Incidence Of Morphological Abnormalities Research Articles

Higher incidence of embryonic defects in mouse offspring conceived with assisted reproduction from fathers with sperm epimutations.

Assisted reproductive technologies (ART) account for 1-6% of births in developed countries. While most children conceived are healthy, increases in birth and genomic imprinting defects have been reported; such abnormal outcomes have been attributed to underlying parental infertility and/or the ART used. Here, we assessed whether paternal genetic and lifestyle factors, that are associated with male infertility and affect the sperm epigenome, can influence ART outcomes. We examined how paternal factors, haploinsufficiency for Dnmt3L, an important co-factor for DNA methylation reactions, and/or diet-induced obesity, in combination with ART (superovulation, in vitro fertilization, embryo culture and embryo transfer), could adversely influence embryo development and DNA methylation patterning in mice. While male mice fed high-fat diets (HFD) gained weight and showed perturbed metabolic health, their sperm DNA methylation was minimally affected by the diet. In contrast, Dnmt3L haploinsufficiency induced a marked loss of DNA methylation in sperm; notably, regions affected were associated with neurodevelopmental pathways and enriched in young retrotransposons, sequences that can have functional consequences in the next generation. Following ART, placental imprinted gene methylation and growth parameters were impacted by one or both paternal factors. For embryos conceived by natural conception, abnormality rates were similar for WT and Dnmt3L+/- fathers. In contrast, paternal Dnmt3L+/- genotype, as compared to WT fathers, resulted in a 3-fold increase in the incidence of morphological abnormalities in embryos generated by ART. Together, the results indicate that embryonic morphological and epigenetic defects associated with ART may be exacerbated in offspring conceived by fathers with sperm epimutations.

Habitat quality affects the incidence of morphological abnormalities in the endangered salamander Ambystoma ordinarium.

Identification of early warning signals previous to the occurrence of population decline or extinction is a major challenge for the conservation of animal species. Prevalence of morphological abnormalities in a population can be one of these signals. We registered morphological abnormalities in the salamander Ambystoma ordinarium. We also evaluated the relation between habitat quality and the prevalence of abnormalities in this species. We used scores from rapid bioassessment protocols (RBPs) to assess the habitat quality of streams inhabited by A. ordinarium. A preliminary survey indicated that of 29 streams where this species has been historically registered, 13 might have few or no A. ordinarium. The association between habitat quality and the incidence of morphological abnormalities was evaluated in these 16 streams. Of 502 sampled individuals, 224 (44.62%) had at least one body abnormality. Of the 224 individuals with body abnormalities, 84 (37.5%) presented more than one abnormality. Of a total of 5,522 evaluated morphological characters, 344 (6.74%) were abnormal. Partial loss of gills and missing digits were the most frequent abnormalities. Results of a binomial logistic regression indicated that the probability of a character of an individual to be abnormal was significantly associated with habitat quality; as the levels of the quality of the habitat increased, the prevalence of morphological abnormalities decreased. These results suggest that RBPs are a quick and useful method for assessing the habitat quality of streams inhabited by A. ordinarium. Given that RBPs provide rapid and cost-effective assessments of the ecological health of aquatic ecosystems, it will be important to test if the RBPs protocols can be used to rapidly assess habitat quality for other species of stream amphibians. The negative association between habitat quality and the prevalence of morpohological abnormalities that we found indicates that habitat condition plays an important role in the high number of abnormalities registered in A. ordinarium. Therefore, our results suggest that one of the several negative effects of habitat degradation on amphibians is an increase in the frequency of morphological abnormalities with marked consequences for the survival and general fitness of aquatic amphibians.

Rock glacier outflows may adversely affect lakes: lessons from the past and present of two neighboring water bodies in a crystalline-rock watershed.

Despite the fact that rock glaciers are one of the most common geomorphological expressions of mountain permafrost, the impacts of their solute fluxes on lakes still remain largely obscure. We examined water and sediment chemistry, and biota of two neighboring water bodies with and without a rock glacier in their catchments in the European Alps. Paleolimnological techniques were applied to track long-term temporal trends in the ecotoxicological state of the water bodies and to establish their baseline conditions. We show that the active rock glacier in the mineralized catchment of Lake Rasass (RAS) represents a potent source of acid rock drainage that results in enormous concentrations of metals in water, sediment, and biota of RAS. The incidence of morphological abnormalities in the RAS population of Pseudodiamesa nivosa, a chironomid midge, is as high as that recorded in chironomid populations inhabiting sites heavily contaminated by trace metals of anthropogenic origin. The incidence of morphological deformities in P. nivosa of ∼70% persisted in RAS during the last 2.5 millennia and was ∼40% in the early Holocene. The formation of RAS at the toe of the rock glacier most probably began at the onset of acidic drainage in the freshly deglaciated area. The present adverse conditions are not unprecedented in the lake’s history and cannot be associated exclusively with enhanced thawing of the rock glacier in recent years.

Evaluation of the developmental toxicity of the aqueous extract from Trigonella foenum-graecum (L.) in mice

Aim of the study The use of medicinal plant products to treat various ailments is a common practice in many developing countries. However, a lack of information on the adverse effects of these plants raises questions on their safety and possible adverse side effects. This study was undertaken to evaluate the potential toxic effects of fenugreek seeds on pregnant mice and foetal development. Materials and methods Lyophilized aqueous extract from fenugreek seeds (LAE-FS) was administered to mated female mice during the entire period of pregnancy, at doses of 500 and 1000 mg/kg/day. Females were examined for standard parameters of reproductive performance. Foetuses were weighed and examined for externally visible malformations. Results In pregnant females, there were no obvious symptoms of toxicity, LAE-FS-related deaths or macroscopic abnormalities. Developmental toxicity in offspring included an increase in the foetal death rate, a decrease in the litter size, and a reduction in the foetal body weight. In addition there was an increase in the incidence of morphological abnormalities. Conclusions Based on these results, it was concluded that fenugreek seeds extract may have deleterious toxic effects on reproductive performance and potential teratogenic effects in foetuses.

Fluctuating asymmetry, abnormalities and parasitism as indicators of environmental stress in cultured stocks of goldfish and carp

Knowledge about the effects of captivity and environmental stress on fish populations is basic to culture them for ornamental, conservation or exploitation purposes. The aim of this study was to test how captivity affect morphological development of bilateral characters and whether levels of fluctuating asymmetry, morphological abnormalities and ectoparasites reflect developmental stress caused by adverse environmental conditions in two species of cyprinids, goldfish Carassius auratus and two varieties of carp Cyprinus carpio, scale and mirror carp. Samples from captivity were caught in an artificial pond (Madrid City, Spain), which presents poor environmental conditions; while samples from nature were captured in the Ebro River basin (NE Spain). Six meristic and four morphometric bilateral characters were measured and compared between the two samples. Additionally, the incidence of morphological abnormalities and ectoparasites was also recorded. Captive goldfish presented significant lower number of scales of the lateral line, scale rows above lateral line and length of pectoral and ventral fins. Captive carps showed significant shorter first barbels and longer ventral fins. Ornamental goldfish showed significant higher levels of fluctuating asymmetry than wild samples for number of branched rays of pectoral fin, lateral line, scale rows below lateral line and length of pectoral and ventral fins. Ornamental carps presented a similar trend for the same characters, except for branched rays and length of pectoral fins, together with the length of second barbels. In the artificial pond, the incidence of abnormalities was higher in carp, whereas goldfish showed a higher occurrence of ectoparasites. These facts support the hypothesis of a different species response to environmental stress. The overall results indicate that fish from the artificial pond are subjected to environmental stress caused by adverse conditions such as overcrowding and lower water quality. Moreover, estimated parameters in this study mean a useful tool to detect developmental instability in confined fish.

Morphological Abnormalities in Amphibians in Agricultural Habitats: A Case Study of the Common Frog Rana Temporaria

Recent studies suggest that the incidence of morphological abnormalities has increased in many amphibian populations, often exceeding the estimated background deformity frequency of 0–5%. Many chemical contaminants, including agrochemicals, can cause abnormalities in amphibians, but data on the occurrence of morphological abnormalities in wild amphibian populations in Europe is anecdotal at best. In a largescale study covering 264 ha and 26 farmland breeding populations of the Common frog (Rana temporaria) in southern Finland, we investigated whether the incidence of morphological abnormalities in metamorphs differed from the background level of 0– 5% and among populations along an agrochemical gradient. Abnormalities occurred in a low frequency (1% of the studied individuals; 40/4115), the highest populationspecific frequency being 4%. We found no evidence for increased abnormality frequencies in the habitats most likely exposed to agrochemicals. Hence, the data suggest that current Finnish agrochemical practices are not causing increased incidences of morphological abnormalities in Common frog populations breeding in farmland areas.

Effect of short periods of high incubation temperature on hatchability and incidence of embryo pathology of turkey eggs

1. Turkey eggs were incubated at 38.0° and 38.5°C at different stages of embryo development and for periods of 3 to 25 d. Results were compared with control eggs incubated at 37.5°C. The age of mortality, the incidence of malpositions and the incidence of morphological abnormalities were recorded from all unhatched eggs. 2. Eggs incubated at 38.5°C for 5 or more days hatched significantly less well than eggs incubated at 37.5°C. Eggs incubated at 38.5°C for 3 d hatched worse than controls but not significantly so. Eggs incubated between 0 and 25 d and 7 and 12 d but not between 0 and 6, 13 and 18 and 19 and 25 d, at 38.0°C had significantly lower hatchabilities than eggs incubated at 37.5°C. 3. Lowest hatchabilities were obtained when the eggs were incubated at high temperatures between 7 to 12 d and 6 to 10 d, indicating that embryos at this stage of development are more likely to succumb to high temperature than at other ages. 4. Increases in embryo mortality due to overheating were seen in weeks 3 and 4 of incubation and at the pipping stage. This was observed even when the period of overheating occurred in weeks 1 and 2 of incubation. 5. Embryos malpositioned with their head in the small end of the egg were seen at a higher incidence when overheating in the 2nd or 3rd quarter of the incubation period.

Effect of incubation temperature on the gross pathology of turkey embryos

1. Turkey eggs were incubated at 36.5, 37.5 and 38.5 degrees C. The age of mortality, the incidence of malpositions and the incidence of morphological abnormalities were recorded from all unhatched eggs. 2. Eggs incubated at 36.5 degrees C hatched later than eggs incubated at 37.5 degrees C but did not differ in age of mortality or incidence of malpositions and abnormalities. 3. Eggs incubated at 38.5 degrees C hatched significantly less well than eggs incubated at 37.5 degrees C and showed significant differences in time of embryo mortality. Overheated embryos had a mortality peak between 15 and 20 d of incubation and an increased mortality after 24 d of incubation. 4. Overheated eggs were characterised by a high incidence of embryos with head in small end, with excess albumen, ruptured yolk sacs, oedematous heads, eye cataracts and swollen down-plumules.

Detecting Ecosystem Responses to Anthropogenic Stress

Recent ecological work on aquatic populations, communities, and ecosystems is reviewed for advances which show promise as early indicators of anthropogenic stress in aquatic ecosystems. Work at the Experimental Lakes Area (ELA) in northwestern Ontario indicates that among the earliest of responses to stress are changes in species composition of small, rapidly-reproducing species with wide dispersal powers such as phytoplankton, and the disappearance of sensitive organisms from aquatic communities. Work elsewhere illustrates that the incidence of morphological abnormalities in benthic invertebrates is also highly sensitive to pollution stress. For several categories of pollutants, this sensitivity of benthic organisms may be due to the greater concentrations of pollutants in sediments than in the water column. Variables reflecting ecosystem functions such as primary production, nutrient cycling, and respiration, were not altered by eutrophication, acidification, or cadmium addition at ELA, and are relatively poor indicators of early stress. Species diversity of phytoplankton was also insensitive to low levels of stress. Mesocosm experiments appear to be fruitful for addressing chemical- or plankton-related problems, but are less useful for addressing community- or ecosystem-level questions. Among population-level approaches, life-table population studies of invertebrates appear to be the most sensitive early indicators of stress on ecosystems.Relative sensitivities of freshwater and forested terrestrial ecosystems exposed to airborne pollutants are compared. Primary production seems to be reduced at a much earlier stage of air pollution stress in terrestrial ecosystems than in aquatic systems. Soils, like lake sediments, tend to be sinks for pollutants. This may protect the pelagic regions of lakes from influxes of toxins that would occur if watersheds and sediments were unreactive, but cause additional stresses to the fauna and flora of soils and sediments. In extreme cases, high concentrations of toxins may inhibit the replacement of terrestrial producers.The importance of long-term monitoring in distinguishing natural from anthropogenic stress is discussed. It is suggested that paleoecological techniques be rapidly developed and calibrated with whole-ecosystem experiments to resolve certain inadequacies of past monitoring records.

Motor endplate alterations in schizophrenic patients.

NEUROMUSCULAR pathology has been described in a variety of mentally ill patients, primarily those suffering from schizophrenia or the affective psychosis. Some psychotic patients have increased electrical activity of skeletal muscle at rest1, abnormal electromyograms2, perform poorly on various tests of neuromuscular coordination3, have elevated serum creatine phosphokinase activity during an acute psychotic episode4 and show an increased incidence of morphological abnormalities of skeletal muscle5,6. Such studies have suggested that there may be an alteration of muscle innervation in such patients. We have previously reported that psychotic patients have an increased incidence of branching and sprouting of intramuscular nerve twigs6. We now report significant alterations in the morphology of the nerve terminals at the motor endplate in psychotic patients. This suggests that there may be an abnormality of transmission at neuromuscular synapses in some psychotic patients.

Effects of X-rays on morphogenesis in the housefly

Studies on the radiosensitivity of the imaginal disks in developing housefly pupae show that morphogenetic movements associated with the eversion of the head and appendages are not affected by doses of X-rays up to 10,000 R, whereas differentiation is drastically affected. With increase in age of the pupa at the time of irradiation, there is a progressive reduction in the incidence of morphological abnormalities. It is also evident that there is an anteroposterior gradient with respect to radiosensitivity and that it corresponds to the temporal pattern of differentiation. The head is the most resistant to radiation, the thorax less so, and the abdomen is the most sensitive. The epidermal cells of the head and thorax are less sensitive than those of the abdomen. The various imaginal disks show differential sensitivity to X-radiation. Moreover, the different fields in a single disk are also differentially sensitive to X-radiation. The prothoracic leg disks are the most resistant followed by the meso- and metathoracic leg disks. In addition, the distal regions of the appendages are more resistant than the proximal ones. In irradiated groups, the appendages of the head are reduced in size but are well differentiated, whereas the thoracic appendages, though of normal length, are poorly differentiated. The critical phase of radiosensitivity of the developing imaginal disks ends after the evagination of the head, and probably reflects the completion of the gene activation process in the cells.