somatic embryogenesis

[J Clark]

Hi,

I just got a request from Suparna that I'd
be interested in getting some feedback on. I've
summarised my questions below.

The request is at at:

[ 1247346 ] somatic embryogenesis
https://sourceforge.net/tracker/index.php?func=detail&aid=1247346&group_id=36855&atid=440764

Thanks for reading.

Best wishes,

Jen



Request:
========

[i]embryonic development (sensu Magnoliophyta) ; GO:0009793
---[i]somatic embryogenesis ; GO:new

term: somatic embryogenesis ; GO:new
Def: Initiation of embryos from previously differentiated somatic cells.
Ref: http://www.uwrf.edu/~dc01/somatlab.html

The easy bit
============

It seems to me that the main parent for this is

[i]plantlet formation on parent plant ; GO:0048624
---[p]somatic embryogenesis ; GO:new

Problem 1
=========

Suparna also requested
embryonic development (sensu Magnoliophyta) ; GO:0009793
as a parent, which seems almost sensible since the
definition is:

embryonic development (sensu Magnoliophyta) ;
GO:0009793 is:
def: The process whose specific outcome is the
progression of an embryo from zygote formation
until the end of its embryonic life stage. The end
of the embryonic stage is organism-specific and
may be somewhat arbitrary. For example, it would
be at birth for mammals, larval hatching for
insects and seed dormancy in plants.

So the def describes the concept in which:

1) An embryo is being made. [good]
2) There's no scope for an embryo being made from anything other than a
zygote.[bad]

This is a problem for the somatic embryogenesis parentage.

Proposal: I can change the def to:

embryonic development (sensu Magnoliophyta) ;
GO:0009793 is:
def: The process whose specific outcome is the
progression of an embryo from initial formation to
the end of its embryonic life stage. Initial
formation can be at zygote formation or at the
stage of determination of the embryogenic fate of
a somatic cell. The end
of the embryonic stage is organism-specific and
may be somewhat arbitrary. For example, it would
be at birth for mammals, larval hatching for
insects and seed dormancy in plants.


Problem 2
=========

Perhaps Suparna will one day also want

'morphogenesis of a somatic embryo ; GO:new'


The definition for embryonic morphogenesis
is quite different from that of embryonic development:

Term: embryonic morphogenesis
Def: The process by
which anatomical structures are generated and
organized _during_the_embryonic_phase_.
Morphogenesis pertains to the creation of form.
The embryonic phase begins with zygote formation.
The end of the embryonic phase is
organism-specific and may be somewhat arbitrary.
For example, it would be at birth for mammals,
larval hatching for insects and seed dormancy in
plants.

So the development term describes the development of an embryo
but the morphogenesis term describes morphogenesis during the embryonic phase.

Should these two terms be more similar? i.e. Either:

Term: embryonic development
Def: development of an embryo
Term embryonic morphogenesis
Def: morphogenesis of an embryo

or

Term: embryonic development
Def: development taking place during the embryonic phase
Term embryonic morphogenesis
Def: morphogenesis taking place during the embryonic phase


Problem 3
=========

I think that in talking about somatic embryogenesis we start with gene products
acting in a somatic cell of an adult plant and we end up with gene products
acting in a somatic embryo. There may be a problem with the gene products acting
in the initial stages if the morphogenesis term is saying that the gene product
is acting 'during the embryonic phase.'

Does anybody have any thoughts on this?

Thanks,

Jen