Internal embryonic development in a non-copulatory, egg-laying teleost, the three-spined stickleback, Gasterosteus aculeatus

Offspring from females that experience stressful conditions during reproduction often exhibit altered phenotypes and many of these effects are thought to arise owing to increased exposure to maternal glucocorticoids. While embryos of placental vertebrates are known to regulate exposure to maternal glucocorticoids via placental steroid metabolism, much less is known about how and whether egg-laying vertebrates can control their steroid environment during embryonic development. We tested the hypothesis that threespine stickleback ( Gasterosteus aculeatus ) embryos can regulate exposure to maternal steroids via active efflux of maternal steroids from the egg. Embryos rapidly (within 72 h) cleared intact steroids, but blocking ATP-binding cassette (ABC) transporters inhibited cortisol clearance. Remarkably, this efflux of cortisol was sufficient to prevent a transcriptional response of embryos to exogenous cortisol. Taken together, these findings suggest that, much like their placental counterparts, developing fish embryos can actively regulate their exposure to maternal cortisol. These findings highlight the fact that even in egg-laying vertebrates, the realized exposure to maternal steroids is mediated by both maternal and embryonic processes and this has important implications for understanding how maternal stress influences offspring development.

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Effects of Incubation Conditions and Offspring Sex on Embryonic Development and Survival in the Zebra Finch (Taeniopygia Guttata)

The Auk ◽

10.1093/auk/122.4.1239 ◽

2005 ◽

Vol 122 (4) ◽

pp. 1239-1248 ◽

Cited By ~ 1

Author(s):

Helen E. Gorman ◽

Kate J. Orr ◽

Aileen Adam ◽

Ruedi G. Nager

Keyword(s):

Embryonic Development ◽

Body Condition ◽

Egg Quality ◽

Good Condition ◽

Taeniopygia Guttata ◽

Egg Laying ◽

Male And Female ◽

Embryo Mortality ◽

Offspring Fitness ◽

Offspring Sex

AbstractSuboptimal conditions during embryonic development can affect offspring fitness. Both egg quality and incubation behavior can affect hatching success, hatching mass, and subsequent offspring performance. These effects may differ between male and female offspring. We manipulated the prebreeding body condition of Zebra Finches (Taeniopygia guttata), using diets of different protein content. To separate possible effects on egg quality of parental body condition and incubation conditions, we did a cross-fostering experiment. We analyzed embryo survival and hatching mass with respect to body condition of the egg-laying parent, body condition of the incubating foster parent, and offspring sex. Embryos were not affected by the condition of the egg-laying parent. Eggs incubated by parents in better condition suffered less embryo mortality than those incubated by parents in poorer condition, but only when overall embryo mortality was low. Hatching mass was also affected by the incubating foster parent’s body condition. And hatchlings incubated by parents in good condition were heavier than those incubated by parents in poor condition. Female hatchlings from late-laid eggs were heavier, in comparison with the size of the egg from which they hatched, than female hatchlings from earlier-laid eggs. No such effect was found for males. Therefore, male and female embryos may differ in their sensitivity to suboptimal conditions during embryonic development. These results suggest that parental body condition during incubation can affect offspring fitness.Efectos de las Condiciones de Incubación y el Sexo de las Crías sobre el Desarrollo Embrional y la Supervivencia en Taeniopygia guttata

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Aedes aegypti: egg morphology and embryonic development

Parasites & Vectors ◽

10.1186/s13071-021-05024-6 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Ana Paula Miranda Mundim-Pombo ◽

Hianka Jasmyne Costa de Carvalho ◽

Rafaela Rodrigues Ribeiro ◽

Marisol León ◽

Durvanei Augusto Maria ◽

...

Keyword(s):

Embryonic Development ◽

Aedes Aegypti ◽

Vector Competence ◽

Intermediate Stage ◽

Egg Laying ◽

Control Measures ◽

Limiting Factor ◽

Embryonic Cells ◽

Biomedical Sciences ◽

Egg Morphology

Abstract Background The diseases for which Aedes aegypti is a vector are worrisome. The high vector competence of this mosquito, as well as its anthropophilia and ability to adapt to the urban environment, allows it to exploit many habitats, making its prevention an arduous task. Despite current disease control measures focused on the mosquito, the effectiveness in containing its dispersion still requires improvement; thus greater knowledge about this insect is fundamental. Methods Aedes aegypti egg morphology and embryonic development were analyzed from eggs of the insectary of the Institute of Biomedical Sciences of the University of São Paulo. Optical (light and confocal) and electronic (transmission and scanning) microscopy were used to analyze the morphological and ultrastructural features of the eggs. Embryos were observed in the initial (0–20.5 h after egg-laying), intermediate (20.6–40.1 h after egg-laying), and final (40.2–61.6 h) stages of development, and kept at a temperature of 28 °C ± 1 °C until collection for processing. Results Eggs of Ae. aegypti were whitish at the time of oviposition, and then quickly became black. The egg length was 581.45 ± 39.73 μm and the width was 175.36 ± 11.59. Access to the embryo was difficult due to the egg morphology, point of embryonic development, and difficult permeability of the exochorion (mainly in fixation). Only about 5% of the collected eggs were successfully processed. In the initial stage of embryonic development, characteristics suggestive of intense cellular activity were found. In the intermediate stage, the beginning of the segmentation process was evident. In the final phase, it was possible to differentiate the cephalic region and the thoracic and abdominal segments. Conclusion The chorion was found to be an important protective barrier and a limiting factor for the evaluation of the embryos and mosquito embryonic cells, indicating that further studies need to be carried out to identify the reason that this occurs. Graphical abstract

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Dietary carotenoid supplementation facilitates egg laying in a wild passerine

10.1101/792234 ◽

2019 ◽

Author(s):

Jorge García-Campa ◽

Wendt Müller ◽

Sonia González-Braojos ◽

Emilio García-Juárez ◽

Judith Morales

Keyword(s):

Embryonic Development ◽

Clutch Size ◽

Egg Production ◽

Egg Quality ◽

Antioxidant Properties ◽

Egg Laying ◽

Egg Mass ◽

Blue Tit ◽

Trade Off ◽

Dietary Carotenoid

During egg laying, female birds face a trade-off between self-maintenance and investment into current reproduction. Providing eggs with resources is energetically demanding, since in most species females lay one egg per day. However, the costs of egg laying not only relate to energetic requirements, but also depend on the availability of specific resources that are vital for egg production and embryonic development. One of these compounds are carotenoids, pigments with antioxidant properties and immuno-stimulatory functions, which are crucial during embryonic development. In this study, we explore how carotenoid availability alleviates this trade-off and facilitates egg laying in the blue tit. Blue tit females lay one egg per day and have the largest clutch size of all European passerines. We performed a lutein supplementation experiment, and measured potential consequences for egg laying capacity and egg quality. We found that lutein-supplemented females had less laying interruptions and thus completed their clutch faster than control females. No effects of treatment were found on the onset of egg laying or clutch size. Experimentally enhanced carotenoid availability did not elevate yolk carotenoid levels or egg mass, but negatively affected eggshell thickness. Our results provide hence evidence on the limiting role of carotenoids during egg laying, However, the benefits of laying faster following lutein supplementation were counterbalanced by a lower accumulation of calcium in the eggshell. Thus, even though single components may constrain egg laying, it is the combined availability of a range of different resources which ultimately determines egg quality and thus embryonic development.

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Observations on the Embryonic Development of Octopus tetricus (Mollusca : Cephalopoda)

Marine and Freshwater Research ◽

10.1071/mf9780019 ◽

1978 ◽

Vol 29 (1) ◽

pp. 19 ◽

Cited By ~ 6

Author(s):

LM Joll

Keyword(s):

Embryonic Development ◽

Breeding Season ◽

Wild Population ◽

Yolk Sac ◽

Egg Laying ◽

Larvae And Juveniles ◽

In The Wild

The development of O. tetricus embryos reared in the laboratory is described. The course of embryo-genesis is similar to that of O. vulgaris but the shape of stage-time plots differs. Most embryos undergo two reversions during development but failure to reverse does not prevent continued development. Both naturally and artificially hatched embryos still have the internal yolk sac, which is not fully absorbed until 4 or 5 days after hatchnig. Records of egg-laying in the laboratory and of the presence of larvae and juveniles in the wild population indicate that O. tetricus has a prolonged breeding season.

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Artificial Substrate for Egg Laying and Embryonic Development by the Predatory BugMacrolophus caliginosus(Heteroptera: Miridae)

Biological Control ◽

10.1006/bcon.1996.0077 ◽

1996 ◽

Vol 7 (2) ◽

pp. 140-147 ◽

Cited By ~ 20

Author(s):

Bérengère Constant ◽

Simon Grenier ◽

Guy Bonnot

Keyword(s):

Embryonic Development ◽

Egg Laying ◽

Artificial Substrate

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Fertility and timing of the embryonic development of Cameraria ohridella Deschka & Dimic, 1986 (Lepidoptera: Gracillariidae) in laboratory conditions at different temperatures

Karantin i zahist roslin ◽

10.36495/2312-0614.2019.5-6.27-28 ◽

2019 ◽

pp. 27-28

Author(s):

M. Bashchenko ◽

V. Chayka

Keyword(s):

Survival Rate ◽

Environmental Factors ◽

Embryonic Development ◽

Experimental Studies ◽

Biological Data ◽

The State ◽

Egg Laying ◽

Effect Of Temperature ◽

Moth Population ◽

Laboratory Conditions

Goal. The effect of temperature on fertility and the timing of the embryonic development of the chestnut moth under laboratory conditions was studied. Methods. Laboratory. Selected pupae of the chestnut moth were placed in thermostats (at a temperature of 15, 20, 25, 30). Then, 5 pairs of pupae of different sexes were placed in glass cages in which the paper was pre-inserted, as a substrate for egg laying. Experiments were performed in four versions — 10 replications each. Cages with each variant were placed in polythermostats at temperatures of 15, 20, 25 and 30°С. After the butterflies flew out, the paper was taken out of the cage regularly (every two days) and under a microscope of MBS-9 (eyepiece 0.6 magnification 2), the number of laid eggs and caterpillars that hatch were counted. The results were processed statistically by standard methods for biological data. Results. It was determined that at a temperature of 15°C 50% of caterpillars were released from 40 eggs. At 25°C, out of 187 laid chestnut moth eggs, 65% of caterpillars were released. At 20°C, butterflies laid aside 83 instances. 54% of the caterpillars were released. At 30°C, the female chestnut moth was set aside on 17 instances eggs whose embryonic development has not occurred. It was revealed that at 15 and 30°С females are the least active, thus, optimal temperatures for keeping the chestnut moth in laboratory conditions are in the range of 20—25°С. Under these conditions, butterflies mate and lay eggs, the survival rate of which reaches 54—65%. The technique makes it possible in the laboratory to investigate the influence of environmental factors on the state of the chestnut moth population. Findings. It was determined that in laboratory conditions the optimum temperature for the deposition of chestnut moth eggs is 25°C. Butterflies favor the green substrate. Embryonic development lasts 6.1 ± 0.12 days, the survival rate of the populations is 25%. The method of obtaining chestnut moth eggs allows for in-depth experimental studies of the influence of environmental factors on the state of the chestnut moth population.

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PSVIII-15 Polymorhpism of dysferlin gene in chickens

Journal of Animal Science ◽

10.1093/jas/skz258.552 ◽

2019 ◽

Vol 97 (Supplement_3) ◽

pp. 272-272

Author(s):

Anna Krutikova ◽

Kirill Plemyashov ◽

Natalia Dementeva

Keyword(s):

Body Weight ◽

Embryonic Development ◽

Egg Production ◽

Myoblast Fusion ◽

Egg Laying ◽

Muscle Membrane ◽

Reference Period ◽

Egg Weight ◽

Negative Effect ◽

The Difference

Abstract Dysferlin is associated with the formation of the muscle membrane, is involved in the repair of the muscle membrane and the regulation of myoblast fusion. In humans, mutations in the dysferlin gene lead to various types of muscle pathologies. The effect of dysferlin on the formation of muscle structures was detected in the early stages of embryonic development. We have suggested that mutations in the dysferlin gene in chickens can have a negative effect on the formation of muscle mass and meat traits of chickens. SNP rs16455118 was studied on chickens of different breeds and hybrids of broilers and layers. Body weight was controlled in 7, 49 and 330 days. Layers were used as a contrast. Standard indicators of egg traits (age of the first egg laying, egg production for 6 months, egg weight) were studied. SNP rs16455118 leads to the replacement of adenine by cytosine in the intron of the dysferlin gene. The GWAS method was used. As a result, the association of SNP in the dysferlin gene with meat traits in chickens was not found. But a statistically significant association of certain genotypes with egg trait in Russian white chickens was determined. Chickens with the AA and AC genotypes had more eggs compared to their peers with the SS genotype during the reference period. The difference was 10 eggs an average of (P ≤ 0.05). Project number: AAAA-A18-118021590138-1

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From brooding to hatching: new insights from a female Octopus vulgaris in the wild

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315415001800 ◽

2015 ◽

Vol 96 (6) ◽

pp. 1341-1346 ◽

Cited By ~ 9

Author(s):

Manuel E. Garci ◽

Jorge Hernández-Urcera ◽

Miguel Gilcoto ◽

Raquel Fernández-Gago ◽

Ángel F. González ◽

...

Keyword(s):

Embryonic Development ◽

Natural Habitat ◽

Egg Laying ◽

Laying Date ◽

Octopus Vulgaris ◽

Battery Life ◽

Brooding Period ◽

Data Loggers ◽

In The Wild ◽

Reproductive Events

A brooding Octopus vulgaris female was monitored for 128 days in her natural habitat. The main reproductive events and embryonic development in relation to the temperature inside the spawning den, which was recorded by long-battery-life mini-data loggers, are described in the wild. The den temperature ranged from 12.9 to 19.3°C. The total number of egg strings was 160, and the total number of eggs spawned ranged between 139,040 and 241,760 (mean 190,400). The brooding period, the egg laying interval and the duration of the hatching course lasted 128, 35 and 43 days, respectively. Both egg laying and hatching were intermittent processes. The time taken for embryonic development was variable (85–128 d) and depended on the laying date, temperature and position of the string in the egg cluster and the position of the egg in the egg string. The first hatching observed occurred after a progressive and gradual increase of the temperature from 14.9 to 19.3°C. The 280 min of video recordings taken by scuba divers showed that several times, this female opened and closed a small window in the obstructions of the den entrance to facilitate a way out for the hatchling batches.

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