Introduction of Marine Invertebrates as tools for studies on oocyte maturation, fertilization and early development
Organized by Research Center for Marine Biology, Asamushi, Tohoku University
Overview
About the Course
Marine Invertebrates have been good model systems for analyzing fertilization
and related events such as embryogenesis since late 19th century. They
have been particularly popular as gametes are easy to obtain and handle,
and embryos can be obtained easily via in vitro fertilization. In our course,
we provide a wonderful opportunity for students in college and the early
phase of graduate school to learn basic biology on multiple marine organisms
such as ascidian, sea urchin, and jellyfish in the field of oocyte maturation
through fertilization and embryogenesis. Instructors and lecturers are
the experts and prominent researchers of the field. Participants also have
a chance to discuss about the latest information on the research with the
introduction of new experimental techniques of the field. This may give
you hints for further study on your subject with your organisms in general.
We look forward to seeing you in next June in Asamushi.
Instructors:*Please click each instructor to his/her own homepage.
Dr. Evelyn Houliston, Villefranche-sur-mer Marine Station, France
Dr. Alex McDougall, Villefranche-sur-mer Marine Station, France
Dr. Gary Wessel, Brown University, USA
Lecturers
Dr. Stephen A. Stricker, University of New Mexico, USA
Dr. Luigia Santella, Stazione Zoologica, Anton Dohrn, Italy
Venue
This course will take place at the Asamushi Research Center for Marine
Biology, Tohoku University.
Organizing Committee members
Keiichiro Kyozuka
Atsushi Sogabe
Noriyo Takeda
Gaku Kumano
Schedule
Order of each session may be exchanged according to the condition of sea,
animals or instructor's schedule.
June 18th in the afternoon
Registration
Lecture 1: Dr. S.A. Stricker
Title: Comparative biology of oocyte maturation and fertilization in marine
invertebrates
Lecture 2: Dr. L. Santella
Title: Actin cytoskeleton in the control of maturation and fertilization
of echinoderm eggs
Welcome party (BBQ)
June 19-20th session 1
Instructors: Dr. E. Houliston and Dr. N.Takeda
Title: Hydrozoan jellyfish development and life cycle.
June 21-22nd session 2
Instructor: Dr. G. Wessel
Title: Eggs, Echinoderms, and Mechanisms of Development
June 23-24th session 3
Instructor: Dr. Alex McDougall
Title: Cell biological methods for studying fertilization and early embryonic
development in ascidians.
June 25th in the morning
Total discussion
Program
Session 1: Hydrozoan jellyfish development and life cycle
Instructors: Dr. E. Houliston and Dr. N. Takeda
Cnidaria is a very large and diverse phylum whose species have many different
morphologies, developmental strategies and life cycles. The impressive
expansion of the Cnidaria during evolution occurred in parallel with the
evolution and diversification of its sister taxon, the Bilateria, starting
from a common ancestor whose genome already contained the main known families
of developmental regulator genes. Within the Cnidaria, the Anthozoa (corals,
sea anemones etc) all have a larval form and a polyp adult form in their
life cycle, while the Medusozoa species (including jellyfish, hydra and
siphonophores) can have larvae, medusae and/or polyp forms. Within the
Medusozoa, the class Hydrozoa shows a particularly great diversity of forms,
development and life cycles.
In this session the students will be introduced to these animals through
collecting in the field as well as laboratory observations and experiments,
focused on the biological mechanisms controlling life cycle transitions
such as spawning, fertilisation, larval development and metamorphosis.
Session 2: Eggs, Echinoderms, and Mechanisms of Development
Instructor: Dr. G. Wessel
We will conduct experience-based, research approaches to explore oocyte
growth, meiosis, and embryonic development in a variety of echinoderms.
This important taxon of animals is rich in the Asamushi area and provides
potential to meet a variety of research interests. Important paradigms
of development will be examined in this module, and students will be given
the training, tools, and guidance to cultivate unique projects. Analytical
and experimental techniques integrated into the module include embryological
manipulations, molecular operations, cell biology approaches, and microscopic
and imaging technologies, using state-of-the-art instrumentation and methodology.
Conceptual topics in this module include cell specification and differentiation,
pattern formation, embryonic axis formation, morphogenesis, intercellular
signaling, and transcriptional regulation. Students are exposed to a wide
variety of embryonic systems during this course, and our broad coverage
of metazoan phylogeny allows for the analyses of the developmental strategies
that drive evolutionary change.
Session3: Cell biological methods for studying fertilization and early
embryonic development in ascidians.
Instructor: Dr. A. McDougall
Ascidians are primitive marine chordates whose embryos develop rapidly
in seawater – a swimming tadpole larva forms about 12 hours after fertilization
composed of only ~2600 cells. In the laboratory class we shall observe
some of the key features of early ascidian development from a cell biological
perspective – ooplasmic segregation and meiotic maturation following fertilization,
unequal cleavage of the germ cell lineage from the 8 to 64-cell stage,
the invariant cleavage pattern together with the nomenclature system for
naming every cell (blastomere) up to the gastrula stage, plus how cell
cycle duration and the process of gastrulation are linked. We have developed
many cell biological tools (fluorescent proteins to label microtubules,
centrosomes, plasma membrane etc.) and methods (fluorescent probes) to
study early embryonic development in ascidians. During the laboratory class
we will extend these methods to Ascidiella aspersa, an ascidian species
found in Japan, Europe, and the USA (east coast) that has transparent eggs/embryos
that are perfect for microscopic observations coupled with cell biological
methods. In addition, we will demonstrate how to microinject ascidian eggs
with mRNA encoding fluorescent fusion proteins (GFP/Venus/mCherry) to study
subcellular events during early embryogenesis.
Lecture 1: Comparative biology of oocyte maturation and fertilization in
marine invertebrates
Lecturer: Dr. S.A. Stricker
Nearly all animals are invertebrates, and the vast majority of the approximately
35 extant phyla of animals are composed of invertebrates that live either
exclusively or predominantly in marine habitats. Accordingly, comparative
surveys of the first cell cycle in marine invertebrates can reveal a seemingly
bewildering array of reproductive modes that have evolved throughout the
animal kingdom. In order to help provide an introduction to such diversity,
this lecture aims to describe a few common themes and distinguishing characteristics
of oocyte maturation and fertilization in marine invertebrates. In particular,
topics such as the state of oocyte maturation at the time of fertilization,
the roles of intraoocytic cyclic nucleotides and kinases in re-initiating
meiosis, and the general patterns of fertilization-induced calcium signals
will be considered.
Lecture 2: Actin cytoskeleton in the control of maturation and fertilization
of echinoderm eggs
Lecturer: Dr. L. Santella
For more than a hundred years, starfish and sea urchin eggs have been ideal
model systems to explore the mechanisms of maturation, fertilization and
embryonic development in the natural medium, seawater. They are big cells,
with a quasi-transparent cytoplasm and a large nucleus, properties that
facilitate experiments of microinjection of various fluorescent probes
into sub cellular compartments. During the breeding season, the gonad of
female starfish is full of a synchronized population of the oocytes arrested
at the first prophase of meiosis which can be induced to re-initiate in
vitro by 1-methyladenine, and the subsequent changes in the nucleus (germinal
vesicle breakdown) and cytoplasm can be easily followed. Thus, starfish
have been of great value in studying oocyte maturation. On the other hand,
sea urchin eggs are fertilized after the completion of meiosis, and are
suitable for the study of sperm-egg interaction, early events of egg activation,
and embryonic development. We have found that the deregulation of the actin
cytoskeleton induced by interfering with the components of actin-regulating
pathways, had a profound impact on meiotic maturation, egg activation,
and, particularly, on the intracellular Ca2+ responses, cortical granules
exocytosis and monospermic egg entry.
Qualification and Registration
Registration:
1. Please send an e-mail to the following address with your intention to
participate in the course and your email address for our reply by May 1,
2015.
2. We will then send an application form with additional information about
the course, accommodations and so on.
e-mail address: asamushi(at)bureau.tohoku.ac.jp
Please change (at) to @.
Qualification and skill for the Course:
Graduate and undergraduate students from any Institute in the world, who
major biology and related field or has an interest in biology, especially
developmental biology and embryology. Experiences of handling marine animals
are not necessary. Undergraduate students who want to study on the developmental
biology with marine invertebrates at Asamushi center in near future are
welcome.
Participation students:
Approximately 12 undergraduate and graduate students of any nationality
in total
Accommodation;
Dormitory with cafeteria in the Asamushi center is available in reasonable
cost during the Course. Please see Dormitory for details.
Financial Support:
We have applied for some grants to help your attendance partially. However,
when you have a chance to apply the financial support in your institute
to attend the Course, we would encourage you to apply for it and are willing
to help with your paper work.