Carrion flies of forensic interest: a study of seasonal community composition and succession in Lisbon,Portugal

Information on Diptera community, seasonality and successional patterns in every geographical region is fundamental for the use of flies as forensic indicators of time of death. In order to obtain these data from the Lisbon area (Portugal), experiments were conducted during the four seasons of the year, using piglet carcasses as animal models. Five stages were recognized during the decomposition process. The stages, besides visually defined, could be separated taking into account the occurrence and abundance of the specific groups of Diptera collected. In general, the bloated stage recorded higher abundance and species‐richness values. Seventy‐one species were identified, belonging to 39 families, in a total of 20 144 adult Diptera collected. Autumn yielded the highest values of species richness, whereas winter had the lowest. In all seasons of the year, Calliphoridae was the dominant family; Muscidae and Fanniidae were very abundant as well. Calliphora vicina Robineau‐Desvoidy, Calliphora vomitoria (Linnaeus), Chrysomya albiceps (Wiedemann), Lucilia ampullacea Villeneuve, Lucilia caesar (Linnaeus), Lucilia sericata (Meigen) (Calliphoridae), Hydrotaea ignava (Harris), Muscina prolapsa (Harris), Synthesiomyia nudiseta (van der Wulp) (Muscidae), Piophila megastigmata McAlpine, Stearibia nigriceps (Meigen) (Piophilidae) and Nemopoda nitidula (Fallén) (Sepsidae) were revealed to be very important members of the Diptera community collected. The necrophagous behaviour, demonstrated by their immatures, using carrion as a food source makes them useful forensic indicator species. Also of relevance is the presence of Chrysomya megacephala (Fabricius), S. nudiseta and P. megastigmata, foreign species established in the local carrion communities. This study also marks the first record of S. nudiseta in Portugal.     

Effect of dose of estradiol and age of animals on intranuclear inclusions in mammotrophs of the Mongolian gerbil.

Intranuclear inclusions have been examined in mammotrophs of the Mongolian gerbil. No inclusions were identified in nuclei of newborn females, although inclusions were seen in the pituitary gland of young mature females. The number of inclusions in retired breeders was similar to that in young females. Estradiol benzoate increased the number of inclusions, although 10 mug/day for 5 or 14 days induced more inclusions than 5 or 100 mug for 14 days; significantly fewer inclusions were seen with the higher dose (2.81 +/- 0.10 inclusions per field for 10 mug and 2.19 +/- 0.01 inclusions for 100 mug). Significantly fewer inclusions were present at 3 and 4 weeks. The reduced number of inclusions may be attributable at least in part to cellular hypertrophy of mammotrophs which was especially prominent. Vacuolar inclusions predominated at 3 and 4 weeks and there were fewer membranous types than at previous times.     

Antibody formation by one or both lymphoid populations present in chimeric marmosets

Development of an isoimmune serum capable of identifying a specific leukocyte antigen in the marmoset, Saguinus fuscicollis illigeri, permitted detection of lymphoid cell chimerism in this species by the cytotoxic test. This reagent was then used to identify the cell population in the chimera responsible for antibody production against a test antigen, sheep red blood cells. Primary in vitro antibody formation as measured by plaque-forming cells with blood leukocytes or splenic lymphocytes of six animals chimeric for the leukocyte antigen, MLA-1, revealed an immune response by both cell types of the chimeric population from three animals and a response by only one cell type in the other three.     

Ultrastructural Studies of Spermiogenesis of Conocephalus saltator (Saussure)

The acrosome of the spermatozoa is the organelle involved in its penetration through the ova membranes during the fertilization process. Several features of this process are considered to be related to the fertilization events e.g. some substance coats outside the membrane. During the maturation process the spermatozoa of Conocephalus saltator develop a coat of tubules and filaments which overly some membrane regions in a specific array. The mature spermatozoa are seen to adhere in these regions and form threads of 20 cells long and five to six wide. It is suggested that the external coat plays a role in this 'sticking' phenomenon.     

Intranuclear inclusions in mammotrophs of the Mongolian gerbil: Effect of low doses of estradiol benzoate and a study of females before weaning

The effect of dose of estrogen on induction of intranuclear inclusions was studied in mammotrophs of the Mongolian gerbil. The number of inclusions per high power field increased significantly with 0-5 and 1-0 mug/day of estradiol benzoate but not with the 0-05 mug dose. A form of inclusion was seen in young female gerbils before weaning which suggests that inclusions arise from the cytoplasm. Intranuclear inclusions develop soon after weaning of gerbils (0-06 +/- 0-01 vs. 0-19 +/- 0-03 for young mature females).