Simonetta Lambiase

A new chromosome instability disorder

Chromosome analysis in a 31‐year‐old woman referred for primary amenorrhea, revealed a very high incidence of chromosome aberrations. She had microcephaly and immunodeficiency. Her healthy parents were consanguineous (1/32) and a younger sister, also with primary amenorrhea, died when 20 years old with a malignant lymphoma.

Indirect immunofluorescence of inactive centromeres as indicator of centromeric function

SummaryTwo previous single case reports from the literature showed the presence or absence of centromeric antigens at the site of the inactive centromeres in one (X;X) and in one (9;11) dicentric chromosome. We studied nine different dicentric chromosomes using anticentromeric antibodies and immunofluorescence techniques. In the four autosomal dicentrics the inactive centromere was consistently positive while the dicentrics composed of two X chromosomes were either positive or negative; one case of (X;Y) dicentric was negative. The results indicate that the X chromosome mode of replication may be involved in the suppression of immunofluorescence at the site of the inactive centromere and that one centromere of the dicentric chromosome may lose its function but conserve some of its antigenic properties. This indicates that not all these antigens play a rôle in the microtubules-centromere interaction.

Mortality and tissue damage by heavy metal contamination in the German cockroach, Blattella germanica (Blattaria, Blattellidae)

Abstract The accumulation of lead, cadmium, mercury, and chromium, supplied in the diet under experimental conditions, was studied in adult German cockroaches. Chronic heavy‐metal exposure de termined different rates of mortality, higher in males than in fe males. In both sexes, Hg, Pb, and Cr bioaccumulated in time, whereas Cd remained at constant low concentrations. Histological studies showed that in some organs and structures, such as the ovary, the testis, the alimentary canal and the fat bodies, there were profound and irreversible pathological anomalies in their tis sues. Also the embryos of some treated females suffered heavy damage during development, and the symbiotic relationships be tween bacteria and fat body cells were deeply altered.

Pattern of bacteriocyte formation in Periplaneta americana (L.) (Blattaria: Blattidae)

Abstract In the embryos of Periplaneta americana (L.) (Blattaria: Blattidae), bacterial symbionts, together with vitellophages, form a mycetomic structure inside the deutoplasm; this regresses between the 15th and 16th day after deposition of the ootheca. In this article we describe the migration of bacteria across the wall of the midgut from the mycetome, and the topographic distribution of pre-bacteriocyte cells. We also report that the pre-bacteriocytes are present only on the lateral surface of the internal abdominal fat bodies. We discuss the possible embryological origin and evolution of these cells, and put forward the hypothesis that pre-bacteriocytes are derived from oenocytes activated to perform phagocytosis.

The Cd technique identifies a specific structure related to centromeric function

SummaryThe evidence that the Cd technique identifies the kinetochore was based on the finding that inactive centromeres are C-positive but Cd-negative. The identity between Cd-positivity and centromere function is now confirmed by the reverse procedure: a stable abnormal chromosome is consistently C-negative but Cd-positive at its single centromeric constriction. This demonstrates that the Cd dots are not a relic of C-banding but identify the active centromere.

Spread and Habitat Selection of Chrysomya albiceps (Wiedemann) (Diptera Calliphoridae) in Northern Italy: Forensic Implications

Abstract:  Habitat selection exploited by Chrysomya albiceps during its initial spread in Northern Italy was analyzed in relation to landscape structure. The results of two short studies and a case report are here discussed. C. albiceps was not found on experimental pig carcasses in the urban area of Pavia. It was missing in the woody mountains surrounding Lecco, but it was found in the same area, at a lower altitude, within the typical “urban sprawl” landscape. It was then recorded in a natural reserve, among a rich carrion‐fly population. Indications coming from habitat selection suggest that C. albiceps has not yet saturated its potential ecological niche in newly colonized areas of Northern Italy. Factors like temperature, altitude, and interspecific competition can act as limiting factors, affecting habitat selection and distribution in newly colonized areas; the influence of those factors has to be taken into account for forensic purposes.

Presumptive mosaic origin of an XX/XY female with ambiguous genitalia.

A child with ambiguous genitalia had an XX/XY karyotype in all tissues examined. Analyses of 11 informative polymorphisms, both chromosomal and genetic (Rh and HLA), showed no difference between the two cell lines. It is unlikely that the child originated from fertilisation of the egg and the second polar body by two sperms; therefore, we hypothesise that the child originated from an XXY zygote after mitotic errors during cleavage. Recent findings of differences in the chromosome constitution between the extra-embryonic tissues and the fetus support this view.

Human identification by lice: A Next Generation Sequencing challenge

Rapid and progressive advances in molecular biology techniques and the advent of Next Generation Sequencing (NGS) have opened new possibilities for analyses also in the identification of entomological matrixes. Insects and other arthropods are widespread in nature and those found at a crime scene can provide a useful contribution to forensic investigations. Entomological evidence is used by experts to define the postmortem interval (PMI), which is essentially based on morphological recognition of the insect and an estimation of its insect life cycle stage. However, molecular genotyping methods can also provide an important support for forensic entomological investigations when the identification of species or human genetic material is required. This case study concerns a collection of insects found in the house of a woman who died from unknown causes. Initially the insects were identified morphologically as belonging to the Pediculidae family, and then, human DNA was extracted and analyzed from their gastrointestinal tract. The application of the latest generation forensic DNA assays, such as the Quantifiler(®) Trio DNA Quantification Kit and the HID-Ion AmpliSeq™ Identity Panel (Applied Biosystems(®)), individuated the presence of human DNA in the samples and determined the genetic profile.

Ontogenesis of pleuropodia in different species of Blattaria (Insecta): A comparative study

Abstract The embryonic development of several insects is characterized by the formation of a pair of pleuropodial appendages on the first abdominal segment. The present paper describes the comparative ontogenesis, morphology, and structure of the pleuropodia of a few species of Blattaria belonging to their three differe/it families: Blattidae, Blattellidae, and Blaberidae. The pleuropodia appear when the first abdominal coelomic cavities begin to disintegrate; then they develop quickly, and regress when the dorsal closure of the embryo occurs. A slow process of degeneration leads, in some species, to the formation of a pair of small flaps; in others, the pleuropodial morphology is retained although the organ loses its secretory functions. In all species, the pleuropodia are cast off at embryonic eclosion, together with the first cuticle produced during an intraoothecal moult. The pleuropodia can be bulbiform, filiform, or caliciform. A relationship is suggested between pleuropodial morphology and the modality of reproduction of the cockroaches. In fact, the oviparous and most ancestral false ovo‐viviparous species have a bulbiform pleuropodium, while the phyletically younger false ovoviviparous and the false viviparous species have an elongated pleuropodium. Finally, the hypotheses so far proposed about the functions of these structures in Blattaria are discussed.

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 repair and is mainly 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 performs polymer degradation. The aim of this work was to investigate in the cockroach Periplaneta americana L. (Blattaria: Blattidae) the behaviour of poly(ADP-ribosylation). 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 glycohydrolase in different tissues; and (iii) the role of poly(ADP-ribosylation) during spermatogenesis. 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 found in extracts from testes; and (iii) the synthesis of poly(ADP-ribose) occurs preferentially in differentiating spermatids/spermatozoa. Collectively, our 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 modulated during embryonic development and spermatogenesis.