Motility Defects Research Articles

Airway ciliary microenvironment responses in mice with primary ciliary dyskinesia and central pair apparatus defects

Dysfunction of motile cilia can impair mucociliary clearance in the airway and result in primary ciliary dyskinesia (PCD). We previously showed that mutations in central pair apparatus (CPA) genes perturb ciliary motility and result in PCD in mouse models. However, little is known about how epithelial cell types in the ciliary microenvironment of the upper airway respond to defects in ciliary motility and mucociliary clearance. Here, we have used single-cell RNA sequencing to investigate responses in tracheal epithelial cells from mice with mutations in CPA genes Cfap221/ Pcdp1, Cfap54, and Spef2. Expected cell types were identified, along with an unidentified cell type not expressing markers of typical airway cells. Deuterosomal cells were found to exist in two states that differ largely in expression of genes involved in differentiation into ciliated cells. Functional enrichment analysis of differentially expressed genes (DEGs) revealed important cellular functions and molecular pathways for each cell type that are altered in mutant mice. Overlapping DEGs shed light on general responses to cilia dysfunction, while unique DEGs indicate that some responses may be specific to the individual mutation and ciliary defect.

Metastasis-associated protein 1 participates in regulating luminal acidification of the epididymis via repressing estrogen receptor alpha transcription.

As a component of the nucleosome remodeling and deacetylating (NuRD) complex, metastasis-associated protein 1 (MTA1) has been reported to be abundant in male reproductive system and might participate in spermatogenesis and sperm maturation, whereas the precise functional role of MTA1 in these processes is still undetermined. To investigate the effect and potential function of MTA1 in male fertility. Mta1 knockout mice (Mta1-/-) were employed to detect their reproductive phenotype. The pH value of Mta1-/- epididymal luminal fluid was measured, and the potential mechanism of MTA1 involved in regulating luminal acidification was detected in vivo and in vitro. A vasectomy model with abnormal pH of epididymal lumen was established to further detect the effect of MTA1 on epididymal luminal microenvironment. Mta1-/- mice were fertile without any detectable defects in spermatogenesis or sperm motility while the deficiency of MTA1 could acidify the initial segment of epididymis to a certain extent. MTA1 could interact with estrogen receptor alpha (ERα) and inhibit the transcription of ERα target gene, hydrogen exchanger 3 (NHE3), and ultimately affect the epididymal luminal milieu. After vasectomy, the Mta1-/- mice presented a more acidic epididymal lumen which was closer to the normal state compared to the wild-type model. MTA1 is dispensable for male fertility in mice, but plays a potentially important function in regulating luminal acidification of the epididymis.

CABS1 Is Essential for Progressive Motility and the Integrity of Fibrous Sheath in Mouse Epididymal Spermatozoa.

The calcium-binding protein spermatid-associated 1 (CABS1) localizes to the principal piece of mature sperm flagella. Deletion of CABS1 results in subfertility in male mice, possibly due to an impaired annulus in the sperm flagella. However, it is unknown whether there are other mechanisms by which CABS1 affects male fertility. Our current investigation has uncovered that CABS1 is located in the midsection of the flagellum in testicular sperm and the principal piece in epididymal sperm. Moreover, male mice lacking CABS1 exhibit a defect in the progressive motility of sperm. Furthermore, the regulation of calcium levels, which has been reported to have a significant impact on sperm motility, capacitation, and the acrosome reaction, is also affected when sperm are exposed to alkalized high-salt buffer (pH 8.0) and progesterone (100 μM) in Cabs1-null spermatozoa. This alteration in calcium response may contribute to changes in the phosphorylation of PKA substrates and subsequent phosphorylation of tyrosine residues. Additionally, the absence of CABS1 leads to a defective fibrous sheath and abnormal configuration of doublet microtubules in post-testicular sperm. These findings indicate that the absence of CABS1 also disrupts the structural integrity of the fibrous sheath, resulting in male subfertility. The highly conserved nature of CABS1 in humans suggests that it could potentially be a contributing factor to asthenozoospermia in men.

A flagellar accessory protein links chemotaxis to surface sensing.

Bacteria find suitable locations for colonization by sensing and responding to surfaces. Complex signaling repertoires control surface colonization, and surface contact sensing by the flagellum plays a central role in activating colonization programs. Caulobacter crescentus adheres to surfaces using a polysaccharide adhesin called the holdfast. In C. crescentus, disruption of the flagellum through interactions with a surface or mutation of flagellar genes increases holdfast production. Our group previously identified several C. crescentus genes involved in flagellar surface sensing. One of these, fssF, codes for a protein with homology to the flagellar C-ring protein FliN. We show here that a fluorescently tagged FssF protein localizes to the flagellated pole of the cell and requires all components of the flagellar C-ring for proper localization, supporting the model that FssF associates with the C-ring. Deleting fssF results in a severe motility defect, which we show is due to a disruption of chemotaxis. Epistasis experiments demonstrate that fssF promotes adhesion through a stator-dependent pathway when late-stage flagellar mutants are disrupted. Separately, we find that disruption of chemotaxis through deletion of fssF or other chemotaxis genes results in a hyperadhesion phenotype. Key genes in the surface sensing network (pleD, motB, and dgcB) contribute to both ∆flgH-dependent and ∆fssF-dependent hyperadhesion, but these genes affect adhesion differently in the two hyperadhesive backgrounds. Our results support a model in which the stator subunits of the flagella incorporate both mechanical and chemical signals to regulate adhesion.IMPORTANCEBacterial biofilms pose a threat in clinical and industrial settings. Surface sensing is one of the first steps in biofilm formation. Studying surface sensing can improve our understanding of biofilm formation and develop preventative strategies. In this study, we use the freshwater bacterium Caulobacter crescentus to study surface sensing and the regulation of surface attachment. We characterize a previously unstudied gene, fssF, and find that it localizes to the cell pole in the presence of three proteins that make up a component of the flagellum called the C-ring. Additionally, we find that fssF is required for chemotaxis behavior but dispensable for swimming motility. Lastly, our results indicate that deletion of fssF and other genes required for chemotaxis results in a hyperadhesive phenotype. These results support that surface sensing requires chemotaxis for a robust response to a surface.

The NHR-23-regulated putative protease inhibitor mlt-11 gene is necessary for C. elegans cuticle structure and function.

C. elegans molting offers a powerful entry point to understanding developmentally programmed apical extracellular matrix remodeling. However, the gene regulatory network controlling this process remains poorly understood. Focusing on targets of NHR-23, a key transcription factor that drives molting, we confirmed the Kunitz family protease inhibitor gene mlt-11 as an NHR-23 target. Through reporter assays, we identified NHR-23-binding sites that are necessary and sufficient for epithelial expression. We generated a translational fusion and demonstrated that MLT-11 is localized to the cuticle and lined openings to the exterior (vulva, rectum, mouth). We created a set of strains expressing varied levels of MLT-11 by deleting endogenous cis-regulatory element sequences. Combined deletion of two cis-regulatory elements caused developmental delay, motility defects, and failure of the cuticle barrier. Inactivation of mlt-11 by RNAi produced even more pronounced defects. mlt-11 is necessary to pattern every layer of the adult cuticle, suggesting a broad patterning role prior to the formation of the mature cuticle. Together these studies provide an entry point into understanding how individual cis-regulatory elements function to coordinate expression of oscillating genes involved in molting and how MLT-11 ensures proper cuticle assembly.

EMC1 Is Required for the Sarcoplasmic Reticulum and Mitochondrial Functions in the Drosophila Muscle

EMC1 is part of the endoplasmic reticulum (ER) membrane protein complex, whose functions include the insertion of transmembrane proteins into the ER membrane, ER–mitochondria contact, and lipid exchange. Here, we show that the Drosophila melanogaster EMC1 gene is expressed in the somatic musculature and the protein localizes to the sarcoplasmic reticulum (SR) network. Muscle-specific EMC1 RNAi led to severe motility defects and partial late pupae/early adulthood lethality, phenotypes that are rescued by co-expression with an EMC1 transgene. Motility impairment in EMC1-depleted flies was associated with aberrations in muscle morphology in embryos, larvae, and adults, including tortuous and misaligned fibers with reduced size and weakness. They were also associated with an altered SR network, cytosolic calcium overload, and mitochondrial dysfunction and dysmorphology that impaired membrane potential and oxidative phosphorylation capacity. Genes coding for ER stress sensors, mitochondrial biogenesis/dynamics, and other EMC components showed altered expression and were mostly rescued by the EMC1 transgene expression. In conclusion, EMC1 is required for the SR network’s mitochondrial integrity and influences underlying programs involved in the regulation of muscle mass and shape. We believe our data can contribute to the biology of human diseases caused by EMC1 mutations.

Tristetraprolin affects invasion-associated genes expression and cell motility in triple-negative breast cancer model.

Tristetraprolin (TTP) is an RNA-binding protein that negatively regulates its target mRNAs and has been shown to inhibit tumor progression and invasion. Tumor invasion requires precise regulation of cytoskeletal components, and dysregulation of cytoskeleton-associated genes can significantly alter cell motility and invasive capability. Several genes, including SH3PXD2A, SH3PXD2B, CTTN, WIPF1, and WASL, are crucial components of the cytoskeleton reorganization machinery and are essential for adequate cell motility. These genes are also involved in invasion processes, with SH3PXD2A, SH3PXD2B, WIPF1, and CTTN being key components of invadopodia-specialized structures that facilitate invasion. However, the regulation of these genes is not well understood. This study demonstrates that ectopic expression of TTP in MDA-MB-231 cells leads to decreased mRNA levels of CTTN and SH3PXD2A, as well as defects in cell motility and actin filament organization. Additionally, doxorubicin significantly increases TTP expression and reduces the mRNA levels of cytoskeleton-associated genes, enhancing our understanding of how doxorubicin may affect the transcriptional profile of cells. However, doxorubicin affects target mRNAs differently than TTP ectopic expression, suggesting it may not be the primary mechanism of doxorubicin in breast cancer (BC) treatment. High TTP expression is considered as a positive prognostic marker in multiple cancers, including BC. Given that doxorubicin is a commonly used drug for treating triple-negative BC, using TTP as a prognostic marker in this cohort of patients might be limited since it might be challenging to understand if high TTP expression occurred due to the favorable physiological state of the patient or as a consequence of treatment.

Levels of Amyloid Beta (Aβ) Expression in the Caenorhabditis elegans Neurons Influence the Onset and Severity of Neuronally Mediated Phenotypes.

A characteristic feature of Alzheimer's disease (AD) is the formation of neuronal extracellular senile plaques composed of aggregates of fibrillar amyloid β (Aβ) peptides, with the Aβ1-42 peptide being the most abundant species. These Aβ peptides have been proposed to contribute to the pathophysiology of the disease; however, there are few tools available to test this hypothesis directly. In particular, there are no data that establish a dose-response relationship between Aβ peptide expression level and disease. We have generated a panel of transgenic Caenorhabditis elegans strains expressing the human Aβ1-42 peptide under the control of promoter regions of two pan-neuronal expressed genes, snb-1 and rgef-1. Phenotypic data show strong age-related defects in motility, subtle changes in chemotaxis, reduced median and maximum lifespan, changes in health span indicators, and impaired learning. The Aβ1-42 expression level of these strains differed as a function of promoter identity and transgene copy number, and the timing and severity of phenotypes mediated by Aβ1-42 were strongly positively correlated with expression level. The pan-neuronal expression of varying levels of human Aβ1-42 in a nematode model provides a new tool to investigate the in vivo toxicity of neuronal Aβ expression and the molecular and cellular mechanisms underlying AD progression in the absence of endogenous Aβ peptides. More importantly, it allows direct quantitative testing of the dose-response relationship between neuronal Aβ peptide expression and disease for the first time. These strains may also be used to develop screens for novel therapeutics to treat Alzheimer's disease.

Activation of the heat shock response as a therapeutic strategy for tau toxicity.

Alzheimer's disease is associated with the misfolding and aggregation of two distinct proteins, beta-amyloid and tau. Previously, it has been shown that activation of the cytoprotective heat shock response (HSR) pathway reduces beta-amyloid toxicity. Here, we show that activation of the HSR is also protective against tau toxicity in a cell-autonomous manner. Overexpression of HSF-1, the master regulator of the HSR, ameliorates the motility defect and increases the lifespan of transgenic C. elegans expressing human tau. By contrast, RNA interference of HSF-1 exacerbates the motility defect and shortens lifespan. Targeting regulators of the HSR also affects tau toxicity. Additionally, two small-molecule activators of the HSR, Geranylgeranylacetone (GGA) and Arimoclomol (AC), have substantial beneficial effects. Taken together, this research expands the therapeutic potential of HSR manipulation to tauopathies and reveals that the HSR can impact both beta-amyloid and tau proteotoxicity in Alzheimer's disease.

Regulation of TIR-1/SARM-1 by miR-71 Protects Dopaminergic Neurons in a C. elegans Model of LRRK2-Induced Parkinson's Disease.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by symptoms such as bradykinesia, resting tremor, and rigidity, primarily driven by the degradation of dopaminergic (DA) neurons in the substantia nigra. A significant contributor to familial autosomal dominant PD cases is mutations in the LRRK2 gene, making it a primary therapeutic target. This study explores the role of microRNAs (miRNAs) in regulating the proteomic stress responses associated with neurodegeneration in PD using C. elegans models. Our focus is on miR-71, a miRNA known to affect stress resistance and act as a pro-longevity factor in C. elegans. We investigated miR-71's function in C. elegans models of PD, where mutant LRRK2 expression correlates with dopaminergic neuronal death. Our findings reveal that miR-71 overexpression rescues motility defects and slows dopaminergic neurodegeneration in these models, suggesting its critical role in mitigating the proteotoxic effects of mutant LRRK2. Conversely, miR-71 knockout exacerbates neuronal death caused by mutant LRRK2. Additionally, our data indicate that miR-71's neuroprotective effect involves downregulating the toll receptor domain protein tir-1, implicating miR-71 repression of tir-1 as vital in the response to LRRK2-induced proteotoxicity. These insights into miR-71's role in C. elegans models of PD not only enhance our understanding of molecular mechanisms in neurodegeneration but also pave the way for potential research into human neurodegenerative diseases, leveraging the conservation of miRNAs and their targets across species.

Residues 2 to 7 of α-synuclein regulate amyloid formation via lipid-dependent and lipid-independent pathways

Amyloid formation by α-synuclein (αSyn) occurs in Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies. Deciphering the residues that regulate αSyn amyloid fibril formation will not only provide mechanistic insight but may also reveal targets to prevent and treat disease. Previous investigations have identified several regions of αSyn to be important in the regulation of amyloid formation, including the non-amyloid-β component (NAC), P1 region (residues 36 to 42), and residues in the C-terminal domain. Recent studies have also indicated the importance of the N-terminal region of αSyn for both its physiological and pathological roles. Here, the role of residues 2 to 7 in the N-terminal region of αSyn is investigated in terms of their ability to regulate amyloid fibril formation in vitro and in vivo. Deletion of these residues (αSynΔN7) slows the rate of fibril formation in vitro and reduces the capacity of the protein to be recruited by wild-type (αSynWT) fibril seeds, despite cryo-EM showing a fibril structure consistent with those of full-length αSyn. Strikingly, fibril formation of αSynΔN7 is not induced by liposomes, despite the protein binding to liposomes with similar affinity to αSynWT. A Caenorhabditis elegans model also showed that αSynΔN7::YFP forms few puncta and lacks motility and lifespan defects typified by expression of αSynWT::YFP. Together, the results demonstrate the involvement of residues 2 to 7 of αSyn in amyloid formation, revealing a target for the design of amyloid inhibitors that may leave the functional role of the protein in membrane binding unperturbed.

Flagellar stator genes control a trophic shift from obligate to facultative predation and biofilm formation in a bacterial predator.

The ability of bacteria to form biofilms is a central research theme in biology, medicine, and the environment. We show that cultures of the obligate (host-dependent) "solitary" predatory bacterium Bdellovibrio bacteriovorus, which cannot replicate without prey, can use various genetic routes to spontaneously yield host-independent (H-I) variants that grow axenically (as a single species, in the absence of prey) and exhibit various surface attachment phenotypes, including biofilm formation. These routes include single mutations in flagellar stator genes that affect biofilm formation, provoke motor instability and large motility defects, and disrupt cyclic-di-GMP intracellular signaling. H-I strains also exhibit reduced predatory efficiency in suspension but high efficiency in prey biofilms. These changes override the requirements for prey, enabling a shift from obligate to facultative predation, with potential consequences on community dynamics.

P-089 Sperm motility and sperm DNA fragmentation evaluation after irradiation with a 633nm He-Ne laser in donor samples. An in vitro pilot study

Abstract Study question Does a 633nm laser irradiation on sperm samples improve sperm motility safely? Summary answer 633 nm wavelength He-Ne laser irradiation for 5 and 10 minutes increases slow progressive and non-progressive sperm motility without modification of the DNA fragmentation. What is known already Sperm motility has been hypothesized to increase after light radiation excitation of cytochrome c- oxidase, which boost adenosin triphosphate (ATP) synthesis, in a range of wavelength between 600-1000 nm. One of the main problems of this stimulation is the generation of Reactive Oxigen Species (ROS) that may affect sperm DNA integrity. Previous studies have approached to this field showing different results. Study design, size, duration In vitro pilot study of 15 sperm samples donated for research between June 2022 and October 2023 which were irradiated with a 633nm wavelength He-Ne laser. Each sample was split in 4 aliquots of 10 microliters. To study sperm motility analysis, two videos of each were recorded, before and after irradiation, anonymized and evaluated later by a single embryologist. Sperm motility was annotated according to WHO 2021 criteria. Participants/materials, setting, methods After laser calibration and alignment, sperm samples were irradiated at 37 ºC in a Makler chamber with a continuous emission laser with a gaussian-like beam thirty cm. away for 5,10,15 and 20 minutes. Two videos were obtained for each aliquot, before and after irradiation. Radiant exposure was calculated using the equation y = 1030 x-1,626. Sperm Chromatine Dispersion (SCD) test was employed in 50 µl aliquots to study DNA fragmentation. Shapiro-Wilk and paired t-student tests were employed. Main results and the role of chance We observed a significant increase in slowly progressive motility; -0.075 [-0.12 – 0.024] (p = 0.007); and non-progressive motility; -0.023 [-0.041 – -0.006] (p = 0.011); after irradiating samples between 5 and 10 minutes with a total radiant exposure, 0.4830 and 0.9661 (mW/mm2 * min). Also, for total progressive motility; -0.075 [-0.13 – -0.01] (p = 0.024), and total motility; -0.069 [-0.126 – -0.012) (p = 0.021). No differences were found in sperm DNA fragmentation index after irradiating for 10 minutes; -1.347 [-4.073 - 1.380] (p = 0.32) nor for 20 minutes of irradiation -1.587 [-4.400 - 1.227] (p = 0.25). According to our results, irradiation of sperm samples between 5 and 10 minutes with a 633nm wavelength laser, increases type b and type c motility spermatozoa without affecting sperm DNA fragmentation. Longer irradiations, 15 and 20 minutes, do not show an improvement in sperm motility, neither in sperm DNA fragmentation in our set of data. Limitations, reasons for caution This in vitro pilot study has not been proved in samples to clinical use and our findings need a confirmation with clinical samples in animals to ensure the safety in the conceptions and offspring. We included samples with normal sperm values. Results should be confirmed in samples with motility defects. Wider implications of the findings Our findings are the first step in a new way to modify the sperm motility in vitro throughout laser exposition, which may benefit patients with severe asthenozoospermia without the use of chemical motility inductors. We hope to confirm the safe clinical use in animals before translation to humans. Trial registration number 1909-VGO-082-JA

Involvement of ArlI, ArlJ, and CirA in archaeal type IV pilin-mediated motility regulation.

Many prokaryotes use swimming motility to move toward favorable conditions and escape adverse surroundings. Regulatory mechanisms governing bacterial flagella-driven motility are well-established; however, little is yet known about the regulation underlying swimming motility propelled by the archaeal cell surface structure, the archaella. Previous research showed that the deletion of the adhesion pilins (PilA1-6), subunits of the type IV pili cell surface structure, renders the model archaeon Haloferax volcanii non-motile. In this study, we used ethyl methanesulfonate mutagenesis and a motility assay to identify motile suppressors of the ∆pilA[1-6] strain. Of the eight suppressors identified, six contain missense mutations in archaella biosynthesis genes, arlI and arlJ. In trans expression of arlI and arlJ mutant constructs in the respective multi-deletion strains ∆pilA[1-6]∆arlI and ∆pilA[1-6]∆arlJ confirmed their role in suppressing the ∆pilA[1-6] motility defect. Additionally, three suppressors harbor co-occurring disruptive missense and nonsense mutations in cirA, a gene encoding a proposed regulatory protein. A deletion of cirA resulted in hypermotility, while cirA expression in trans in wild-type cells led to decreased motility. Moreover, quantitative real-time PCR analysis revealed that in wild-type cells, higher expression levels of arlI, arlJ, and the archaellin gene arlA1 were observed in motile early-log phase rod-shaped cells compared to non-motile mid-log phase disk-shaped cells. Conversely, ∆cirA cells, which form rods during both early- and mid-log phases, exhibited similar expression levels of arl genes in both growth phases. Our findings contribute to a deeper understanding of the mechanisms governing archaeal motility, highlighting the involvement of ArlI, ArlJ, and CirA in pilin-mediated motility regulation.IMPORTANCEArchaea are close relatives of eukaryotes and play crucial ecological roles. Certain behaviors, such as swimming motility, are thought to be important for archaeal environmental adaptation. Archaella, the archaeal motility appendages, are evolutionarily distinct from bacterial flagella, and the regulatory mechanisms driving archaeal motility are largely unknown. Previous research has linked the loss of type IV pili subunits to archaeal motility suppression. This study reveals three Haloferax volcanii proteins involved in pilin-mediated motility regulation, offering a deeper understanding of motility regulation in this understudied domain while also paving the way for uncovering novel mechanisms that govern archaeal motility. Understanding archaeal cellular processes will help elucidate the ecological roles of archaea as well as the evolution of these processes across domains.

Structure and function of FAP47 in the central pair apparatus of Chlamydomonas flagella.

Motile cilia have a so-called "9 + 2" structure, which consists of nine doublet microtubules and a central pair apparatus. The central pair apparatus (CA) is thought to interact mechanically with radial spokes and to control the flagellar beating. Recently, the components of the CA have been identified by proteomic and genomic analyses. Still, the mechanism of how the CA contributes to ciliary motility has much to be revealed. Here, we focused on one CA component with a large molecular weight: FAP47, and its relationship with two other CA components with large molecular weight: HYDIN, and CPC1. The analyses of motility of the Chlamydomonas mutants revealed that in contrast to cpc1 or hydin, which swam more slowly than the wild type, fap47 cells displayed wild-type swimming velocity and flagellar beat frequency, yet interestingly, fap47 cells have phototaxis defects and swim straighter than the wild-type cells. Furthermore, the double mutant fap47cpc1 and fap47hydin showed significantly slower swimming than cpc1 and hydin cells, and the motility defect of fap47cpc1 was rescued to the cpc1 level with GFP-tagged FAP47, indicating that the lack of FAP47 makes the motility defect of cpc1 worse. Cryo-electron tomography demonstrated that the fap47 lacks a part of the C1-C2 bridge of CA. Taken together, these observations indicate that FAP47 maintains the structural stiffness of the CA, which is important for flagellar regulation.

Reversible male contraception by targeted inhibition of serine/threonine kinase 33.

Men or mice with homozygous serine/threonine kinase 33 (STK33) mutations are sterile owing to defective sperm morphology and motility. To chemically evaluate STK33 for male contraception with STK33-specific inhibitors, we screened our multibillion-compound collection of DNA-encoded chemical libraries, uncovered potent STK33-specific inhibitors, determined the STK33 kinase domain structure bound with a truncated hit CDD-2211, and generated an optimized hit CDD-2807 that demonstrates nanomolar cellular potency (half-maximal inhibitory concentration = 9.2 nanomolar) and favorable metabolic stability. In mice, CDD-2807 exhibited no toxicity, efficiently crossed the blood-testis barrier, did not accumulate in brain, and induced a reversible contraceptive effect that phenocopied genetic STK33 perturbations without altering testis size. Thus, STK33 is a chemically validated, nonhormonal contraceptive target, and CDD-2807 is an effective tool compound.

Temporal trends in paediatric hydrocephalus - Rising prematurity and persistent ophthalmological challenges.

To study changes in aetiology, prematurity, comorbidity and ophthalmological outcomes in children with surgically treated hydrocephalus to provide information needed to maintain the best possible healthcare for a fragile and changing population. Two population-based cohorts, born two decades apart in Region Västra Götaland Sweden, surgically treated for hydrocephalus at Sahlgrenska University Hospital in Gothenburg were recruited at approximately 10 years of age. The participants were examined according to an ophthalmological protocol, including history taking regarding perceptual visual dysfunction (PVD). Gestational age, aetiology and comorbidities were registered. The 1989-1993 group, comprised 52 children (48% girls; mean age 10, range 7.7-12.8 years), was compared with 24 children, born in 2007-2012 (29% girls; mean age 10, range 7.0-13.8 years). Extreme prematurity (gestational age ≤ 28 weeks) increased over time (p = 0.001). The vast majority of the children showed ophthalmological abnormalities, although motility defects and nystagmus decreased in the latter population. Subnormal visual acuity was associated with extreme prematurity (RR = 4.69; p = 0.030), and PVD with learning disability (RR = 2.44; p = 0.032). Paediatric hydrocephalus populations may change with improved healthcare. Since a high percentage shows ophthalmological abnormalities and more children are born extremely preterm, the entirety needs consideration both neurologically and ophthalmologically.

Influence of two collection frequency intervals on sperm quality of standard and miniature bull Terriers during short breeding periods: A clinical field study.

The quality of canine sperm can be influenced by many factors, such as breed, body weight, age, ejaculatory frequency, nutrition, and environment. In the UK, it is common practice for standard Bull Terriers (SBT) and miniature Bull Terriers (MBT) to require male donors during a short breeding period. The aim of this study was to evaluate the effect of semen collection frequency on ejaculate volume and nine sperm parameters in SBT and MBT males, considering age and body condition score (BCS). Ejaculates from six adult SBTs and four MBTs were collected 5 times at two consecutive intervals (Time Series [TS]1, 24 h vs. TS2, 48 h), 1 week apart. Ejaculate volume, concentration, total output, viability (live sperm), subjective total motility, vigor, and total morphological defects, including head, midpiece, and tail defects of sperm, were evaluated. A multivariable mixed linear model for repeated measures was used to analyze the effects of semen collection frequency, age, breed, and BCS on ejaculate volume and sperm parameters. Semen collection frequency, age, and, to a lesser extent, breed, and BCS significantly affected sperm parameters. Semen collection frequency affected all sperm parameters (p < 0.05) but not ejaculate volume (p > 0.05). Total sperm output, sperm vigor, total motility, and tail defects decreased (p < 0.05) at the end of TS1. However, sperm parameters remained relatively constant (p > 0.05) in TS2 between semen collection sessions. Overall, poorer sperm parameters were observed in older dogs (aged 5-8 years) than in younger dogs (aged 4 years). MBT produced less (p < 0.001) ejaculate volume (3.2 ± 0.2 mL vs. 4.3 ± 0.2 mL: Least Squares Mean ± Standard Error of Mean), lower total sperm output (221.8 ± 19.2 × 106 vs. 348.6 ± 19.2 × 106) and lower total morphological defects (25.0 ± 1.1% vs. 31.3 ± 0.9%), and a higher percentage of live sperm (77.0 ± 1.4% vs. 71.7 ± 1.1%) than SBT. In addition, a BCS of 4 positively influenced (p < 0.05) viability, vigor, and total sperm motility. Despite differences in age, breed, and BCS, better sperm parameter values were observed in all semen collection sessions. However, intensive semen collection (TS1) appears to be less effective in maintaining good sperm quality. For breeding or artificial insemination purposes, a 48-h interval between collection sessions is recommended for both breeds. The results of this study could be used to further optimize assisted reproductive technologies in both breeds.

The swimming defect caused by the absence of the transcriptional regulator LdtR in Sinorhizobium meliloti is restored by mutations in the motility genes motA and motS.

The flagellar motor is a powerful macromolecular machine used to propel bacteria through various environments. We determined that flagellar motility of the alpha-proteobacterium Sinorhizobium meliloti is nearly abolished in the absence of the transcriptional regulator LdtR, known to influence peptidoglycan remodeling and stress response. LdtR does not regulate motility gene transcription. Remarkably, the motility defects of the ΔldtR mutant can be restored by secondary mutations in the motility gene motA or a previously uncharacterized gene in the flagellar regulon, which we named motS. MotS is not essential for S. meliloti motility and may serve an accessory role in flagellar motor function. Structural modeling predicts that MotS comprised an N-terminal transmembrane segment, a long-disordered region, and a conserved β-sandwich domain. The C terminus of MotS is localized in the periplasm. Genetics based substitution of MotA with MotAG12S also restored the ΔldtR motility defect. The MotAG12S variant protein features a local polarity shift at the periphery of the MotAB stator units. We propose that MotS may be required for optimal alignment of stators in wild-type flagellar motors but becomes detrimental in cells with altered peptidoglycan. Similarly, the polarity shift in stator units composed of MotB/MotAG12S might stabilize its interaction with altered peptidoglycan.

High paternal homocysteine causes ventricular septal defects in mouse offspring

Maternal hyperhomocysteinemia is widely considered as an independent risk of congenital heart disease (CHD). However, whether high paternal homocysteine causes CHD remains unknown. Here, we showed that increased homocysteine levels of male mice caused decreased sperm count, sperm motility defect and ventricular septal defect of the offspring. Moreover, high levels of paternal homocysteine decrease sperm DNMT3A/3B, accompanied with changes in DNA methylation levels in the promoter regions of CHD-related genes. Folic acid supplement could decrease the occurrence of VSD in high homocysteine male mice. This study reveals that increased paternal homocysteine level increases VSD risk in the offspring, indicating that decreasing paternal homocysteine may be an intervening target of CHD.