Expression profile of a Laccase2 encoding gene during the metamorphic molt in Apis mellifera (Hymenoptera,Apidae)

Expression profile of a Laccase2 encoding gene during the metamorphic molt in Apis mellifera (Hymenoptera, Apidae). Metamorphosis in holometabolous insects occurs through two subsequent molting cycles: pupation (metamorphic molt) and adult differentiation (imaginal molt). The imaginal molt in Apis mellifera L. was recently investigated in both histological and physiological-molecular approaches. Although the metamorphic molt in this model bee is extremely important to development, it is not well-known yet. In the current study we used this stage as an ontogenetic scenario to investigate the transcriptional profile of the gene Amlac2, which encodes a laccase with an essential role in cuticle differentiation. Amlac2 expression in epidermis was contrasted with the hemolymph titer of ecdysteroid hormones and with the most evident morphological events occurring during cuticle renewal. RT-PCR semiquantitative analyses using integument samples revealed increased levels of Amlac2 transcripts right after apolysis and during the subsequent pharate period, and declining levels near pupal ecdysis. Compared with the expression of a cuticle protein gene, AmelCPR14, these results highlighted the importance of the ecdysteroid-induced apolysis as an ontogenetic marker of gene reactivation in epidermis for cuticle renewal. The obtained results strengthen the comprehension of metamorphosis in Apis mellifera. In addition, we reviewed the literature about the development of A. mellifera, and emphasize the importance of revising the terminology used to describe honey bee molting cycles.

Cloning of the novel putative apoptosis-related gene of Spirometra erinacei (Order Pseudophyllidae)

We postulated that apolysis was processed in accordance with apoptotic changes occurring in a cestode, Spirometra erinacei (Pseudophyllidea). We cloned the novel putative apoptosis-associated gene from S. erinacei via screening of a S. erinacei cDNA library with a ced-3 gene (activator of apoptosis) probe from Caenorhabditis elegans. We identified a 261-bp cDNA sequence, which encodes for an 86-amino acid protein. The cloned gene expression was observed in the neck and gravid proglottids via Northern blotting, using cloned cDNA inserts as probes, but the clone was not expressed in any of other tissues. We suggest that this gene may be involved in the apolysis of S. erinacei during normal tissue development and differentiation in cestode parasites.