Forensic Science: Current State and Perspective by a Group of Early Career Researchers

Forensic science and its influence on policing and the criminal justice system have increased since the beginning of the twentieth century. While the philosophies of the forensic science pioneers remain the pillar of modern practice, rapid advances in technology and the underpinning sciences have seen an explosion in the number of disciplines and tools. Consequently, the way in which we exploit and interpret the remnant of criminal activity are adapting to this changing environment. In order to best exploit the trace, an interdisciplinary approach to both research and investigation is required. In this paper, nine postdoctoral research fellows from a multidisciplinary team discuss their vision for the future of forensic science at the crime scene, in the laboratory and beyond. This paper does not pretend to be exhaustive of all fields of forensic science, but describes a portion of the postdoctoral fellows’ interests and skills.     

Mutations in genes in the renin-angiotensin system are associated with autosomal recessive renal tubular dysgenesis

Autosomal recessive renal tubular dysgenesis is a severe disorder of renal tubular development characterized by persistent fetal anuria and perinatal death, probably due to pulmonary hypoplasia from early-onset oligohydramnios (Potter phenotype). Absence or paucity of differentiated proximal tubules is the histopathological hallmark of the disease and may be associated with skull ossification defects. We studied 11 individuals with renal tubular dysgenesis, belonging to nine families, and found that they had homozygous or compound heterozygous mutations in the genes encoding renin, angiotensinogen, angiotensin converting enzyme or angiotensin II receptor type 1. We propose that renal lesions and early anuria result from chronic low perfusion pressure of the fetal kidney, a consequence of renin-angiotensin system inactivity. This is the first identification to our knowledge of a renal mendelian disorder linked to genetic defects in the renin-angiotensin system, highlighting the crucial role of the renin-angiotensin system in human kidney development.     

Activities of cystathionase,cysteine sulphinic acid decarboxylase and serine dehydrase in the liver of tumour-bearing rats

Résumé Dans le foie de rats porteurs de tumeurs (épithéliome de Guérin et sarcome de l'estomac), les activités de la cystathionase, de la décarboxylase de l'acide cysteine sulfinique et de la sérine déhydrase sont considérablement diminuées: cette diminution est de l'ordre de 50%, 15 jours après implantation de ces tumeurs. Si à ce moment le sarcome (qui ne provoque pas de métastases) est chirurgicalement extirpé, on observe une restauration des activités enzymatiques qui, après 15 jours, est totale pour la cystathionase et très significative pour la décarboxylase.

---

---

Equipe de Recherche C.N.R.S. No. 43.     

Epithelial cell swelling during incubation of rat small intestine in vitro

Résumé L'augmentation du fluide du tissu de l'intestin grèle incubé in vitro s'accompagne d'un accroissement du volume des cellules épithéliales.     

Mitotic frequency in normal and regenerating tail tips ofRana pipiens embryos

Résumé L'auteur détermine la fréquence mitotique au cours du développement normal et de la régénération caudale chezRana pipiens. Les observations s'étendent du stade 18 (embryon de 4 mm) au stade 25 (jeune têtard). Les numérations sont faites sur des préparations par écrasement de l'extrémité de la queue.Développement normal: la fréquence est tout d'abord basse (18–21) puis atteint son maximum au stade 22 et s'abaisse ensuite jusqu'à un faible niveau (23–25).Régénération: si la queue a été amputée au stade 18, la fréquence mitotique augmente lentement du stade 19 au stade 24, la courbe étant horizontale du stade 21 au stade 23. Au stade 25, la fréquence augmente subitement et retombe ensuite. L'amputation au stade 19 déplace aussi la fréquence maximum du stade 22 au stade 25.

---

---

Aided by an Institutional Grant from the American Cancer Society.     

Small molecule inhibitors reveal Niemann-Pick C1 is essential for Ebola virus infection

Ebola virus (EboV) is a highly pathogenic enveloped virus that causes outbreaks of zoonotic infection in Africa. The clinical symptoms are manifestations of the massive production of pro-inflammatory cytokines in response to infection and in many outbreaks, mortality exceeds 75%. The unpredictable onset, ease of transmission, rapid progression of disease, high mortality and lack of effective vaccine or therapy have created a high level of public concern about EboV. Here we report the identification of a novel benzylpiperazine adamantane diamide-derived compound that inhibits EboV infection. Using mutant cell lines and informative derivatives of the lead compound, we show that the target of the inhibitor is the endosomal membrane protein Niemann-Pick C1 (NPC1). We find that NPC1 is essential for infection, that it binds to the virus glycoprotein (GP), and that antiviral compounds interfere with GP binding to NPC1. Combined with the results of previous studies of GP structure and function, our findings support a model of EboV infection in which cleavage of the GP1 subunit by endosomal cathepsin proteases removes heavily glycosylated domains to expose the amino-terminal domain, which is a ligand for NPC1 and regulates membrane fusion by the GP2 subunit. Thus, NPC1 is essential for EboV entry and a target for antiviral therapy.     

Mutagenicity of melanin from human red hair

Summary TheSalmonella typhimurium histidine reversion test of Ames et al. was used to demonstrate that pheomelanin, the red-brown polymeric pigment produced in human skin and hair, becomes mutagenic after exposure to long wave-length UV-light; a finding consistent with the UV-induced somatic mutation hypothesis for the origin of freckles and the high susceptibility of redheads and blonds to sunlight-induced skin cancers.Acknowledgments.S. typhimurium strains were kindly provided by Dr Bruce N. Ames. Z. Harzanyi was supported by NIEHS grant 00675-03 and an Andrew W. Mellon Teacher-Scientist Award. M. Chedekel thanks The Ohio State University Graduate School for financial assistance.     

The Phaeodactylum genome reveals the evolutionary history of diatom genomes

Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes ( approximately 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.     

Multimodal warning signals for a multiple predator world

Aposematism is an anti-predator defence, dependent on a predator's ability to associate unprofitable prey with a prey-borne signal. Multimodal signals should vary in efficacy according to the sensory systems of different predators; however, until now, the impact of multiple predator classes on the evolution of these signals had not been investigated. Here, using a community-level molecular phylogeny to generate phylogenetically independent contrasts, we show that warning signals of tiger moths vary according to the seasonal and daily activity patterns of birds and bats-predators with divergent sensory capacities. Many tiger moths advertise chemical defence using conspicuous colouration and/or ultrasonic clicks. During spring, when birds are active and bats less so, we found that tiger moths did not produce ultrasonic clicks. Throughout both spring and summer, tiger moths most active during the day were visually conspicuous. Those species emerging later in the season produced ultrasonic clicks; those that were most nocturnal were visually cryptic. Our results indicate that selective pressures from multiple predator classes have distinct roles in the evolution of multimodal warning displays now effective against a single predator class. We also suggest that the evolution of acoustic warning signals may lack the theoretical difficulties associated with the origination of conspicuous colouration.