A taxonomic revision of the genus Hydnora (Hydnoraceae)

Summary: A systematic monograph is presented for Hydnora (Hydnoraceae), a poorly known genus of holoparasitic plants distributed across Africa, Madagascar and southern Arabia. Species of Hydnora are characterised by their underground habit, unusual fleshy flowers and complete absence of leaves or photosynthetic tissue. This is the first detailed monograph of the genus Hydnora since 1935 and is informed by a comprehensive survey of herbarium specimens and literature. Detailed descriptions, full synonymy, distribution maps and discussion concerning confusable taxa are provided for each species, along with notes on ethnobotany, ecology and conservation. We place particular emphasis on the taxonomic value of osmophore geometry and positioning in living and dried material, which are highly consistent within species. We also provide the first detailed assessment of host range across the genus. Hydnora hanningtonii Rendle and H. solmsiana Dinter are reinstated from synonymy, and H. bolinii S.Hatt is newly described here. The infrageneric classification is reviewed and a key is provided for both living and dried material. Species are accompanied by both illustrations and photographs of living and dried material where possible

Transcription at the proximity of the nuclear pore: A role for the THP1-SAC3-SUS1-CDC31 (THSC) complex

4 páginas, 1 figura.A key aspect of eukaryotic gene expression is the coupling of transcription with RNA processing, polyadenylation and export. The use of new techniques based on tandem affinity purification (TAP) and chromatin immunoprecipitation (ChIP), and of genetic and cell biology approaches has contributed to the beginning of deciphering the network of protein-mRNA interactions accompanying this coupling. Although an extensive amount of work has shed light on this matter, the order of participation and precise role of the different proteins remain to be deciphered. It seems that different and sequential protein interactions must converge to finally promote the anchoring of genes to the nuclear periphery. Here we discuss the new data on the coupling of gene expression and RNA export, with emphasis on the THP1-SAC3-SUS1-CDC31 complex and the possible implications of these results on transcription at the nuclear pore.Research in A.A.’s lab is funded by grants from the Spanish Ministry of Science and Education and the Junta de Andalucía.Peer reviewe

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified

Vepris onanae (Rutaceae), a new Critically Endangered cloud-forest tree species, and the endemic plant species of Bali Ngemba Forest Reserve, Bamenda Highlands Cameroon.

We revise and update the records of strict and near-endemic species of the Bali Ngemba Forest Reserve, the largest known surviving patch (c. 8 km in area) of submontane or cloud forest in the Bamenda Highlands, Cameroon which have lost &gt;96 % of their original forest due to human activities. Nine strict endemics, and 11 near endemics are now documented, a drop from the number recorded after the first survey in 2004, since when five of the provisionally named species have been validly published. We test the hypothesis that a further one of the provisionally named putative Bali Ngemba new species, sp. A, an 8 – 20 m tall tree from cloud forest in the 1310 – 1700 m altitudinal band, is indeed new to science. We compare it morphologically with other multicarpellate, apocarpous, trifoliolate Cameroon tree species formerly placed in the genus Pierre until they were subsumed into by Mziray (1992). These are (Engl.) Mziray and (Pierre) Mziray. We conclude that sp. A is a new undescribed species here named as . The new species is illustrated, mapped and its conservation status assessed as Critically Endangered using the 2012 IUCN standard due to severe fragmentation and the threats of habitat clearance from agricultural pressures at its three locations all of which remain formally unprotected. appears unique among the Guineo-Congolian African oricioid species of in that it occurs in cloud forest, the other species, apart from (G.C.C.Gilbert) Mziray of the Albertine Rift, occurring in lowland forest. It also differs in the very broad, (7.8 –) 11.3 – 18 cm wide leaflets of the flowering stems which have a 6 – 18 (– 30) mm long, narrowly triangular acumen (vs leaflets &lt;12 cm wide, acumen absent or short) and in having both subsessile and pedicellate (pedicels 0.25 – 0.3 mm long and 1 (– 2) mm long) male flowers (vs male flower pedicels all sessile, or all c. 3 mm long). We report for the first time on stage-dependent leaf heteromorphy in and characterise a level of sexual dimorphism more advanced than usual in the genus. We highlight the importance of protecting Bali Ngemba and other forest patches in the Bamenda Highlands if species such as are not soon to become extinct

A morphological analysis of Syzygium, with a focus on fibre bundles and description of a new subgenus.

Syzygium is a large genus (1200–1500 species) of Old World tropical trees, currently divided into five subgenera containing widely different numbers of species. Syzygium subgenus Perikion was defined by the presence of fibre bundles in the hypanthium wall, although until now this feature has not been investigated or images published. Furthermore, discovery of fibre bundles in certain species outside Syzygium subgenus Perikion calls for reassessment of the subgenus. In this paper, a morphological analysis is presented for all species previously associated with Syzygium subgenus Perikion or known to have fibre bundles. Results indicate the need for description of a new subgenus, Syzygium subgenus Oborapi, characterized by a distinctly goblet-shaped calyx, presence of fibre bundles in the hypanthium/mesocarp, prominent black lenticels on the abaxial leaf surface, ascending ovule orientation and species diversity centred on the Sunda Shelf. Fibre bundles are photographed and documented for the first time from a range of species and at different magnifications. A preliminary list of species is presented for Syzygium subgenus Perikion and Syzygium subgenus Oborapi, with recommendations for further investigation

Tmem16b is Specifically Expressed in the Cilia of Olfactory Sensory Neurons

Calcium-activated chloride channels (CaCCs) are involved in many physiological processes, including sensory signal transduction, but only little is known to date about their structure and function. We performed a proteome analysis of the olfactory epithelium (OE) membrane proteome and identified so far uncharacterized membrane proteins as candidate channels. One of the most abundant membrane proteins in olfactory sensory neurons (OSNs) was Tmem16b, a member of a recently identified family of CaCCs. In addition to former studies performed on Tmem16b, we show here that Tmem16b expression is highly specific for the OE, in contrast to the closely related Tmem16a, which shows a broad expression pattern in secretory epithelial cells. Native Tmem16b is localized in the cilia of the OSNs, which is in agreement with previous electrophysiological recordings

The BEACH Protein LRBA Promotes the Localization of the Heterotrimeric G-protein Golf to Olfactory Cilia

BEACH domain proteins are involved in membrane protein traffic and human diseases, but their molecular mechanisms are not understood. The BEACH protein LRBA has been implicated in immune response and cell proliferation, and human LRBA mutations cause severe immune deficiency. Here, we report a first functional and molecular phenotype outside the immune system of LRBA-knockout mice: compromised olfaction, manifesting in reduced electro-olfactogram response amplitude, impaired food-finding efficiency, and smaller olfactory bulbs. LRBA is prominently expressed in olfactory and vomeronasal chemosensory neurons of wild-type mice. Olfactory impairment in the LRBA-KO is explained by markedly reduced concentrations (20-40% of wild-type levels) of all three subunits alpha(olf), beta(1) and gamma(13) of the olfactory heterotrimeric G-protein, G(olf), in the sensory cilia of olfactory neurons. In contrast, cilia morphology and the concentrations of many other proteins of olfactory cilia are not or only slightly affected. LRBA is also highly expressed in photoreceptor cells, another cell type with a specialized sensory cilium and heterotrimeric G-protein-based signalling; however, visual function appeared unimpaired by the LRBA-KO. To our knowledge, this is the first observation that a BEACH protein is required for the efficient subcellular localization of a lipid-anchored protein, and of a ciliary protein

Characterization of non-olfactory GPCRs in human sperm with a focus on GPR18

G protein-coupled receptors (GPCRs) transduce external chemical cues into intracellular signals and are involved in a plethora of physiological processes, but knowledge regarding the function of these receptors in spermatozoa is limited. In the present study, we performed RNA-Seq and analyzed the expression of the all GPCRs except olfactory receptors in human spermatozoa. We revealed the expression of up to 223 different GPCR transcripts in human spermatozoa (FPKM > 0.1) and identified GPR18, a newly described cannabinoid receptor, together with GPR137 and GPR135, as one of the three most highly expressed GPCRs. To date, the expression of GPR18 was completely unknown in human spermatozoa. We confirmed GPR18 expression using RT-PCR and immuncytochemistry experiments and localized the GPR18 protein in the midpiece of human spermatozoa. Stimulation of human spermatozoa with the GPR18 ligand N-arachidonoylglycine induced the phosphorylation of 12 protein kinases, some of them are for example known to be involved in the acrosome reaction. In line with this, N-arachidonoylglycine affected the cytoskeleton by changing levels of F-actin and inducing the acrosome reaction in human spermatozoa in a concentration-dependent manner. Our results indicate that GPR18 might be involved in physiological processes of human spermatozoa, suggesting GPR18 to be a potential player in sperm physiology