102,513 research outputs found
Micro-magnetic resonance imaging study of live quail embryos during embryonic development
No full textEggs containing live Japanese quail embryos were imaged using micro-magnetic resonance imaging (μMRI) at 24-h intervals from Day 0 to 8, the period during which the main body axis is being laid down and organogenesis is taking place. Considerable detail of non-embryonic structures such as the latebra was revealed at early stages but the embryo could only be visualized around Day 3. Three-dimensional (3D) changes in embryo length and volume were quantified and also changes in volume in the extra- and non-embryonic components. The embryo increased in length by 43% and nearly trebled in volume between Day 4 and Day 5. Although the amount of yolk remained fairly constant over the first 5 days, the amount of albumen decreases significantly and was replaced by extra-embryonic fluid (EEF). 1H longitudinal (T1) and transverse (T2) relaxation times of different regions within the eggs were determined over the first 6 days of development. The T2 measurements mirrored the changes in image intensity observed, which can be related to the aqueous protein concentrations. In addition, a comparison of the development of Day 0 to 3 quail embryos exposed to radiofrequency (rf) pulses, 7 T static magnetic fields and magnetic field gradients for an average of 7 h with the development of control embryos did not reveal any gross changes, thus confirming that μMRI is a suitable tool for following the development of live avian embryos over time from the earliest stages
The pH and ionic composition of the sub-embryonic fluid of the Japanese quail (Coturnix c. japonica)
No full textThe current theory of acid-base chemistry regards [H+] as a dependent variable: changes in pH of a fluid can only occur by alteration of strong ion concentrations ([Na+], [K+], [Cl-]). The objective of this study was to determine whether manipulation of sub-embryonic fluid strong ion composition would alter [H+] in the direction predicted by theory. Changes to fluid strong ion concentrations decreased pH in the way predicted and the changes in Cl- suggest a passive distribution. Also, changes in organic anions suggest an essential role for these in acid-base chemistry of this fluid. It was notable that both Na and HCO3- were unaffected by the treatments emphasising the importance of these two ions in fluid production by the quail blastoderm
Rapid manufacturing technique used in the development of a regenerative pump impeller
No full textThis paper presents a method of rapid manufacture used in the development of a regenerative pump impeller. Rapid manufacturing technology was used to create complex impeller blade profiles for testing as part of a regenerative pump optimisation process. Regenerative pumps are the subject of increased interest in industry. Ten modified impeller blade profiles, from the standard radial configuration, were evaluated with the use of computational fluid dynamics and experimental testing. Prototype impellers were needed for experimental validation of the CFD results. The manufacture of the complex blade profiles using conventional milling techniques is a considerable challenge for skilled machinists. The complexity of the modified blade profiles would normally necessitate the use of expensive CNC machining with 5 axis capability. With an impeller less than 75 mm in diameter and a maximum blade thickness of 1.3mm, a rapid manufacturing technique enabled production of complex blade profiles that were dimensionally accurate and structurally robust enough for testing. As more advanced rapid prototyping machines become available in the study in the future, e.g. 3D photopolymer jetting machine, the quality of the parts particularly in terms of surface finish will improve and the amount of post processing operations will reduce. This technique offers the possibility to produce components of increased complexity whilst ensuring quality, strength, performance and speed of manufacture. The ability to manufacture complex blade profiles that are robust enough for testing, in a rapid and cost effective manner is proving essential in the overall design optimisation process for the pump
Assembly of the Inner Perivitelline Layer, a Homo log of the Mammalian Zona Pellucida: An Immunohistochemical and Ultrastructural Study
No full textThe avian inner perivitelline layer (IPVL), a homologous structure to the mammalian zona pellucida, is deposited between the granulosa cells and the oocyte cell membrane during folliculogenesis. The glycoprotein meshwork of the IPVL forms a 3-dimensional matrix and possesses important functions in the fertilization process: it contributes to the binding of avian spermatozoa to the oocyte and induces acrosomal exocytosis. In contrast to the zona pellucida of mammals, the IPVL does not prevent the physiological polyspermy found in birds. Previous studies have shown that in the Japanese quail (Cotumix japonica) at least 5 glycoproteins are constituents of the IPVL (ZP1, ZP2, ZP3, ZP4, and ZPD). In this study, we investigated the spatiotennporal assembly pattern of the IPVL during folliculogenesis using immunohistochemical and ultrastructural methods. The obtained results clearly show that these glycoproteins are incorporated into the IPVL at distinct points during follicular development, supporting the hypothesis that ZP2 and ZP4 form a type of prematrix into which ZP1, ZP3, and ZPD are integrated at a later stage of development. Copyright (C) 2011 S. Karger AG, Base
Electrolyte and Water Balance of the Early Avian Embryo: Effects of Egg Turning
No full textFormation of sub-embryonic fluid (SEF) is a key aspect of the physiology of the early avian embryo.Here we review the process of SEF formation and the factors which influence its composition and the rate of SEF production and depletion in the Japanese quail and domestic fowl.There is particular emphasis on the role of turning of the egg during incubation and we briefly consider
the broader role of egg turning during avian incubation. The bulk of the review deals with the growth of the area vasculosa of the yolk sac membrane, the cellular processes of SEF formation, and the water and electrolyte physiology of the avian embryo during the first half of incubation.We conclude with a brief discussion of the areas for future investigation
Effect of photoperiod on body weight gain, and daily energy intake and energy expenditure in Japanese quail (Coturnix c. Japonica)
No full textEffect of photoperiod and food duration on body weight gain, energy intake, energy expenditure, and sexual development were investigated in two strains of Japanese quail (Coturnix c. japonica), bred for meat (broilers) or egg production (layers), from 7 to 71 days of age. In a first experiment chicks were subjected to 18L:6D, 15L:9D, 12L:12D, 9L:15D, or 6L:18D, with ad lib food during the light period. In a second experiment birds were exposed to a long photoperiod (18L:6D or 15L:9D) with ad lib food during part of the light period (first 6 or 9 h, respectively). Longer photoperiods were associated with larger weight gains. In 18L:6D broilers total body weight gain was 262 g compared to 213 g in 6L:18D broilers. In layers, corresponding values were 182 and 131 g. This effect of photoperiod on weight gain was primarily due to the effect of photoperiod on food availability. The photoperiod below which detrimental effects on weight gain occurred was 9L:15D for both strains. Chicks subjected to 9L:15D or 6L:18D exploited crop filling to enhance energy intake. They also decreased nocturnal metabolic rates to a greater extent compared to levels during the light phase than chicks subjected to light periods of 12 h or more. Sexual maturation was stimulated by photoperiod. At the age of 71 days, eight out of nine females subjected to 18L:6D were producing eggs, but none of the 6L:18D females. It is concluded that changes in feeding behavior and energy expenditure shown under short photoperiods are part of a strategy that allow chicks to gain weight continuously.
Fractionation and characterization of satellite dna in Pharoah Quail, 1978
No full textDNA of Pharoah Quail embryos was examined using iso- pycnic centrifugation in neutral CsCl. Two low density minor bands (collectively termed satellite DNA) were detected in addition to the main band DNA. Main DNA has a higher buoyant density (density value) than the satellite DNAs, reasoning that the satellite DNAs banded at the top of the gradient. When total DNA was analyzed in alkaline CsCl, three bands were observed. The larger of the three (main peak DNA) peaked near the bottom of the gradient, indicating that the satellite DNAs have a lower G+C content, as compared to the main band DNA. Taken together, the minor (satellite DNA) bands constitute about 20% of the total DNA. The gradient profile obtained after centrifuga�tion of total DNA in the preparative ultracentrifuge shows the satellite DNAs as shoulders on the low density side of the main band. Main band DNA has a 54% G+C content and a 46% A+T content. Satellite I has a 47% G+C content and a 53% A+T content. Satellite II has a 35% G+C content and a 65% A+T content. Satellite I has a Tm of 62 C; satellite II has a Tm of 54 C, and main peak DNA has a Tm of 75 C. Microdensitometer tracing of Pharoah quail DNA centrifuged in CsCl indicated two satellite peaks comprising two classes of DNA molecules. Satellite DNAs show buoyant densities and melting profiles which are significantly different from main DNA components. Total DNA, when separated into distinct bands during isopycnic CsCl centrifugation and characterized, has allowed us to emphasize the widely divergent properties of A+T rich satellite DNA isolated from Pharoah quail tissues
Faecal analysis reveals the insectivorous diet of the Black-breasted Button-quail Turnix melanogaster
No full textThe threatened Black- breasted Button-quail Turnix melanogaster is thought to have an omnivorous diet comprising seeds and invertebrates; however, very little study has been undertaken to confirm or refute this claim. A thorough understanding of a species’ diet is required for its effective conservation management. To determine the species’ diet, T. melanogaster faeces were collected from within or near platelets found on Fraser Island and in Yarraman State Forest, two different habitats, and analysed microscopically. Analysis showed that T. melanogaster has a diet comprised almost entirely of invertebrates and that it preferentially preys upon Dermaptera, Pseudoscorpionida and Coleoptera
Experimental Toxoplasmosis in Japanese Quail
No full text Twenty-four 5-month-old battery-hatched Japanese quail were inoculated orally with 105 (ME 49 strain, group A, 6 birds), 103 (ME 49 strain, group B, 6 birds), 105 (GT-1 strain, group C, 6 birds), and 103 (GT-1 strain, group D, 6 birds) Toxoplasma gondii oocysts. All birds in group C died or were euthanized within 8 days after inoculation (DAI). Five of the 6 birds in group D died or were euthanized 8, 9, 15, 19, and 23 DAI. One of the 6 quail in group A died 9 DAI, and 1 of the 6 birds in group D died 16 DAI. The 11 quail (1 from group D and 10 from groups A and B) were euthanized 63 DAI; T. gondii was isolated by bioassays in mice from the brains of 10, hearts of 10, and skeletal muscles of all 11 quail. Quail that survived marked small intestinal and splenic toxoplasmosis lived long enough to develop severe protozoal pneumonia, myocarditis, or meningoencephalitis. The quail that survived only to be examined at 63 DAI had moderate multifocal nonpurulent encephalitis and myositis and had a hypertrophic spleen that contained hemosiderin-laden macrophages. Toxoplasma gondii antibodies were found in the sera of all quail examined 63 DAI. Antibody titers to T. gondii in the modified agglutination test were higher than in the indirect hemagglutination and latex agglutination tests. Antibodies were not detected in quail sera examined by the Sabin-Feldman dye test. </jats:p
T-maze behavior and early egg production in Japanese quail selected for contrasting adrenocortical responsiveness
No full textBroiler chicks that traverse a T-maze quickly to reinstate contact with their companions (HP, high performance) are known to grow faster, be more social, and exhibit a reduced plasma corticosterone (B) response to acute stress than slower (LP, low performance) chicks. Genetic lines of Japanese quail selected for reduced (LS, low stress) or exaggerated (HS, high stress) plasma B response to brief restraint also differ in sociality and performance. In the present study, we asked if divergence in early T-maze behavior was associated with differential attainment of puberty and early egg production in these lines. At 3 d of age, LS and HS quail were categorized as HP or LP birds based on running times in a T-maze. Thus, there were four treatment combinations: HP-LS, HP-HS, LP-LS, and LP-HS birds. Daily egg records were kept for 8 wk. The average ages at first egg lay (FIRST), at 25% egg production (A25%EP), and weekly and cumulative hen-day egg production (HDEP) where calculated. Daily egg weight (EWT) data were also collected, and BW measures were made at the end of the trial. Mean FIRST and A25%EP responses were lower (P < 0.02) and cumulative HDEP was greater (P < 0.04) in HP than in LP quail. Despite considerable numerical reductions in FIRST and A25%EP, as well as 5% elevation in cumulative HDEP in LS quail, line differences in these variables were not significant. On the other hand, FIRST and A25%EP were reduced (P < 0.05) in HP-LS quail when compared to LP-HS ones, whereas HP-HS and LP-LS quail showed intermediate and similar responses that did not differ from the other two treatment groups. Mean cumulative HDEP findings for the interactive effect of performance category with line mimicked these puberty findings. EWI and BW measures were not affected by any of the treatments or their interactions. Our results suggest that rapid negotiation of the T-maze by quail chicks is associated with accelerated puberty and increased HDEP in quail of two genetically diverse lines. This effect is particularly evident in quail selected for reduced adrenocortical responsiveness, suggesting possible additive effects.Fil: Marin, Raul Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. State University of Louisiana; Estados UnidosFil: Satterlee, D. G.. State University of Louisiana; Estados UnidosFil: Cadd, G. G.. State University of Louisiana; Estados UnidosFil: Jones, R. B.. Roslin Institute; Reino Unid
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