Factors Related to Shell Deaths During Artificial Incubation of Ostrich Eggs.

The ostrich industry experiences a high rate of embryonic mortalities during artificial incubation of eggs. Embryonic deaths were studied from data recorded on 37 740 fertile eggs incubated artificially during the 1998–2005 breeding seasons. Roughly 10 000 eggs that sustained embryonic mortalities were classified according to the stage and nature of death, i.e. before 21 days of incubation, after 21 days of incubation, deaths after pipping and rotten eggs. Although infection may have played a role in ~1300 rotten eggs, no detailed knowledge of the pathogens involved was available. The remainder of deaths could not be related to pathogens and the deaths were thus generally referred to as non-infectious. The overall level of embryonic mortality in all the eggs studied was 28.5 %. Overall embryonic mortality was affected by incubator, with higher levels (57.0 %) found in eggs incubated in an African Incubator® and also in eggs that were transferred between incubators during incubation (38.1 %). Overall embryonic mortality also increased in eggs produced by older females. Eggs produced in the autumn had the highest level of embryonic mortality at 53.6 %, whereas eggs produced in the winter had a marginally higher level of embryonic mortalities of 29.2 % compared with eggs produced during summer (27.4 %). Eggs produced by South African (SA) Black males crossed to Zimbabwean Blue females had high levels of embryonic losses of 45.7 %. The embryonic mortality of eggs produced by SA Blacks or Zimbabwean Blue breeding birds subjected to pure breeding was similar at ~33–34 %, but embryonic mortality was improved in eggs produced by Zimbabwean Blue males crossed to SA Black females (27 %). Embryonic mortality was increased in eggs that were set directly (32.0 %) or subjected to longer than 6 days of storage (43.5 %). Embryonic mortality was affected by year. The results that were obtained will assist in determining non-infectious factors that have a negative effect on hatching success. Steps can thus be taken to eliminate such factors that may compromise hatching success

Acute toxicity of arsenic and oxidative stress responses in the embryonic development of the common South American toad Rhinella arenarum

Arsenic (As), a natural element of ecological relevance, is found in natural water sources throughout Argentina in concentrations between 0.01mg/L and 15mg/L. The autochthonous toad Rhinella arenarum was selected to study the acute toxicity of As and the biochemical responses elicited by the exposure to As in water during its embryonic development. The median lethal concentration (LC50) value averaged 24.3mg/L As and remained constant along the embryonic development. However, As toxicity drastically decreased when embryos were exposed from heartbeat-stage on day 4 of development, suggesting the onset of detoxification mechanisms. Given the environmental concentrations of As in Argentina, there is a probability of exceeding lethal levels at 1% of sites. Arsenic at sublethal concentrations caused a significant decrease in the total antioxidant potential but generated an increase in endogenous glutathione (GSH) content and glutathione S-transferase (GST) activity. This protective response might prevent a deeper decline in the antioxidant system and further oxidative damage. Alternatively, it might be linked to As conjugation with GSH for its excretion. The authors conclude that toad embryos are more sensitive to As during early developmental stages and that relatively high concentrations of this toxic element are required to elicit mortality, but oxidative stress may be an adverse effect at sublethal concentrations.Fil: Mardirosian, Mariana Noelia. Universidad Nacional del Comahue. Facultad de Ingeniería. Departamento de Química. Laboratorio de Investigaciones Bioquímicas, Químicas y de Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lascano, Cecilia Ines. Universidad Nacional del Comahue. Facultad de Ingeniería. Departamento de Química. Laboratorio de Investigaciones Bioquímicas, Químicas y de Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ferrari, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energias Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energias Alternativas; ArgentinaFil: Bongiovanni, Guillermina Azucena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energias Alternativas. Universidad Nacional del Comahue. Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energias Alternativas; ArgentinaFil: Venturino, Andres. Universidad Nacional del Comahue. Facultad de Ingeniería. Departamento de Química. Laboratorio de Investigaciones Bioquímicas, Químicas y de Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects of sedimentation and periphyton communities on embryonic rainbow smelt, Osmerus mordax

The decline of anadromous rainbow smelt (Osmerus mordax) populations has been suspected to be linked to anthropogenic causes. Increased runoff from agriculture and urbanization has led to additional sediment inputs and eutrophying compounds in rivers. The aim of this study was to assess the survival of embryonic rainbow smelt from fertilization through hatching under varying levels of sedimentation (0.00, 0.25, 1.00, and 6.00 g per 45.6 cm 2) and with periphyton communities of different biomass and algal composition. Additionally, embryo survival was assessed when cultured on periphyton in combination with sterilized sediment or eutrophying compounds (nitrates and phosphates). Oxygen consumption was monitored from embryos cultured alone, on periphyton layers, and under sediment. Survival was significantly reduced under the highest sediment treatment and attributed to low oxygen availability to the embryos. Embryonic survival was also significantly reduced on the highest periphyton biomass (251.5 g/m2 dry weight, 15.7 g/m 2 ash free dry weight), and periphyton containing a high cyanobacteria content (50%). These results suggest that embryonic survival could be reduced in rivers with heavy sedimentation or a high standing biomass of periphyton

Global distribution of two fungal pathogens threatening endangered sea turtles

This work was supported by grants of Ministerio de Ciencia e Innovación, Spain (CGL2009-10032, CGL2012-32934). J.M.S.R was supported by PhD fellowship of the CSIC (JAEPre 0901804). The Natural Environment Research Council and the Biotechnology and Biological Sciences Research Council supported P.V.W. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Thanks Machalilla National Park in Ecuador, Pacuare Nature Reserve in Costa Rica, Foundations Natura 2000 in Cape Verde and Equilibrio Azul in Ecuador, Dr. Jesus Muñoz, Dr. Ian Bell, Dr. Juan Patiño for help and technical support during samplingPeer reviewedPublisher PD

The chicken embryo and its micro environment during egg storage and early incubation

When egg storage periods are prolonged (>7 days), hatchability and chick quality declines. The reason for this decline has been investigated, but is still not completely understood. At oviposition the developmental stage of the chicken embryo varies and so do the total number of viable cells. During storage, changes can occur in the embryo. Embryo viability at the end of storage seems to be dependent on the number of viable cells and the developmental stage of the embryo at oviposition. When the hypoblast is completely formed (during the quiescent developmental stage), the embryo seems to be more able to endure prolonged storage periods than embryos that are less or more advanced. During storage, changes also occur in egg characteristics such as albumen viscosity, albumen pH and yolk pH. There appears to be an interaction between albumen pH and embryo viability during early incubation and perhaps also during storage. An albumen pH of 8.2 seems to be optimal for embryo development. Albumen pH may influence embryo viability, but embryo viability may in turn, affect albumen pH. It has been hypothesised that an embryo in which the hypoblast is completely formed is better able to provide an effective barrier between the internal embryo and the exterior (yolk and albumen) and/or is better able to produce sufficient amount of carbon dioxide, which will reduce the pH level in the micro environment of the embryo to the optimal pH of 8.2. It appears that, to maintain hatchability and chick quality after prolonged storage periods, embryonic development should be advanced to the stage in which the hypoblast is completely formed or the atmosphere during storage and early incubation should be altered in such a way that albumen pH is maintained at the optimal level of 8.2

Mutation in the guanine nucleotide-binding protein beta-3 causes retinal degeneration and embryonic mortality in chickens

PURPOSE. To identify the gene defect that causes blindness and the predisposition to embryonic death in the retinopathy globe enlarged (rge) chicken. METHODS. Linkage analysis, with previously uncharacterized microsatellite markers from chicken chromosome 1, was performed on 138 progeny of an rge/+ and an rge/rge cross, and candidate genes were sequenced. RESULTS. The rge locus was refined and the gene for guanine nucleotide-binding protein β-3 (GNB3), which encodes a cone transducin β subunit, was found to have a 3-bp deletion (D153del) that segregated with the rge phenotype. This mutation deleted a highly conserved aspartic acid residue in the third of seven WD domains in GNB3. In silico modeling suggested that this mutation destabilized the protein. Furthermore, a 70% reduction was found in immunoreactivity to anti-GNB3 in the rge-affected retina. CONCLUSIONS. These findings implicate the β-subunit of cone transducin as the defective protein underlying the rge phenotype. Furthermore, GNB3 is ubiquitously expressed, and the c.825C→T GNB3 splicing variant (MIM 139130) has been associated with hypertension, obesity, diabetes, low birth weight, coronary heart disease, and stroke in the human population. It therefore seems likely that the defect underlying these human diseases also causes reduced embryonic viability in the rge chicken, making it a powerful model for studying the pathology involved in these associations

Sargassum polyceratium (Phaeophyceae, Fucaceae) surface molecule activity towards fouling organisms and embryonic development of benthic species

International audienceCoral reefs have undergone profound ecological changes over recent decades. Areas formerly covered by scleractinian coral species are now often overgrown by macroalgae. In Martinique (West Indies), this phenomenon has lead to the colonisation of numerous coral reefs by algae, amongst which Sargassum is one of the most prominent. This study focuses on potential defence molecules produced by Sargassum polyceratium. The hexane dipping method was employed to extract surface molecules on fresh material, and their bioactivities were assessed against bacteria (marine and estuarine), and marine tropical invertebrates wan annelid (Pseudonereis sp.), a bivalve (Codakia orbicularis) and a sea urchin (Diadema antillarum)x. Extracts were active against all microorganisms tested (MICs150 or 300 mg ml-1), early stages of development in Pseudonereis sp. (MICs100 mg ml-1) and embryos of C. orbicularis and D. antillarum (MICs5 mg ml-1), suggesting the production of defence compounds by S. polyceratium

The Influence of Difference Temperature Against the Rate of Embryonic Development and Larval Abnormality of Cantik Grouper (Epinephelus SP.)

Cantikgrouper is the hybridization results grouper or cross-breeding between Epinephelus fuscoguttatus as a female and Epinephelus microdon as a male. The main barriers faced in the development of this commodity is still low levels of spawning up to seeding grouper. Based on the background, this study aimed to investigate optimum temperature observations against the rate of embryonic development Epinephelus sp.larvae. This study used the results of artificial spawning eggs.The fertilized eggs were incubated on six pieces of the container temperature treatment;each treatment there was repeated three times.The incubation temperature was kept on (A) 21-22°C; (B) 23-24°C; (C) 25-26°C; (D) 27-28°C; (E) 29-30°C; (F) 31-32°C. Results showed that eggswere incubated at a temperature of 21-22 ℃ embryonic development to a halt in the blastula, and temperature 23-24°C stalled on phasemyomere embryos. The low-temperature incubation period lasts a long time. Temperature 25-26°C needed 18 hours 6 minutes by 8.33% abnormality rate. Temperature 27-28°C needed 16 hours to hatch witha degree of abnormality of 7.6%. Temperature 29-30°C needed 15 hours 1 minute for the hatch tothe degree of abnormality of 5.33%. The 31-32°C temperature needed 14 hours 6 minutes to hatch witha degree of abnormality of 17.3%. The limits of tolerance for the incubation of the eggs ofcantik grouper (Epinephelusspp.) were 26-32°C.The best temperature of each treatment were obtained at a temperature of 29-30°C. Based on our results, it concluded that the changing temperature affected how long eggs could hatch

A viable mouse model of factor X deficiency provides evidence for maternal transfer of factor X.

BackgroundActivated factor X (FXa) is a vitamin K-dependent serine protease that plays a pivotal role in blood coagulation by converting prothrombin to thrombin. There are no reports of humans with complete deficiency of FX, and knockout of murine F10 is embryonic or perinatal lethal.ObjectiveWe sought to generate a viable mouse model of FX deficiency.MethodsWe used a socket-targeting construct to generate F10-knockout mice by eliminating F10 exon 8 (knockout allele termed F10(tm1Ccmt), abbreviated as '-'; wild-type '+'), and a plug-targeting construct to generate mice expressing a FX variant with normal antigen levels but low levels of FX activity [4-9% normal in humans carrying the defect, Pro343-->Ser, termed FX Friuli (mutant allele termed F10(tm2Ccmt), abbreviated as F)].ResultsF10 knockout mice exhibited embryonic or perinatal lethality. In contrast, homozygous Friuli mice [F10 (F/F)] had FX activity levels of approximately 5.5% (sufficient to rescue both embryonic and perinatal lethality), but developed age-dependent iron deposition and cardiac fibrosis. Interestingly, F10 (-/F) mice with FX activity levels of 1-3% also showed complete rescue of lethality. Further study of this model provides evidence supporting a role of maternal FX transfer in the embryonic survival.ConclusionsWe demonstrate that, while complete absence of FX is incompatible with murine survival, minimal FX activity as low as 1-3% is sufficient to rescue the lethal phenotype. This viable low-FX mouse model will facilitate the development of FX-directed therapies as well as investigation of the FX role in embryonic development