1,603 research outputs found
A novel polymorphism of resistin gene and its association with meat quality traits in Chinese Bos taurus
Searching for candidate gene polymorphisms and their relationship with meat quality traits is an important issue for Bos taurus industry. In this study, we evaluated polymorphism of resistin (RETN) gene involved in energy metabolism. Using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technology, a novel missense substitution single-nucleotide polymorphism (SNP) g.2528T>C was identified in the exon 2 region of the RETN gene. Allele frequencies, gene heterozygosity, effective allele number and polymorphism information content of the bovine RETN SNP in six populations were investigated and calculated by the χ2 test. The distribution of the polymorphism from the studied six B. taurus breeds was not uniform. Our results suggested that Qinchuan, Luxi and Luxi × Simmental were not in Hardy-Weinberg equilibrium. Moreover, the polymorphism and its association with meat quality traits were analyzed in 369 Qinchuan and 73 Nanyang individuals. The analyzed SNP in the RETN revealed a significant association with marbling and intramuscular fat (p < 0.05). We observed that TT genotype was associated with a heightened marbling score when compared with the TC and CC in Qinchuan and Nanyang breeds. In Qinchuan breed, we also found that TT genotype was associated with an increased intramuscular fat content when compared with the TC. Such associations were not observed on backfat thickness, loin-muscle area and loin-muscle depth. This study showed that polymorphism of the RETN gene is potentially associated with B. taurus meat quality traits.Key words: Bos taurus, meat quality traits, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), resistin gene, single nucleotide polymorphism (SNP)
Does meiotic drive alter male mate preference?
Male mate preferences have been demonstrated across a range of species, including the Malaysian stalk-eyed fly, Teleopsis dalmanni. This species is subject to sex-ratio (SR), an X-linked male meiotic driver, which causes the dysfunction of Y-sperm and the production of all-female broods. While there has been work considering female avoidance of meiotic drive males, the mating decisions of drive-bearing males have not been considered previously. Drive males may be less able to bear the cost of choice as SR is associated with a low-frequency inversion that causes reduced organismal fitness. Drive males may also experience weaker selection for preference maintenance if they are avoided by females. Using binary choice trials, across two experiments, we confirmed male preference for large (fecund) females but found no evidence that the strength of male preference differs between drive and standard males. We showed that large eyespan males displayed strong preference for large females, whereas small eyespan males showed no preference. Taken together, these results suggest that, even though meiotic drive is associated with lower genetic quality, it does not directly interfere with male mate preference among available females. However, as drive males tend to have smaller eyespan (albeit only ~5% on average), this will to a minor extent weaken their strength of preference
Does meiotic drive alter male mate preference?
Male mate preferences have been demonstrated across a range of species, including the Malaysian stalk-eyed fly, Teleopsis dalmanni. This species is subject to sex-ratio (SR), an X-linked male meiotic driver, which causes the dysfunction of Y-sperm and the production of all-female broods. While there has been work considering female avoidance of meiotic drive males, the mating decisions of drive-bearing males have not been considered previously. Drive males may be less able to bear the cost of choice as SR is associated with a low-frequency inversion that causes reduced organismal fitness. Drive males may also experience weaker selection for preference maintenance if they are avoided by females. Using binary choice trials, across two experiments, we confirmed male preference for large (fecund) females but found no evidence that the strength of male preference differs between drive and standard males. We showed that large eyespan males displayed strong preference for large females, whereas small eyespan males showed no preference. Taken together, these results suggest that, even though meiotic drive is associated with lower genetic quality, it does not directly interfere with male mate preference among available females. However, as drive males tend to have smaller eyespan (albeit only ~5% on average), this will to a minor extent weaken their strength of preference
KINEMATIC ANALYSIS OF MEN BOBSLED PUSH STARTS
The purpose of this study was to provide a descriptive analysis of selected kinematic variables associated with the push start for brakemen in the two-man bobsled. Eleven male bobsledders served as subjects for this study. The subjects were videotaped at 120 Hz during competition at the Lake Placid, NY bobsled track as they were competing for positions on the men’s 2004 National Bobsled Team. Selected groups of variables measured at specific events in this study included step length, frequency, and foot contact time; COM velocity; and trunk, knee, and elbow angles. A relationship of 0.63 was determined between start time and finish time; an exploratory correlational analysis between start time and COM velocity at 2nd step take-off (TO) was -0.63. Start time is of critical importance in determining final race time
Disseminated phaeohyphomycosis in a beluga sturgeon (Huso huso)
Phaeohyphomycosis is a fungal infection caused by dematiaceous or melanised fungi (Seyedmousavi, Guillot, and de Hoog 2013). Although considered
ubiquitous residents of plant material, soil, and wood, melanised fungi are likely adapted to specific niches that facilitate variable opportunistic or true pathogenic potentials. Exposure is typically associated with inoculation by
minor trauma or inhalation. In mammals, infections are commonly cutaneous, subcutaneous, upper respiratory or primary cerebral, but in cold-blooded vertebrates are often disseminated and accompanied by severe tissue necrosis (Revankar, Sutton, and Rinaldi 2004; Seyedmousavi, Guillot, and de Hoog 2013)
ISM conditions in z~0.2 Lyman-Break Analogs
We present an analysis of far--infrared (FIR) [CII] and [OI] fine structure
line and continuum observations obtained with /PACS, and CO(1-0)
observations obtained with the IRAM Plateau de Bure Interferometer, of Lyman
Break Analogs (LBAs) at . The principal aim of this work is to
determine the typical ISM properties of Main Sequence (MS)
galaxies, with stellar masses between and ,
which are currently not easily detectable in all these lines even with ALMA and
NOEMA. We perform PDR modeling and apply different IR diagnostics to derive the
main physical parameters of the FIR emitting gas and dust and we compare the
derived ISM properties to those of galaxies on and above the MS at different
redshifts. We find that the ISM properties of LBAs are quite extreme (low gas
temperature, high density and thermal pressure) with respect to those found in
local normal spirals and more active local galaxies. LBAs have no [CII] deficit
despite having the high specific star formation rates (sSFRs) typical of
starbursts. Although LBAs lie above the local MS, we show that their ISM
properties are more similar to those of high-redshift MS galaxies than of local
galaxies above the main sequence. This data set represents an important
reference for planning future ALMA [CII] observations of relatively low-mass MS
galaxies at the epoch of the peak of the cosmic star formation.Comment: 19 pages, 12 Figures,8 Tables, Accepted for publication in A&
Comparing [CII], HI, and CO dynamics of nearby galaxies
The HI and CO components of the interstellar medium (ISM) are usually used to
derive the dynamical mass M_dyn of nearby galaxies. Both components become too
faint to be used as a tracer in observations of high-redshift galaxies. In
those cases, the 158 m line of atomic carbon [CII] may be the only way to
derive M_dyn. As the distribution and kinematics of the ISM tracer affects the
determination of M_dyn, it is important to quantify the relative distributions
of HI, CO and [CII]. HI and CO are well-characterised observationally, however,
for [CII] only very few measurements exist. Here we compare observations of CO,
HI, and [CII] emission of a sample of nearby galaxies, drawn from the HERACLES,
THINGS and KINGFISH surveys. We find that within R_25, the average [CII]
exponential radial profile is slightly shallower than that of the CO, but much
steeper than the HI distribution. This is also reflected in the integrated
spectrum ("global profile"), where the [CII] spectrum looks more like that of
the CO than that of the HI. For one galaxy, a spectrally resolved comparison of
integrated spectra was possible; other comparisons were limited by the
intrinsic line-widths of the galaxies and the coarse velocity resolution of the
[CII] data. Using high-spectral-resolution SOFIA [CII] data of a number of star
forming regions in two nearby galaxies, we find that their [CII] linewidths
agree better with those of the CO than the HI. As the radial extent of a given
ISM tracer is a key input in deriving M_dyn from spatially unresolved data, we
conclude that the relevant length-scale to use in determining M_dyn based on
[CII] data, is that of the well-characterised CO distribution. This length
scale is similar to that of the optical disk.Comment: Accepted for publication in the Astronomical Journa
The origin of [C II] 157 μm emission in a five-component interstellar medium : the case of NGC 3184 and NGC 628
With its relatively low ionization potential, C+ can be found throughout the interstellar medium (ISM) and provides one of the main cooling channels of the ISM via the [C II] 157 mu m emission. While the strength of the [C II] line correlates with the star formation rate, the contributions of the various gas phases to the [C II] emission on galactic scales are not well established. In this study we establish an empirical multi-component model of the ISM, including dense H II regions, dense photon dissociation regions (PDRs), the warm ionized medium (WIM), low density and G(0). surfaces of molecular clouds (SfMCs), and the cold neutral medium (CNM). We test our model on ten luminous regions within the two nearby galaxies NGC 3184 and NGC 628. on angular scales of 500-600 pc. Both galaxies are part of the Herschel. key program. KINGFISH,. and are complemented by a large set of ancillary ground-and space-based data. The five modeled phases together reproduce the observed [C II] emission quite well, overpredicting the total flux slightly (about 45%) averaged over all regions. We find that dense PDRs are the dominating component, contributing 68% of the [C II] flux on average, followed by the WIM and the SfMCs, with mean contributions of about half of the contribution from dense PDRs, each. CNM and dense H II regions are only minor contributors with less than 5% each. These estimates are averaged over the selected regions, but the relative contributions of the various phases to the [C II] flux vary significantly between these regions
CHC22 and CHC17 clathrins have distinct biochemical properties and display differential regulation and function
Clathrins are cytoplasmic proteins that play essential roles in endocytosis and other membrane traffic pathways. Upon recruitment to intracellular membranes, the canonical clathrin triskelion assembles into a polyhedral protein coat that facilitates vesicle formation and captures cargo molecules for transport. The triskelion is formed by trimerization of three clathrin heavy-chain subunits. Most vertebrates have two isoforms of clathrin heavy chains, CHC17 and CHC22, generating two clathrins with distinct cellular functions. CHC17 forms vesicles at the plasma membrane for receptor-mediated endocytosis and at the trans-Golgi network for organelle biogenesis. CHC22 plays a key role in intracellular targeting of the insulin-regulated glucose transporter 4 (GLUT4), accumulates at the site of GLUT4 sequestration during insulin resistance, and has also been implicated in neuronal development. Here, we demonstrate that CHC22 and CHC17 share morphological features, in that CHC22 forms a triskelion and latticed vesicle coats. However, cellular CHC22-coated vesicles were distinct from those formed by CHC17. The CHC22 coat was more stable to pH change and was not removed by the enzyme complex that disassembles the CHC17 coat. Moreover, the two clathrins were differentially recruited to membranes by adaptors, and CHC22 did not support vesicle formation or transferrin endocytosis at the plasma membrane in the presence or absence of CHC17. Our findings provide biochemical evidence for separate regulation and distinct functional niches for CHC17 and CHC22 in human cells. Furthermore, the greater stability of the CHC22 coat relative to the CHC17 coat may be relevant to its excessive accumulation with GLUT4 during insulin resistance. [Abstract copyright: Copyright © 2017, The American Society for Biochemistry and Molecular Biology.
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