Early development in mice: II. Sensory motor behavior and genetic analysis

1985 ◽  
Vol 35 (5) ◽  
pp. 659-666 ◽  
Author(s):  
Pierre Roubertoux ◽  
Catherine Semal ◽  
Sylvie Ragueneau
Keyword(s):  
Genetic Analysis ◽  
Early Development ◽  
Motor Behavior ◽  
Sensory Motor

Mutations affecting tail and notochord development in the ascidian Ciona savignyi

Development ◽  
1999 ◽  
Vol 126 (15) ◽  
pp. 3293-3301 ◽  
Author(s):  
Y. Nakatani ◽  
R. Moody ◽  
W.C. Smith
Keyword(s):  
Genetic Analysis ◽  
Early Development ◽  
Nerve Cord ◽  
Induced Mutations ◽  
Ciona Savignyi ◽  
New Information ◽  
Nerve Tracts ◽  
Notochord Cells ◽  
Dorsal Nerve

Ascidians are among the most distant chordate relatives of the vertebrates. However, ascidians share many features with vertebrates including a notochord and hollow dorsal nerve cord. A screen for N-ethyl-N-nitrosourea (ENU)-induced mutations affecting early development in the ascidian Ciona savignyi resulted in the isolation of a number of mutants including the complementing notochord mutants chongmague and chobi. In chongmague embryos the notochord fails to develop, and the notochord cells instead adopt a mesenchyme-like fate. The failure of notochord development in chongmague embryos results in a severe truncation of tail, although development of the tail muscles and caudal nerve tracts appears largely normal. Chobi embryos also have a truncation of the tail stemming from a disruption of the notochord. However, in chobi embryos the early development of the notochord appears normal and defects occur later as the notochord attempts to extend and direct elongation of the tail. We find in chobi tailbud embryos that the notochord is often bent, with cells clumped together, rather than extended as a column. These results provide new information on the function and development of the ascidian notochord. In addition, the results demonstrate how the unique features of ascidians can be used in genetic analysis of morphogenesis.

scholarly journals Functional Assessment of Stroke-Induced Regulation of miR-20a-3p and Its Role as a Neuroprotectant

2021 ◽  
Author(s):  
Taylor E. Branyan ◽  
Amutha Selvamani ◽  
Min Jung Park ◽  
Kriti E. Korula ◽  
Kelby F. Kosel ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Mitochondrial Dynamics ◽  
Infarct Volume ◽  
Neuron Specific Enolase ◽  
Cell Types ◽  
Female Rats ◽  
Therapeutic Window ◽  
Middle Aged ◽  
Stroke Outcomes ◽  
Sensory Motor

AbstractMicroRNAs have gained popularity as a potential treatment for many diseases, including stroke. This study identifies and characterizes a specific member of the miR-17–92 cluster, miR-20a-3p, as a possible stroke therapeutic. A comprehensive microRNA screening showed that miR-20a-3p was significantly upregulated in astrocytes of adult female rats, which typically have better stroke outcomes, while it was profoundly downregulated in astrocytes of middle-aged females and adult and middle-aged males, groups that typically have more severe stroke outcomes. Assays using primary human astrocytes and neurons show that miR-20a-3p treatment alters mitochondrial dynamics in both cell types. To assess whether stroke outcomes could be improved by elevating astrocytic miR-20a-3p, we created a tetracycline (Tet)-induced recombinant adeno-associated virus (rAAV) construct where miR-20a-3p was located downstream a glial fibrillary acidic protein promoter. Treatment with doxycycline induced miR-20-3p expression in astrocytes, reducing mortality and modestly improving sensory motor behavior. A second Tet-induced rAAV construct was created in which miR-20a-3p was located downstream of a neuron-specific enolase (NSE) promoter. These experiments demonstrate that neuronal expression of miR-20a-3p is vastly more neuroprotective than astrocytic expression, with animals receiving the miR-20a-3p vector showing reduced infarction and sensory motor improvement. Intravenous injections, which are a therapeutically tractable treatment route, with miR-20a-3p mimic 4 h after middle cerebral artery occlusion (MCAo) significantly improved stroke outcomes including infarct volume and sensory motor performance. Improvement was not observed when miR-20a-3p was given immediately or 24 h after MCAo, identifying a unique delayed therapeutic window. Overall, this study identifies a novel neuroprotective microRNA and characterizes several key pathways by which it can improve stroke outcomes.

Impairments in Prehension Produced by Early Postnatal Sensory Motor Cortex Activity Blockade

2000 ◽  
Vol 83 (2) ◽  
pp. 895-906 ◽  
Author(s):  
John H. Martin ◽  
Laura Donarummo ◽  
Antony Hacking
Keyword(s):  
Motor Cortex ◽  
Motor Behavior ◽  
Lateral Position ◽  
Postnatal Life ◽  
Contralateral Limb ◽  
Early Postnatal Development ◽  
End Point ◽  
Sensory Motor ◽  
Impaired Limb ◽  
The Right

This study examined the effects of blocking neural activity in sensory motor cortex during early postnatal development on prehension. We infused muscimol, either unilaterally or bilaterally, into the sensory motor cortex of cats to block activity continuously between postnatal weeks 3–7. After stopping infusion, we trained animals to reach and grasp a cube of meat and tested behavior thereafter. Animals that had not received muscimol infusion (unilateral saline infusion; age-matched) reached for the meat accurately with small end-point errors. They grasped the meat using coordinated digit flexion followed by forearm supination on 82.7% of trials. Performance using either limb did not differ significantly. In animals receiving unilateral muscimol infusion, reaching and grasping using the limb ipsilateral to the infusion were similar to controls. The limb contralateral to infusion showed significant increases in systematic and variable reaching end-point errors, often requiring subsequent corrective movements to contact the meat. Grasping occurred on only 14.8% of trials, replaced on most trials by raking without distal movements. Compensatory adjustments in reach length and angle, to maintain end-point accuracy as movements were started from a more lateral position, were less effective using the contralateral limb than ipsilateral limb. With bilateral inactivations, the form of reaching and grasping impairments was identical to that produced by unilateral inactivation, but the magnitude of the reaching impairments was less. We discuss these results in terms of the differential effects of unilateral and bilateral inactivation on corticospinal tract development. We also investigated the degree to which these prehension impairments after unilateral blockade reflect control by each hemisphere. In animals that had received unilateral blockade between postnatal weeks (PWs) 3 and 7, we silenced on-going activity (after PW 11) during task performance using continuous muscimol infusion. We inactivated the right (previously active) and then the left (previously silenced) sensory motor cortex. Inactivation of the ipsilateral (right) sensory motor cortex produced a further increase in systematic error and less frequent normal grasping. Reinactivation of the contralateral (left) cortex produced larger increases in reaching and grasping impairments than those produced by ipsilateral inactivation. This suggests that the impaired limb receives bilateral sensory motor cortex control but that control by the contralateral (initially silenced) cortex predominates. Our data are consistent with the hypothesis that the normal development of skilled motor behavior requires activity in sensory motor cortex during early postnatal life.

Early development in mice. IV. Age at disappearance of the rooting response: Genetic analysis in newborn mice

1987 ◽  
Vol 17 (5) ◽  
pp. 453-464 ◽  
Author(s):  
Pierre L. Roubertoux ◽  
Laurence Baumann ◽  
Sylvie Ragueneau ◽  
Catherine Semal
Keyword(s):  
Genetic Analysis ◽  
Early Development ◽  
Newborn Mice ◽  
Rooting Response

Insect embryogenesis – what is ancestral and what is derived?

Development ◽  
1994 ◽  
Vol 1994 (Supplement) ◽  
pp. 193-199
Author(s):  
Diethard Tautz ◽  
Markus Friedrich ◽  
Reinhard Schröder
Keyword(s):  
Pattern Formation ◽  
Genetic Analysis ◽  
Early Development ◽  
Molecular Mechanisms ◽  
Early Embryogenesis ◽  
Molecular Pathways ◽  
Deep Insight ◽  
Insect Embryogenesis ◽  
Definitive Answer ◽  
Insight Into

The systematic genetic analysis of Drosophila development has provided us with a deep insight into the molecular pathways of early embryogenesis. The question arises now whether these insights can serve as a more general paradigm of early development, or whether they apply only to advanced insect orders. Though it is too early to give a definitive answer to this question, we suggest that there is currently no firm reason to believe that the molecular mechanisms that were elucidated in Drosophila may not also apply to other forms of insect embryogenesis. Thus, many of the Drosophila genes involved in early pattern formation may have comparable functions in other insects and possibly throughout the arthropods.

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