It has been suggested that the karyotype of the marsupials derived from a low diploid number (2n = 14) which originated, through fissions of biarmed chromosomes, the karyotypes with a higher 2n. The telomeric sequence (T2AG3)n was in situ hybridized to the chromosomes of Gracilinanus microtarsus and G. emiliae, Micoureus demerarae and Marmosa murina, species with 2n = 14, in Monodelphis sp., M. domestica, M. kunsi and M. brevicaudata with 2n = 18, and in Lutreolina crassicaudata, Didelphis albiventris, Chironectes minimus, Philander opossum and P. frenata, all of them with 2n = 22. The probe hybridization occurred in the telomeric regions of both arms, short and long, of all chromosomes of the complement of all individuals of all species analysed. However, in some pairs of the karyotypes of Gracilinanus microtarsus and Micoureus demerarae (with 2n = 14), and in Monodelphis sp., M. domestica, M. kunsi and M. brevicaudata (2n = 18) ectopic signs of hybridization were detected proximal to the centromeres, suggesting the retention of this telomeric sequence in the centromeric regions of some chromosomes of these species. Based on these results, it is proposed that the karyotype of marsupials evolved from a 2n = 22 to a 2n = 14, by means of chromosomal fusions.

Animal identification is essential in a large number of forensic cases, including bush meat harvest, unregulated trade in protected species or species' derivatives, introduction of exotic species without a proper permit and food fraud. The analysis of morphological traits has been the most traditional method used for species identification and taxonomy. However, when morphological identification is compromised, genetic identification can be used to associate sequences from unknown samples to a sequence from a reference sample. Based on a standard region of 650 base pairs of the subunit I of cytochrome c oxidase mitochondrial gene (COI) and using a validated reference database, the DNA Barcoding system for cataloging and identifying animal species has been proposed. In order to test the utility of DNA Barcoding in forensic vertebrate species identification, COI sequences from previously identified samples from human and a variety of domestic and wild specimens of Brazilian mammals, birds, fishes were compared against the Barcode of Life Database (BOLD). BOLD provided a correct species-level identification for 12 out of the 20 queried sequences (60%) and presented the correct species as the best matched one for 17 out of 18 samples morphologically identified to this level (94%). Cases where BOLD did not deliver a species level identification were associated with the controversial taxonomic status of some species, the possible occurrence of a biological event like hybridization and the lack of representation of some groups in the database. The results showed that DNA Barcoding is already effective for species identification in many cases and, although presenting some limitations, the use of the tool must be improved and widespread in forensic casework.

Chromosomes of Ommexecha virens and Descampsacris serrulatum (Ommexechidae) were analyzed through conventional staining, C-banding, base specific fluorochromes, silver nitrate impregnation (AgNO3), and fluorescent in situ hybridization (FISH) with probe for 45S rDNA. The two species presented diploid number 2n= 23,X0 in males and acrocentric autosomes, except the pair one that presented submetacentric morphology. The X chromosome has distinct morphology in the two analyzed species, being a medium acrocentric in Ommexecha virens and large submetacentric in Descampsacris serrulatum. The C-banding revealed pericentromeric blocks of constitutive heterochromatin (CH) in all the chromosomes of Descampsacris serrulatum. For Ommexecha virens it was evidenced that the blocks of CH are preferentially located in the pericentromeric area (however some bivalents presents additional blocks) or in different positions. The staining with CMA3/DA/DAPI showed GC rich CH blocks (CMA3+) in some chromosomes of the two species. The nucleolar organizer regions (NORs) were located in the bivalents L2, S9, S10 of Ommexecha virens and M5, M6, M7, S11 of Descampsacris serrulatum. The FISH for rDNA showed coincident results with the pattern of active NORs revealed by AgNO3. This work presents the first chromosomal data, obtained through differential cytogenetics techniques in Ommexechidae, contributing to a better characterization of karyotypic evolution for this grasshopper family.

Resumo. Presente artigo tem como objetivo relatar um caso pericial ocorrido em razão de um acidente aéreo no sul da Bahia, Brasil, no qual a contribuição da odontologia legal foi decisiva nos trabalhos de identificação humana. O desastre vitimou 14 pessoas, sendo 10 adultos e 04 crianças. A análise de dados odontológicos foi utilizada como método primário de identificação humana positivando 57,14% das identificações. O exame dentário comparativo ante e post-mortem foi feito por peritos odontolegistas utilizando informações do prontuário odontológico como fichas, radiografias periapicais e modelos de gesso das vítimas adultas, atingindo a taxa de 71,42% das identificações. Um grande número de crianças falecidas (75%) foi identificado pela estimativa da idade pelo grau de desenvolvimento dentário, destacando-se a importância do RX periapical como técnica eficiente no processo de identificação humana. Evidenciou-se ainda a importância do trabalho pericial dos peritos odontolegistas quando envolvidos nos casos de desastres em massa pela identificação através dos elementos dentários.