otolithic membrane terms

[cerivs]

I would like to propose three new AO terms:

AO-NEW-1: otolithic membrane
DEF: acellular matrix located between an otolith and its corresponding sensory macula. Otoliths form over sensory maculae and are attached to the otolithic membrane, a gelatinous extracellular matrix that provides a physical coupling between the otolith and the underlying sensory epithelium. The otolithic membrane is equivalent to the mammalian otoconial membrane.
TYPE-OF: acellular anatomical structure ( ZFA:0000382 )
START: unknown
END: Adult

AO-NEW-2: saccular otolithic membrane
DEF: otolithic membrane coupling the saccular otolith to the saccular macula.
TYPE-OF: AO-NEW-1: otolithic membrane
PART-OF: saccule ( ZFA:0000428 )
START: unknown
END: Adult

AO-NEW-3: utricular otolithic membrane
DEF: otolithic membrane coupling the utricular otolith to the utricular macula.
TYPE-OF: AO-NEW-1: otolithic membrane
PART-OF: utricle ( ZFA:0000700 )
START: unknown
END: Adult

Journal reference:
Stooke-Vaughan et al., Development. 2015 Mar 15;142(6):1137-45. doi: 10.1242/dev.116632. PubMed: 2575822, ZFIN Pub ZDB-PUB-150312-3

thank you,
Dave Fashena (ZFIN)

Original comment by: dfashena

[cerivs]

Is the composition the same as in mammals? What we have in uberon may be mammal-centric:

 UBERON:0016567 ! statoconial membrane *** 
      po UBERON:0002519 ! otolithic part of statoconial membrane
      po UBERON:0016568 ! gelatinous layer of statoconial membrane
      po UBERON:0016569 ! subcupular meshwork of statoconial membrane

Note the otolithic part is defined "The layer of the statoconial membrane that is composed of otoliths" [PMID:2482728]

This suggests either different modeling or different structures from the zebrafish

Original comment by: cmungall

[cerivs]

Mammals have many tiny otoconia and fish have three big honking otoliths. So the otolithic part of UBERON:0016567 does not have an obvious fishy equivalent. I would guess that the gelatinous layer and subcupular meshwork parts of are comparable, though. Judging from this excerpt from the Stooke-Vaughan at al. paper, it sounds like the full answer is not yet known:

"Several glycoprotein components of the otoconial membrane have been identified in mammals, including otogelin, otogelin-like, α-tectorin, β-tectorin and otolin (Goodyear and Richardson, 2002; Deans et al., 2010; Yariz et al., 2012). The teleost otolithic membrane is thought to have a similar composition to the mammalian otoconial membrane; Otolin-1 has been identified as an otolithic membrane protein in adult rainbow trout, chum salmon and bluegill sunfish (reviewed by Hughes et al., 2006; Lundberg et al., 2006). Little is known, however, about development of the teleost otolithic membrane at embryonic stages or its composition in zebrafish. It is likely that Otolin 1a (Murayama et al., 2005), β-Tectorin (Yang et al., 2011) and Otogelin-like (Yariz et al., 2012) are components of the zebrafish otolithic membrane, based on variable phenotypes (small, fused, supernumerary or untethered otoliths) seen in morphants for these genes. Other components of the zebrafish otolithic membrane have not yet been characterised."

Original comment by: dfashena

[cerivs]

Thanks Dave, this is v useful!

Original comment by: cmungall