Count Your Eggs Before They Invade: Identifying and Quantifying Egg Clutches of Two Invasive Apple Snail Species (Pomacea)

Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea) provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number) of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and managers can quickly identify, quantify and begin eradication of new non-native apple snail populations.     

Targeting PKC-mediated signal transduction pathways using enzastaurin to promote apoptosis in acute myeloid leukemia-derived cell lines and blast cells

Recent studies in acute myeloid leukemia (AML) suggest activation of pro-proliferative signaling cascades including those mediated by protein kinase C (PKC) represent a poor prognostic factor for patients. The classical PKC isoforms α and β generally support survival signaling and have emerged as important targets for anti-cancer therapy. Enzastaurin is a PKC β inhibitor and is in clinical trials for lymphomas, gliomas, and lung cancer. Presently, it is not known if enzastaurin could be effective against AML. In the current study, we found that high dose enzastaurin was found to promote apoptosis in the AML-derived cell lines and in blast cells from AML patients. The mechanism of cell death, however, likely does not involve PKC β as another PKC β inhibitor was not toxic to AML cell lines and did not promote enzastaurin-induced cell killing. While enzastaurin is fairly specific for PKC β, the agent can inhibit other PKC isoforms at higher concentrations. Enzastaurin was effective at inhibiting PKC α phosphorylation and membrane localization in the AML cell lines and suppressed phosphorylation of BCL2. Furthermore, enzastaurin suppressed activation of ERK (which can be activated by PKC α). Analysis of the serine/threonine phosphorylation profile in HL60 cells after enzastaurin treatment revealed that the drug inhibits the phosphorylation of a distinct set of proteins while promoting phosphorylation of another set of proteins. This suggests the drug may regulate multiple signaling pathways. Taken together, these findings suggest that enzastaurin could be effective in the therapy of AML.     

Effect of bait formulation and number of traps on detection of navel orangeworm (Lepidoptera: Pyralidae) oviposition using egg traps

Egg traps are the primary tool for monitoring egg deposition of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae), and for timing treatments for this pest in almonds, Prunus amygdalus Batsch, and pistachios, Pistacia vera L. We compared, in almond and pistachio orchards, the number of eggs per trap in traps baited with almond meal, pistachio meal, or the current standard commercial bait. When considering cumulative eggs captured over an extended period, traps baited with pistachio meal prepared from previous-crop nuts generally captured a similar number of eggs compared with the commercial bait, and more eggs than those baited with almond meal prepared from previous-crop nuts. However, differences in eggs per trap between bait formulations were not as evident when examining individual weeks, particularly in weeks with few eggs per trap, as is typical when treatment decisions are made. The variance in eggs per trap was generally greater than the mean and increased with the mean and, when mean eggs per trap was low, most traps did not have eggs. We discuss implications of these findings for the relative importance of bait type and trap numbers for monitoring, and for experiments comparing egg trap performance.     

Structure-dependent functional properties of human defensin 5

The mucosal epithelium secretes a variety of antimicrobial peptides that act as part of the innate immune system to protect against invading microbes. Here, we describe the functional properties of human defensin (HD) 5, the major antimicrobial peptide produced by Paneth cells in the ileum, in relation to its structure. The antimicrobial activity of HD-5 against Escherichia coli proved to be independent of its structure, whereas the unstructured peptide showed greatly reduced antimicrobial activity against Staphylococcus aureus. We find that HD-5 binds to the cell membrane of intestinal epithelial cells and induced secretion of the chemokine interleukin (IL)-8 in a concentration- and structure-dependent fashion. Incubation of HD-5 in the presence of tumor necrosis factor alpha further increased IL-8 secretion synergistically, suggesting that HD-5 may act as a regulator of the intestinal inflammatory response.     

Nuclear import and retention domains in the amino terminus of RECQL4

Mutations in a human RecQ helicase homologue, RECQL4, have been identified in patients with Type II Rothmund-Thomson syndrome (RTS) with osteosarcoma predisposition, RAPADILINO syndrome, and Baller-Gerold syndrome. A role in DNA replication initiation has been demonstrated and mapped to the amino terminus upstream of the helicase domain; however, no nuclear localization signal (NLS) has been identified by sequence analysis. Here, we show both endogenous and green fluorescent protein (GFP)-tagged RECQL4 are nuclear and cytoplasmic in transformed cell lines. Using GFP-tagged constructs we identified a major nuclear localization domain within amino acids (aa) 363-492 (exons 5-8) sufficient for nuclear localization of GFP and necessary for nuclear localization of RECQL4 as GFP-RECQL4 deleted for aa 363-492 is entirely cytoplasmic. Additional mapping within this domain revealed that a conserved block of 22 basic amino acids (aa 365-386; exons 5-6) is sufficient for nuclear localization of GFP, but not required for nuclear import of RECQL4. Conversely, even though the region encoded by exon 7-8 is not sufficient for nuclear import of GFP, GFP-RECQL4 deleted for exon 7 (aa 420-463), a mutation found in all reported patients with RAPADILINO syndrome, is cytoplasmic. Nuclear localization of the exon 7 deletion construct is increased in cells treated with leptomycin B suggesting that exon 7 encodes a domain required for nuclear retention of RECQL4. This retention activity is partially conveyed by a conserved VLPLY motif (aa 450-454) in exon 7 of the human sequence. In summary, unlike other RecQ proteins with carboxyl terminal NLS, RECQL4 nuclear localization and retention activities are amino terminal. This location would provide nuclear transport of putative truncated proteins encoded by RTS mutant alleles consistent with the proposed essential replication function in the amino terminus of RECQL4.     

Nest Building in Captive Gorilla gorilla gorilla

Although various aspects of gorilla nest building have been described in wild populations, nest-building behavior of captive gorillas has not been subject to much scientific review. We observed nest building in 17 gorillas during three periods: summer baseline, winter baseline, and winter treatment, in which the amount of available nesting material was doubled. We conducted observations exclusively in the indoor holding area in the hour following evening departure of animal care staff. During baseline, gorillas engaged in nest-building on 3.1% of scans and were on a constructed nest on 27.9% of scans. Overall, gorillas spent significantly more time on elevated nests than on floor nests. There were no statistically significant sex, age class, or rearing history differences in nest building, time spent on a nest, or nest location preference. Nest building consisted of both gathering and manipulating materials. The gorillas spent significantly more time building nests in winter than in summer. Additionally, they were more often on elevated nests during winter than summer. Doubling the amount of nesting material did not increase nest building, but it increased the number of floor nests. Our results suggest that providing adequate materials to captive gorillas for nest building may facilitate performance of species-typical nest-building, minimize competition among individuals for nesting sites and materials, and permit individual thermoregulation.     

Kentsin: tetrapeptide from hamster embryos produces naloxone-sensitive effects without binding to opioid receptors

The opioid nature of kentsin (Thr-Pro-Arg-Lys) and its ability to alter pain perception and intestinal transit were examined. Kentsin (30,000 nM) did not inhibit electrically stimulated contractions of the guinea pig ileum (GPI) or mouse vas deferens (MVD), nor did it cause a rightward displacement of the inhibitory concentration-response curves of the mu-selective opioid agonist PL017 in the GPI or the delta-selective agonist DPDPE in the MVD. Kentsin (10,000 nM) did not displace [3H] naloxone from rat brain homogenates. These results indicate that kentsin lacks opioid agonist and mu and delta opioid antagonist properties and does not bind to opioid receptors. In vivo, kentsin produced dose-dependent analgesia in both the hotplate and abdominal stretch tests when administered intracerebroventricularly (ICV) and intrathecally but not intravenously. The central analgesic effect of kentsin was partially antagonized by the opioid antagonist naloxone. Kentsin inhibited intestinal transit in a dose-dependent manner after ICV administration only. The intestinal antitransit effect of kentsin was not blocked by pretreatment with naloxone. These results suggest that kentsin acts centrally to produce both opioid and non-opioid effects. Further, the opioid-mediated analgesic effects of kentsin involve mechanisms other than direct interaction with opioid receptors.     

Comparing applesnails with oranges: the need to standardize measuring techniques when studying <Emphasis Type="Italic">Pomacea</Emphasis>

Although invaders come in all shapes and sizes, several mollusks have recently achieved notoriety as both economically and ecologically costly invaders. Applesnails of the genus Pomacea get their name from reaching the size of an apple. Native to South America, the species P. insularum has recently established reproducing, and potentially invasive, populations in Texas, Alabama, Georgia, and Florida. In contrast to the widely invasive golden applesnail (P. canaliculata), few studies of the channeled species P. insularum exist. In studying similar invasive applesnail species, scientists use several methods of measurement. We have explored the relationships among shell height, operculum width, and weight among juvenile and adult P. insularum and tested their inter-measurer reliability. We also investigated the use of shell height, shell length, and operculum width measurements in P. canaliculata studies and observed whether or not those studies defined their measurements. We found that operculum width served as a significantly more reliable measure among researchers. Furthermore, operculum width better predicted weight than shell height. The majority of articles that measured P. canaliculata did not define their measurements, which may cause problems when comparing studies between native and exotic populations or when comparing the two species. We recommend that future studies of P. insularum use operculum width to measure snails and explore a possible sex dimorphism in the operculum width of adult P. insularum.     

Conformationally constrained cyclic enkephalin analogs with pronounced delta opioid receptor agonist selectivity

The enkephalin analogs, [D-Pen2,L-Cys5]- and [D-Pen2,D-Cys5]-enkephalin are cyclic compounds, conformationally constrained by virtue of their 14-membered, disulfide containing rings and by the rigidizing effect of the beta, beta dimethyl substituents of the penicillamine side chain. The analogs exhibit profound delta receptor specificity as assessed by their relative potencies in the guinea pig ileum (GPI) and mouse vas deferens (MVD) assays, exhibiting, respectively, 666 and 215 times higher potency in the latter assay system. By contrast, the receptor selectivities measured in rat brain binding assays in the absence of sodium were much more modest, the cyclic analogs being, respectively, 15.2 and 6.0 times more effective at displacing [3H] [D-Ala2,D-Leu5]enkephalin than [3H]naloxone. However, for binding assays performed in the presence of a sodium concentration equivalent to that used in the GPI and MVD assays, these binding selectivities increased to 167 and 49, respectively.