval growth was comparable to growth achieved on live feed controls. This study forms a basis for further investigations into nutritional requirements of penaeid prawns.

A device, utilising the suction produced by a disposable syringe, was developed to restrain a range of very small organisms in flowing seawater. The technique was developed during an investigation of the swimming response of barnacle nauplii to changes in temperature. The combination of beat frequency and the proportion of time spent active was held constant for B. balanoides and B. hameri but steadily increased with temperature for C. montagui and B. amnhitrite. E. modestus showed an intermediate response. Methods for utilising video-tape recordings and a micro-impedance pneumograph for analysing limb beat activity, were developed during an investigation of the feeding behaviour of nauplii. The feeding mechanism was reappraised and an increase in the volume of water handled by the larvae noted in the presence of food organisms. This increase was shown by E. modestus nauplii in response to dissolved organic substances, indicating that the nauplii could determine when to feed, and what was edible, from the shell of dissolved material surrounding food particles. A quantitative study of the grazing of E. modestus nauplii showed that the ingestion rate of algal cells increased up to concentrations of 150 - 200 cells/ul, then remained steady. Larger algal cells were taken from algal mixtures, in preference to smaller ones. Restraint techniques and video-recordings of free-swimming cypris larvae showed them to be prodigeous swimmers, with considerable control over the direction and magnitude of the thrust produced. The close observation of larvae allowed by the restraint technique enabled mechanical stimulation of particular sense organs. The function of these organs had been interpreted from their structure by previous authors. In some instances, a mechano-receptive function was confirmed, but in others, doubt was cast. Restrained cyprids responded to complex sound fields by swimming less often. A dual mode sound chamber was used to differentiate between sound pressure and displacement, but negative results were obtained. The cyprids did, however, respond to substrate vibrations, at low frequencies, by swimming off the substrate. All the developed techniques were further employed to show that the classical copepod feeding swirls were artefacts. Temora produced'only a posteriorly flowing current for feeding and swimming, when restrained in larger volumes of seawater. The amount of water handled by Temora was also shown to increase when food algae were present.

Orientador: Manoel Victor Franco Lemos / Banca: Lucia Maria Carareto Alves / Banca: Vitor Fernandes Oliveira da Miranda / Banca: Cristina Lacerda Soares Petrarolha Silva / Banca: Renato Pariz Maluta / Resumo: Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle / Abstract: Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control / Doutor

A preliminary cytotaxonomic study of the common Chironomidae in a series of saline waters in the southern interior of British Columbia has been undertaken. The banding pattern of the salivary gland chromosomes, once it had been described, was used as a taxonomic criterion and as an indicator of the relationships between the groups involved. In order to obtain associated stages in the life cycle, the larvae were reared in individual vials. The polytene chromosome analysis revealed seven well defined larval species. The subsequent morphological analysis showed that five of these larval species could usually be separated by their external morphology. However, two cytologically distinct species are morphologically indistinguishable. Recent work on sibling species in Drosophila and Chironomus (Diptera) has shown that sibling species have salivary gland chromosomes with an identical banding pattern but, differ from one another in the frequency of inversions. The present study suggests that the morphologically identical larvae mentioned above are sibling species in larval morphology but are clearly separable by chromosome analysis. The fact that they occur together in the same lake tends to eliminate the view that they are distinct populations of a single species. That there may be more than one species involved in those here considered to be a single taxa, should however not be forgotten. / Science, Faculty of / Zoology, Department of / Graduate