Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Directing Effect of Substituents: meta-Directing Groups01:09

Directing Effect of Substituents: meta-Directing Groups

6.1K
Substituents on the benzene ring that direct an incoming electrophile to undergo substitution at the meta position are called meta directors. All meta directors either have a positive charge on the atom directly bonded to the ring or a partial positive charge. These groups function by withdrawing electrons from the ring through inductive and resonance effects. Consider the carbocation intermediates formed upon the addition of an electrophile on nitrobenzene at the...
6.1K
Directing Effect of Substituents: ortho–para-Directing Groups01:14

Directing Effect of Substituents: ortho–para-Directing Groups

8.7K
Ortho–para directors are substituent groups attached to the benzene ring and direct the addition of an electrophile to the positions ortho or para to the substituent. All electron-donating groups are considered ortho–para directors. They donate electrons to the ring and make the ring more electron-rich. The ring is therefore susceptible to the addition of electrophiles. Substituents such as amino, hydroxy, or alkoxy, containing lone pairs on the atom adjacent to the ring, donate...
8.7K
Sustainable Development01:43

Sustainable Development

15.2K
As the human population continues to grow and use resources, we must be mindful of our planet’s natural limits. Sustainable development provides a pathway to maintain and improve human life now while also ensuring that future generations will have the resources that they need. The long-term success of sustainability efforts rests on understanding the interplay between human actions and ecological systems.
15.2K
Directional Terms01:14

Directional Terms

17.2K
Directional terms are essential for describing the relative locations of different body structures. For instance, an anatomist might describe one band of tissue as "inferior to" another, or a physician might describe a tumor as "superficial to" a deeper body structure. These terms often use comparative terms in pairs to trace out the relative locations of one body part to another or descriptions of body tissues like the deeper ones from superficially present with reference to...
17.2K
Directional Relays01:25

Directional Relays

623
Directional relays, essential for managing unidirectional fault currents, enhance the safety and efficiency of power systems. On power lines equipped with directional relays, faults downstream (to the right) of the current transformer typically cause the fault current to lag the bus voltage by approximately 90 degrees, known as the forward direction. In contrast, upstream (left-side) faults may result in the fault current leading the bus voltage by nearly 90 degrees, termed the reverse...
623
Direct Motor Pathways01:11

Direct Motor Pathways

4.6K
The direct motor pathways, also known as the pyramidal tracts, are a group of neural pathways that originate in the brain and descend through the spinal cord. They control the voluntary movement of the body. There are two major direct motor pathways: the corticospinal and the corticobulbar tracts.
The corticospinal tract is responsible for the voluntary movement of the limbs and trunk. It originates in the cerebral cortex of the brain and descends through the cerebrum's internal capsule and...
4.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

p58, a Cytoskeletal Protein, Is Associated With Muscle Cell Determinants in Ascidian Eggs.

The Biological bulletin·2017
Same author

Evolutionary Implications of FGF and Distal-Less Expressions During Proximal-Distal Axis Formation in the Ampulla of a Direct-Developing Ascidian, Molgula pacifica.

The Biological bulletin·2017
Same author

Regulation of metamorphosis in ascidians involves NO/cGMP signaling and HSP90.

The Journal of experimental zoology·2001
Same author

The evolution of anural larvae in molgulid ascidians.

Seminars in cell & developmental biology·2001
Same author

Developmental roles of nuclear complex factors released during oocyte maturation in the ascidians Halocynthia roretzi and Boltenia villosa.

Zoological science·1998
Same author

Evolutionary modifications of morphogenetic mechanisms and alternate life history strategies in ascidians.

Microscopy research and technique·1993

Related Experiment Video

Updated: Feb 16, 2026

Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development
10:40

Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development

Published on: January 7, 2011

14.8K

Direct Development in the Ascidian Molgula retortiformis (Verrill, 1871).

W R Bates

    The Biological Bulletin
    |December 28, 2017
    PubMed
    Summary

    Directly developing ascidians like Molgula retortiformis lack muscle cells at hatching. This may be due to a missing factor in the egg cytoplasm, impacting muscle development and evolution.

    Area of Science:

    • Developmental Biology
    • Evolutionary Biology
    • Cellular Biology

    Background:

    • Ascidians exhibit diverse developmental strategies, including direct and indirect development.
    • Understanding these differences aids in comprehending the evolution of developmental processes.
    • Molgula retortiformis is a direct-developing ascidian species suitable for such studies.

    Purpose of the Study:

    • To investigate the cellular features of the direct-developing ascidian Molgula retortiformis.
    • To compare developmental processes between direct and indirect developing ascidians.
    • To explore the reasons behind the absence of muscle cells in newly hatched M. retortiformis.

    Main Methods:

    • Transmission electron microscopy
    • Histochemistry

    More Related Videos

    Genome Editing and Directed Differentiation of hPSCs for Interrogating Lineage Determinants in Human Pancreatic Development
    09:37

    Genome Editing and Directed Differentiation of hPSCs for Interrogating Lineage Determinants in Human Pancreatic Development

    Published on: March 5, 2017

    13.6K
    Home-Based Transcranial Direct Current Stimulation Device Development: An Updated Protocol Used at Home in Healthy Subjects and Fibromyalgia Patients
    11:26

    Home-Based Transcranial Direct Current Stimulation Device Development: An Updated Protocol Used at Home in Healthy Subjects and Fibromyalgia Patients

    Published on: July 14, 2018

    18.0K

    Related Experiment Videos

    Last Updated: Feb 16, 2026

    Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development
    10:40

    Direct Delivery of MIF Morpholinos Into the Zebrafish Otocyst by Injection and Electroporation Affects Inner Ear Development

    Published on: January 7, 2011

    14.8K
    Genome Editing and Directed Differentiation of hPSCs for Interrogating Lineage Determinants in Human Pancreatic Development
    09:37

    Genome Editing and Directed Differentiation of hPSCs for Interrogating Lineage Determinants in Human Pancreatic Development

    Published on: March 5, 2017

    13.6K
    Home-Based Transcranial Direct Current Stimulation Device Development: An Updated Protocol Used at Home in Healthy Subjects and Fibromyalgia Patients
    11:26

    Home-Based Transcranial Direct Current Stimulation Device Development: An Updated Protocol Used at Home in Healthy Subjects and Fibromyalgia Patients

    Published on: July 14, 2018

    18.0K
  • Immunocytochemistry using a vertebrate intermediate filament antibody (NN18)

    • Main Results:

    • M. retortiformis eggs contain abundant yolk and glycogen.
    • Newly hatched juveniles show similar cell ultrastructure, with deeper cells richer in yolk and glycogen.
    • Differentiated muscle cells and acetylcholinesterase (AChE) activity were absent in hatchlings.

    Conclusions:

    • The absence of muscle cells in M. retortiformis juveniles may stem from a lack of a specific factor in the egg's myoplasm.
    • This finding supports the "substrate hypothesis" regarding ascidian direct development.
    • Further research can elucidate the evolution of developmental patterns in ascidians.