scholarly journals Aimed limb movements in a hemimetabolous insect are intrinsically compensated for allometric wing growth by developmental mechanisms

2019 ◽  
Vol 222 (16) ◽  
pp. jeb208553 ◽  
Author(s):  
Alexandra J. Patel ◽  
Thomas Matheson
Keyword(s):  
Limb Movements ◽  
Developmental Mechanisms ◽  
Hemimetabolous Insect ◽  
Wing Growth

scholarly journals Aimed Limb Movements in a Hemimetabolous Insect are Intrinsically Compensated for Allometric Wing Growth by Developmental Mechanisms

2019 ◽  
Author(s):  
Alexandra J. Patel ◽  
Thomas Matheson
Keyword(s):  
Motor Pattern ◽  
Distal Tibia ◽  
The Body ◽  
Limb Movements ◽  
Body Morphology ◽  
Hemimetabolous Insect ◽  
Kinematic Analyses ◽  
Wing Growth ◽  
External Stimuli ◽  
Wing Tip

ABSTRACTFor aimed limb movements to remain functional they must be adapted to developmental changes in body morphology and sensory-motor systems. Insects use their limbs to groom the body surface or to dislodge external stimuli, but they face the particular problem of adapting these movements to step-like changes in body morphology during metamorphosis or moulting. Locusts are hemimetabolous insects in which the imaginal moult to adulthood results in a sudden and dramatic allometric growth of the wings relative to the body and the legs. We show that, despite this, hind limb scratches aimed at mechanosensory stimuli on the wings remain targeted to appropriate locations after moulting. In juveniles, the tips of the wings extend less than half way along the abdomen, but in adults they extend well beyond the posterior end. Kinematic analyses were used to examine the scratching responses of juveniles (5th instars) and adults to touch of anterior (wing base) and posterior (distal abdomen) targets that develop isometrically, and to wing tip targets that are anterior in juveniles but posterior in adults. Juveniles reach the (anterior) wing tip with the distal tibia of the hind leg using anterior rotation of the thoraco-coxal and coxo-trochanteral (‘hip’) joints and flexion of the femoro-tibial (‘knee’) joint. Adults, however, reach the corresponding (but now posterior) wing tip using posterior rotation of the hip and extension of the knee, reflecting a different underlying motor pattern. This change in kinematics occurs immediately after the adult moult without learning, indicating that the switch is developmentally programmed.SUMMARY STATEMENTA developmentally programmed change in the scratching movements of locusts permits adult animals to aim their movements at new wing tip targets, without learning.

scholarly journals Distinct developmental pathways underlie independent losses of flight in ratites

2017 ◽  
Vol 13 (7) ◽  
pp. 20170234 ◽  
Author(s):  
Cynthia Faux ◽  
Daniel J. Field
Keyword(s):  
Body Size ◽  
Developmental Trajectories ◽  
Large Body ◽  
Developmental Pathways ◽  
Large Body Size ◽  
Phylogenetic Studies ◽  
Developmental Mechanisms ◽  
Wing Growth ◽  
Range Of Variation

Recent phylogenetic studies question the monophyly of ratites (large, flightless birds incorporating ostriches, rheas, kiwis, emus and cassowaries), suggesting their paraphyly with respect to flying tinamous (Tinamidae). Flightlessness and large body size have thus likely evolved repeatedly among ratites, and separately in ostriches ( Struthio ) and emus ( Dromaius ). Here, we test this hypothesis with data from wing developmental trajectories in ostriches, emus, tinamous and chickens. We find the rate of ostrich embryonic wing growth falls within the range of variation exhibited by flying taxa (tinamous and chickens), but that of emus is extremely slow. These results indicate flightlessness was acquired by different developmental mechanisms in the ancestors of ostriches (peramorphosis) and the emu–cassowary clade (paedomorphosis), and corroborate the hypothesis that flight loss has evolved repeatedly among ratites.

scholarly journals A wing growth organizer in a hemimetabolous insect suggests wing origin

2021 ◽  
Author(s):  
Takahiro Ohde ◽  
Taro Mito ◽  
Teruyuki Niimi
Keyword(s):  
Body Wall ◽  
The Body ◽  
Marker Genes ◽  
Wing Development ◽  
Gryllus Bimaculatus ◽  
Genetic Changes ◽  
Origin And Evolution ◽  
Insect Wings ◽  
Hemimetabolous Insect ◽  
Wing Growth

ABSTRACTThe origin and evolution of insect wings remain enigmatic after a century-long discussion. Molecular dissection of wing development in hemimetabolous insects, in which the first functional wings evolved, is key to understand genetic changes required for wing evolution. We investigatedDrosophilawing marker genes in the cricket,Gryllus bimaculatus, and foundapterousandvestigialshow critical functions in nymphal tergal identity and margin formation, respectively. We further demonstrate that margin cells in the lateral-anterior tergal region constitute a growth organizer of wing blades. Transcriptome and RNAi analyses unveiled that Wnt, Fat-Dachsous, and Hippo pathways are involved in disproportional growth ofGrylluswings. Our data collectively support the idea that tergal margin cells of a wingless ancestor gave rise to the body wall extension required for evolution of the first powered flight.

Das Restless-Legs-Syndrom, eine diagnostische und therapeutische Herausforderung bei Kindern und Jugendlichen

2019 ◽  
Vol 19 (03) ◽  
pp. 194-199
Author(s):  
Silvano Vella
Keyword(s):  
Periodic Limb Movements ◽  
Wird Eine ◽  
Limb Movements ◽  
Kognitive Leistungsfähigkeit ◽  
Restless Legs ◽  
Restless Legs Syndrom

ZusammenfassungDas Restless-Legs-Syndrom (RLS) ist eine zentralnervöse, genetisch prädisponierte, durch biochemische Faktoren getriggerte chronisch-progrediente sensomotorische Störung, oft mit Beginn im Kindes- oder Jugendalter. Zugrundeliegend wird eine zerebrale Störung des Eisen- und Dopamin-Stoffwechsels postuliert. Diese manifestiert sich durch den unwiderstehlichen Zwang seine Extremitäten bewegen zu müssen, verbunden mit Parästhesien und Dysästhesien. Die Beschwerden nehmen in Ruhe und in der Nacht zu und bessern sich durch Bewegung. RLS sollte eigentlich mit Restless-Limbs-Syndrome übersetzt werden, da langfristig auch Beschwerden in den Armen auftreten können. Kinder ab 18 Monaten können bereits betroffen sein. Die Prävalenz im Kindes- und Jugendalter beträgt 2–4 %, in Assoziation mit ADHS noch höher. Die Diagnose des RLS beruht auf anamnestischen und somit subjektiv geprägten Aussagen, die bei Kindern mit beschränkten sprachlichen Ausdrucksmöglichkeiten schwierig zu werten sind. Bis zu 75 % der RLS-Betroffenen entwickeln im Schlaf periodische Extremitätenbewegungen, welche die Nachtruhe empfindlich stören können (PLMS, periodic limb movements in sleep). Mitbetroffen sind die kognitive Leistungsfähigkeit, Stimmung und Lebensqualität am Tag. Eisenmangel, Genussmittel und gewisse Medikamente können die Beschwerden verstärken. Im Gegensatz zum RLS können PLMS mit neurophysiologischen Messungen objektiviert werden. Therapeutisch steht an erster Stelle die Behandlung eines allfälligen Eisenmangels. Entwickelt wurden Algorithmen für intravenöse Therapien. Falls angezeigt, kommen L-Dopa oder Dopamin-Agonisten zur Anwendung. Da auch Kinder eine Zunahme der RLS-Symptome unter dieser Therapie erleben (Augmentationen), wird zunehmend eine primäre Gabe von Alpha-2-Liganden bevorzugt.Dieser Artikel möchte auf die wichtige Aufgabe von Kinderärzten und Grundversorgern bei der rechtzeitigen Erkennung und Behandlung von RLS/PLMS hinweisen.

Moving Hands or Moving Feet: Cortical Connectivity during isolated limb movements

2012 ◽  
Vol 43 (01) ◽  
Author(s):  
C Grefkes ◽  
AS Sarfeld ◽  
EM Pool ◽  
SB Eickhoff ◽  
GR Fink
Keyword(s):  
Limb Movements ◽  
Cortical Connectivity

Actimetry-documented persistent Periodic Limb Movements during EEG-confirmed deep General Anesthesia: a case report.

2019 ◽  
Author(s):  
Friedrich Lersch ◽  
Pascal Jerney ◽  
Heiko Kaiser ◽  
Cédric Willi ◽  
Katharina Steck ◽  
...  
Keyword(s):  
Case Report ◽  
Motor Activity ◽  
General Anesthesia ◽  
Burst Suppression ◽  
Periodic Limb Movements ◽  
Deep Sclerectomy ◽  
Limb Movements ◽  
Periodic Leg Movements ◽  
Increase Motor Activity ◽  
Leg Movements

Motor activity during general anesthesia (GA) without curarization is often interpreted as reflecting insufficient analgosedation. Here we present the case of an octogenarian scheduled for deep sclerectomy receiving opioid-sparing electroencephalography-(EEG)-guided anesthesia. Periodic Leg Movements (PLM) made their appearance with ongoing surgery while his raw EEG displayed a pattern of deep GA (burst suppression). To the best of our knowledge, this is the first description of actimetry-documented persisting PLM during EEG-monitored GA. Recognizing PLM in the context of GA is of importance for anesthesiologists, as increasing sedation may increase motor activity.

scholarly journals The Genomic Architecture of Bladder Exstrophy Epispadias Complex

Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1149
Author(s):  
Glenda M. Beaman ◽  
Raimondo M. Cervellione ◽  
David Keene ◽  
Heiko Reutter ◽  
William G. Newman
Keyword(s):  
Urinary Tract ◽  
Animal Models ◽  
Abdominal Wall ◽  
Current Knowledge ◽  
Bladder Exstrophy ◽  
Genomic Architecture ◽  
Developmental Mechanisms ◽  
Anatomical Characterization

The bladder exstrophy–epispadias complex (BEEC) is an abdominal midline malformation comprising a spectrum of congenital genitourinary abnormalities of the abdominal wall, pelvis, urinary tract, genitalia, anus, and spine. The vast majority of BEEC cases are classified as non-syndromic and the etiology of this malformation is still unknown. This review presents the current knowledge on this multifactorial disorder, including phenotypic and anatomical characterization, epidemiology, proposed developmental mechanisms, existing animal models, and implicated genetic and environmental components.

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