Molecular cloning, characterization and expression analysis of the ecdysone receptor from the spiny lobster Panulirus homarus (Linnaeus, 1758) (Decapoda, Palinuridae)

Crustaceana ◽  
2020 ◽  
Vol 93 (7) ◽  
pp. 769-783
Author(s):  
Hong B. Zhuo ◽  
Hua F. Liang ◽  
Cai X. Cai ◽  
Jia J. Luo ◽  
Fei S. Liang ◽  
...  

Abstract The ecdysone receptor (EcR) is a crucial nuclear transcription factor that participates in ecdysteroid signalling. In this study, cDNA of EcR in Panulirus homarus (Linnaeus, 1758) (PhEcR) was cloned and characterized. PhEcR cDNA was 3141 bp, in which a 12 bp insert/deletion splice variant region in the hinge domain was identified. PhEcR mRNA presented the most abundant expression in the ovary. PhEcR mRNA expression was rapidly upregulated in the premoult stage and downregulated in the ecdysis stage. PhEcR mRNA maintained a relatively high expression level from egg-nauplius stage to embryo stage with compound eye pigments formed. The transcript levels of PhEcR in muscle were up-regulated on the 5th and 10th day after antenna ablation. These data suggest that PhEcR may not only play a vital role in the ecdysteroid signalling, but also have relation to embryonic development and limb regeneration.

Insects ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 139 ◽  
Author(s):  
Wen-Jia Yang ◽  
Kang-Kang Xu ◽  
Yu Cao ◽  
Yong-Lu Meng ◽  
Yan Liu ◽  
...  

Small heat shock proteins (sHsps) are molecular chaperones that play crucial roles in the stress adaption of insects. In this study, we identified and characterized four sHsp genes (LsHsp19.4, 20.2, 20.3, and 22.2) from the cigarette beetle, Lasioderma serricorne (Fabricius). The four cDNAs encoded proteins of 169, 180, 181, and 194 amino acids with molecular weights of 19.4, 20.2, 20.3, and 22.2 kDa, respectively. The four LsHsp sequences possessed a typical sHsp domain structure. Quantitative real-time PCR analyses revealed that LsHsp19.4 and 20.3 transcripts were most abundant in pupae, whereas the transcript levels of LsHsp20.2 and 22.2 were highest in adults. Transcripts of three LsHsp genes were highly expressed in the larval fat body, whereas LsHsp20.2 displayed an extremely high expression level in the gut. Expression of the four LsHsp genes was dramatically upregulated in larvae exposed to 20-hydroxyecdysone. The majority of the LsHsp genes were significantly upregulated in response to heat and cold treatments, while LsHsp19.4 was insensitive to cold stress. The four genes were upregulated when challenged by immune triggers (peptidoglycan isolated from Staphylococcus aureus and from Escherichia coli 0111:B4). Exposure to CO2 increased LsHsp20.2 and 20.3 transcript levels, but the LsHsp19.4 transcript level declined. The results suggest that different LsHsp genes play important and distinct regulatory roles in L. serricorne development and in response to diverse stresses.


Author(s):  
L. V. Leak ◽  
J. F. Burke

The vital role played by the lymphatic capillaries in the transfer of tissue fluids and particulate materials from the connective tissue area can be demonstrated by the rapid removal of injected vital dyes into the tissue areas. In order to ascertain the mechanisms involved in the transfer of substances from the connective tissue area at the ultrastructural level, we have injected colloidal particles of varying sizes which range from 80 A up to 900-mμ. These colloidal particles (colloidal ferritin 80-100A, thorium dioxide 100-200 A, biological carbon 200-300 and latex spheres 900-mμ) are injected directly into the interstitial spaces of the connective tissue with glass micro-needles mounted in a modified Chambers micromanipulator. The progress of the particles from the interstitial space into the lymphatic capillary lumen is followed by observing tissues from animals (skin of the guinea pig ear) that were injected at various time intervals ranging from 5 minutes up to 6 months.


Author(s):  
E. R. Macagno ◽  
C. Levinthal

The optic ganglion of Daphnia Magna, a small crustacean that reproduces parthenogenetically contains about three hundred neurons: 110 neurons in the Lamina or anterior region and about 190 neurons in the Medulla or posterior region. The ganglion lies in the midplane of the organism and shows a high degree of left-right symmetry in its structures. The Lamina neurons form the first projection of the visual output from 176 retinula cells in the compound eye. In order to answer questions about structural invariance under constant genetic background, we have begun to reconstruct in detail the morphology and synaptic connectivity of various neurons in this ganglion from electron micrographs of serial sections (1). The ganglion is sectioned in a dorso-ventra1 direction so as to minimize the cross-sectional area photographed in each section. This area is about 60 μm x 120 μm, and hence most of the ganglion fit in a single 70 mm micrograph at the lowest magnification (685x) available on our Zeiss EM9-S.


Author(s):  
Matti Järvilehto ◽  
Riitta Harjula

The photoreceptor cells in the compound eyes of higher diptera are clustered in groups (ommatidia) of eight receptor cells. The cells from six adjacent ommatidia are organized into optical units, neuro-ommatia sharing the same visual field. In those ommatidia the optical axes of the photopigment containing structures (rhabdomeres) are parallel. The rhabdomeres of the photoreceptor cells are separated from each other by an interstitial i.e innerommatidial space (IOS). In the photoreceptor cell body, besides of the normal cell organelles, a cellular matrix is a structurally apparent component. Similar kind of reticular formation is also found in the IOS containing some unidentified filamentary substance, of which composition and functional significance for optical properties of vision is the aim of this report.The prefixed (2% PA + 0.2% GA in 0.1-n phosphate buffer, pH 7.4, for 1h), frozen section blocks of the compound eye of the blowfly (Calliphora erythrocephala) were prepared by immuno-cryo-techniques. The ultrathin cryosections were incubated with antibodies of monoclonal α-tubulin and polyclonal smooth muscle actin. Control labelings of excess of antigen, non-immune serum and non-present antibody were perforated.


Author(s):  
M.B. Braunfeld ◽  
M. Moritz ◽  
B.M. Alberts ◽  
J.W. Sedat ◽  
D.A. Agard

In animal cells, the centrosome functions as the primary microtubule organizing center (MTOC). As such the centrosome plays a vital role in determining a cell's shape, migration, and perhaps most importantly, its division. Despite the obvious importance of this organelle little is known about centrosomal regulation, duplication, or how it nucleates microtubules. Furthermore, no high resolution model for centrosomal structure exists.We have used automated electron tomography, and reconstruction techniques in an attempt to better understand the complex nature of the centrosome. Additionally we hope to identify nucleation sites for microtubule growth.Centrosomes were isolated from early Drosophila embryos. Briefly, after large organelles and debris from homogenized embryos were pelleted, the resulting supernatant was separated on a sucrose velocity gradient. Fractions were collected and assayed for centrosome-mediated microtubule -nucleating activity by incubating with fluorescently-labeled tubulin subunits. The resulting microtubule asters were then spun onto coverslips and viewed by fluorescence microscopy.


2014 ◽  
Vol 4 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Stephanie Chow ◽  
Stephen Yortsos ◽  
Najmedin Meshkati

This article focuses on a major human factors–related issue that includes the undeniable role of cultural factors and cockpit automation and their serious impact on flight crew performance, communication, and aviation safety. The report concentrates on the flight crew performance of the Boeing 777–Asiana Airlines Flight 214 accident, by exploring issues concerning mode confusion and autothrottle systems. It also further reviews the vital role of cultural factors in aviation safety and provides a brief overview of past, related accidents. Automation progressions have been created in an attempt to design an error-free flight deck. However, to do that, the pilot must still thoroughly understand every component of the flight deck – most importantly, the automation. Otherwise, if pilots are not completely competent in terms of their automation, the slightest errors can lead to fatal accidents. As seen in the case of Asiana Flight 214, even though engineering designs and pilot training have greatly evolved over the years, there are many cultural, design, and communication factors that affect pilot performance. It is concluded that aviation systems designers, in cooperation with pilots and regulatory bodies, should lead the strategic effort of systematically addressing the serious issues of cockpit automation, human factors, and cultural issues, including their interactions, which will certainly lead to better solutions for safer flights.


Sign in / Sign up

Export Citation Format

Share Document