These differences raise the question of what the ancestral clock was like before the divergence of protostomes
The NK cluster in the last common ancestor to protostomes
and deuterostomes probably contained a cluster of nine NK genes: Msx, NKl/slouch, NK3/bagpipe, NK4/tinman, Tlx/cl5, NK7, NK6/hgtx, NK5/Hmx, and Lbxl ladybird genes (Holland 2001, Garcia-Fernandez 2005, Larroux et al.
Roles of Src family kinases during fertilization and the first cell cycle in the marine protostome
Based on the lack of homology between the postoral ciliated bands and on recent phylogenies of protostomes
and polychaetes, a broader definition of trochophore is more likely to reflect the plesi-omorphic condition: a larva with a preoral ciliated band derived from trochoblasts (prototroch) (Damen and Dictus, 1994; Rouse, 1999; Maslakova et al., 2004).
It is also important to note that, due to high sequence conservation, the polyclonal Hb-like antibody is not likely to distinguish multiple copies of Hb in protostome
genomes; therefore the molluscan proteins are referred to as Hb-like homologs.
) using human genes implicated in wound healing in the initial query Extracellular matrix ID Protostome
E proteins hit value Human query SLRPs (small leucine-rich-repeal proteins) Biglycan AAA52287 XM_001649763 3e-21 Chondroadherin AAK51556 XM_970227 3e-26 Decorin AAB60901 No match n/a Fibrinidulin CAA53233 AJ549813 9e-21 Keratocan NP_008966 XM_001650288 8e-16 Lumican AAA91639 XM_395331 3e-17 Opticin CAB53459 XM_001606218 4e-11 Osteoglyein CAI16695 NM_206253 4e-04 PRELP CAG47066 XM_001360484 2e-15 Other extraceluar matrix proteins Asporin CAI16697 XM_967172 2e-28 Dermatan Sulf.
Many molecular feedback mechanisms of this system have been preserved, suggesting that they already operated in the ancestors of protostomes
In N-linked saccharide chains of species belonging to protostomes
(nematode, squid, and limpets, etc.), galactose residues at the non-reducing ends are known to bind to a fucose residue attaching to the innermost GlcNAc residue via [beta]1-4 linkage.
The same collagen-proteoglycan-adhesive glycoprotein ECM is found in both protostomes
Eggs of these protostomes
have certain features that make them more similar to mammalian oocytes than to echinoderm or coelenterate eggs.
The formation of the germ cells at the poste-riormost region of embryos is also observed in protostomes
, suggesting that the manner of germ cell formation is conserved among protostomes
Finally, we examined representative metazoan genomes and found highly conserved usherin genes throughout the deuterostome lineage as well as in some protostomes