#9127 tail tip morphogenesis - rename

[Chris Mungall]

"The process in which the anatomical structures of the tail tip are generated and organized. The tail tip undergoes morphogenesis to form a copulatory structure. The most posterior hypodermal cells in the tail define a specialized, sexually dimorphic compartment in which cells fuse and retract in the male, changing their shape from a tapered cone to a blunt dome. An example of this process is found in Caenorhabditis elegans"

"tail tip" is a very broad term and can be found in XAO, MA, etc. The current GO term clearly doesn't refer to these, although it's not immediately obvious from the term.

I don't know nematode anatomy, but http://www.wormatlas.org/glossary/tglossary.htm
suggests "tail spike" might be a better term. I might go even further and suggest "copulatory tail spike"

WBbt has this:

[Term]
id: WBbt:0006979
name: tail spike
namespace: worm_anatomy
def: "an acellular thin cuticle whip formed at the very end of the tail during embryogenesis." [WB:rynl, WBPaper:00038216]
comment: LINKOUT::WORMATLAS::<http://www.wormatlas.org/ver1/handbook/hypodermis/hypsupportother.htm#tailspikecells>
relationship: part_of WBbt:0005741 ! tail

I also find the parent grouping class "tail morphogenesis" somewhat odd, it's a terminological grouping. I would instead have groupings for post-anal tails and more generally the posterior end of the organism, maybe

[RFoulger]

Our resident elegans expert, Kimberly, said she'd take a look at the anatomy for the worm part of this one.

[KM Van Auken]

Hi--

In looking at this term and how we've used it to annotate, I think that we could transfer these annotations to GO:0048808 male genitalia morphogenesis, or create a child term of GO:0048808, male copulatory structure morphogenesis.

I agree that tail tip morphogenesis is not specific enough and that we need a better term.

What do you think of a new term male copulatory structure morphogenesis?

--Kimberly

[RFoulger]

Hi Kimberly,

I like your suggestion of obsoleting 'tail tip morphogenesis', and having:

male genitalia morphogenesis ; GO:0048808
--[partof]male copulatory structure morphogenesis ; GO:NEW

To try and tie-in with the WB anatomy ontology, is it possible to specify which structures make up the copulatory structure? (e.g. copulatory spicules etc)?

tail morphogenesis ; GO:0035121 has been annotated (manually) to a whole range of organisms, so agree it needs to be split out:
mouse (51)
zebrafish (16)
C.elegans (11)
rat (5)
human (5)
chicken (3)
Xenopus (1)
Drosophila (1)
Takifugu fish (1)

Searches for post-anal tails suggests it should be restricted to Chordates. Do we want to group fish tails with mouse tails tho? How would you describe a worm tail Kimberly?

Thanks,
Becky

[KM Van Auken]

Hi Becky,

Here is a definition for the C. elegans male tail including the names of the key, individual components that make up the copulatory structure:

The C. elegans male tail is a bilaterally symmetric structure that includes a fan-like arrangement of nine pairs of chemosensory organs known as rays, sclerotized spicules, the gubernaculum, the hook sensillum, and associated musculature. The C. elegans male tail, similar in shape to the hermaphrodite tail spike during early larval stages, is reshaped during late postembryonic development to form a scalloped shaped tail.

Two relevant references are:

PMID:7409314 and PMID:18050419

Here are some xrefs also to WB anatomy ontology terms:

ray : WBbt:0006941
spicule : WBbt:0005312
hook sensillum : WBbt:0006930
gubernaculum : WBbt:0008424
cloaca : WBbt:0005774

Let me know if you need more info.

Thanks,
--Kimberly

[RFoulger]

Does this proposal work for you?

1/ OBSOLETE tail morphogenesis ; GO:0035121
Reason for obsoletion:
It's a grouping term that has different meaning in different organisms; In some cases it's used to mean the posterior end of an organism. Its child 'tail tip morphogenesis' is intended for use in worms.

2/ Create new replacement term:
post-anal tail morphogenesis ; GO:NEW
The process in which a post-anal tail is generated and organized. A post-anal tail is a muscular region of the body that extends posterior to the anus. The post-anal tail may aid locomotion and balance.
is_a: anatomical structure morphogenesis ; GO:0009653
Wikipedia:Chordate
Taxon restriction: Chordata (7711)

For non-chordates, consider instead annotating to:
analia morphogenesis ; GO:0048809
or terms under regionalization ; GO:0003002

3/ Rename, redefine and rehouse GO:0045138'
from:
tail tip morphogenesis ; GO:0045138
The process in which the anatomical structures of the tail tip are generated and organized. The tail tip undergoes morphogenesis to form a copulatory structure. The most posterior hypodermal cells in the tail define a specialized, sexually dimorphic compartment in which cells fuse and retract in the male, changing their shape from a tapered cone to a blunt dome. An example of this process is found in Caenorhabditis elegans.
is_a: tail morphogenesis ; GO:0035121
>
male copulatory structure morphogenesis ; GO:0045138
synonym: male tail tip morphogenesis
The process in which the anatomical structures of the male copulatory structure in nematodes are generated and organized. The copulatory apparatus is a specialized tail structure reshaped during late post-embryonic development, that includes a fan-like arrangement of nine pairs of chemosensory organs known as rays, sclerotized spicules, the gubernaculum, the hook sensillum, and associated musculature.
PMID:7409314
PMID:18050419
GOC:kmv
taxon restriction: Nematoda (6231)
is_a: anatomical structure morphogenesis ; GO:0009653

One question:
Would you need a term to cover development of the hermaphrodite tail?

Thanks,
Becky

[RFoulger]

Created new term: post-anal tail morphogenesis ; GO:0036342

Renamed, redefined and rehoused 'tail tip morphogenesis ; GO:0045138'.

Sent obsoletion notice for: tail morphogenesis ; GO:0035121

Just the obsoletion of GO:0035121 left to do on this SF item.

[RFoulger]

Obsoleted:
tail morphogenesis ; GO:0035121