(reprints available via email)

Frati, F., Fanciulli, P.P., Carapelli, A., Dell'Ampio, E., Nardi, F., Spinsanti, G., Dallai, R. DNA sequence analysis to study the evolution of Antartic Collembola. Italian Journal of Zoology, Supplement 1: 133-139 (2000)

Carapelli, A., Frati, F., Nardi, F., Dallai, R., Simon, C. Molecular phylogeny of the apterygotan insects based on nuclear and mitochondrial genes. Pedobiologia 44, 361-373 (2000).

Nardi, F., Carapelli, A., Fanciulli, P.P., Dallai, R., Frati, F. The complete mitochondrial DNA sequence of the basal hexapod Tetrodontophora bielanensis: evidence for heteroplasmy and tRNA translocations. Molecular Biology and Evolution 18, 1293-1304 (2001).

Dallai, R., Lupetti, P., Frati, F., Nardi, F., Afzelius, B.A. Sperm ultrastructure and spermiogenesis in the relic species Tricholepidion gertschi Wygodzinski (Insecta, Zygentoma). Tissue & Cell 13, 596-605 (2001).

Dallai, R., Lupetti, P., Frati, F., Nardi, F., Afzelius, B.A. Binucleate and biflagellate spermatozoa in Tricholepidion gertschi Wygodzinski (Insecta, Zygentoma). Tissue & Cell 13, 606-613 (2001).

CONGRESSI:

Nardi, F., Carapelli, A., Frati, F., Simon, C. Filogenesi molecolare degli insetti atterigoti ricostruita usando le sequenze del Fattore di Allungamento 1alpha. 59° Congresso dell’Unione Zoologica Italiana. San Benedetto del Tronto, 20-24 Settembre, 1998. Poster e comunicazione orale.

Carapelli, A., Frati, F., Nardi, F., Simon, C. Evoluzione e struttura secondaria del dominio III del gene mitocondriale ribosomale 12S negli insetti apterigoti, e sua rilevanza nello studio delle loro relazioni filogenetiche. 59° Congresso dell’Unione Zoologica Italiana San Benedetto del Tronto, 20-24 Settembre, 1998. Poster

Carapelli, A., Frati, F., Nardi, F., Simon, C. Molecular phylogeny of apterygotan insects based on nuclear and mitochondrial genes. Vth International Seminar on Apterygota Cordoba, Spagna, 9-13 Settembre,1998. Poster

Nardi, F., Carapelli, A., Fanciulli, P.P., Dallai, R., Frati, F. The complete mitochondrial DNA sequence of the basal hexapod Tetrodontophora bielanensis: evidence for heteroplasmy and tRNA translocations. Evolution 2000 Bloominghton, Indiana, 23-27 Giugno 2000. Comunicazione orale

Carapelli, A., Frati, F., Nardi, F., Dallai, R., Simon, C. The phylogeny of basal insects: molecular and morphological data compared XXI International Congress of Entomology Iguassu Falls, Brasile, 20 –26 Agosto, 2000. Poster

Nardi, F., Frati, F., Carapelli, A., Dallai, R. Mitochondrial DNA of Tetrodontophora bielanensis and the phylogeny of apterygotan insects. X International Colloquium on Apterygota Ceské Budejovice, Repubblica Ceca, 21-24 Agosto 2000. Poster

Dos Santos, P., Nardi, F., Roderick, G. Nuclear mitochondrial pseudogenes in Drosophila. Evolution 2001 Knoxville, Tennessee, 26 Giugno-1 Luglio 2001. Comunicazione orale

Lupetti, P., Frati, F., Carapelli F., Mercati, D., Nardi, F., Dallai, R. Lo spermatozoo degli Zygentoma (Exapoda). 62° Congresso Nazionale dell’Unione Zoologica Italiana. San Remo, 23-27 Settembre 2001. Poster

Carapelli, A., Frati, F., Nardi, F., Campagna, E., Fanciulli, P.P., Dallai, R., Simon, C. Filogenesi degli ordini basali di Hexapoda. 62° Congresso Nazionale dell’Unione Zoologica Italiana. San Remo, 23-27 Settembre 2001. Poster

Nardi, F., Roderick, G. Variabilità intraspecifica del retrotrasposone yoyo in popolazioni naturali di mosca mediterranea (Ceratitis capitata). 62° Congresso Nazionale dell’Unione Zoologica Italiana. San Remo, 23-27 Settembre 2001. Poster

Mitochondrial genomics in basal hexapods

The possibility to sequence entire mitochondrial genomes leads to a detailed study of these molecules at various levels. It is possible to describe these systems from a structural point of view, and to analize, besides the mere sequence, other features such as gene order, secondary structures, recombination events and heteroplasmy. In addition, the sequencing of complete genomes can give information about genes, such as ATPases, NAD dehydrogenses, tRNAs and the Control Region, that are rarely sequenced otherwise. Mitochondrial gene order is presently considered as one of the most promising characters to resolve ancient phylogenetic relationships. The entire mitochondrial sequence has been obtained for a basal hexapod, Tetrodontophora bielanensis (Hexapoda: Collembola), and has been analysed in detail from both a structural and phylogenetic viewpoint, applying Maximum Parsimony and Maximum Likelihood to concatenated aminoacidic sequences of mitochondrial protein coding genes. This showed some peculiarities of the molecule, such as the translocation of two tRNAs, some interesting secondary structures, and biases in base composition and rate of evolution. These will be investigate in the extended contest of basal hexapods (ìapterygotansî). The sequencing of another collembolan, Isotoma klovstadi, and the primitive tysanuran Tricholepidion gertschii, is being completed. Other organisms will be selected as representatives of most families of all basal hexapod orders.
Collaborators: Antonio Carapelli, Francesco Frati, Giacomo Spinanti, Jeffrey Boore, Romano Dallai.

Phylogeography of the Olive Fly, Bactrocera oleae.

The olive fly is the most important parasite of the olive tree, and produces serious damages to the olive coltivation in the Mediterranean region and in all its geographical range. In order to investigate the genetic structure of this species, for possible biological control applications and to try to limit its range expansion, it is necessary to develop markers that can resolve the relationships between local populations in detail. We are presently setting up various nuclear and mitochondrial markers, and microsatellite loci are currently being isolated and carachterized.
Collaborators: Francesco Frati, Romano Dallai, Kim Hoelmer, Massimo Cristofaro.

Variability of yoyo retrotransposon in the genome of the Mediterranean Fruit Fly, Ceratitis capitata (Diptera, Tephritidae).

Two fragments of yoyo retrotransposon have been amplified and sequenced in specimens of Ceratitis capitata from all its geographic range and for some outgroups. Multiple copies, ten for each specimen, have been sequenced in order to obtain variability estimates a various levels. A hierarchical variation analysis has shown that a significant variation is present between different species and between different copies in single specimens, while different specimens seem to have an uniform subpopulation of retrotransposons, regardless of their geographic source location. Mismatch distributions analysis showed a significant demographic increase of yoyo, that can be dated around 1,5my ago. A parallel analysis on nuclear markers of Ceratitis capitata did not show the same trend, demonstrating that the demographic expansion occurred for yoyo itself, and not for the entire genome of the Mediterranean Fruit Fly.
Collaborators: George Roderick, Francesco Frati.

Description of a mitochondrial peseudogene family in the nuclear genome of species of the genus Anastrepha of the ìfraterculusî group.

A fragment of the mitochondrial genome, corresponding to cox1, nad1, A+T rich region and rRNAs has been amplified in a single reaction and sequenced in various species of the fraterculus group of the genus Anastrepha. Many amplifications produced multiple bands, and many copies of one of these have been sequenced for a single species. These sequences are clearly not functional, and, once identified as pseudogenes, have been tentatively considered as encoded in the nuclear genome. The distribution of deletions, present in the pseudogenes and not in the mitochondrial genes, shows a common origin of the former, and suggests a translocation process followed by a proliferation of copy number. The size of this pseudogene structure, over 4kb, corresponding to 6kb in the mitochondrial genome, is one of the largest described for mitochondrial pseudogenes.
Collaborators: Priscila Dos Santos, George Roderick, Francesco Frati.

Nuclear mitochondrial pseudogenes in the nuclear genome of Drosophila melanogaster.

The complete sequence of the nuclear genome of Drosophila melanogaster, recently completed and published, has been analysed for traces of translocations of mitochondrial genetic material into the nucleus. The methods applied are based essentially on BLAST searches and similarity algorithms. Six insertions have been identified, and one, corresponding to genes nad2 and cox1, is fairly large in size. The pseudogenes, together with the flanking region, are being sequenced in various species of the genus Drosophila, in order to date the translocation event.
Collaborators: Priscila dos Santos, Gorge Roderick

Description of some morphological and genetic peculiarities of the living fossil Tricholepidion gertschii (Lepidotrichidae: Zygentoma).

A few rare specimens of Tricholepidion gertschii, the only living representative of the family Lepidotrichidae, and probably one of the first evolutionary offshoots of the Zygentoma, have been collected in the Mendocino forest, CA (U.S.A.). Many peculiarities of the spermatozoon and spermiogenesys have been described using light microscopy, electron microscopy, and microcinematography. In order to determine the phylogenetic and evolutive context of the species, the mitochondrial genome is currently being sequenced at the ìJGI-Genomic center, Walnut Creek, CA, USAî.
Collaborators: Romano Dallai, Pietro Lupetti, Francesco Frati, Jeffrey Boore.

Molecular phylogeny of basal hexapods, sequences from the ribosomal genes 28S and 12S, and from the Elongation Factor 1-alpha.

Partial 28S, 12S and nearly all the coding region of Elongation Factor 1-alpha have been sequenched in representatives for many families of basal hexapods, and these have been analyzed in order to reconstruct the phylogenetic relationships between these groups. Regardless of the scarce support at some nodes, and the present impossibility to discriminate between the competing motphological hypotheses, these analyses gave some interesting and promising results.
Collaborators: Antonio Carapelli, Erica Campagna, Francesco Frati, Chris Simon, Romano Dallai.