Tanya Berardini, Donghui Li, Jennifer Clark
We have done a great deal on 'female gametophyte development' and its child terms in today's meeting. Specifically:
female gametophyte development
Replaced the term name 'female gametophyte development' with 'embryo sac development'. Included 'female gametophyte development' as a synonym of 'embryo sac development'.
Created a separate term 'megagametogenesis' (GO:0009561). Regrouped the child terms of 'embryo sac development' into 'megagametogeneis' and 'megasporogenesis'.
'megagametogenesis' was previously used as a synonym to 'female gametophyte development' (or embryo sac development). We have adopted the definitions by Howell (1998, Molecular Genetics of Plant Development, Cambridge University Press, ISBN 0-521-58784-0) and divided 'embryo sac development' into 'megasporogenesis' (refering to the formation of megaspores from megasporocyte) and 'megagametogenesis' (from megaspores to embryo sac).
antipodal cell differentiation (GO:0009557)
Unchanged. Now a child of 'megagametogenesis'.
cellularization of megagametophyte (GO:0009558)
Definition revised. Now a child of 'megagametogenesis'.
female gametophyte central cell differentiation (GO:0009559)
Renamed: embryo sac central cell differentiation to be consistent with 'embryo sac development' and other related terms. New definition. Now a child of 'megagametogenesis'.
female gametophyte egg cell differentiation (GO:0009560)
Renamed to 'embryo sac egg cell differentiation'. New definition. Now a child of 'megagametogenesis'.
female gametophyte morphogenesis (GO:0048314)
Renamed to 'embryo sac morphogenesis'. Defintion revised. Now a child of 'megagametogenesis'.
megagametophyte nuclear division (GO:0009561)
Now becomes a synonym of 'megagametogensis' (GO:0009561).
megagametophyte nuclear migration (GO:0009562)
Renamed to 'embryo sac nuclear migration'. Defition revised. Now a child of 'megagametogenesis'. Created two new child terms:
nuclear migration to embryo sac poles (GO:0023002) nuclear migration to the embryo sac center (GO:0023003)
polar nucleus fusion
See Action Item 1.
synergid differentiation (GO:0009563)
Now a child of 'megagametogenesis'; otherwise untouched.
egg apparatus differentiation, ovule primordium differentiation, ovule primordium dvelopment
In the original SourceForge item, Jen has requested the above and other related regulation terms. We have decided not to create these terms.
This term was requested in the SF item. We did not create this term because the formation of megaspores from megasporocyte ('megasporocyte differentiation') is a meiosis, not a differentiation process.
Action Item 1: Tanya
Term 'polar nucleus fusion' (GO:0010197). Need to examine the nature of the 'nucleus fusion' prior to the endosperm fertilization. Also need to look at existing annotations associated with this term. Need to figure out the relationship between this term and 'embryo sac central cell differentiation'?
Donghui: I have come across a paper which describes the female gametophyte development in Arabidopsis. The paper mentions the polar neucleus fusion 'prior to fertilization'. Could be useful in sorting out this term.
Action Item 2:
Term 'megasporogenesis' currently is a child of 'anatomical structure development'. However, the outcome of this process is the formation of an multicellular organism 'embryo sac'. Note that 'megasporogenesis' is a child of 'embryo sac development' which in turn is a child of 'multicellular organism development'. We could leave the parentage of this term as it is.