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71.
Analyses of the genetic population structure of spotted seatrout Cynoscion nebulosus along the south‐eastern U.S. coast using 13 microsatellites suggest significant population differentiation between fish in North Carolina (NC) compared with South Carolina (SC) and Georgia (GA), with New River, NC, serving as an area of integration between northern and southern C. nebulosus. Although there is a significant break in gene flow between these areas, the overall pattern throughout the sampling range represents a gradient in genetic diversification with the degree of geographic separation. Latitudinal distance and estuarine density appear to be main drivers in the genetic differentiation of C. nebulosus along the south‐eastern U.S. coast. The isolation‐by‐distance gene‐flow pattern creates fine‐scale differences in the genetic composition of proximal estuaries and dictates that stocking must be confined to within 100 km of the location of broodstock collection in order to maintain the natural gradient of genetic variation along the south‐eastern U.S. coast. 相似文献
72.
The enlarged (major) claw of male fiddler crabs is used in contestsover breeding burrows and is waved to attract females. We recentlydiscovered that males of the red-jointed fiddler crab, Uca minax,also use the claw to kill smaller-sized fiddler crabs, U. pugnaxand U. pugilator, with which they co-occur in Atlantic coastsalt marshes. Large U. minax males use walking legs or the enlargedclaw to capture prey feeding on moist sand flats. On sand flats,small U. minax males and females are much less common than largemales, suggesting that large males move onto sand flats to seekprey. Males of prey species use the major claw against attackingpredators and, consequently, are more likely than females toescape. In laboratory experiments, large U. minax males weremore likely to attack and kill small-clawed males and femalesthan large-clawed males, consistent with a preference for morevulnerable, less threatening prey. The size of the major clawis a positive allometric function of body size. The allometricfunction varies little among species. Also, the mechanical advantageand indices of closing speed and closing force of the majorclaw, when corrected for body size, are not consistently greaterin U. minax relative to prey species. Thus, predation by U.minax males may reflect the opportunity afforded by larger bodysize and positive allometric growth, which result in a majorclaw that is more massive than the prey it is directed against. 相似文献
73.
Ganatra MB Vainauskas S Hong JM Taylor TE Denson JP Esposito D Read JD Schmeisser H Zoon KC Hartley JL Taron CH 《FEMS yeast research》2011,11(2):168-178
Secretion of recombinant proteins is a common strategy for heterologous protein expression using the yeast Kluyveromyces lactis. However, a common problem is degradation of a target recombinant protein by secretory pathway aspartyl proteases. In this study, we identified five putative pfam00026 aspartyl proteases encoded by the K. lactis genome. A set of selectable marker-free protease deletion mutants was constructed in the prototrophic K. lactis GG799 industrial expression strain background using a PCR-based dominant marker recycling method based on the Aspergillus nidulans acetamidase gene (amdS). Each mutant was assessed for its secretion of protease activity, its health and growth characteristics, and its ability to efficiently produce heterologous proteins. In particular, despite having a longer lag phase and slower growth compared with the other mutants, a Δyps1 mutant demonstrated marked improvement in both the yield and the quality of Gaussia princeps luciferase and the human chimeric interferon Hy3, two proteins that experienced significant proteolysis when secreted from the wild-type parent strain. 相似文献
74.
Denson Donald D.; Worrell Roger T.; Middleton Pamela; Eaton Douglas C. 《American journal of physiology. Cell physiology》1999,276(1):C201
To test thehypothesis that intracellular Ca2+activation of large-conductanceCa2+-activatedK+ (BK) channels involves thecytosolic form of phospholipase A2 (cPLA2), we first inhibited theexpression of cPLA2 by treating GH3 cells with antisenseoligonucleotides directed at the two possible translation start siteson cPLA2. Western blot analysis and a biochemical assay of cPLA2activity showed marked inhibition of the expression ofcPLA2 in antisense-treated cells.We then examined the effects of intracellularCa2+ concentration([Ca2+]i)on single BK channels from these cells. Open channel probability (Po) for thecells exposed to cPLA2 antisenseoligonucleotides in 0.1 µM intracellularCa2+ was significantly lower thanin untreated or sense oligonucleotide-treated cells, but the voltagesensitivity did not change (measured as the slope of thePo-voltagerelationship). In fact, a 1,000-fold increase in[Ca2+]ifrom 0.1 to 100 µM did not significantly increasePoin these cells, whereas BK channels from cells in the other treatmentgroups showed a normalPo-[Ca2+]iresponse. Finally, we examined the effect of exogenous arachidonic acidon thePoof BK channels from antisense-treated cells. Although arachidonic aciddid significantly increasePo,it did so without restoring the[Ca2+]isensitivity observed in untreated cells. We conclude that although [Ca2+]idoes impart some basal activity to BK channels inGH3 cells, the steepPo-[Ca2+]irelationship that is characteristic of these channels involves cPLA2. 相似文献
75.
All known complications which occurred during and after LSD treatment of 237 psychiatric patients on an open ward of a general hospital are described and classified. The results imply that clinical research with lysergide can be carried out in similar settings with relative safety. 相似文献
76.
J. S. Denson 《The Western journal of medicine》1951,74(2):118-120
The Anesthesia Department at the Los Angeles County Hospital established a Nerve Block Clinic for the purpose of alleviating pain and providing helpful information for diagnosis in a number of diseases.During the first year of operation of this Nerve Block Clinic, over one thousand injections were made. The patients who received the injections were referred to the Nerve Block Clinic by staff members who had been apprised of the services offered. 相似文献
77.
78.
The activity of purified DNA photolyase from Baker's yeast is enhanced by a compound (Activator (III)) obtained from yeast by chloroform extraction ion exchange chromatography and gel filtration. Thin layer chromatography and spectral data indicate that the compound is homogeneous. Activator III emits at 350 and 440 nm when excited at 290 nm, and emits at 440 nm when excited at 358 nm. After acid hydrolysis, emission at 440 nm is produced only by excitation at 358 nm, indicating that activator (III) contains two separate chromophoric moieties. The chromophore excited by 358 nm light has a pK of 9-11, while the other chromophore has a pK of 4-5, and possibly of 9-11. The enhancement of photolytic activity by activator (III) at a concentration equimolar with that of the enzyme and the similarity of the fluorescent spectra of the activator with that of heat-denatured photolyase, suggests that the activator may be the chromophore associated with the enzyme. 相似文献
79.
Denson Kelly McLain 《Journal of Insect Behavior》1992,5(6):729-739
Caged females of Neacoryphus bicrucis(Hemiptera: Lygaeidae) were permitted to settle upon and oviposit within a small or large ragwort patch, each of which contained both maturing (= adult food/water source) and dehisced (=oviposition substrate/resource for nymphs) flower heads. The proportion of females settling in the large patch was significantly greater than for the small patch but not significantly greater than expected based on the proportion of maturing flower heads contained in each patch. Also, the number of egg masses laid in each patch was proportional to the number of females that settled there. However, egg mass size was significantly skewed toward larger numbers of eggs in the larger patch. Within the large patch egg mass size was significantly larger where the number of dehisced flower heads was greater and accounts for the between-patch difference in number of eggs per mass. Thus, female settlement does not demonstrate a resource concentration effect but females do appear to evaluate patches after settlement with regard to suitability for oviposition. 相似文献
80.
The expansion of genome sequencing projects has produced accumulating evidence for lateral transfer of genes between prokaryotic
and eukaryotic genomes. However, it remains controversial whether these genes are of functional importance in their recipient
host. Nikoh and Nakabachi, in a recent paper in BMC Biology, take a first step and show that two genes of bacterial origin are highly expressed in the pea aphid Acyrthosiphon pisum. Active gene expression of transferred genes is supported by three other recent studies. Future studies should reveal whether
functional proteins are produced and whether and how these are targeted to the appropriate compartment. We argue that the
transfer of genes between host and symbiont may occasionally be of great evolutionary importance, particularly in the evolution
of the symbiotic interaction itself. 相似文献