Molecular characterization of an inhibitor of apoptosis in the Egyptian armyworm, Spodoptera littoralis, and midgut cell death during metamorphosis.
The cDNA corresponding to an inhibitor of apoptosis (IAP) from the Egyptian armyworm, Spodoptera littoralis, was cloned by RT-PCR. Sequence analysis showed that the IAP of S. littoralis (SlIAP) contains two baculoviral IAP repeat (BIR) motifs, followed by a RING finger, an organization which is very similar to that of other lepidopteran IAPs. SlIAP mRNA was detected in ovary, testis, salivary gland, fat body, epidermis, brain and midgut of S. littoralis. During the last larval instar, prepupal and pupal stages, brain mRNA levels remained approximately constant, whereas those of midgut showed a large peak centred in the prepupal stage. Midgut morphology changed during metamorphosis from a semi-transparent, cylindrical structure in last instar larvae to a brownish globular mass in pupae. TUNEL assays, LysoTracker staining and caspase-3 immunohistochemistry, indicated that programmed cell death in midgut starts actively at the onset of pupation process, coinciding with the dramatic decrease of SlIAP mRNA levels observed at the same time.
Vilaplana
Lluïsa
L
Department of Physiology and Molecular Biodiversity, Institut de Biologia Molecular de Barcelona (CSIC), Jordi Girona, 18-26, 08034 Barcelona, Spain.
Pascual
Nuria
N
Perera
Nathalia
N
Bellés
Xavier
X
D000588:Amines; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000502:physiology*; D041981:Gastrointestinal Tract / Q000254:growth & development / Q000378:metabolism; D015870:Gene Expression; D020287:In Situ Nick-End Labeling; D051034:Inhibitor of Apoptosis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008675:Metamorphosis, Biological / Q000502:physiology*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D017422:Sequence Analysis, DNA; D018411:Spodoptera / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D000588:Amines; D051034:Inhibitor of Apoptosis Proteins; C493330:Red DND-99; D053148:Caspase 3