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PubMed2007

Abnormal motion of the medial femoral condyle in lateral knee osteoarthritis.

The pattern of knee motion in patients with lateral osteoarthritis may be associated with the pathogenesis of this disease. Based on previous findings of decreased anteroposterior femoral condylar translation in knees with medial knee osteoarthritis, we asked whether a similar pattern of knee kinematics in lateral osteoarthritis could be related to the wear pattern on the tibial plateau. We used sequential radiostereometric images to study kinematics during active weightbearing extension in five knees with lateral osteoarthritis and 11 control knees. At 45 degrees of flexion, the posterior circular center of the lateral femoral condyle displaced posteriorly at 45 degrees and moved anteriorly during extension in both groups. There was also a proximal displacement with extension, but from a more distal position in the osteoarthritis group. We could only partly relate the kinematics of knees with lateral osteoarthritis to the wear pattern on the tibial plateau. Contrary to our hypothesis of normal anterior displacement of the medial and increased posterior displacement of the lateral femoral condyle, we observed no change of anterior-posterior displacements of the lateral condyle.

Adolescent↗
PubMed1995

Ontogeny of the head of the Pacific hagfish (Eptatretus stouti, Myxinoidea): development of the lateral line system.

The head of adult hagfishes (jawless craniates, Myxinoidea) of the family Eptatretidae displays a number of skin grooves of uncertain origin. These grooves have been homologized to the neuromast lines of other craniates, and they are innervated by two ganglionated cranial nerves that have been interpreted as lateral line nerves. The grooves do not, however, contain the compound receptors that are typical of a lateral line (i.e. neuromasts or electroreceptors), and both their development and function have remained enigmatic. To elucidate the embryonic origin of the grooves (which should develop from placodes if they are homologues of the lateral line system), embryos of Pacific hagfish were examined by means of three-dimensional reconstructions from serial sections. Because of the scarcity of specimens of embryonic hagfishes, only two embryos were reconstructed, but these reconstructions clearly show that a number of placodes and placodal derivatives (i.e. sensory ridges, receptor primordia, and cranial ganglia) occur in the head of embryonic eptatretid hagfishes. Some of these placodes correspond to the lens and epibranchial placodes of other craniates, but there are also three other placodes which represent possible homologues of lateral line placodes. The topology of the placodes in this latter group corresponds to the topology of the grooves of adult hagfishes, and we therefore reach three conclusions: (i) that an embryonic lateral line system is present in hagfishes; (ii) that the grooves of adult hagfishes in all probability derive from lateral line placodes; and (iii) that the presence of lateral line placodes is a primitive character of craniates.

Afferent Pathways↗
PubMed1995

A pathway for lateral root formation in Arabidopsis thaliana.

In plants, the hormone indole-3-acetic acid (IAA) can initiate the developmental program for lateral root formation. We have isolated mutants that have permitted the dissection of this program into initiation and maturation of lateral roots. The alf1-1 mutation causes hyperproliferation of lateral roots, alf4-1 prevents initiation of lateral roots, and alf3-1 is defective in the maturation of lateral roots. The alf3-1 mutant can be rescued by IAA, whereas the alf4-1 mutant is not rescued. Our data suggest a model in which IAA is required for at least two steps in lateral root development: (1) to initiate cell division in the pericycle, and (2) to promote cell division and maintain cell viability in the developing lateral root.

Arabidopsis↗
PubMed2001

Body-force effect on the lateral movement of cellular flames at low Lewis numbers.

The body-force effect on the lateral movement of cellular flames is studied by unsteady calculations of reactive flows at low Lewis numbers. We employ the compressible Navier-Stokes equation including chemical reaction to take account of the hydrodynamic effect caused by thermal expansion. A sinusoidal disturbance with the linearly most unstable wavelength is superimposed on a plane flame to simulate the formation of a cellular flame. The superimposed disturbance grows initially with time, and then the flame front changes from a sinusoidal to a cellular shape. After the cell formation, the cellular flame moves laterally at Lewis numbers lower than unity. The reason is that the diffusive-thermal effect, and the nonlinear effect of the flame front, play a primary role in the appearance of the lateral movement of cells. The body-force effect has a great influence on the lateral velocity of cells. When flames are propagated upward, the lateral velocity decreases as the acceleration increases, even though the body-force effect has a destabilizing influence. When flames are propagated downward, on the other hand, the lateral velocity takes a maximum value at the specific acceleration and decreases with an increase in acceleration. The dependence of lateral velocity on the acceleration is due to the augmentation and diminution in maximum flame temperature and to the broadness and narrowness of a high-temperature region behind a convex flame front.

Journal Article↗
PubMed2005

Isolation, characterization, and pericycle-specific transcriptome analyses of the novel maize lateral and seminal root initiation mutant rum1.

The monogenic recessive maize (Zea mays) mutant rootless with undetectable meristems 1 (rum1) is deficient in the initiation of the embryonic seminal roots and the postembryonic lateral roots at the primary root. Lateral root initiation at the shoot-borne roots and development of the aerial parts of the mutant rum1 are not affected. The mutant rum1 displays severely reduced auxin transport in the primary root and a delayed gravitropic response. Exogenously applied auxin does not induce lateral roots in the primary root of rum1. Lateral roots are initiated in a specific cell type, the pericycle. Cell-type-specific transcriptome profiling of the primary root pericycle 64 h after germination, thus before lateral root initiation, via a combination of laser capture microdissection and subsequent microarray analyses of 12k maize microarray chips revealed 90 genes preferentially expressed in the wild-type pericycle and 73 genes preferentially expressed in the rum1 pericycle (fold change >2; P-value <0.01; estimated false discovery rate of 13.8%). Among the 51 annotated genes predominately expressed in the wild-type pericycle, 19 genes are involved in signal transduction, transcription, and the cell cycle. This analysis defines an array of genes that is active before lateral root initiation and will contribute to the identification of checkpoints involved in lateral root formation downstream of rum1.

Biological Transport↗
PubMed2001

Cooperative action of SLR1 and SLR2 is required for lateral root-specific cell elongation in maize.

Lateral roots play an important role in water and nutrient uptake largely by increasing the root surface area. In an effort to characterize lateral root development in maize (Zea mays), we have isolated from Mutator (Mu) transposon stocks and characterized two nonallelic monogenic recessive mutants: slr1 and slr2 (short lateral roots1 and 2), which display short lateral roots as a result of impaired root cell elongation. The defects in both mutants act specifically during early postembryonic root development, affecting only the lateral roots emerging from the embryonic primary and seminal roots but not from the postembryonic nodal roots. These mutations have no major influence on the aboveground performance of the affected plants. The double mutant slr1; slr2 displays a strikingly different phenotype than the single mutants. The defect in slr1; slr2 does not only influence lateral root specific cell elongation, but also leads to disarranged cellular patterns in the primary and seminal roots. However, the phase-specific nature of the single mutants is retained in the double mutant, indicating that the two loci cooperate in the wild type to maintain the lateral root specificity during a short time of early root development.

Genes, Plant↗
PubMed1968

Lateral movement of auxin in phototropism.

Lateral movement of indoleacetic acid-1-(14)C in corn coleoptiles was measured as radioactivity moving laterally following unilateral application of the auxin. The data suggest that there is an endogenous lateral movement of auxin, and that phototropic stimulation of the coleoptile depresses lateral movement towards the light and enhances lateral movement away from the light. The lateral movement was found to be principally as indoleacetic acid. In experiments using sunflower hypocotyl sections, evidence is also presented to support the suggestion that lateral redistribution of auxin may be effected by a deflection of auxin around a barrier to basipetal transport.

Journal Article↗
PubMed1995

LRP1, a gene expressed in lateral and adventitious root primordia of arabidopsis.

We describe a gene that is expressed in lateral and adventitious root primordia of Arabidopsis. The gene was identified by expression of a transposon-borne promoterless beta-glucuronidase gene in lateral root primordia. The gene, designated LRP1 for lateral root primordium 1, and its corresponding cDNA were cloned and sequenced. The expression pattern of the gene in lateral root primordia was confirmed by in situ hybridization with LRP1 cDNA probes. The LRP1 gene encodes a novel protein. LRP1 expression is activated during the early stages of root primordium development and is turned off prior to the emergence of lateral roots from the parent root. Insertion of the transposon in the LRP1 gene disrupted its expression. To evaluate the homozygous insertion line for a mutant phenotype, several aspects of wild-type lateral root development were analyzed. A mutant phenotype has not yet been identified in the insertion line; however, there is evidence that the gene belongs to a small gene family. LRP1 provides a molecular marker to study the early stages of lateral and adventitious root primordium development.

Amino Acid Sequence↗
PubMed2005

A comparison of the lateral, Oxford and sitting positions for performing combined spinal-epidural anaesthesia for elective Caesarean section.

One hundred women were randomly allocated to the left lateral, Oxford or sitting position for induction of combined spinal-epidural anaesthesia for Caesarean section using 2.5 ml hyperbaric bupivacaine 0.5% and 10 mug fentanyl. Women in the left lateral were then turned to the right lateral position; women in the Oxford position were turned to the same position on their opposite side; and women in the sitting group were turned to the supine left tilt position. Women remained in these positions until ready for surgery, which was conducted in the supine position with a wedge placed under the right hip. Ephedrine requirements before re-positioning for surgery were less in the sitting position than in the other two positions: median (IQR [range]) doses for the lateral, Oxford and sitting groups were 21 (12-30 [6-48]), 18 (7.5-24 [6-48]) and 12 (6-21 [6-42]) mg, respectively; p = 0.04. Sensory block to touch sensation at the T5 dermatomal level was most quickly achieved in the lateral position with median (IQR [range]) block onset times for the lateral, Oxford and sitting groups of 9 (6-13 [4-30]), 15.5 (9-22 [4-34]) and 14 (9-18[6-36]) min, respectively; p = 0.004. In the Oxford position, more epidural catheters required dosing to achieve a sensory block of T5 before surgery: the number of patients (proportion) bolused in the lateral, Oxford and sitting groups was 1 (3%), 7 (22%) and 1 (3%), respectively; p = 0.01. We did not demonstrate any advantage in using the Oxford position for combined spinal-epidural anaesthesia for elective Caesarean section.

Adult↗
PubMed2004

Cytokinins play opposite roles in lateral root formation, and nematode and Rhizobial symbioses.

We used the cytokinin-responsive Arabidopsis response regulator (ARR)5 gene promoter fused to a beta-glucuronidase (GUS) reporter gene, and cytokinin oxidase (CKX) genes from Arabidopsis thaliana (AtCKX3) and maize (ZmCKX1) to investigate the roles of cytokinins in lateral root formation and symbiosis in Lotus japonicus. ARR5 expression was undetectable in the dividing initial cells at early stages of lateral root formation, but later we observed high expression in the base of the lateral root primordium. The root tip continues to express ARR5 during subsequent development of the lateral root. These results suggest a dynamic role for cytokinin in lateral root development. We observed ARR5 expression in curled/deformed root hairs, and also in nodule primordia in response to Rhizobial inoculation. This expression declined once the nodule emerged from the parent root. Root penetration and migration of root-knot nematode (RKN) second-stage larvae (L2) did not elevate ARR5 expression, but a high level of expression was induced when L2 reached the differentiating vascular bundle and during early stages of the nematode-plant interaction. ARR5 expression was specifically absent in mature giant cells (GCs), although dividing cells around the GCs continued to express this reporter. The same pattern was observed using a green fluorescent protein (GFP) reporter driven by the ARR5 promoter in tomato. Overexpression of CKX genes rendered the transgenic hairy roots resistant to exogenous application of the cytokinin [N6-(Delta2 isopentenyl) adenine riboside] (iPR). CKX roots have significantly more lateral roots, but fewer nodules and nematode-induced root galls per plant, than control hairy roots.

Animals↗
PubMedDate not supplied

A comparison of the effects of unilateral thyroarytenoid lateralization versus cricoarytenoid laryngoplasty on the area of the rima glottidis and clinical outcome in dogs with laryngeal paralysis.

OBJECTIVE: To compare the clinical effects of unilateral thyroarytenoid lateralization versus unilateral cricoarytenoid laryngoplasty for the treatment of canine laryngeal paralysis. Study Design-A prospective, clinical trial. ANIMALS: Twenty client-owned dogs admitted to Glasgow University Veterinary Hospital (GUVH) between 1997 and 1999 with a diagnosis of laryngeal paralysis. METHODS: A thorough evaluation of each dog was undertaken that included history, physical and neurologic examinations, complete blood count, serum biochemistry profile, serum thyroxine (T4) level, and thyroid-stimulating hormone (TSH) assay. The exercise tolerance of each dog was investigated by assessing respiratory rate and arterial blood gas analysis at rest and after 5 minutes of mild exercise. Animals were included in the study on the basis of a definitive diagnosis of laryngeal paralysis made by endoscopic observation of the larynx in the lightly anesthetized patient. The animals were randomly assigned to 1 of 2 treatment groups: unilateral thyroarytenoid lateralization or unilateral cricoarytenoid laryngoplasty, with all procedures being performed by the same surgeon. Video images of the rima glottidis were recorded pre- and postoperatively using video endoscopy. Video images were digitized and the area of the rima glottidis measured using image-analysis software. An increase in the area of the rima glottidis was expressed as a percentage of the preoperative area. All animals were reassessed 6 weeks' postoperatively, and exercise tolerance tests were repeated. RESULTS: The mean increase in the area of the rima glottidis postoperatively when compared with the preoperative area was 140% for those animals undergoing unilateral thyroarytenoid lateralization (range, 120%-158%) and 207% for those animals undergoing unilateral cricoarytenoid laryngoplasty (range, 183%-228%). This difference was statistically significant (P < .0001). At the 6-week postoperative examination, there was no significant difference in improvement between the 2 groups when compared on either a clinical basis or exercise tolerance tests. The mean surgical time in the 2 groups was 25 minutes for thyroarytenoid lateralization and 43 minutes for cricoarytenoid laryngoplasty. This was a statistically significant difference (P = .002). CONCLUSION: Although increase in area of the rima glottidis was significantly greater after unilateral cricoarytenoid laryngoplasty compared with unilateral thyroarytenoid lateralization, no difference in clinical outcome could be detected. However, the cricoarytenoid laryngoplasty procedure required significantly more surgical time. CLINICAL RELEVANCE: Both unilateral cricoarytenoid laryngoplasty and unilateral thyroarytenoid lateralization are successful methods for the treatment of laryngeal paralysis; however, thyroarytenoid lateralization requires less surgical time to perform.

Animals↗
PubMed2005

Managing congenitally missing lateral incisors. Part I: Canine substitution.

UNLABELLED: Dentists often encounter patients with missing or malformed teeth. The maxillary lateral incisor is the second most common congenitally absent tooth. There are three treatment options that exist for replacing missing lateral incisors. They include canine substitution, a tooth-supported restoration, or a single-tooth implant. Selecting the appropriate option depends on the malocclusion, specific space requirements, tooth-size relationship, and size and shape of the canine. The ideal treatment is the most conservative option that satisfies individual esthetic and functional requirements. Often the ideal option is canine substitution. Although the orthodontist positions the canine in the most esthetic and functional location, the restorative dentist often needs to place a porcelain veneer or crown to re-create normal lateral incisor shape and color. This article closely examines patient selection and illustrates the importance of interdisciplinary treatment planning to achieve optimal esthetics. It is the first in a three-part series discussing the three treatment alternatives for replacing missing lateral incisors. CLINICAL SIGNIFICANCE: Patients with congenitally missing lateral incisors often raise difficult treatment planning issues. Therefore, to produce the most predictable esthetic results, it is important to choose the treatment that will best address the initial diagnosis. This article is the first in a three-part series that describes the different treatments available for patients with congenitally missing lateral incisors. This first article focuses on canine substitution as a method of tooth replacement for these missing teeth. The general dentist will learn to evaluate specific patient selection criteria and determine whether canine substitution is an appropriate treatment alternative for replacing missing lateral incisors. The orthodontist will understand how to position the canines to satisfy functional requirements and achieve proper esthetics. Finally, the importance of interdisciplinary team treatment planning is emphasized as a requirement for achieving optimal final esthetics.

Adolescent↗
PubMed2004

The human lateral pterygoid muscle: a review of some experimental aspects and possible clinical relevance.

The clinical notion that some disturbance to the activity of the lateral pterygoid muscle plays a role in the aetiology of temporomandibular disorders (TMD) is still widely accepted and influences management strategies. However, there is no rigorous scientific evidence to support this clinical notion and the role of the lateral pterygoid muscle in normal function is still controversial. The classically defined functions of each head of the muscle are that the superior head is active on closing, retrusion, and ipsilateral jaw movements, while the inferior head is active on opening, protrusion and contralateral jaw movements. However, recent data indicate that these concepts are too simplistic. For example, recent evidence suggests that parts of the superior head may also be active on opening, protrusion and contralateral jaw movements, and that the superior head may consist of three mediolaterally arranged functional zones. Given these complexities, the proposal that clicking and/or locking conditions arise in the temporomandibular joint through some form of lack of co-ordination between the two heads of the muscle needs re-evaluation. Despite earlier reports to the contrary, both heads of the lateral pterygoid muscle appear to be electrically silent at the postural or resting jaw position, and therefore appear to play no role in the anteroposterior positioning of the jaw at the postural position. An important role has also been demonstrated electromyographically for progressive changes in activity in the inferior head as the direction of horizontal jaw force shifts from one side to the other. This suggests an important role for the lateral pterygoid muscle in the generation of side-to-side and protrusive jaw forces. The lateral pterygoid muscle is likely therefore to play an important role in parafunctional excursive jaw movements and also possibly a role in influencing jaw position in patients where the maxillomandibular relationship records change from session to session. The above data provide new insights into the normal function of the lateral pterygoid muscle. The proposal that the lateral pterygoid muscle plays some role in the aetiology of TMD needs now to be rigorously tested.

Bite Force↗
PubMed1982

Lateral hypothalamic neurones: osmosensitivity and the influence of activating magnocellular neurosecretory neurones.

1. The activity of single cells in the supraoptic nucleus and the lateral hypothalamus of urethane-anaesthetized rats was studied during electrical stimulation of the neural stalk.2. Neurones activated antidromically from the neural stalk were either unaffected or, rarely, slightly affected by single shocks or by brief trains of shocks presented at an intensity just below that necessary for antidromic invasion. Thus there does not appear to be a strong synaptic coupling between rat supraoptic neurones.3. In contrast, many lateral hypothalamic neurones, and particularly those in the perinuclear zone, were strongly affected by neural stalk stimulation, being either orthodromically excited or inhibited. Thus, rat magnocellular neurosecretory neurones appear to project, directly or indirectly, to the lateral hypothalamus.4. Thirty-one lateral hypothalamic neurones were studied following an I.P. injection of 1 ml. 1.5 M-NaCl. Eighteen neurones responded to this osmotic stimulus with a change of at least 1 spike/sec in mean firing rate.5. Fifteen of the thirty-one neurones were strongly affected by neural stalk stimulation (eight inhibited, seven excited). Ten of these fifteen neurones were affected in the same way by osmotic stimulation. The remaining sixteen out of thirty-one neurones were unresponsive to neural stalk stimulation, and of these, ten were also unresponsive to osmotic stimulation. Thus most lateral hypothalamic neurones responded in a similar way to neural stalk stimulation and to systemic osmotic stimulation.6. Thus the osmosensitivity of some neurones in the lateral hypothalamus may be mediated by synaptic input arising from the magnocellular neurosecretory neurones. However, the osmosensitivity of some lateral hypothalamic neurones cannot be explained in this way, and probably derives from osmoreceptors other than the magnocellular neurones.

Animals↗
PubMed1998

Automated lung segmentation in digital lateral chest radiographs.

We are developing a fully automated computerized scheme for segmenting the lung fields in digital lateral chest radiographs. Existing computer-aided diagnostic (CAD) schemes and automated lung segmentation methods have focused exclusively on the posteroanterior view, despite the diagnostic importance of the lateral view. Information from the lateral radiograph is routinely incorporated by radiologists in their decision-making process, and thus computer analysis of lateral images may potentially add another dimension to current CAD schemes. Automated analysis of the lung fields in lateral images will necessarily require accurate segmentation. Our scheme employs an initial procedure to eliminate external and subcutaneous pixels. Global gray-level histogram analysis then allows for the identification of a range of gray-level thresholds. An iterative gray-level thresholding scheme is implemented using this range of thresholds to construct a series of binary images in which contiguous regions are identified and geometrically analyzed. Regions determined to be outside the lungs are prevented from contributing to binary images at later iterations. Adaptive local gray-level thresholding is applied along the initial contour that results from the global thresholding procedure to extend the contour closer to the true lung borders. This local thresholding method uses regions of interest of various dimensions, depending on the enclosed anatomy. Smoothing and polynomial curve fitting complete the segmentation. A database of 100 normal and 100 abnormal lateral images was analyzed. Quantitative comparison of computer-segmented lung regions with lung regions manually delineated by two radiologists indicated that 83% and 84% of normal and abnormal images, respectively, displayed segmentation contours within three standard deviations of the mean inter-radiologist contour degree-of-overlap value.

Automation↗
PubMed1999

Some aspects of the lateralization of echoed sound in man. II. The role of the stimulus spectrum.

The lateralization of clicks and their "echoes" was investigated with a view to determining the role of spectral characteristics in lateralization. Lateralization-discrimination performance was measured in a number of two-interval, two-alternative forced-choice experiments using three pairs of binaural clicks designed to elucidate how spectral cues are used in lateralization. The stimulus in one observation interval comprised a diotic click followed, after the interclick interval (ICI), by a dichotic click with either (1) an interaural time delay or (2) an interaural amplitude difference. The dichotic click was in turn followed, after an ICI of the same size, by another diotic click. In the second observation interval, the signals to the two ears were interchanged. The stimulus has the property that the signals delivered to the two ears had either (1) identical energy-density spectra but nonzero interaural-phase differences (IPDs) or (2) zero IPDs but nonidentical energy-density spectra. Under certain circumstances, observers perceived these stimuli as arising from the side of the head opposite that which would be predicted from the direction of the interaural cue in the temporal waveform. Joint consideration of the psychophysical data and the spectral characteristics of the stimuli strongly suggest a spectral "dominance region" for lateralization near 750 Hz, observers' lateralization performance was determined predominantly by the IPD cues from this region. In general, the results demonstrate that echoes of transients that arrive within about 2-3 ms of an initial transient are not suppressed, but have a substantial effect on lateralization through their contribution to the resultant spectral characteristics. The results contradict models that represent the precedence effect as the temporary suppression or inhibition of directional information in echoes over 2-3 ms after an initial transient.

Adult↗
PubMed2002

Lateral flagella and swarming motility in Aeromonas species.

Swarming motility, a flagellum-dependent behavior that allows bacteria to move over solid surfaces, has been implicated in biofilm formation and bacterial virulence. In this study, light and electron microscopic analyses and genetic and functional investigations have shown that at least 50% of Aeromonas isolates from the species most commonly associated with diarrheal illness produce lateral flagella which mediate swarming motility. Aeromonas lateral flagella were optimally produced when bacteria were grown on solid medium for approximately 8 h. Transmission and thin-section electron microscopy confirmed that these flagella do not possess a sheath structure. Southern analysis of Aeromonas reference strains and strains of mesophilic species (n = 84, varied sources and geographic regions) with a probe designed to detect lateral flagellin genes (lafA1 and lafA2) showed there was no marked species association of laf distribution. Approximately 50% of these strains hybridized strongly with the probe, in good agreement with the expression studies. We established a reproducible swarming assay (0.5% Eiken agar in Difco broth, 30 degrees C) for Aeromonas spp. The laf-positive strains exhibited vigorous swarming motility, whereas laf-negative strains grew but showed no movement from the inoculation site. Light and scanning electron microscopic investigations revealed that lateral flagella formed bacterium-bacterium linkages on the agar surface. Strains of an Aeromonas caviae isolate in which lateral flagellum expression was abrogated by specific mutations in flagellar genes did not swarm, proving conclusively that lateral flagella are required for the surface movement. Whether lateral flagella and swarming motility contribute to Aeromonas intestinal colonization and virulence remains to be determined.

Aeromonas↗
PubMed2006

Analysis of the lateral flagellar gene system of Aeromonas hydrophila AH-3.

Mesophilic Aeromonas strains express a polar flagellum in all culture conditions, and certain strains produce lateral flagella on semisolid media or on surfaces. Although Aeromonas lateral flagella have been described as a colonization factor, little is known about their organization and expression. Here we characterized the complete lateral flagellar gene cluster of Aeromonas hydrophila AH-3 containing 38 genes, 9 of which (lafA-U) have been reported previously. Among the flgLL and lafA structural genes we found a modification accessory factor gene (maf-5) that is involved in formation of lateral flagella; this is the first time that such a gene has been described for lateral flagellar gene systems. All Aeromonas lateral flagellar genes were located in a unique chromosomal region, in contrast to Vibrio parahaemolyticus, in which the analogous genes are distributed in two different chromosomal regions. In A. hydrophila mutations in flhAL, lafK, fliJL, flgNL, flgEL, and maf-5 resulted in a loss of lateral flagella and reductions in adherence and biofilm formation, but they did not affect polar flagellum synthesis. Furthermore, we also cloned and sequenced the A. hydrophila AH-3 alternative sigma factor sigma54 (rpoN); mutation of this factor suggested that it is involved in expression of both types of flagella.

Aeromonas hydrophila↗