Apical Processes Research Articles

Radial glia progenitor polarity in health and disease.

Radial glia (RG) are the main progenitor cell type in the developing cortex. These cells are highly polarized, with a long basal process spanning the entire thickness of the cortex and acting as a support for neuronal migration. The RG cell terminates by an endfoot that contacts the pial (basal) surface. A shorter apical process also terminates with an endfoot that faces the ventricle, with a primary cilium protruding in the cerebrospinal fluid. These cell domains have particular subcellular compositions that are critical for the correct functioning of RG. When altered, this can affect proper development of the cortex, ultimately leading to cortical malformations, associated with different pathological outcomes. In this review, we focus on the current knowledge concerning the cell biology of these bipolar stem cells and discuss the role of their polarity in health and disease.

Lipid Nanoparticle-Mediated Delivery of mRNA Into the Mouse and Human Retina and Other Ocular Tissues.

Lipid nanoparticles (LNPs) show promise in their ability to introduce mRNA to drive protein expression in specific cell types of the mammalian eye. Here, we examined the ability of mRNA encapsulated in LNPs with two distinct formulations to drive gene expression in mouse and human retina and other ocular tissues. We introduced mRNA-carrying LNPs into two biological systems. Intravitreal injections were tested to deliver LNPs into the mouse eye. Human retinal pigment epithelium (RPE) and retinal explants were used to assess mRNA expression in human tissue. We analyzed specificity of expression using histology, immunofluorescence, and imaging. In mice, mRNAs encoding GFP and ciliary neurotrophic factor (CNTF) were specifically expressed by Müller glia and RPE. Acute inflammatory changes measured by microglia distribution (Iba-1) or interleukin-6 (IL-6) expression were not observed 6hours post-injection. Human RPE also expressed high levels of GFP. Human retinal explants expressed GFP in cells with apical and basal processes consistent with Müller glia and in perivascular cells consistent with macrophages. We demonstrated the ability to reliably transfect subpopulations of retinal cells in mouse eye tissues in vivo and in human ocular tissues. Of significance, intravitreal injections were sufficient to transfect the RPE in mice. To our knowledge, we demonstrate delivery of mRNA using LNPs in human ocular tissues for the first time. Ocular gene-replacement therapies using non-viral vector methods are a promising alternative to adeno-associated virus (AAV) vectors. Our studies show that mRNA LNP delivery can be used to transfect retinal cells in both mouse and human tissues without inducing significant inflammation. This methodology could be used to transfect retinal cell lines, tissue explants, mice, or potentially as gene-replacement therapy in a clinical setting in the future.

The saccus vasculosus of the neotropical cichlid fish Cichlasoma dimerus: characterization, developmental studies and its response to photoperiod.

The saccus vasculosus is an organ present in gnathostome fishes, located ventral to the hypothalamus and posterior to the pituitary gland, whose structure is highly variable among species. In some fishes, this organ is well-developed; however, its physiological function is still under debate. Recently, it has been proposed that this organ is a seasonal regulator of reproduction. In the present work, we examined the histology, ultrastructure, and development of the saccus vasculosus in Cichlasoma dimerus. In addition, immunohistochemical studies of proteins related to reproductive function were performed. Finally, the potential response of this organ to different photoperiods was explored. C. dimerus presented a well-developed saccus vasculosus consisting of a highly folded epithelium, composed of coronet and supporting cells, closely associated with blood vessels, and a highly branched lumen connected to the third ventricle. Coronet cells showed all the major characteristics described in other fish species. In addition, some of the vesicles of the globules were positive for thyrotropin beta subunit, while luteinizing hormone beta subunit immunostaining was observed at the edge of the apical processes of some coronet cells. Furthermore, neuropeptide Y and gonadotropin inhibitory hormone innervation in the saccus vasculosus of C. dimerus were shown. Finally, animals exposed to the long photoperiod showed lower levels of thyrotropin beta and common alpha subunits expression in the saccus compared to those of animals exposed to short photoperiod. All these results support the hypothesis that the saccus vasculosus is involved in the regulation of reproductive function in fish.

Redescription of Rhyacophila clemens Tsuda 1940 (Trichoptera, Rhyacophilidae), with descriptions of five new, allied species from Japan

Japanese species of the Rhyacophila clemens Species Group Ross 1956 are revised, and six species including five new allied species are recognized: R. clemens Tsuda 1940, R. vesperalis sp. nov., R. inazui sp. nov., R. angulicauda sp. nov., R. parvicauda sp. nov., and R. furcicauda sp. nov. Adult males and females of all species are described or redescribed, and the male genitalia of a Korean species, R. kumgangsanica Kumanski 1990, also belonging to this species group, are illustrated for comparison. The lectotype of R. clemens is designated for nomenclatural stability. The main diagnostic characters for the R. clemens Species Group are provided as follows: (1) Segment X bears an apical hinged process posteroventrally; (2) two pairs of anal sclerites have a common internal root; (3) a pair of large apical bands surrounds the anus and the root of the anal sclerites; (4) the aedeagus bears a large sclerotized ventral plate.

A new genus and species of mud cricket (Orthoptera: Ripipterygidae) from mid-Cretaceous Kachin amber of northern Myanmar

The Ripipterygidae is a small orthopteran family which comprises several bizarre species. A new genus and species of Ripipterygidae, Kallosripipteryx zhangi sp. nov., is described based on a well-preserved inclusion from mid-Cretaceous Kachin amber. The new genus and species are established based on the following combination of characters: wider interocular distance, prosternal process present, fusiform mesotibia, metatibia apical spurs about 1/3rd of metatarsus in length; paraproctal lobe two-segmented; and paraproctal lobe distinctly longer than ovipositor. Additionally, we recognize a kind of metatarsal structure among most Mesozoic ripipterygids: the outer side of apical process is triangular in lateral view. Our new find enriches the biodiversity of fossil Ripipterygidae as well as Tridactyloidea, and provides a new interpretation of biogeography of Tridactyloidea.

Mining phase separation-related diagnostic biomarkers for endometriosis through WGCNA and multiple machine learning techniques: a retrospective and nomogram study.

The objective of this study was to investigate the role of phase separation-related genes in the development of endometriosis (EMs) and to identify potential characteristic genes associated with the condition. We used GEO database data, including 74 non-endometriosis and 74 varying-degree EMs patients. Our approach involved identifying significant gene modules, exploring gene intersections, identifying core genes, and screening for potential EMs biomarkers using weighted gene co-expression network analysis (WGCNA) and various machine learning approaches. We also performed gene set enrichment analysis (GSEA) to understand relevant pathways. This comprehensive approach helps investigate EMs genetics and potential biomarkers. Nine genes were identified at the intersection, suggesting their involvement in EMs. GSEA linked DEGs to pathways like complement and coagulation cascades, DNA replication, chemokines, apical plasma membrane processes, and diseases such as Hepatitis B, Human T-cell leukemia virus 1 infection, and COVID-19. Five feature genes (FOS, CFD, CCNA1, CA4, CST1) were selected by machine learning for an effective EMs diagnostic nomogram. GSEA indicated their roles in mismatch repair, cell cycle regulation, complement and coagulation cascades, and IL-17 inflammation. Notable differences in immune cell proportions (CD4 T cells, CD8 T cells, DCs, macrophages) were observed between normal and disease groups, suggesting immune involvement. This study suggests the potential involvement of phase separation-related genes in the pathogenesis of endometriosis (EMs) and identifies promising biomarkers for diagnosis. These findings have implications for further research and the development of new therapeutic strategies for EMs.

Kinrentius Wei, Dietrich & Webb, 2010 (Hemiptera: Cicadellidae: Deltocephalinae): description of two new species and taxonomic key to the genus.

Two new species of the South American genus Kinrentius are described and illustrated. Kinrentius catuaba sp. nov. from Brazil (Acre, Amazonas and Rondnia states) can be distinguished by the male pygofer with multidentate anteroventral and posteroventral processes with short dentiform processes between them and aedeagus with dorsal projection forming a distinct process and apex with paired apical processes, each subrectangular, with apical margin irregularly serrated in caudal view. Kinrentius peruvianus sp. nov. from Peru (Cusco and Madre de Dios departments) has short male pygofer posteroventral processes and aedeagus more robust and parallel sided in dorsal view, with paired apical processes, each subquadrate, with apical portion weekly sclerotized, and apical margin approximately straight and slightly serrate in caudal view. A taxonomic key to males and a distribution map of all four species of the genus are provided.

Revision of the bark louse genus Bicuspidatus (Psocodea: Peripsocidae) with description of a new species from China.

Bicuspidatus is a small genus of the family Peripsocidae, erected by Li (1993) with B. pulchipunctatus as the type species. Adults of this genus can be easily distinguished from other peripsocids by the phallosome with bicuspid apical process in males or by the subgenital plate with modestly elongated, distally bilobed posterior lobe in females. Bicuspidatus currently comprises three species: B. guangdongensis Li, 1993, B. pulchipunctatus Li, 1993 and B. sigillatus Li, 1993, all are known only from Guangdong Province, China. According to previous studies, these three species can be distinguished by the markings on the forewings and a few characteristics of phallosome (Li 1993, 2002). In this study, we present a taxonomic revision of Bicuspidatus based on examination of 40 specimens collected from various localities, including the type specimens of B. guangdongensis, B. pulchipunctatus and B. sigillatus. Furthermore, 12 of them were used for molecular analyses based on partial sequences of COI gene. As a result, B. guangdongensis and B. sigillatus are here considered as junior synonyms of B. pulchipunctatus. We redescribe B. pulchipunctatus and describe a new species from Xizang Autonomous Region, China. An updated distribution map and a revised key to the species of Bicuspidatus are also provided.

A new genus and species of Cicadellini (Insecta: Hemiptera: Cicadellidae: Cicadellinae) from the Brazilian Atlantic Forest

The remarkable sharpshooter Prodigiella silvanoi gen. et sp. nov. is described and illustrated (including the external form, color, male and female terminalia) from the Atlantic Forest of southern and southeastern Brazil (states of Paraná and Rio de Janeiro). The new genus can be distinguished from other Neotropical genera of the Cicadellini by a combination of various morphological features, including an asymmetrical aedeagus with a bifid shaft and peculiar basal and apical processes and ovipositor valvula II distinctly expanded beyond basal curvature, its dorsal margin with 35–40 teeth, and ventral margin without preapical prominence. A discussion comparing Prodigiella with superficially similar taxa of the genera Macugonalia Young, 1977, Ruppeliana Young, 1977, and Versigonalia Young, 1977 is provided. The discovery of this peculiar new genus indicates that much collecting work in the remaining parts of the Atlantic Forest is clearly and urgently needed.

Claudin-3 in the non-neural ectoderm is essential for neural fold fusion in chicken embryos

The neural tube, the embryonic precursor to the brain and spinal cord, begins as a flat sheet of epithelial cells, divided into non-neural and neural ectoderm. Proper neural tube closure requires that the edges of the neural ectoderm, the neural folds, to elevate upwards and fuse along the dorsal midline of the embryo. We have previously shown that members of the claudin protein family are required for the early phases of chick neural tube closure. Claudins are transmembrane proteins, localized in apical tight junctions within epithelial cells where they are essential for regulation of paracellular permeability, strongly involved in apical-basal polarity, cell-cell adhesion, and bridging the tight junction to cytoplasmic proteins. Here we explored the role of Claudin-3 (Cldn3), which is specifically expressed in the non-neural ectoderm. We discovered that depletion of Cldn3 causes folic acid-insensitive primarily spinal neural tube defects due to a failure in neural fold fusion. Apical cell surface morphology of Cldn3-depleted non-neural ectodermal cells exhibited increased membrane blebbing and smaller apical surfaces. Although apical-basal polarity was retained, we observed altered Par3 and Pals1 protein localization patterns within the apical domain of the non-neural ectodermal cells in Cldn3-depleted embryos. Furthermore, F-actin signal was reduced at apical junctions. Our data presents a model of spina bifida, and the role that Cldn3 is playing in regulating essential apical cell processes in the non-neural ectoderm required for neural fold fusion.

Volumetric Reconstruction of a Human Retinal Pigment Epithelial Cell Reveals Specialized Membranes and Polarized Distribution of Organelles.

Despite the centrality of the retinal pigment epithelium (RPE) in vision and retinopathy our picture of RPE morphology is incomplete. With a volumetric reconstruction of human RPE ultrastructure, we aim to characterize major membranous features including apical processes and their interactions with photoreceptor outer segments, basolateral infoldings, and the distribution of intracellular organelles. A parafoveal retinal sample was acquired from a 21-year-old male organ donor. With serial block-face scanning electron microscopy, a tissue volume from the inner-outer segment junction to basal RPE was captured. Surface membranes and complete internal ultrastructure of an individual RPE cell were achieved with a combination of manual and automated segmentation methods. In one RPE cell, apical processes constitute 69% of the total cell surface area, through a dense network of over 3000 terminal branches. Single processes contact several photoreceptors. Basolateral infoldings facing the choriocapillaris resemble elongated filopodia and comprise 22% of the cell surface area. Membranous tubules and sacs of endoplasmic reticulum represent 20% of the cell body volume. A dense basal layer of mitochondria extends apically to partly overlap electron-dense pigment granules. Pores in the nuclear envelope form a distinct pattern of rows aligned with chromatin. Specialized membranes at the apical and basal side of the RPE cell body involved in intercellular uptake and transport represent over 90% of the total surface area. Together with the polarized distribution of organelles within the cell body, these findings are relevant for retinal clinical imaging, therapeutic approaches, and disease pathomechanisms.

Microstructural Evaluation of the Mineralized Apical Barrier Induced by a Calcium Hydroxide Paste Containing Iodoform: A Case Report

IntroductionA 65-year-old man had nonsurgical retreatment using an iodoform and calcium hydroxide paste in a maxillary left canine with persistent apical periodontitis. An apical mineralized barrier (AMB) was observed 3-months postoperatively. Unfortunately, the tooth was extracted due to a cementum tear. This provided an opportunity to analyze the AMB histologically, as there is a lack of previous reports on its microstructure. MethodsAfter extraction and removal of the granulation tissue from the root surface, the canine was processed, and observed using micro–computed tomography (μCT) and light microscopy. Thereafter, the specimen was resin-embedded specimen was evaluated by scanning electron microscopy, micro–X-ray fluorescence spectroscopy and Raman spectroscopy to understand the mechanism and nature of the AMB formation during apical healing. ResultsNonsurgical retreatment was clinically successful based on the absence of clinical symptoms of apical periodontitis and the radiographic presence of an AMB. The AMB was opaque and could be readily differentiated from dentin under a light microscope. Micro–computed tomography analysis revealed that the AMB had the same mineral density as dentin. Scanning electron microscopy revealed that the AMB had two distinct layers based on the size of the calcified particles. Elemental mapping using micro–X-ray fluorescence spectroscopy showed that the localization of calcium and phosphorus differed between AMB and other areas of biomineralization. Raman spectral mapping revealed that the surface layer of the AMB consisted of collagen, calcium carbonate, and hydroxyapatite. ConclusionsThis study explored new analytical methods for elucidating the apical wound-healing process and the nature of the mineralized repair. The findings provided detailed information on the AMB highlighting a bilaminar structure with high calcium components higher on the inside and a brightness similar to cementum not dentin and the presence of hydroxyapatite.

Microscopic anatomy of the subcommissural organ in the brain of the adult greater cane rat (Rodentia: Thryonomyidae).

The subcommissural organ (SCO) is a well-developed gland present in the brain of vertebrates. The SCO secretes glycoproteins into the circulating cerebrospinal fluid and these assemble to form Reissner's fibre. It also plays an important function in neurogenesis and axonal guidance during embryogenesis. This study delves into the microscopic anatomy of the SCO in the adult greater cane rat (GCR), shedding light on its histoarchitectural characteristics. By utilizing histological techniques and microscopic analysis, we investigated the SCO's location and cellular composition within the brain of adult GCR. Our findings showed that the SCO in this species is located ventrally to the posterior commissure (PC) and dorsally to the third ventricle. The SCO consists of specialized ependymal or nuclear cell layer and apical processes lining the third ventricle. Moreover, the SCO's proximity to the PC and the third ventricle highlights its strategic position within the brain's ventricular system. With immunohistochemical analyses, the SCO cells expressed glial fibrillary protein when immunolabelled with Glial fibrillary acid protein (GFAP) antibody, a marker for astrocytes/astrocytic-like cells. Few microglia-like cells were immuno-positive for Ionized calcium-binding adapter molecule 1 (Iba1) antibody, that are existing within the SCO. However, the SCO in the GCR showed a negative immunostaining to NeuN antibody. This study contributes to our understanding of the microscopic anatomy of the SCO in a lesser-studied mammalian species. Further research into the SCO's functional significance especially during development in the GCR, may hold promise for more insights into neurological health and pathology.

Enteric Nervous System: Identification of a Novel Neuronal Sensory Network in the Duodenal Epithelium.

The communication between the intestinal epithelium and the enteric nervous system has been considered indirect. Mechanical or chemical stimuli activate enteroendocrine cells inducing hormone secretion, which act on sub-epithelial nerve ends, activating the enteric nervous system. However, we identified an epithelial cell that expresses NKAIN4, a neuronal protein associated with the β-subunit of Na+/K+-ATPase. This cell overexpresses Na+/K+-ATPase and ouabain-insensitive Na+-ATPase, enzymes involved in active sodium transport. NKAIN4-positive cells also express neuronal markers as NeuN, acetylcholine-esterase, acetylcholine-transferase, α3- and α7-subunits of ACh receptors, glutamic-decarboxylase, and serotonin-receptor-7, suggesting they are neurons. NKAIN4-positive cells show a polarized shape with an oval body, an apical process finished in a knob-like terminal in contact with the lumen, a basal cilia body at the base of the apical extension, and basal axon-like soma projections connecting sub-epithelial nerve terminals, lymphoid nodules, glial cells, and enterochromaffin cells, forming a network that reaches the epithelial surface. We also showed, using retrograde labeling and immunofluorescence, that these cells receive afferent signals from the enteric nervous system. Finally, we demonstrated that acetylcholine activates NKAIN4-positive cells inducing Ca2+ mobilization and probably serotonin secretion in enterochromaffin cells. NKAIN4-positive cells are neurons that would form a part of a duodenal sensory network for physiological or noxious luminal stimuli.

On the taxonomy of Philyra sagittifera (Alcock, 1896) and P. concinnus Ghani & Tirmizi, 1995 (Decapoda, Brachyura, Leucosiidae), with description of a new genus from the Indian Ocean.

The identity of the leucosiid crabs, Philyra sagittifera (Alcock, 1896) and P. concinnus Ghani & Tirmizi, 1995, originally described from Pakistan is clarified. Redescription of the lectotype male of Philyra sagittifera (Alcock, 1896) and fresh material of both species collected from the Persian Gulf revealed that these two species show significant morphological differences from the generic characters of Philyra sensu stricto and other allied genera in possessing three broad tuberculated ridges united to form a "broad-arrow" pointing forwards on the carapace, and male G1 with apical process curved, with or without a spatulate tip. Therefore, a new genus Tirmilyra n. gen. is established to accommodate both species.

Discernibility of the Interdigitation Zone (IZ), a Potential Optical Coherence Tomography (OCT) Biomarker for Visual Dysfunction in Aging

Purpose Photoreceptor (PR) outer segments, retinal pigment epithelium apical processes, and inter-PR matrix contribute to the interdigitation zone (IZ) of optical coherence tomography (OCT). We hypothesize that this interface degrades over adulthood, in concert with a delay of rod mediated dark adaptation (RMDA). To explore this idea, we determined IZ discernibility and RMDA in younger and older adults. Methods For this cross-sectional study, eyes of 20 young (20–30 years) and 40 older (≥60 years) participants with normal maculas according to the AREDS 9-step grading system underwent OCT imaging and RMDA testing at 5° superior to the fovea. Custom FIJI plugins enabled analysis for IZ discernibility at 9 eccentricities in 0.5 mm steps on one single horizontal B-scan through the fovea. Locations with discernible IZ met two criteria: visibility on B-scans and a distinct peak on a longitudinal reflectivity profile. The frequency of sites meeting both criteria was compared between both age groups and correlated with rod intercept time (RIT). Results The median number of locations with discernible IZ was significantly higher (foveal, 4 vs. 0, p = 0.0099; extra-foveal 6 vs. 0, p < 0.001) in eyes of young (26 ± 3 years) compared to older (73 ± 5 years) participants. For the combined young and older sample, the higher frequency of discernible IZ was correlated with shorter RIT (faster dark adaptation) (r s = –0.56, p < 0.0001). This association was significant within young eyes (r s = –0.54; p = 0.0134) and not within older eyes (r s = –0.29, p = 0.706). Conclusions Results suggest that the interface between outer segments and apical processes degrades in normal aging, potentially contributing to delayed rod-mediated dark adaptation. More research is needed to verify an age-related association between IZ discernibility and rod-mediated dark adaptation. If confirmed in a large sample, IZ discernibility might prove to be a valuable biomarker and predictor for visual function in aging.

Paropsocolis, a new pentatomid genus with two new species from Brazil (Heteroptera, Pentatomidae, Ochlerini).

When examining specimens of the Janeirona Distant, 1911 clade of Ochlerini (Discocephalinae) we found males and females of two undescribed species. Though clearly similar to the genera in the Janeirona clade, these two species lack the diagnostic characteristics of any of them. We made a cladistic analysis to verify the placement of the two new species in Discocephalinae. A total of 38 taxa and 60 morphological characters were included in the analysis. Character polarization followed the outgroup comparison method, and the most parsimonious trees were calculated in TNT using an implied weighting approach. The analysis resulted in one most parsimonious tree where the two new species form a monophyletic group within the Ochlerini, sister to Janeirona. We propose Paropsocolis Sampaio & Campos, gen. nov. for the two new species Paropsocolis convergens Sampaio & Campos, sp. nov. and Paropsocolis divergens Sampaio & Campos, sp. nov.. The new genus is recognized by having an inconspicuous labial intercalary segment, metasternum anteriorly carinated, parameres with a basal dish-shaped process and a bifurcated apex, theca with one apical ventral process, endosoma with one dorsal and one ventral processes, laterotergites IX surpassing the mediotergite VIII, and thickening of vaginal intima circular. P. convergens Sampaio & Campos, sp. nov. and P. divergens Sampaio & Campos, sp. nov. are described to Brazil. A distributional map is provided.

The First Report of the Acrotretoid Brachiopod Hadrotreta from the Tsinghsutung Formation Cambrian (Series 2, Stage 4), Guizhou, South China.

Hadrotreta is a worldwide acrotretoid brachiopod reported from the Cambrian Series 2 to Miaolingian. Here, a number of well-preserved fossils of Hadrotreta, identified as Hadrotreta cf. H. timchristiorum, were found in the Protoryctocephalus arcticus Zone of the Tsinghsutung Formation of Cambrian Series 2, Stage 4 in Jianhe, Guizhou, south China. This is the first report of Hadrotreta in China, which enriches its global palaeogeographical distribution. Hadrotreta is very similar to acrotretoids such as Kostjubella, Vandalotreta, Linnarssonia, and Eohadrotreta. It differs from them with its well-developed ventral boss-like apical process, apical pits, and dorsal median sulcus. In view of the palaeogeography of Hadrotreta, this genus was mainly distributed in low-latitude regions. Hadrotreta was only found in south China and Laurentia during the Cambrian Age 4, then expanded its distribution to other regions such as Siberia, Baltica, the Kazakh Terranes, the Far East, and Gondwana Pange during the Miaolingian Epoch. Hadrotreta seems to have shifted from deeper water to shallow-water environments during the period from the Cambrian Series 2 to the Miaolingian.

The genus Sofiella gen. nov. (Hemiptera, Cicadellidae, Cicadellini) with description of two new species from Brazil.

The Neotropical sharpshooter Sofiella gen. nov. is described and illustrated from the Araucaria moist forest in Southern and Southeastern Brazil (States of Paraná, Rio Grande do Sul and São Paulo) based on two new species, S. takiyae sp. nov. (type-species) and S. nicolasi sp. nov. The new genus shares features with Exogonia but can be differentiated by the pronotal width slightly narrower than the transocular width of the head; pygofer without setose processes; aedeagus bearing a pair of apical processes; female sternite VII with posterior margin convex; and second valvula with few long, not prominent teeth and a well developed preapical prominence.

Two new feather mite species (Acarina: Psoroptidia) from the Chestnut Bulbul, Hemixos castanonotus (Passeriformes: Pycnonotidae), in China

Two new species of feather mites from the bird host Hemixos castanonotus Swinhoe, 1870 (Pycnonotidae) collected in China are described: Trouessartia bulbuli sp. nov. (Trouessartiidae) and Pteroherpus guangdongensis sp. nov. (Pteronyssidae). Trouessartia bulbuli sp. nov. is close to T. latisetata Gaud, 1952 and differs in having the following features: in males of T. bulbuli tibia IV has apical thorn-like process at base of solenidia φ, epimerites IVa are wide and with a small extension of irregular form on the anterior end; in females, the copulatory opening is on the small wide-angular projection (external copulatory tube) on the margin of interlobar membrane and h1 setae are filiform. Pteroherpus guangdongensis sp. nov. belongs to the hoplophorus species group and is most close to P. meghalayensis Constantinescu, 2014.The new species has the following distinctive characters: in males, a very long genital apparatus and the epiandrum with long branches, extending beyond the base of setae 4a, a pair of small additional sclerites posterior to prodorsal shield is present, and adanal shield is shaped as a small longitudinal sclerite of irregular form; in females, the hysterosomal shield is split into unpaired anterior hysteronotal sclerite shaped as shaped as dumb-bell, central sclerite of triangular form, paired lateral opisthosomal sclerites and pygidial sclerites (similar to those in other species of hoplophorus group), and the hysteronotal gland openings gl are situated on the striated tegument.