Embryos In Water Research Articles

Mosquito Embryo Microinjection under Halocarbon Oil or in Aqueous Solution.

The process of genetically modifying mosquitoes requires skilled delivery of reagents for modification. Plasmids, RNA, DNA, and/or protein must be transported into the developing embryo during an appropriate time in development when these agents will have access to the genome. Embryo microinjection has been the main method by which such modifying agents have been delivered. Ideally the microinjection process will deliver these modifying agents in sufficient quantity to effect the genetic modification without severely damaging or killing the injected embryo in the process. As semiaquatic insects, mosquitoes have embryos that are susceptible to desiccation and the degree to which embryos are susceptible is based on species. Two microinjection methods are outlined here. The first method describes embryo microinjections performed under Halocarbon-27 oil. The oil is used to reduce desiccation during the injection process. A second method limits desiccation by injecting the mosquito embryos in water. In both procedures, the embryos are first aligned and then injected before the embryos cellularize, ∼1 h and 45 min after oviposition.

TINGKAT KEBERHASILAN TRANSFER EMBRIO (TE) BERDASARKAN KEGIATAN SELEKSI RESIPIEN DAN PELAKSANAAN TE DARI TAHUN 2018 SAMPAI DENGAN 2021 DI KABUPATEN ROKAN HULU

Implementation of the application of embryo transfer technology (ET), requires a program that can meet the wishes of the livestock community in terms of improving the genetic quality of liverstock quickly. The program is related to the proposal of beef cattle by field officers, selection of recipient cattele by the embryo transfer team which includes: exterior assessment, such as the Body Condition Score (BSC), interior assessment such as rectal palpation of the internal genitals (cervix, uterus an ovaries). The next activity is the implementation of embryo transfer such as how handle recipient cattel; wheather the recipient has been in Artificial Insemination (AI) (twinning program) or single ET, epidural anastesi, thowing frozen embryos in water at 38℃, insertion of embryo straw into the ET gun/plastic ET, rectal palpation, cervical examination, insertion of the ET gun, embryo deposition to the uterine horn, recording the results of ET, examination of pregnancy results of ET at the age of 2 months, monitoring of recipients who are already pregnant until elivery, reporting the results of single ET briths and ET twinning(AI/ET).
 This technical report is the result of the embryo transfer (ET) program activities that took place from 2012,2018,2019,2020,and 2021, which in this technical report discusses the success rate of embryo transfer (ET) based on recipient selection and impelemtation activities embryo transfer (ET).

Alternative oxidase gives Ciona colonists a head start in rotten egg water

Throughout the history of life on Earth, there have always been locations where some species thrive while others fail. And, as climate change and environmental degradation continue apace, some habitats are becoming more inhospitable as toxins such as hydrogen sulphide begin accumulating in zones when oxygen becomes scarce. The situation has rarely been so rosy for invasive creatures, such as the sea squirt Ciona intestinalis. But what might be giving these intruders the upper hand? Katharina Bremer from Tampere University, Finland, explains that the sea squirt is equipped with a specially adapted enzyme – known as ‘alternative oxidase’ – which allows them to produce the energy they require to survive in the presence of toxic hydrogen sulphide gas that smells of rotten eggs. The close relative of this critical enzyme – used by most creatures – is fatally poisoned by hydrogen sulphide. Could alternative oxidase prove to be the essential key that allows sea squirt invaders to colonise hydrogen sulphide hotspots where others perish?However, for pioneering sea squirts to gain a new foothold, they must send in a first wave of pilgrim settlers, and, in the case of the sea squirt, that means newly fertilized eggs and larvae. So, Bremer, Paul Debes (Hólar University, Iceland), Hitoyoshi Yasuo (Laboratoire de Biologie du Développement de Villefranche-sur-mer, France) and Howard Jacobs (Tampere University) needed to find out how toxic the dissolved gas is for freshly fertilized sea squirt eggs. After immersing the embryos in water ranging from 0 to 50 μmol l−1 hydrogen sulphide, which can prove fatal for fish, the team found that ∼80% of the youngsters successfully developed into larvae after 18.5 h in fresh seawater, with their survival rate falling to ∼60% when bathed in 10 μmol l−1 hydrogen sulphide. But then the youngsters began to struggle, with only ∼25% developing into larvae in 20 μmol l−1 hydrogen sulphide and none succeeding at 50 μmol l−1. Even with their specially adapted hydrogen-sulphide-proof alternative oxidise, the youngsters were only able to survive reasonably well in hydrogen sulphide concentrations of up to 15 μmol l−1.But then the team needed to check whether the embryos’ alternative oxidase provided them with their resistance to the toxin, or whether they were resorting to another strategy to survive the poison. The scientists injected the embryos with a molecule that prevented the youngsters from producing alternative oxidase, forcing the developing embryos to depend on other forms of the enzyme for survival in 15 μmol l−1 hydrogen sulphide. Without the key enzyme, their survival plummeted by 81% to 12%. However, when the team provided the impaired youngsters with an additional source of alternative oxidase, their survival rate returned to 27%; the same as normal sea squirt embryos in fresh seawater.In addition, the team measured whether the embryos were activating the gene responsible for the essential enzyme – and therefore likely to be producing the alternative oxidase – while developing in 15 μmol l−1 hydrogen sulphide, and it was clear that they had increased expression of the gene to combat the toxin. Their alternative oxidase source of energy is the key to the youngsters’ survival when their water reeks of rotten eggs. Bremer also warns that natural increases in hydrogen sulphide in waters across the globe that are becoming deoxygenated could provide other species that possess a hydrogen-sulphide-proof alternative oxidase with the advantage they require to go forth and colonise locations where other species can barely hang on.

Vascular toxicity of ultra-small TiO2 nanoparticles and single walled carbon nanotubes in vitro and in vivo

Ultra-small nanoparticles (USNPs) at 1–3 nm are a subset of nanoparticles (NPs) that exhibit intermediate physicochemical properties between molecular dispersions and larger NPs. Despite interest in their utilization in applications such as theranostics, limited data about their toxicity exist. Here the effect of TiO2-USNPs on endothelial cells in vitro, and zebrafish embryos in vivo, was studied and compared to larger TiO2-NPs (30 nm) and to single walled carbon nanotubes (SWCNTs). In vitro exposure showed that TiO2-USNPs were neither cytotoxic, nor had oxidative ability, nevertheless were genotoxic. In vivo experiment in early developing zebrafish embryos in water at high concentrations of TiO2-USNPs caused mortality possibly by acidifying the water and caused malformations in the form of pericardial edema when injected. Myo1C involved in glomerular development of zebrafish embryos was upregulated in embryos exposed to TiO2-USNPs. They also exhibited anti-angiogenic effects both in vitro and in vivo plus decreased nitric oxide concentration. The larger TiO2-NPs were genotoxic but not cytotoxic. SWCNTs were cytotoxic in vitro and had the highest oxidative ability. Neither of these NPs had significant effects in vivo. To our knowledge this is the first study evaluating the effects of TiO2-USNPs on vascular toxicity in vitro and in vivo and this strategy could unravel USNPs potential applications.

Imbibition of white spruce seeds and somatic embryos: A study of morphological changes in an environmental scanning electron microscope and potassium leakage

Potassium leakage and morphological changes during imbibition of white spruce [Picea glauca (Moench) Voss] seeds and somatic embryos were investigated. A single desiccated somatic embryo, a single somatic embryo exposed to a high relative humidity environment for 2 d, and a single dry zygotic embryo leaked similar amounts of potassium over a 120-min period of imbibition in liquid germination medium. A seed without a seed coat leaked two and eight times more potassium than a single whole seed and a single zygotic embryo, respectively. Nearly 50% of the potassium leaked for all tissues was leaked within the first 20 min of imbibition. Exposure of somatic embryos to an environment with high relative humidity resulted in a reduction in the percentage of potassium leaked after 80 and min to levels equivalent to those for zygotic embryos. Using an environmental scanning electron microscope, we found that desiccated somatic embryos and dry zygotic embryos had wrinkled surface cells, with cells in the surface of zygotic embryos being more shrunken in appearance. Imbibition of both types of embryos in water resulted in turgid surface cells after 2 h. Imbibition in liquid germination medium did not cause much hydration of surface cells, which still had wrinkled appearances after 2 h. Finally, imbibition on filter paper on semisolidified germination medium resulted in slower hydration of somatic and zygotic embryos. Cells near the medium appeared hydrated while cotyledon surface cells furthest from the medium resembled cells in desiccated embryos.

Field studies on abscisic acid and embryonic germinability in winter wheat

Wheat ( Triticum aestivum L.) cultivars differ in resistance to preharvest sprouting, which can occur when rains precede harvest. The objective of this study was to determine of sprouting resistance was related to endogenous levels of embryonic abscisic acid ( ABA) and/or to the degree of embryonic sensitivity (capability of ABA to block embryonic germination) to exogenously applied ABA. Embryonic ABA levels and sensitivity were compared during the grain development period in 1983 and 1984 in a sprouting-resistant cultivar, ‘Brevor’, and a susceptible cultivar, ‘Greer’. The ABA levels were influenced by environment and year but not by cultivar, except at the soft-dough/ hard-dough transition stage of development in both years and at hard-dough stage in 1983. At those stages, Brevor had higher levels of free ABA than Greer. Embryonic ABA level and rate of germination of dissected embryos in water were not related, but the rate of germination was reduced by exogenous ABA (5×10 −5 M), and was reduced more in Brevor than in Greer. Differences in embryonic sensitivity to ABA, modulated by environmental conditions during the grain-filling period, may contribute to cultivar differences in resistance to preharvest sprouting.

Acid-shock, aluminium, and presence of Sphagnum aurantiacum: effects on embryological development in the common frog, Rana temporaria and the moor frog, Rana arvalis.

During the last two decades, several effects of acidification have been shown, e.g., enhanced leaching of metals from sediments and soil. Furthermore, an increased growth of Sphagnum aurantiacum frequently occurs in acidified waters. The aim of the present study is to investigate some effects of acidification on the embryological development on two Anurans. The toxicity of aluminium is thought to vary with pH. The highest toxicity of aluminium in the hydroxyl form have been found at pH 5. In the present study a laboratory experiment was performed to investigate the toxicity of Al to frog embryos in water with pH 5.0. In acidified waters Sphagnum and especially S. aurantiacum, is competitive and quickly become established. It has been indicated that frog spawn deposited on Sphagnum show an unusually high mortality and questions have been raised if Sphagnum reinforces the detrimental effects of acidification on Anuran reproduction.

The influence of external cation concentration on the hatching of amphibian embryos in water of low pH

Amphibian embryos exposed to water of low pH were killed by two distinct mechanisms. At very low pH levels, embryos stopped development soon after exposure to test solutions. At higher but still lethal pH levels, embryos became curled within a shrunken perivitelline space and failed to hatch (curling defect). The addition of Ca, Mg, and to a lesser extent Na (> 10 mg/L), prevented the early mortality of embryos in acidic water. However, increasing concentrations of these ions also caused the curling defect. Embryos of Ambystoma maculatum and Ambystoma jeffersonianum were generally able to hatch even though they became curled, but Rana sylvatica remained trapped and died. Consequently, as the concentration of Ca, Mg, or Na was increased at low pH, greater numbers of embryos of A. maculatum and A. jeffersonianum hatched, while survival of embryos of R. sylvatica was drastically reduced.

A negative test for mutagenic action of microwave radiation in Drosophila melanogaster

Microwave radiation (2450 MHz CW) was tested for mutagenicity in Drosophila melanogaster. Embryos in water were exposed to the electromagnetic field with a mean specific absorption rate of 100 W/kg. A sensitive somatic test system was used, in which mutagenicity was measured as the frequency of somatic mutations for eye pigmentation. With the test system used, microwaves did not show any mutagenic activity.

The growth physics and water relations of red-light-induced germination in lettuce seeds

A study of photodormant lettuce embryos germinating in water showed that red light induces an increased rate of water uptake. Determinations of the water potential, carried out by a modified gravimetric technique which eliminates errors introduced by solute penetration into cellular osmotic space, showed that the water potential of embryos germinating in water after dark and red light treatment was equivalent and equal to the osmotic potential of a 0.0 to 0.1 molal mannitol solution. Osmotic potentials of the embryos were determined using two new methods. One of the methods utilizes penetration of deuterated water; the other, penetration of a labeled osmoticum into the tissue. For both light- and dark-treated embryos in water, the osmotic potential was equivalent to that of a 0.34 to 0.41 molal mannitol solution. Lettuce embryos thus require that turgor pressure reach a threshold considerably above zero before growth can occur.

Dormancy in Seeds of Charlock: III. OCCURRENCE AND MODE OF ACTION OF AN INHIBITOR ASSOCIATED WITH DORMANCY

The dormancy of charlock seeds appears to be associated with the presence of an inhibitor which accumulates within the seed. This inhibitor diffuses into the external solution when seeds are placed in water under germination conditions or controlled experimental conditions. A small quantity of inhibitor diffuses from the seed coats but most arises from the embryo. The increase in temperature was measured by comparing the relative growth-rates of the radicles of excised charlock embryos in water and in test solutions of diffusate. The results suggest that the rate of accumulation of inhibitor in the external solution is controlled by diffusion, and that there is continuous production of inhibitor in the tissues of the embryo which have a low oxgyen tension. The critical concentration of the inhibitor which completely prevents cell elongation is rapidly attained in seeds which are dormant. The inhibitor is unlikely to be a mustard oil, such as allylisothio-cyanate.