A rich fauna of subterranean short-range endemic Anillini (Coleoptera, Carabidae, Trechinae) from semi-arid regions of Western Australia.

Globally, the great majority of Anillini species are endogean, adapted to live in the interstices of soil and leaf litter, while the extremely low vagility of these minute ground beetles gives rise to numerous shortrange endemic species. Until recently the Australian Anillini fauna was known only from leaf litter in rain forests and eucalypt forests in the wetter, forested regions of eastern and south eastern Australia, as well as Lord Howe and Norfolk islands. The first hypogean Anillini in Australia (17 species in six genera) were described in 2016 from mineral exploration drill holes in iron-ore bearing rocks of the Pilbara region in Western Australia, representing the first finding of the tribe deep underground in a semi-arid climate region. A further eight new genera and 20 new species are described herein, mostly from the Pilbara region as well as the semi-arid Kimberley and Goldfields regions; all were collected in mineral exploration drill holes. The following new genera are described: Erwinanillus gen. nov., Gregorydytes gen. nov., Pilbaraphanus gen. nov., Neoillaphanus gen. nov., Kimberleytyphlus gen. nov., Gilesdytes gen. nov., Pilbaradytes gen. nov., and Bylibaraphanus gen. nov. The following new species are described: Erwinanillus baehri sp. nov.; Gracilanillus hirsutus sp. nov., G. pannawonicanus sp. nov.; Gregorydytes ophthalmianus sp. nov.; Pilbaraphanus chichesterianus sp. nov., P. bilybarianus sp. nov.; Magnanillus firetalianus sp. nov., M. sabae sp. nov., M. salomonis sp. nov., M. regalis sp. nov., M. serenitatis sp. nov.; Neoillaphanus callawanus sp. nov.; Kimberleytyphlus carrboydianus sp. nov.; Austranillus jinayrianus sp. nov.; Gilesdytes pardooanus sp. nov., G. ethelianus sp. nov.; Pilbaradytes abydosianus sp. nov., P. webberianus sp. nov.; Bylibaraphanus cundalinianus sp. nov.; and Angustanillus armatus sp. nov. Identification keys are provided for all Australian anilline genera, and Western Australian species. All the described species are known from a single locality and qualify as short-range endemics. The Anillini are recognised as a significant and diverse element making up part of Western Australia's remarkable subterranean fauna, and whose conservation may potentially be impacted by mining developments.

High rates of organic carbon processing in the hyporheic zone of intermittent streams.

Organic carbon cycling is a fundamental process that underpins energy transfer through the biosphere. However, little is known about the rates of particulate organic carbon processing in the hyporheic zone of intermittent streams, which is often the only wetted environment remaining when surface flows cease. We used leaf litter and cotton decomposition assays, as well as rates of microbial respiration, to quantify rates of organic carbon processing in surface and hyporheic environments of intermittent and perennial streams under a range of substrate saturation conditions. Leaf litter processing was 48% greater, and cotton processing 124% greater, in the hyporheic zone compared to surface environments when calculated over multiple substrate saturation conditions. Processing was also greater in more saturated surface environments (i.e. pools). Further, rates of microbial respiration on incubated substrates in the hyporheic zone were similar to, or greater than, rates in surface environments. Our results highlight that intermittent streams are important locations for particulate organic carbon processing and that the hyporheic zone sustains this fundamental process even without surface flow. Not accounting for carbon processing in the hyporheic zone of intermittent streams may lead to an underestimation of its local ecological significance and collective contribution to landscape carbon processes.

ß-1,3-Glucans are components of brown seaweed (Phaeophyceae) cell walls.

LAMP is a cell wall-directed monoclonal antibody (mAb) that recognizes a ß-(1,3)-glucan epitope. It has primarily been used in the immunolocalization of callose in vascular plant cell wall research. It was generated against a brown seaweed storage polysaccharide, laminarin, although it has not often been applied in algal research. We conducted in vitro (glycome profiling of cell wall extracts) and in situ (immunolabeling of sections) studies on the brown seaweeds Fucus vesiculosus (Fucales) and Laminaria digitata (Laminariales). Although glycome profiling did not give a positive signal with the LAMP mAb, this antibody clearly detected the presence of the ß-(1,3)-glucan in situ, showing that this epitope is a constituent of these brown algal cell walls. In F. vesiculosus, the ß-(1,3)-glucan epitope was present throughout the cell walls in all thallus parts; in L. digitata, the epitope was restricted to the sieve plates of the conductive elements. The sieve plate walls also stained with aniline blue, a fluorochrome used as a probe for callose. Enzymatic digestion with an endo-ß-(1,3)-glucanase removed the ability of the LAMP mAb to label the cell walls. Thus, ß-(1,3)-glucans are structural polysaccharides of F. vesiculosus cell walls and are integral components of the sieve plates in these brown seaweeds, reminiscent of plant callose.

Cryptic Species or Inadequate Taxonomy? Implementation of 2D Geometric Morphometrics Based on Integumental Organs as Landmarks for Delimitation and Description of Copepod Taxa.

Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a paleochannel, where their conservation may be threatened by proposed mining.

Loss of Arabidopsis GAUT12/IRX8 causes anther indehiscence and leads to reduced G lignin associated with altered matrix polysaccharide deposition.

GAlactUronosylTransferase12 (GAUT12)/IRregular Xylem8 (IRX8) is a putative glycosyltransferase involved in Arabidopsis secondary cell wall biosynthesis. Previous work showed that Arabidopsis irregular xylem8 (irx8) mutants have collapsed xylem due to a reduction in xylan and a lesser reduction in a subfraction of homogalacturonan (HG). We now show that male sterility in the irx8 mutant is due to indehiscent anthers caused by reduced deposition of xylan and lignin in the endothecium cell layer. The reduced lignin content was demonstrated by histochemical lignin staining and pyrolysis Molecular Beam Mass Spectrometry (pyMBMS) and is associated with reduced lignin biosynthesis in irx8 stems. Examination of sequential chemical extracts of stem walls using 2D (13)C-(1)H Heteronuclear Single-Quantum Correlation (HSQC) NMR spectroscopy and antibody-based glycome profiling revealed a reduction in G lignin in the 1 M KOH extract and a concomitant loss of xylan, arabinogalactan and pectin epitopes in the ammonium oxalate, sodium carbonate, and 1 M KOH extracts from the irx8 walls compared with wild-type walls. Immunolabeling of stem sections using the monoclonal antibody CCRC-M138 reactive against an unsubstituted xylopentaose epitope revealed a bi-lamellate pattern in wild-type fiber cells and a collapsed bi-layer in irx8 cells, suggesting that at least in fiber cells, GAUT12 participates in the synthesis of a specific layer or type of xylan or helps to provide an architecture framework required for the native xylan deposition pattern. The results support the hypothesis that GAUT12 functions in the synthesis of a structure required for xylan and lignin deposition during secondary cell wall formation.

An Arabidopsis cell wall proteoglycan consists of pectin and arabinoxylan covalently linked to an arabinogalactan protein.

Plant cell walls are comprised largely of the polysaccharides cellulose, hemicellulose, and pectin, along with ∼10% protein and up to 40% lignin. These wall polymers interact covalently and noncovalently to form the functional cell wall. Characterized cross-links in the wall include covalent linkages between wall glycoprotein extensins between rhamnogalacturonan II monomer domains and between polysaccharides and lignin phenolic residues. Here, we show that two isoforms of a purified Arabidopsis thaliana arabinogalactan protein (AGP) encoded by hydroxyproline-rich glycoprotein family protein gene At3g45230 are covalently attached to wall matrix hemicellulosic and pectic polysaccharides, with rhamnogalacturonan I (RG I)/homogalacturonan linked to the rhamnosyl residue in the arabinogalactan (AG) of the AGP and with arabinoxylan attached to either a rhamnosyl residue in the RG I domain or directly to an arabinosyl residue in the AG glycan domain. The existence of this wall structure, named ARABINOXYLAN PECTIN ARABINOGALACTAN PROTEIN1 (APAP1), is contrary to prevailing cell wall models that depict separate protein, pectin, and hemicellulose polysaccharide networks. The modified sugar composition and increased extractability of pectin and xylan immunoreactive epitopes in apap1 mutant aerial biomass support a role for the APAP1 proteoglycan in plant wall architecture and function.

Austromesocypris bluffensis sp. n. (Crustacea, Ostracoda, Cypridoidea, Scottiinae) from subterranean aquatic habitats in Tasmania, with a key to world species of the subfamily.

Austromesocypris bluffensissp. n. is described and we report another species, Austromesocypris sp., both collected from subterranean aquatic habitats in Tasmania. This discovery adds a major taxonomic group to the already diverse invertebrate cave fauna of Tasmania, and is of interest because, globally, obligate subterranean aquatic species (stygobites) are poorly represented within the family Cyprididae. The genus Austromesocypris Martens, De Deckker & Rossetti, 2004 is otherwise known to comprise entirely "terrestrial or semi-terrestrial" species. The second species is not described because only juvenile specimens were collected. Both species stand apart from their congeners by the carapace shape, which is rectangular in Austromesocypris bluffensis and triangular and asymmetrical in the unnamed species. Another unique feature of the new species is the almost symmetrical uropodal rami. We also identify some broader systematic issues within the Scottiinae including the position of two New Zealand species, Scottia audax (Chapman, 1961) and Scottia insularis Chapman, 1963 in the genus, and point out their closer relationship to the Gondwana genera of Scottiinae, Austromesocypris and Mesocypris Daday, 1910, than to the Palearctic genus Scottia Brady & Norman, 1889, based on the morphology of the maxillula and mandibula. The identity of the Australian records of Scottia audax (Chapman, 1961), Austromesocypris australiensis (De Deckker, 1983) and the Boreal records of Scottia pseudobrowniana Kempf, 1971 are all considered doubtful. A key to the world species of Scottiinae is provided.

Mutations in multiple XXT genes of Arabidopsis reveal the complexity of xyloglucan biosynthesis.

Xyloglucan is an important hemicellulosic polysaccharide in dicot primary cell walls. Most of the enzymes involved in xyloglucan synthesis have been identified. However, many important details of its synthesis in vivo remain unknown. The roles of three genes encoding xylosyltransferases participating in xyloglucan biosynthesis in Arabidopsis (Arabidopsis thaliana) were further investigated using reverse genetic, biochemical, and immunological approaches. New double mutants (xxt1 xxt5 and xxt2 xxt5) and a triple mutant (xxt1 xxt2 xxt5) were generated, characterized, and compared with three single mutants and the xxt1 xxt2 double mutant that had been isolated previously. Antibody-based glycome profiling was applied in combination with chemical and immunohistochemical analyses for these characterizations. From the combined data, we conclude that XXT1 and XXT2 are responsible for the bulk of the xylosylation of the glucan backbone, and at least one of these proteins must be present and active for xyloglucan to be made. XXT5 plays a significant but as yet uncharacterized role in this process. The glycome profiling data demonstrate that the lack of detectable xyloglucan does not cause significant compensatory changes in other polysaccharides, although changes in nonxyloglucan polysaccharide amounts cannot be ruled out. Structural rearrangements of the polysaccharide network appear responsible for maintaining wall integrity in the absence of xyloglucan, thereby allowing nearly normal plant growth in plants lacking xyloglucan. Finally, results from immunohistochemical studies, combined with known information about expression patterns of the three genes, suggest that different combinations of xylosyltransferases contribute differently to xyloglucan biosynthesis in the various cell types found in stems, roots, and hypocotyls.

Mechanical damage to pollen aids nutrient acquisition in Heliconius butterflies (Nymphalidae).

Neotropical Heliconius and Laparus butterflies actively collect pollen onto the proboscis and extract nutrients from it. This study investigates the impact of the processing behaviour on the condition of the pollen grains. Pollen samples (n = 72) were collected from proboscides of various Heliconius species and Laparus doris in surrounding habitats of the Tropical Research Station La Gamba (Costa Rica). Examination using a light microscope revealed that pollen loads contained 74.88 ± 53.67% of damaged Psychotria pollen, 72.04 ± 23.4% of damaged Psiguria/Gurania pollen, and 21.35 ± 14.5% of damaged Lantana pollen (numbers represent median ± first quartile). Damaged pollen grains showed deformed contours, inhomogeneous and/or leaking contents, or they were empty. Experiments with Heliconius and Laparus doris from a natural population in Costa Rica demonstrated that 200 min of pollen processing behaviour significantly increased the percentage of damaged pollen of Psychotria compared to pollen from anthers (P = 0.015, Z = -2.44, Mann-Whitney U-test). Examination of pollen loads from green house reared Heliconius butterflies resulted in significantly greater amounts of damaged Psiguria pollen after 200 min of processing behaviour compared to pollen from flowers (P < 0.001, Z = -4.583, Mann-Whitney U-test). These results indicate that pollen processing functions as extra oral digestion whereby pollen grains are ruptured to make the content available for ingestion.

Moss and liverwort xyloglucans contain galacturonic acid and are structurally distinct from the xyloglucans synthesized by hornworts and vascular plants.

Xyloglucan is a well-characterized hemicellulosic polysaccharide that is present in the cell walls of all seed-bearing plants. The cell walls of avascular and seedless vascular plants are also believed to contain xyloglucan. However, these xyloglucans have not been structurally characterized. This lack of information is an impediment to understanding changes in xyloglucan structure that occurred during land plant evolution. In this study, xyloglucans were isolated from the walls of avascular (liverworts, mosses, and hornworts) and seedless vascular plants (club and spike mosses and ferns and fern allies). Each xyloglucan was fragmented with a xyloglucan-specific endo-glucanase and the resulting oligosaccharides then structurally characterized using NMR spectroscopy, MALDI-TOF and electrospray mass spectrometry, and glycosyl-linkage and glycosyl residue composition analyses. Our data show that xyloglucan is present in the cell walls of all major divisions of land plants and that these xyloglucans have several common structural motifs. However, these polysaccharides are not identical because specific plant groups synthesize xyloglucans with unique structural motifs. For example, the moss Physcomitrella patens and the liverwort Marchantia polymorpha synthesize XXGGG- and XXGG-type xyloglucans, respectively, with sidechains that contain a beta-D-galactosyluronic acid and a branched xylosyl residue. By contrast, hornworts synthesize XXXG-type xyloglucans that are structurally homologous to the xyloglucans synthesized by many seed-bearing and seedless vascular plants. Our results increase our understanding of the evolution, diversity, and function of structural motifs in land-plant xyloglucans and provide support to the proposal that hornworts are sisters to the vascular plants.