Evidence of poly (ADP-ribosylation) in the cockroach Periplaneta americana.

Poly(ADP-ribosylation) is a post-translational modification of nuclear proteins typical of most eukaryotic cells. This process participates in DNA replication and repakandisnlainly regulated by two enzymes, poly(ADP-ribose) polymerase, which is responsible for the synthesis of polymers of ADP-ribose, and poly(ADP-ribose) glycohydrolase, which perfonns polymer degradation. The aim 'of this work was to investigate in the cockroach Periplaneta americana L. (Blattaria: Blattidae) the behaviour of poly(ADPribosylation). In particular, we addressed: (i) the possible modulation of poly(ADP-ribosylation) during the embryonic development; (ii) the expression of poly(ADP-ribose) polymerase and glycobydrolase in dilierent tissues; and (iii) the role of poly(ADPribosylation) during spennatogenesis. In this work we demonstrated that: (i) as revealed, by specific biochemical assays, active poly(ADP-ribose) polymerase and glycohydrolase are present exclusively in P. americana embryos at early stages of development; (ii) an activity carrying out poly(ADP-ribose) synthesis was fouod in extracts from testes; and (iii) the synthesis of poly(ADPribose) occurs preferentia1ly in differentiating spermatids/spennatozoa. CoHectively, oUI results indicate that the poly(ADP-ribosylation) process in P. americana, which is a hemimetabolous insect, displays catalytical and structural features similar to those described in the holometabolous insects and in 'mammalian cells. Furthermore, this process appears to be modulatedduring embryonic development and spermatogenesis.