Axial (apical-basal) expression of pro-apoptotic and pro-survival genes in the lake baikal demosponge Lubomirskia baicalensis.
Like in all other Metazoa, also in sponges (Porifera) proliferation, differentiation, and death of cells are controlled by apoptotic processes, thus allowing the establishment of a Bauplan (body plan). The demosponge Lubomirskia baicalensis from the Lake Baikal is especially suitable to assess the role of the apoptotic molecules, since its grade of construction is highly elaborated into an encrusting base and branches composed of modules lined up along the apical-basal axis. The four cDNAs, ALG-2, BAK, MA-3, and Bcl-2, were isolated from this sponge species. The expression levels of these genes follow characteristic gradients. While the proapoptotic genes are highly expressed at the base of the branches and comparably low at the top, the pro-survival gene follows an opposite gradient. Parallel with the tuned expression of these genes, the activities of the apoptosis-executing enzymes caspase-8 (IETDase activity) and caspase-3 (DEVDase activity) are lowest at the top of the branch and highest at their base. This characteristic expression/activity pattern of the genes/enzymes, which had been determined in a few specimens, collected from an unpolluted, natural site, appears reversed in specimens collected from an anthropogenically polluted site. These findings indicate the involvement of apoptotic proteins in the axis formation (branches) in L. baicalensis.
Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität Mainz, Mainz, Germany.
Matthias
M
Wiens
Sergey I
SI
Belikov
Oxana V
OV
Kaluzhnaya
Heinz C
HC
Schröder
Bojan
B
Hamer
Sanja
S
Perovic-Ottstadt
Alexandra
A
Borejko
Bérengère
B
Luthringer
Isabel M
IM
Müller
Werner E G
WE
Müller
D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015152:Blotting, Northern; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases / Q000032:analysis; D016764:Cell Polarity / Q000235:genetics*; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D020832:EF Hand Motifs; D005618:Fresh Water; D015870:Gene Expression; D005979:Glutathione Peroxidase / Q000032:analysis; D008954:Models, Biological; D008969:Molecular Sequence Data; D010802:Phylogeny; D011161:Porifera / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012426:Russia; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D019253:Proto-Oncogene Proteins c-bcl-2; D005979:Glutathione Peroxidase; D053148:Caspase 3; D053181:Caspase 8; D020169:Caspases