China
Africa
Explore chapters and articles related to this topic
Functional Omics and Big Data Analysis in Microalgae
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Chetan Paliwal, Tonmoy Ghosh, Asha A. Nesamma, Pavan P. Jutur
The genotypic characteristics of an organism can be predicted through a study of its genome, while th e phenotypic characteristics are usually a result of changed protein expression. A study on C. reinhardtii has focused on its centrioles and eyespot apparatus (Jamers et al. 2009), while Vener (2007) has reviewed the reversible phosphorylation of the thylakoid proteins in plants and C. reinhardtii in response to ambient light, CO2, and redox conditions (Vener 2007). Together, these reports have advanced our understanding of the proteins involved in the light harvesting, flagella, and eyespot apparatus formation in C. reinhardtii.
Clonorchis
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Morphology of the larval stages is discribed in detail by Posokhov6 and Besprozvannykh.17 Miracidium is slightly oval in shape, ciliated, with peaked apical papilla. It has the gland of penetration, hatching gland, and also excretory, generative, and somatic cells. The sporocyst resembles a hollow and simple sac with often visible developing rediae within a body. Rediae have a very simple worm structure, with visible developing cercariae. The pharinx is round; the esophagus is absent; the intestine is bag-shaped and short. Cercaria resembles a small adult with a tail supplied by the well-developed swimming membranes; a body is covered with spines. It has two pigmented eyespots (unlike an adult), penetration glands, and accumulations of brown pigment. The pharynx is small; the genital system is rudimental. Encysted metacercaria has very thick walls and does not look like a fluke. It loses the eyespots and tail; the maturing fluke (its suckers) is visible.
Diseases and Parasites of Pufferfish and Their Management
Published in Ramasamy Santhanam, Biology and Ecology of Toxic Pufferfish, 2017
Diagnosis of the parasite: Body is plump with smooth tegument. Eyespot pigment is absent. Ventral sucker is with transverse opening which is 60–69% (65%) of body width. Prepharynx is absent. Esophagus is long. There is an intestinal bifurcation near mid forebody. Caeca are blind, not reaching posterior end of body. Gonads are located in mid third of body. Testes are symmetrical, chiefly interracial. Cirrus sac is ovoid, containing bipartite spherical or ovoid seminal vesicle. Posterior segment is larger than anterior one. Cirrus is short. Ovary is weakly trilobed and is anterior to right testis.
Antioxidant responses and lipid peroxidation can be used as sensitive indicators for the heavy metals risk assessment of the Wei River: a case study of planarian Dugesia Japonica
Published in Biomarkers, 2021
Yingyu Liu, Jinzi Chen, Zimei Dong, Guangwen Chen, Dezeng Liu
Based on the results of acute toxicity experiments, we set different orders of magnitude between the concentration of heavy metal ions of the same amount as the Wei River sample and the LC50 on 48 h. It was found that 1/10 of 48 h LC50 was the critical concentration for the obvious changes of regenerative fragments, so we selected this concentration as the exposure concentration for the subsequent experiments. After the toxicological exposure of heavy metal ions, the worms appeared a variety of regeneration deformities. The wound was healed at 1 d and the blastema was clearly visible at 3 d after amputation in control. While after Cr3+ exposure, the sides of worms were depressed deformation, the size of new tissues was reduced, and regeneration rate was slowed down (8/10). In the Hg2+ exposure group, deformity on both sides of the body, malformation of the eyespots and significantly inhibition of regeneration were observed (8/10). For the stress induced by the Pb2+ treatment, the blastema could not be regenerated normally as well as the worms appeared the body curls (6/10). In summary, heavy metal ions affected the regeneration of the worms and destroyed the maintenance of steady state, which meant that three heavy metal ions all had toxic effects on planarians (Figure 3).
Exploring the regulatory role of nitric oxide (NO) and the NO-p38MAPK/cGMP pathway in larval settlement of the bryozoan Bugula neritina
Published in Biofouling, 2018
Xiao-Xue Yang, Yue Him Wong, Yu Zhang, Gen Zhang, Pei-Yuan Qian
Endogenous localization of NO in the swimming larvae was determined using the NO-specific fluorescent probe, DAF-FM diacetate (Kojima et al. 1998). The aboral view (Figure 1A) indicates that NO was present at radial ciliated cells and the neural plate within the apical disk. NO was also detected in intercoronal cells, which form synapses with adjacent coronal cells. NO was also localized along an important sensory organ, the pyriform complex (Figure 1B). The aboral view and lateral view (Figure 1A and C) indicate that NO was present at the nerve ring that circumscribes the larval equator and the pigmented eyespots. Overall, all NO positive organs in B. neritina larvae, as summarized in the schematic drawing shown in Figure 1E and F, have been implicated in the larval sensory functions in B. stolonifera and B. neritina (Reed et al. 1988; Santagata 2008a).
A review of mammalian in vivo genotoxicity of hexavalent chromium: implications for oral carcinogenicity risk assessment
Published in Critical Reviews in Toxicology, 2021
Chad M. Thompson, Marilyn J. Aardema, Melissa M. Heintz, James T. MacGregor, Robert R. Young
Not only are there uncertainties regarding the overall magnitude and dose-response for eye spots reported in Kirpnick-Sobol et al. (2006), but also in the potential mechanism. According to Reliene et al. (2004) there is a high frequency of spontaneous reversion in the pun gene; such reversions result in functional genes leading to pigmented cells (eye spots). In the absence of historical control data from this laboratory, it is not possible to determine if the increase seen with Cr is biologically relevant or within normal variation. Another consideration is that spontaneous reversions in the pun gene are a result of homologous recombination, which might be elevated in the presence of DNA strand breaks observed following Cr(VI) exposure, which itself might be the result of oxidative DNA damage. Indeed, it was previously shown that oral exposure to 300 mg/L titanium dioxide significantly increased eye spots 1.3-fold, which the study authors posited might be secondary to oxidative stress as indicated by increased 8-OHdG in livers from adult male mice exposed to titanium dioxide (Trouiller et al. 2009). Neither oxidative mechanisms nor the eye spot data are consistent with a linear dose-response or mutagenic linear no threshold MOA. Given that the eye spot test might be detecting mutations in a specific population of retinal epithelium precursor cells, it is notable that TGR assays have not detected increased mutations in the small intestine—which would arise from either crypt stem cells or some heretofore unidentified stem cell population in villi. While it is conceivable that the negative TGR assays in the intestine are due to their limited ability to detect large scale mutations, other assays (e.g., MN assays) address the potential for such damage in crypt enterocytes (see below).