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Steven D Mims - One of the best experts on this subject based on the ideXlab platform.
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Alterations of digestive enzyme activities, intestinal morphology and microbiota in juvenile paddlefish, Polyodon spathula , fed dietary probiotics
Fish physiology and biochemistry, 2014Co-Authors: Cheng Fang, Tongjun Ren, Steven D MimsAbstract:The effects of dietary supplementation of probiotics on digestive enzymes activities, intestinal morphology and microbiota in juvenile paddlefish (Polyodon spathula) were studied. A total of 400 fish were reared in two cages and fed with a basal diet (control group, CG) or diet supplemented with commercial probiotics (treatment group, TG) for 80 days. Enzymes activities analysis indicated that protease and α-amylase activities increased (P < 0.01 or P < 0.05) in TG. Light microscopy observation demonstrated the decrease of wall thickness and muscularis thickness in foregut (P < 0.01), the increase of those in hindgut (P < 0.05), the increase of folds height in foregut (P < 0.01) and midgut in TG (P < 0.05). DGGE results of PCR-amplified 16S rRNA confirmed that the richness and diversity of intestinal microbial species increased in TG. The similarity between the commercial bacteria product and intestinal microbiota of TG were higher than the microbiota from CG. The quantities of bacterium, Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria, present an increasing trend from foregut to hindgut both in two groups. To our knowledge, this is the first in vivo study to reveal the effect of dietary probiotics on intestinal digestive enzymes activities, morphology and microbiota in paddlefish.
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Effects of body mass and water temperature on routine metabolism of American paddlefish Polyodon spathula
Journal of Fish Biology, 2013Co-Authors: J. T. Patterson, Steven D Mims, Russell A. WrightAbstract:: This study quantified the effects of temperature and fish mass on routine metabolism of the American paddlefish Polyodon spathula. Thermal sensitivity, as measured by Q(10) value, was low in P. spathula. Mean Q(10) was 1·78 while poikilotherms are generally expected to have Q(10) values in the 2·00-2·50 range. Mass-specific metabolism did not decrease with increased fish size to the extent that this phenomenon is observed in teleosts, as evidenced by a mass exponent (β) value of 0·92 for P. spathula compared with 0·79 in a review of teleost species. Other Acipenseriformes have exhibited relatively high β values for mass-specific respiration. Overall P. spathula metabolism appears to be more dependent on body mass and less dependent on temperature than for many other fishes. An equation utilizing temperature and fish mass to estimate gross respiration for P. spathula was derived and this equation was applied to respiratory data from other Acipenseriformes to assess inter-species variation. Polyodon spathula respiration rates across water temperature and fish mass appear most similar to those of Atlantic sturgeon Acipenser naccarii and white sturgeon Acipenser transmontanus.
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Improved Cryopreservation of Sperm of Paddlefish (Polyodon spathula)
Journal of the World Aquaculture Society, 2006Co-Authors: Ákos Horváth, Steven D Mims, Béla Urbányi, William B. Bean, Boris Gomelsky, Terrence R. TierschAbstract:Experiments were performed to improve protocols for sperm cryopreservation of paddlefish (Polyodon spathula), a species for which there has been limited study. The first experiment was conducted to investigate the effects of two extenders (modified Tsvetkova’s extender: mT and modified Hanks’ balanced salt solution: mHBSS) in combination with methanol (MeOH) and dimethyl sulfoxide in two concentrations (5 and 10%) on the postthaw motility and fertilization rates of cryopreserved sperm. The highest postthaw motility (85 6 5%) was observed when sperm were frozen using mT extender with 10% MeOH as cryoprotectant. Extenders (P 5 0.0018) and cryoprotectants (P 5 0.0040) each had a significant effect on the postthaw motility of paddlefish sperm. The highest fertilization (80 6 3%) was found when eggs were fertilized with sperm frozen with mT extender in combination with 10% MeOH. However, there was no significant difference among fertilization rates when MeOH was used as a cryoprotectant in either concentration or in combination with either mTor mHBSS extenders. In the second experiment, 4000 eggs were fertilized with the pooled contents of five straws of thawed sperm (total volume of 1.25 mL) using mTextender in combination with 5% MeOH, and hatch rates as high as 79 6 5% were observed. A third experiment was also conducted to clarify the role of MeOH concentration; however, no significant difference was found among fertilization and hatch rates when either 5 or 10% MeOH was used as a cryoprotectant. These results suggest that MeOH is a safe and reliable cryoprotectant for freezing of paddlefish sperm and obtaining viable postthaw sperm for consistent fertilization and hatch rates. Further, this experimental protocol is relatively simple and applicable for commercial hatchery production of paddlefish.
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Effects of ions on the motility of fresh and demembranated paddlefish (Polyodon spathula) spermatozoa.
Reproduction (Cambridge England), 2002Co-Authors: O. Linhart, Steven D Mims, William L. Shelton, Jacky Cosson, Marek RodinaAbstract:This study investigated the effects of different environmental conditions on the motility parameters of paddlefish (Polyodon spathula) spermatozoa. Paddlefish spermatozoa demonstrated the following characteristics: (i) all spermatozoa were motile 10 s after activation with a velocity of 130-160 microm s(-1); (ii) after 2 min, velocity decreased to 80-130 microm s(-1); and (iii) motility was maintained for up to 9 min. Concentrations of 0.5-5.0 mmol KCl l(-1) prevented activation of spermatozoa. After transfer into a swimming medium (20 mmol Tris l(-1), pH 8.2 and 1 mg BSA ml(-1)) containing 0.5 mmol KCl l(-1) (combined with 5 mmol NaCl or MgCl(2) l(-1)), 80-100% of cells were motile with a velocity of about 120-150 microm s(-1). MgCl(2) significantly improved the velocity of spermatozoa at 10, 40, 50 and 60 s after activation and the stable velocity of spermatozoa was about 140 microm s(-1). Very low concentrations of CaCl(2) (0.125 mmol l(-1)) combined with 0.5 mmol KCl l(-1) initiated motility in 20% of spermatozoa, whereas all spermatozoa were activated after 2 min with 0.25 mmol CaCl(2) l(-1) in similar medium for the full period of swimming with velocity of about 120 microm s(-1). This study demonstrated that potassium (5-15 mmol l(-1)) inhibits demembranated spermatozoa. Thus, initiation of movement in paddlefish spermatozoa is under the reciprocal control of potassium and calcium ion concentrations.
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Characteristics of sperm acrosin-like activity of paddlefish (Polyodon spathula Walbaum)
Comparative biochemistry and physiology. Part B Biochemistry & molecular biology, 2000Co-Authors: Andrzej Ciereszko, Steven D Mims, Konrad Dabrowski, Jan GlogowskiAbstract:Spermatozoa of paddlefish and sturgeon fishes (Acipenseriformes), unlike teleost fish, have an acrosome. The objectives of this study were to characterize acrosin-like activity of cryopreserved sperm of paddlefish (Polyodon spathula) and to test and compare stability of paddlefish acrosin-like activity with that of lake sturgeon and bull spermatozoa. Mean acrosin-like activity of cryopreserved paddlefish sperm was 0.3729 0.067 mU:10 6 spermatozoa. This activity was 79% higher in the whole semen than in spermatozoa. Highest activity was recorded at pH 8.0 and 8.5. Triton X-100, zinc ions and 4%-acetamidophenyl 4-guanidinobenzoate (AGB) inhibited the activity. Amidase activity was also inhibited by N-a-p-tosyl-L-lysine chloromethyl ketone (TLCK) and N-tosyl-L-phenylalanine chloromethyl ketone (TPCK). TLCK at concentrations of 0.1 and 1.0 mM gave a significant decrease in activity of 19 and 61%, respectively. However, TPCK significantly inhibited amidase activity (by 19%) only at concentration 1.0 mM. After acidification and 60 min incubation at 4°C of sperm suspensions only 4% of the activity was retained. A similar phenomenon was observed in the case of lake sturgeon but not bull sperm. These results suggest that trypsin-like activity of Acipenserid fish resembles rather fish trypsin that mammalian one. In frozen‐thawed paddlefish sperm a minute chymotrypsin-like activity was also indicated, when GPNA was used as substrate. This activity amounted to 0.04159 0.0138 mU:10 6 spermatozoa and was 18% of total amidase activity. This suggests that chymotrypsin-like activity may also be present in paddlefish spermatozoa. © 2000
Shunping He - One of the best experts on this subject based on the ideXlab platform.
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Evolution of MHC class I genes in two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis)
FEBS Letters, 2010Co-Authors: Dengqiang Wang, Lei Zhong, Shunping HeAbstract:Here we present the first isolation of major histocompatibility complex (MHC) class I genes from two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis). Seventeen sequences obtained showed high polymorphism and positive natural selection with d(N)/d(S) > 1. Evolutionary relationships revealed that sequences from paddlefish and Chinese sturgeon distinguished from other vertebrate class I and had an intermingling of alleles, which indicates that Acipenseriformes have a common ancestral gene of class I and a trans-species polymorphism across Acipenseriformes. We also found clear evidence of recombination among class I genes of paddlefish and Chinese sturgeon. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
E J Perkins - One of the best experts on this subject based on the ideXlab platform.
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characterization of paddlefish Polyodon spathula rostrum stellate bones
Bioinspired biomimetic and nanobiomaterials, 2014Co-Authors: P G Allison, J F Deang, Alfredo J Diaz, A R Poda, J J Hoover, M F Horstemeyer, E J PerkinsAbstract:The electrosensory capabilities of the rostrum of the paddlefish (Polyodon spathula) were investigated previously. However, the structure–property relationship associated with the rostrum has yet t...
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Characterization of paddlefish ( Polyodon spathula ) rostrum stellate bones
Bioinspired Biomimetic and Nanobiomaterials, 2014Co-Authors: P G Allison, J F Deang, Alfredo J Diaz, A R Poda, J J Hoover, M F Horstemeyer, E J PerkinsAbstract:The electrosensory capabilities of the rostrum of the paddlefish (Polyodon spathula) were investigated previously. However, the structure–property relationship associated with the rostrum has yet to be explored. In this study, the stellate bone properties of the rostrum are examined as a function of spatial location on the rostrum using nanoindentation and Fourier transform infrared spectroscopy. Nanoindentation results indicated a constant elastic modulus along the middle section of the rostrum. However, the elastic modulus exhibited a gradient along the side of the rostrum, with the maximum modulus at the base of the rostrum. This study is part of an overall research project examining the electrosensory capabilities, hydrodynamics and structure–property relationships of the rostrum to develop new materials for force protection applications.
Otilia Zarnescu - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructure of the skin melanophores and iridophores in paddlefish, Polyodon spathula
Micron (Oxford England : 1993), 2006Co-Authors: Otilia ZarnescuAbstract:Abstract The ultrastructure of melanophores and iridophores of Polyodon spathula has been examined by transmission electron microscopy. In the skin, two types of chromatophores, melanophores and iridophores were founded. Melanophores were localized both in epidermis and dermis. Epidermal melanophores were present on the dorsal region of the trunk, sides, outer surface of the operculum and rostrum. Iridophores were founded in the dermis from ventral skin. The cytoplasm of iridophores is filled with reflecting platelets with variable orientation. The length of the long axis of the platelets varies from 1 to 2.10 μm.
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Ultrastructural study of spermatozoa of the paddlefish, Polyodon spathula.
Zygote (Cambridge England), 2005Co-Authors: Otilia ZarnescuAbstract:Paddlefish, Polyodon spathula , spermatozoa were examined by transmission electron microscopy. Their structure has the same characteristic architectural features as sturgeon spermatozoa. Paddlefish spermatozoa are of the primitive type and consist of a rod-shaped head, a midpiece and a long flagellum. The head is about 5.15 mm in length and contains the nucleus and an apical acrosomal complex. Inside the nucleus there are three nuclear channels that begin in the subacrosomal area and have a triple helical arrangement. An nuclear fossa is present centrally, at the posterior end of the nucleus. The midpiece contains a pair of centrioles in a perpendicular arrangement, mitochondria and a narrow cytoplasmic sleeve. The flagellum has a central axoneme with a 9+2 pattern and two lateral projections or fins.
Dengqiang Wang - One of the best experts on this subject based on the ideXlab platform.
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Evolution of MHC class I genes in two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis)
FEBS Letters, 2010Co-Authors: Dengqiang Wang, Lei Zhong, Shunping HeAbstract:Here we present the first isolation of major histocompatibility complex (MHC) class I genes from two ancient fish, paddlefish (Polyodon spathula) and Chinese sturgeon (Acipenser sinensis). Seventeen sequences obtained showed high polymorphism and positive natural selection with d(N)/d(S) > 1. Evolutionary relationships revealed that sequences from paddlefish and Chinese sturgeon distinguished from other vertebrate class I and had an intermingling of alleles, which indicates that Acipenseriformes have a common ancestral gene of class I and a trans-species polymorphism across Acipenseriformes. We also found clear evidence of recombination among class I genes of paddlefish and Chinese sturgeon. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
