scholarly journals Diminished foraging performance of a mutant zebrafish with reduced population of ultraviolet cones

2016 ◽  
Vol 283 (1826) ◽  
pp. 20160058 ◽  
Author(s):  
Iñigo Novales Flamarique

Ultraviolet (UV) cones are photoreceptors that sense light in the range 300–450 nm and are found in the retinas of non-mammalian vertebrates and small mammals. Despite their widespread presence across taxa, the functions that these cones exert in the lives of animals remain largely unknown. In this study, I used the zebrafish lor (lots of rods) mutant, characterized by a diminished UV cone population compared to that of wild-type zebrafish, to test whether its foraging performance differed from that of the wild-type (control). The mean location distance and angle (variables that are reliable indicators of foraging performance) at which control fish detected zooplankton prey were, on average, 24 and 90% greater than corresponding measures for lor fish. Such inferior foraging performance of the mutant could be explained by reduced contrast perception of the prey, resulting from the diminished population of UV cones and associated sensitivity. Thus, UV cones enhance the foraging performance of zebrafish, a crucial ecological function that may explain why small zooplanktivorous fishes retain UV cones throughout their lives.

Animals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Ying Zhao ◽  
Zixiang Lin ◽  
Zhaoyan Lin ◽  
Chaoyu Zhou ◽  
Gang Liu ◽  
...  

Mucin 1 (MUC1), a transmembrane protein, is closely associated with the malignancy and metastasis of canine mammary tumors; however, the role of overexpressed MUC1 in the development of cancer cells and response to drug treatment remains unclear. To address this question, we developed a new canine mammary tumor cell line, CIPp-MUC1, with an elevated expression level of MUC1. In vitro studies showed that CIPp-MUC1 cells are superior in proliferation and migration than wild-type control, which was associated with the upregulation of PI3K, p-Akt, mTOR, Bcl-2. In addition, overexpression of MUC1 in CIPp-MUC1 cells inhibited the suppressing activity of disulfiram on the growth and metastasis of tumor cells, as well as inhibiting the pro-apoptotic effect of disulfiram. In vivo studies, on the other side, showed more rapid tumor growth and stronger resistance to disulfiram treatment in CIPp-MUC1 xenograft mice than in wild-type control. In conclusion, our study demonstrated the importance of MUC1 in affecting the therapeutical efficiency of disulfiram against canine mammary tumors, indicating that the expression level of MUC1 should be considered for clinical use of disulfiram or other drugs targeting PI3K/Akt pathway.


Genetics ◽  
1997 ◽  
Vol 147 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Kathrin Schrick ◽  
Barbara Garvik ◽  
Leland H Hartwell

Abstract The mating process in yeast has two distinct aspects. One is the induction and activation of proteins required for cell fusion in response to a pheromone signal; the other is chemotropism, i.e., detection of a pheromone gradient and construction of a fusion site available to the signaling cell. To determine whether components of the signal transduction pathway necessary for transcriptional activation also play a role in chemotropism, we examined strains with null mutations in components of the signal transduction pathway for diploid formation, prezygote formation and the chemotropic process of mating partner discrimination when transcription was induced downstream of the mutation. Cells mutant for components of the mitogen-activated protein (MAP) kinase cascade (ste5, ste20, ste11, ste7 or fus3 kss1) formed diploids at a frequency 1% that of the wild-type control, but formed prezygotes as efficiently as the wild-type control and showed good mating partner discrimination, suggesting that the MAP kinase cascade is not essential for chemotropism. In contrast, cells mutant for the receptor (ste2) or the β or γ subunit (ste4 and stel8) of the G protein were extremely defective in both diploid and prezygote formation and discriminated poorly between signaling and nonsignaling mating partners, implying that these components are important for chemotropism.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Madhavi Latha Gandla ◽  
Niklas Mähler ◽  
Sacha Escamez ◽  
Tomas Skotare ◽  
Ogonna Obudulu ◽  
...  

Abstract Background Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. Results In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20–44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26–50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. Conclusions The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.


Author(s):  
Ailin Beznec ◽  
Paula Faccio ◽  
Daniel J. Miralles ◽  
Leonor G. Abeledo ◽  
Cecilia Decima Oneto ◽  
...  

Abstract Background The heterologous expression of isopentenyl transferase (IPT) under the transcriptional control of the senescence-associated receptor-like kinase (SARK) promoter delayed cellular senescence and, through it, increased drought tolerance in plants. To evaluate the effect of pSARK::IPT expression in bread wheat, six independent transgenic events were obtained through the biolistic method and evaluated transgene expression, phenology, grain yield and physiological biomass components in plants grown under both drought and well-irrigating conditions. Experiments were performed at different levels: (i) pots and (ii) microplots inside a biosafety greenhouse, as well as under (iii) field conditions. Results Two transgenic events, called TR1 and TR4, outperformed the wild-type control under drought conditions. Transgenic plants showed higher yield under both greenhouse and field conditions, which was positively correlated to grain number (given by more spikes and grains per spike) than wild type. Interestingly, this yield advantage of the transgenic events was observed under both drought and well-watered conditions. Conclusions The results obtained allow us to conclude that the SARK promoter-regulated expression of the IPT gene in bread wheat not only reduced the yield penalty produced by water stress but also led to improved productivity under well-watered conditions.


1984 ◽  
Vol 62 (6) ◽  
pp. 1101-1107 ◽  
Author(s):  
C. M. Pueschel ◽  
J. P. van der Meer

Ultrastructural examination of a green-pigmented mutant of the red alga Palmaria palmata (L.) O. Kuntze revealed unusual features of the chloroplasts. Encircling peripheral thylakoids, characteristic of the wild-type plastids and florideophyte plastids generally, were lacking. Parallel evenly spaced thylakoids occurred in groups, leaving large volumes of thylakoid-free stroma. Irregularly shaped, electron-dense inclusions with an amorphous substructure and diameters up to 3 μm occurred in some plastids. Cells of the sporeling holdfasts contained structures resembling prolamellar bodies. Attempts to induce formation of prolamellar bodies in blades by dark treatment for 5 weeks were unsuccessful. However, some plastids did develop highly corrugated thylakoids with the crests of one thylakoid apposed to the troughs of the adjacent thylakoid. Thylakoid morphology of the wild-type control was not altered by the absence of light.


1990 ◽  
Vol 68 (12) ◽  
pp. 2468-2476 ◽  
Author(s):  
W. H. Tam ◽  
J. N. Fryer ◽  
B. Valentine ◽  
R. J. J. Roy

Maturing brook trout were exposed to pH 4.5 at the beginning of the rapid oocyte development phase in mid-June. The number of atretic follicles containing vitellogenic oocytes in acid-treated trout gradually increased with time, to exceed that of control fish on day 30, reaching a maximum (22–24% of all vitellogenic oocytes) between days 45 and 60 of acid exposure, before declining on day 73. Follicular atresia reduced the number of healthy vitellogenic oocytes in the acid-stressed fish to 59% of controls by day 60. Plasma vitellogenin and estrogen levels were not consistently affected by acid exposure. During the first 45 days of acid exposure, the mean weight of the healthy vitellogenic oocytes and the plasma levels of estrogen in the acid-exposed fish were at times significantly higher than those of control trout, but after day 45 these differences were no longer observed. Ultrastructural morphometry showed that secretory activity of the gonadotropes in the female acid-stressed brook trout was suppressed. Throughout the experimental period, the acid-exposed trout showed various symptoms characteristic of acid stress, such as elevated ACTH and cortisol secretion, hyperglycemia, acidosis, and hyponatremia. Food intake was reduced to 14% of the control value. These results suggest that the disruptive physiological changes and (or) reduced nutritional status associated with acid stress are responsible for the reduction in activity of the gonadotropes and oocyte atresia.


2020 ◽  
Author(s):  
Chrysoula Zografou ◽  
Maria Dimou ◽  
Panagiotis Katinakis

AbstractFklB is a member of the FK506-binding proteins (FKBPs), a family that consists of five genes in Escherichia coli. Little is known about the physiological and functional role of FklB in bacterial movement. In the present study, FklB knock-out mutant ΔfklB presented an increased swarming and swimming motility and biofilm formation phenotype, suggesting that FklB is a negative regulator of these cellular processes. Complementation with Peptidyl-prolyl isomerase (PPIase)-deficient fklB gene (Y181A) revealed that the defects in biofilm formation were not restored by Y181A, indicating that PPIase activity of FklB is modulating biofilm formation in E. coli. The mean cell length of ΔfklB swarming cells was significantly smaller as compared to the wild-type BW25113. Furthermore, the mean cell length of swarming and swimming wild-type and ΔfklB cells overexpressing fklB or Y181A was considerably larger, suggesting that PPIase activity of FklB plays a role in cell elongation and/or cell division. A multi-copy suppression assay demonstrated that defects in motility and biofilm phenotype were compensated by overexpressing sets of PPIase-encoding genes. Taken together, our data represent the first report demonstrating the involvement of FklB in cellular functions of E. coli.


Author(s):  
Tri Ramadhani ◽  
Upik Kusuma Hadi ◽  
Susi Soviana ◽  
Zubaidah Irawati ◽  
Sunaryo Sunaryo

Culex quinquefasciatus is the main vector of limfatic filariasis in Pekalongan City. Sterile Insect Tehnique could be an alternative vector control efforts to eliminate filariasis. The success of this technique is depend on the ability of laboratory-reared sterile males with the wild-type females. Indicator of SIT Aplication is determined by the value of the mating competitiveness and sterility to Culex quinquefasciatus (Diptera:Culicidae). The design of the research is an experimental. Gamma irradiation on the pupae (age . 15 hours) with the  doses of 0 Gy, 60 Gy, 65 Gy,70 Gy, 75 Gy and 80 Gy in BATAN Jakarta.  Male mosquitoes which emerged from the pupa then matting with a normal female. This research observed the mean  of females laying eggs ,fecundity, fertility and  mating competitiveness. This experimental research was conducted in the laboratory and the data were analyzed by ANOVA.The result showed that irradiation at the trial doses had an effect on fertility of Culex quinquefasciatus, but not  had significant effect on  fecundity and mating competitiveness . A dose of 70 Gy is the optimum dose with a fertility rate of 1.8% (sterility 98.2%) and C indexs 0,568 can be recommended for futher  semi field assays. The number of sterile males were six times compared with the wild population to increase the chances of  mating with wild-type females.


1995 ◽  
Vol 307 (2) ◽  
pp. 457-463 ◽  
Author(s):  
D A Brooks ◽  
D A Robertson ◽  
C Bindloss ◽  
T Litjens ◽  
D S Anson ◽  
...  

The sulphatase family of enzymes have regions of sequence similarity, but relatively little is known about either the structure-function relationships of sulphatases, or the role of highly conserved amino acids. The sequence of amino acids CTPSR at position 91-95 of 4-sulphatase has been shown to be highly conserved in all of the sequenced sulphatase enzymes. The cysteine at amino acid 91 of 4-sulphatase was selected for mutation analysis due to its potential role in either the active site, substrate-binding site or part of a key structural domain of 4-sulphatase and due to the absence of naturally occurring mutations in this residue in mucopolysaccharidosis type VI (MPS VI) patients. Two mutations, C91S and C91T, altering amino acid 91 of 4-sulphatase were generated and expressed in Chinese hamster ovary cells. Biochemical analysis of protein from a C91S cell line demonstrated no detectable 4-sulphatase enzyme activity but a relatively normal level of 4-sulphatase polypeptide (180% of the wild-type control protein level). Epitope detection, using a panel of ten monoclonal antibodies, demonstrated that the C91S polypeptide had a similar immunoreactivity to wild-type 4-sulphatase, suggesting that the C91S substitution does not induce a major structural change in the protein. Reduced catalytic activity associated with normal levels of 4-sulphatase protein have not been observed in any of the MPS VI patients tested and all show evidence of structural modification of 4-sulphatase protein with the same panel of antibodies [Brooks, McCourt, Gibson, Ashton, Shutter and Hopwood (1991) Am. J. Hum. Genet. 48, 710-719]. The loss of enzyme activity without a detectable protein conformation change suggests that Cys-91 may be a critical residue in the catalytic process. In contrast, analysis of protein from a C91T cell line revealed low levels of catalytically inactive 4-sulphatase polypeptide (0.37% of the wild-type control protein level) which had missing or masked epitopes, suggesting an altered protein structure or conformation. Subcellular fractionation studies of the C91T cell line demonstrated a high proportion of 4-sulphatase polypeptide content in organelles characteristic of microsomes. The aberrant intracellular localization and the reduced cellular content of 4-sulphatase polypeptide was consistent with the observed structural modification leading to retention and degradation of the protein within an early vacuolar compartment.


Blood ◽  
2000 ◽  
Vol 96 (7) ◽  
pp. 2479-2486 ◽  
Author(s):  
István Balogh ◽  
Gabriella Szôke ◽  
Levente Kárpáti ◽  
Ulla Wartiovaara ◽  
Éva Katona ◽  
...  

Abstract Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) is located in the activation peptide (AP) just 3 amino acids away from the thrombin cleavage site. This mutation has been associated with a protective effect against occlusive arterial diseases and venous thrombosis; however, its biochemical consequences have not been explored. In the current study it was demonstrated that the intracellular stability and the plasma concentration of FXIII of different Val34Leu genotypes are identical, which suggests that there is no difference in the rate of synthesis and externalization of wild-type and mutant FXIII-A. In contrast, the release of AP by thrombin from the Leu34 allele proceeded significantly faster than from its wild-type Val34 counterpart. By molecular modeling larger interaction energy was calculated between the Leu34 variant and the respective domains of thrombin than between the Val34 variant and thrombin. In agreement with these findings, the activation of mutant plasma FXIII by thrombin was faster and required less thrombin than that of the wild-type variant. Full thrombin activation of purified plasma FXIII of different genotypes, however, resulted in identical specific transglutaminase activities. Similarly, the mean specific FXIII activity in the plasma was the same in the groups with wild-type, heterozygous, and homozygous variants. Faster activation of the Leu34 allele hardly could be associated with its presumed protective effect against venous thrombosis. No such protective effect was observed in a large group of patients with familial thrombophilia.


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