scholarly journals A SoxB gene acts as an anterior gap gene and regulates posterior segment addition in a spider

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Christian Louis Bonatto Paese ◽  
Anna Schoenauer ◽  
Daniel J Leite ◽  
Steven Russell ◽  
Alistair P McGregor
Keyword(s):  
Posterior Segment ◽  
Parasteatoda Tepidariorum ◽  
Gap Gene ◽  
Sequential Addition ◽  
Soxb Gene ◽  
Sox Gene ◽  
Anterior Segments ◽  
Conserved Gene ◽  
Sox Genes

Sox genes encode a set of highly conserved transcription factors that regulate many developmental processes. In insects, the SoxB gene Dichaete is the only Sox gene known to be involved in segmentation. To determine if similar mechanisms are used in other arthropods, we investigated the role of Sox genes during segmentation in the spider Parasteatoda tepidariorum. While Dichaete does not appear to be involved in spider segmentation, we found that the closely related Sox21b-1 gene acts as a gap gene during formation of anterior segments and is also part of the segmentation clock for development of the segment addition zone and sequential addition of opisthosomal segments. Thus, we have found that two different mechanisms of segmentation in a non-mandibulate arthropod are regulated by a SoxB gene. Our work provides new insights into the function of an important and conserved gene family, and the evolution of the regulation of segmentation in arthropods.

scholarly journals A SoxB gene acts as an anterior gap gene and regulates posterior segment addition in the spider Parasteatoda tepidariorum

2018 ◽  
Author(s):  
Christian L. B. Paese ◽  
Anna Schoenauer ◽  
Daniel J. Leite ◽  
Steven Russell ◽  
Alistair P. McGregor
Keyword(s):  
Gene Family ◽  
Parasteatoda Tepidariorum ◽  
Gap Gene ◽  
Sequential Addition ◽  
Soxb Gene ◽  
Sox Gene ◽  
Conserved Gene ◽  
Group B ◽  
Embryonic Segmentation

SummaryThe Sox gene family encode a set of highly conserved HMG domain transcription factors that regulate many key processes during metazoan embryogenesis. In insects, the SoxB gene Dichaete is the only Sox gene known to be involved in embryonic segmentation. To determine if similar mechanisms are used in other arthropods, we investigated the role of Sox genes during segmentation in the spider Parasteatoda tepidariorum. While Dichaete does not appear to be involved in spider segmentation, RNAi knockdown of the closely related Sox21b-1 gene results in a gap like phenotype in the developing prosoma and also perturbs the sequential addition of opisthosomal segments. We show that this is in part due to a role for Sox21b-1 in regulating the expression of Wnt8 and influencing Delta-Notch signalling during the formation of the segment addition zone. Thus, we have found that two different mechanisms for segmentation in a non-mandibulate arthropod are regulated by a Group B Sox gene. Our work provides new insights into the function of an important and conserved gene family across arthropods, and the evolution of the regulation of segmentation in these animals.

scholarly journals The evolution of Sox gene repertoires and regulation of segmentation in arachnids

2020 ◽  
Author(s):  
Luis Baudouin-Gonzalez ◽  
Anna Schoenauer ◽  
Amber Harper ◽  
Grace Blakeley ◽  
Michael Seiter ◽  
...  
Keyword(s):  
Regulatory Networks ◽  
Close Relative ◽  
System Specification ◽  
Germline Development ◽  
Simultaneous Formation ◽  
Parasteatoda Tepidariorum ◽  
Stem Cell Maintenance ◽  
Arthropod Species ◽  
Anterior Segments ◽  
Sox Genes

AbstractThe Sox family of transcription factors regulate many different processes during metazoan development, including stem cell maintenance, nervous system specification and germline development. In addition, it has recently become apparent that SoxB genes are involved in embryonic segmentation in several arthropod species. Segmentation in arthropods occurs in two main ways: long germ animals form all segments at once, best exemplified in the well-studied Drosophila melanogaster system, and short germ animals form anterior segments simultaneously, with posterior segments added sequentially from a segment addition zone. In both D. melanogaster and the short germ beetle Tribolium castaneum, the SoxB gene Dichaete is required for correct segmentation and, more recently, we showed that a close relative of Dichaete, Sox21b-1, is required for the simultaneous formation of prosomal segments and sequential addition of opisthosomal segments in the spider Parasteatoda tepidariorum. Here we further analysed the function and expression of Sox21b-1 in P. tepidariorum. We found that while this gene regulates the generation of both prosomal and opisthosomal segments, it plays different roles in the formation of these tagma reflecting their contrasting modes of segmentation and deployment of gene regulatory networks with different architectures. To further investigate the evolution of Sox genes and their roles we characterised the repertoire of the gene family across several arachnid species with and without an ancestral whole genome duplication, and compared Sox expression between P. tepidariorum and the harvestman Phalangium opilio. The results suggest that Sox21b-1 was likely involved in segmentation ancestrally in arachnids, but that other Sox genes could also regulate this process in these animals. We also found that most Sox families have been retained as duplicates or ohnologs after WGD and evidence for potential subfunctionalisation and/or neofunctionalization events.

scholarly journals Duplication and divergence of Sox genes in spiders

2017 ◽  
Author(s):  
Christian L. B. Paese ◽  
Daniel J. Leite ◽  
Anna Schoenauer ◽  
Alistair P. McGregor ◽  
Steven Russell
Keyword(s):  
Limb Development ◽  
Evolutionary History ◽  
Genome Duplication ◽  
Regulatory Mechanism ◽  
Recent Analysis ◽  
Parasteatoda Tepidariorum ◽  
Arthropod Species ◽  
Sox Gene ◽  
And Function ◽  
Sox Genes

AbstractBackgroundThe Sox family of transcription factors are present and conserved in the genomes of all metazoans examined to data and are known to play important developmental roles in vertebrates and insects. However, outside the commonly studied Drosophila model little is known about the extent or conservation of the Sox family in other arthropod species. Here we characterise the Sox family in two chelicerate species, the spiders Parasteatoda tepidariorum and Stegodyphus mimosarum, which have experienced a whole genome duplication (WGD) in their evolutionary history.ResultsWe find that virtually all of the duplicate Sox genes have been retained in these spiders after the WGD. Analysis of the expression of Sox genes in P. tepidariorum embryos indicates that it is likely that some of these genes have neofunctionalised after duplication. Our expression analysis also strengthens the view that an orthologue of vertebrate Group B1 genes, SoxNeuro, is implicated in the earliest events of CNS specification in both vertebrates and invertebrates. In addition, a gene in the Dichaete/Sox21b class is dynamically expressed in the spider segment addition zone, suggestive of an ancient regulatory mechanism controlling arthropod segmentation as recently suggested for flies and beetles. Together with the recent analysis of Sox gene expression in the embryos of other arthropods, our findings are also indicative of conserved functions for some of these genes, including a role for SoxC and SoxD genes in CNS development, SoxF in limb development and a tantalising suggestion that SoxE genes may be involved in gonadogenesis across the metazoa.ConclusionsOur study provides a new chelicerate perspective to understanding the evolution and function of Sox genes and how the retention of duplicates of such important tool-box genes after WGD has contributed to different aspects of spider embryogenesis. Future characterisation of the function of these genes in spiders will help us to better understand the evolution of the regulation of important developmental processes in arthropods and other metazoans including neurogenesis and segmentation.

scholarly journals Author response: A SoxB gene acts as an anterior gap gene and regulates posterior segment addition in a spider

2018 ◽  
Author(s):  
Christian Louis Bonatto Paese ◽  
Anna Schoenauer ◽  
Daniel J Leite ◽  
Steven Russell ◽  
Alistair P McGregor
Keyword(s):  
Posterior Segment ◽  
Author Response ◽  
Gap Gene ◽  
Soxb Gene

scholarly journals THE ENHANCEMENT OF BACTERIAL PHAGOCYTOSIS BY SERUM

1969 ◽  
Vol 129 (6) ◽  
pp. 1275-1290 ◽  
Author(s):  
Richard B. Johnston ◽  
Martin R. Klemperer ◽  
Chester A. Alper ◽  
Fred S. Rosen
Keyword(s):  
Normal Serum ◽  
Phagocytic Index ◽  
Peptidase Activity ◽  
Complement Components ◽  
Serum Factors ◽  
Heat Labile ◽  
Dye Reduction ◽  
Sequential Addition ◽  
Enzymatic Inactivation

The role of serum factors in the phagocytosis of pneumococci was studied employing a spectrophotometric assay which measures reduced nitro blue tetrazolium (NBT) dye. Dye reduction occurs within the phagocyte shortly after bacterial ingestion as measured by the phagocytic index technique and by the uptake of 125I-pneumococci. Bacteria prepared with γG antibody were not phagocytosed unless a small volume of fresh normal serum was added. Using fresh sera deficient in single complement components, it was demonstrated that the first four components are necessary for optimal bacterial phagocytosis. When highly purified complement components were added to the antibody-coated pneumococci, enhancement of phagocytosis was achieved only with the sequential addition of C1, C4, C2, and C3. Evidence has been presented that human C3 bound to an immune complex exhibits peptidase activity and that this activity is essential for phagocytosis. A heat-labile, dialyzable serum cofactor which enhances C3 peptidase activity enhanced the phagocytosis of pneumococci prepared with purified complement components. A second phagocytosis-promoting cofactor, which is not a complement component, was found to be a heat-labile, 5–6S, beta pseudoglobulin. This protein may stabilize C3 peptidase activity or inhibit enzymatic inactivation of C3.

scholarly journals EvolClust: automated inference of evolutionary conserved gene clusters in eukaryotes

2019 ◽  
Author(s):  
Marina Marcet-Houben ◽  
Toni Gabaldón
Keyword(s):  
Secondary Metabolism ◽  
Computational Prediction ◽  
Gene Clusters ◽  
Supplementary Information ◽  
Supplementary Data ◽  
Automated Inference ◽  
Or Gene ◽  
Conserved Gene ◽  
Genome Comparisons

Abstract Motivation The evolution and role of gene clusters in eukaryotes is poorly understood. Currently, most studies and computational prediction programs limit their focus to specific types of clusters, such as those involved in secondary metabolism. Results We present EvolClust, a python-based tool for the inference of evolutionary conserved gene clusters from genome comparisons, independently of the function or gene composition of the cluster. EvolClust predicts conserved gene clusters from pairwise genome comparisons and infers families of related clusters from multiple (all versus all) genome comparisons. Availability and implementation https://github.com/Gabaldonlab/EvolClust/. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals Posterior Segment Ophthalmic Drug Delivery: Role of Muco-Adhesion with a Special Focus on Chitosan

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1685
Author(s):  
Ayah Mohammad Burhan ◽  
Butsabarat Klahan ◽  
Wayne Cummins ◽  
Vanessa Andrés-Guerrero ◽  
Mark E. Byrne ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Posterior Segment ◽  
Special Focus ◽  
Topical Drug Delivery ◽  
Ophthalmic Drug Delivery ◽  
Mucoadhesive Polymers ◽  
Eye Tissues ◽  
Successful Design ◽  
Ophthalmic Drug

Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the potential of a more patient friendly topical route has been widely investigated. Mucoadhesive formulations can decrease precorneal clearance while prolonging precorneal residence. Thus, they are expected to enhance the chances of adherence to corneal and conjunctival surfaces and as such, enable increased delivery to the posterior eye segment. Among the mucoadhesive polymers available, chitosan is the most widely explored due to its outstanding mucoadhesive characteristics. In this review, the major PSEDs, their treatments, barriers to topical delivery, and routes of topical drug absorption to the posterior eye are presented. To enable the successful design of mucoadhesive ophthalmic drug delivery systems (DDSs), an overview of mucoadhesion, its theory, characterization, and considerations for ocular mucoadhesion is given. Furthermore, chitosan-based DDs that have been explored to promote topical drug delivery to the posterior eye segment are reviewed. Finally, challenges of successful preclinical to clinical translation of these DDSs for posterior eye drug delivery are discussed.

scholarly journals CLK-2/TEL2 is a conserved component of the nonsense-mediated mRNA decay pathway

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244505
Author(s):  
Yanwu Guo ◽  
Cristina Tocchini ◽  
Rafal Ciosk
Keyword(s):  
Mrna Decay ◽  
Forward Genetics ◽  
Morphological Effect ◽  
Dna Damage Signaling ◽  
Mrna Surveillance ◽  
Genetic Landscape ◽  
Nonsense Mediated Mrna Decay ◽  
Novel Strategy ◽  
Conserved Gene

Nonsense-mediated mRNA decay (NMD) controls eukaryotic mRNA quality, inducing the degradation of faulty transcripts. Key players in the NMD pathway were originally identified, through genetics, in Caenorhabditis elegans as smg (suppressor with morphological effect on genitalia) genes. Using forward genetics and fluorescence-based NMD reporters, we reexamined the genetic landscape underlying NMD. Employing a novel strategy for mapping sterile mutations, Het-Map, we identified clk-2, a conserved gene previously implicated in DNA damage signaling, as a player in the nematode NMD. We find that CLK-2 is expressed predominantly in the germline, highlighting the importance of auxiliary factors in tissue-specific mRNA decay. Importantly, the human counterpart of CLK-2/TEL2, TELO2, has been also implicated in the NMD, suggesting a conserved role of CLK-2/TEL2 proteins in mRNA surveillance. Recently, variants of TELO2 have been linked to an intellectual disability disorder, the You-Hoover-Fong syndrome, which could be related to its function in the NMD.

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