Review of the Palaearctic Acomopterella Zaitzev (Diptera, Sciaroidea, Mycetophilidae)

The distribution of Acomopterella species in the Palaearctic region has been re-examined in this study, using recently collected material. The European species was found to be distributed in the eastern Palaearctic as well. A second Palaearctic species from Honshu (Japan) is herein described. The morphology of adult specimens was studied by light microscopy and scanning electron microscopy. The shape of functional specialized setae on mid tibiae in Acomopterella and seven further fungus gnat genera is described and the suitability of this character for systematic studies is discussed. Details of a “hind tibial organ” are described.The position of Acomopterella in the tribe Gnoristini is briefly discussed. Acomopterella is found to be more closely related to Speolepta Edwards, 1925, than to any other recent genus

Paramorganiella adventurosa Tonnoir 1929

<i>Paramorganiella adventurosa</i> Tonnoir 1929 <p>Tonnoir 1929: 606.</p> <p> <b>Remarks on identification.</b> We identified our specimens on the basis of the male description by Tonnoir (1929), which includes a figure of the unmistakable mouthparts (text fig. 5). It is important to note that the wing figures 14 and 15 in Tonnoir´s paper were mistakenly inverted, and the <i>Paramorganiella</i> wing is actually shown in fig. 14, not 15. We did not study the holotype of <i>P. adventurosa</i>, which according to Bugledich (1999) is allocated in the Australian National Insect Collection, Canberra.</p> <p> <b>Male redescription. Head.</b> Fourth flagellomere 1.8 times as long as wide. Clypeus elongate ovate, on basal half convex, with large setae, on distal half clearly concave, basket-shaped, with sparse fine setae (Fig. 2A). Surface of stipes with microtrichia arranged in lines, lateral setae; stipites fused anteriorly, forming Ushape, with sclerotized longitudinal axis. Lacinia, if correctly identified, present as sclerotized rib between stipes and base of second maxillary palpus segment (Fig. 4C). Palpus 5-segmented, segments 1–4 more or less strongly modified (Fig. 2C–E, 4C). Segment 1 fused medially with proboscis, large setae dorsally, subtriangular process apically to receive segment 2. Segment 2 swollen, largest of all, short setae dorsomedially, 6–7 sensilla coeloconica arranged in line ventromedially. Segment 3 short, inserted subapically on segment 2, 2 short stiff setae medially and long sclerotized process dorsally which bears 4–5 setulae apically, otherwise bare, without specialized sensilla. Segment 4 with 6–7 long stiff setae medially, 2 sclerotized processes, dorsal process broad, with 3–4 large setae, otherwise bare, margin occasionally irregularly serrate, lateral process narrow, dagger-shaped, bare. Segment 5 elongate, slightly club-shaped, 10– 12 stiff setae on apical half. Prementum very large, bilobed, lobes separate medially, densely microtrichose (Fig. 2B). Premental apodemes touching each other medially, forming X-shape. Basal segment of labellum asetose, apical segment setose (Fig. 4C).</p> <p> <b>Wing</b> (Fig. 3). Length 2.3–2.8 mm. Slightly fumose in the distal region of R1 and R5. Halter whitish.</p> <p> <b>Legs.</b> Tarsomere 4 of fore leg with crest of 3–4 short stiff setae ventrolaterally, tarsomere 5 with 2 setae of same kind but shorter, both groups of setae together forming clamping apparatus when tarsomeres are folded (Fig. 3B).</p> <p> <b>Terminalia.</b> St 9 fused with gonocoxites, identifiable as sclerotized rib close to basal margin of gonocoxites (Fig. 4B). Tg 9 subrectangular, densely setose, apical margin slightly emarginate (Fig. 4B). Gonocoxites largely fused ventrally, on apical half separated by narrow cleft, short ventral and longer lateral setae, on apical margin 2 pairs of processes, lateral pair hook-like, medial pair short subtriangular (Fig. 4B). PostGA convoluted, fringed apically, with finger-like medial process tipped by one thick macroseta (Fig. 4A). AntGA very large, rounded (Fig. 4A). Gonostylus directed medially, slender, tapered towards apex, with a few short setae including 4 strong, stiff setae in line on ventral margin, and 2 subapical setulae (Fig. 4A). Parameres fused to form short tegmen with deeply notched apical margin, strongly sclerotized, parameral apodemes large, rounded (Fig. 4A). Hypoproct slightly shorter than cerci (Fig. 4B), separate apicomedially, with dense large microtrichia and a few apical setae. Cerci separate medially (Fig. 4B), dense microtrichia, setae of various sizes including several thick stiff setae pointing ventrally.</p> <p> <b>Female description. Head.</b> Antenna much shorter than in male, fourth flagellomere 1.4 times as long as wide. Clypeus convex (Fig. 3A). Lacinia style-like (Fig. 3A). Palpus segment 2 thicker than other segments, segment 3 without sensilla cochleariformis (Fig. 3A), which are usually present in Mycetophilidae (Søli 1997).</p> <p> <b>Thorax.</b> Shallower than in male. <b>Wing.</b> Length 2.8 mm. As the male (Fig. 3C).</p> <p> <b>Preabdomen.</b> St 4–7 with numerous short stiff blunt-tipped setae among ordinary setae. <b>Terminalia.</b> In accordance with the mycetophilid ground pattern (cf. Søli 1997: fig. 37B). Disticercus somewhat shorter than basicercus.</p> <p> <b>Specimens studied.</b> <i>Slide mounted:</i> Australia, Tasmania, Warra, Mt Weld, N. Doran & R. Bashford, 27 Feb. 2001, 1 male (sample FT #19) and 3 males (FT #26); 18 Dec. 2001, 1 male (FT #5743); 22 Jan. 2002, 1 male (FT # 5840); 27 Feb. 2002, 2 males (FT #5923); Warra, Manuka Road, R. Bashford, 17 March 2004, 6 males (FT #30518); 7 Feb. 2007, 1 male (FT #40010); Warra, Manuka Road, Bird Observation Track, M. & C. Jaschhof, 7 Dec. 2007 – 7 Jan. 2008, 6 males, 1 female (lacking head). <i>In ethanol:</i> Warra, Manuka Road, Bird Observation Track, M. & C. Jaschhof, 7 Dec. 2007 – 7 Jan. 2008, 23 males, 1 female.</p>Published as part of <i>Jaschhof, Mathias, Blank, Stephan M. & Kallweit, Uwe, 2010, Adult morphology of Paramorganiella adventurosa Tonnoir (Diptera: Mycetophilidae: Sciophilinae), including a description of the unique maxillary palpi, pp. 36-46 in Zootaxa 2559 (1)</i> on pages 41-44, DOI: 10.11646/zootaxa.2559.1.3, <a href="http://zenodo.org/record/5301714">http://zenodo.org/record/5301714</a&gt

Fibronectin-Integrin Signaling Is Required for L-Glutamine’s Protection against Gut Injury

<div><h3>Background</h3><p>Extracellular matrix (ECM) stabilization and fibronectin (FN)-Integrin signaling can mediate cellular protection. L-glutamine (GLN) is known to prevent apoptosis after injury. However, it is currently unknown if ECM stabilization and FN-Integrin osmosensing pathways are related to GLN’s cell protective mechanism in the intestine.</p> <h3>Methods</h3><p>IEC-6 cells were treated with GLN with or without FN siRNA, integrin inhibitor G<u>RGD</u>SP, control peptide G<u>RGE</u>SP or ERK1/2 inhibitors PD98059 and UO126 under basal and stressed conditions. Cell survival measured via MTS assay. Phosphorylated and/or total levels of cleaved caspase-3, cleaved PARP, Bax, Bcl-2, heat shock proteins (HSPs), ERK1/2 and transcription factor HSF-1 assessed via Western blotting. Cell size and F-actin morphology quantified by confocal fluorescence microscopy and intracellular GLN concentration by LC-MS/MS.</p> <h3>Results</h3><p>GLN’s prevention of FN degradation after hyperthermia attenuated apoptosis. Additionally, inhibition of FN-Integrin interaction by G<u>RGD</u>SP and ERK1/2 kinase inhibition by PD98059 inhibited GLN’s protective effect. G<u>RGD</u>SP attenuated GLN-mediated increases in ERK1/2 phosphorylation and HSF-1 levels. PD98059 and G<u>RGD</u>SP also decreased HSP levels after GLN treatment. Finally, G<u>RGD</u>SP attenuated GLN-mediated increases in cell area size and disrupted F-actin assembly, but had no effect on intracellular GLN concentrations.</p> <h3>Conclusion</h3><p>Taken together, this data suggests that prevention of FN degradation and the FN-Integrin signaling play a key role in GLN-mediated cellular protection. GLN’s signaling via the FN-Integrin pathway is associated with HSP induction via ERK1/2 and HSF-1 activation leading to reduced apoptosis after gut injury.</p> </div

GRGDSP’s effect on cell area size, F-actin morphology and intracellular GLN concentration.

<p>A) Cell area size is shown by fluorescence microscopy in IEC-6 cells under 0 mM GLN conditions and 10 mM GLN treatment without inhibitor G<u>RGD</u>SP (Images A, C, E, G) or after 1 h prior treatment with G<u>RGD</u>SP (Images C, D, F, H) in basal and stressed conditions (43°C). F-actin is shown in green and nuclei in blue. All images taken 15 min following exposure of cells to GLN in non-HS cells and 15 min post-HS in stressed cells. All images were aquired using the same exposure times, and were renormalized the same for optical comparison (n = 4). Scalebars = 33 µm. B) Cell area size data are shown in fold increase under non-HS (37°C) and HS (43°C) conditions (n = 3–4) C) IEC-6 cells were treated as descibed in A). GLN levels in cell extracts were quantified using LC-MS/MS and are shown as fold change± SEM ratioed to 0 mM GLN group (n = 6–7). D) Fluorescence microscopy was used for the morphological analysis of the distribution of F-actin. Microfilaments were visualized with Alexa Flour 488 phalloidin antibody. Representative results are shown from 4 independent fluorescence microscopy experiments for each condition. Scalebars: 45 µm.</p

GLN is protective by preventing FN degradation after HS.

<p>A) FN levels from IEC-6 cells, with or without GLN treatment under unstressed or stressed conditions, were determined by Western blot with ß-actin as loading control after 0 h recovery. Densitometric analysis of FN expression as mean fold change relative to 0 mM GLN cells±SEM (n = 4). B) Western blot and densitometric analysis of FN after 3 h recovery is shown (n = 4). C) FN expression of transfected IEC-6 cells with no siRNA, NC siRNA, or FN siRNA (n = 3) are presented. D) Caspase-3 and cleaved caspase-3 expression was determined via Western blot in basal and HS conditions after IEC-6 cells were transfected with no siRNA, NC siRNA, or FN siRNA (n = 3). E) Densitometric analysis of cleaved caspase-3 levels is shown as mean fold change relative to HS 0 mM GLN cells ±SEM (n = 3).</p

Proposed working model.

<p>GLN is protective in the intestine by preventing FN degradation after thermal injury, as well as by activating the protective FN-Integrin signaling pathway. GLN phosphorylates ERK1/2 via the FN-Integrin pathway leading to HSF-1 activation, which enhances HSP expression to prevent apoptosis.</p

ERK1/2 activation is involved in GLN’s protective mechanism and attenuates after FN-Integrin pathway inhibition.

<p>A) IEC-6 cells were treated with different concentrations of GLN (0, 2, 10, and 20 mM) with or without 1 h prior PD98059 treatment. Cell survival was measured via MTS assay. Results are shown as mean±SEM (n = 3). B) [T(P)²⁰²/Y(P)²⁰⁴]ERK1/2 and total ERK1/2 levels were determined by Western blot analysis after basal and stressed 43°C conditions without recovery. ERK1/2 activation is shown as mean fold change relative to total ERK1/2±SEM and ratioed to 0 mM GLN (n = 3).</p

GLN’s intestinal protection is inhibited by GRGDSP.

<p>A) IEC-6 cells were treated for 1 h with either media, G<u>RGD</u>SP or G<u>RGE</u>SP before the cells were treated with 0, 2, 10 or 20 mM GLN. Cell survival, following lethal HS (44°C), was measured via MTS assay. All groups were normalized to their non-HS controls to account for differences in cell growth. Assays were carried out in triplicate, experiments were performed 4 times and shown as mean±SEM. B) IEC-6 cells were treated as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050185#pone-0050185-g002" target="_blank">Fig. 2A</a>, but they underwent non-lethal HS (43°C). After 3 hours recovery at 37°C, Bax and Bcl-2 levels were measured by Western blot. Bax was ratioed to anti-apoptotic marker Bcl-2 and shown in fold change±SEM (n = 4). C) Representative Western blot of PARP and cleaved PARP and densitometric analysis of cleaved PARP ratioed to HS 0 mM GLN are displayed. Cleaved PARP levels are presented as fold change±SEM (n = 4).</p

GRGDSP and PD98059 affect GLN-mediated increases in HSP70 expression.

<p>A) IEC-6 cells were treated as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050185#pone-0050185-g002" target="_blank">Fig. 2B</a>. HSP70 expression was determined by Western blot analysis. In addition, ß-actin was monitored to normalize total blotted protein. Data are shown as mean fold change relative to HS 0 mM GLN±SEM (n = 5). B) Western blot of HSP70 and ß-actin are shown after PD98059 treatment. Results are ratioed to HS 0 mM GLN groups and represent means±SEM (n = 3).</p