G. Montana et al., CLONING, EXPRESSION, AND LOCALIZATION OF A NEW MEMBER OF A PARACENTROTUS-LIVIDUS CELL-SURFACE MULTIGENE FAMILY, Molecular reproduction and development, 44(1), 1996, pp. 36-43
We have isolated and characterized a cDNA clone corresponding to a new
member of bep (butanol, extracted, proteins) Paracentrotus lividus mu
ltigene family coding for cell surface proteins. The cDNA, called bep3
, encodes a 370 amino acid protein and shares the same structural orga
nization in the coding region with other members of the same gene fami
ly already characterized. Expression of this clone studied by Northern
blot and by whole mount hybridization shows that the bep3 messenger i
s transcribed during oogenesis and utilized till the gastrula stage, w
hereas at the prism stage, unlike other members of the same gene famil
y, new synthesis of messenger occurs. By whole mount hybridization spa
tial distribution of bep3 messenger in egg and embryos is established.
This messenger appears located in the animal half of the unfertilized
egg and moves to the cortical zone after fertilization; it is not pre
sent in the structures derived by the vegetal part of the embryo, such
as the micromeres of the 16-cell stage, the primary mesenchyme cells
of the blastula, and the primary intestine of the gastrula. At the pri
sm stage instead, hybridization of bep3 messenger is restricted to the
part of the embryo that will give origin to the oral region as succes
sively confirmed by hybridization at the pluteus stage. The result of
whole mount hybridization was confirmed by Northern blot hybridization
of separated meso-macromere and micromere RNAs. A Southern blot exper
iment demonstrates that bep3 is codified by a single copy gene. Conser
vation of the bep multigene family in several Mediterranean and Japane
se sea urchin species has also been analyzed. (C) 1996 Wiley-Liss, Inc
.