Genetic and environmental variability of adult size in some stocks of the edible snail, Helix aspersa

This paper aims at providing a better knowledge of factors determining body size (especially the importance of heredity) in Helix aspersa Müller.
A preliminary investigation of snails from Maghreb allowed us to show the importance of heredity in the variability of body size and to produce an efficient design for a subsequent reliable estimation of heritabilities. All traits measured (diameter, height and weight) were highly correlated and weight appeared to be the most convenient measure of size.
The second experiment provided 4150 snails born from known individuals among 500 wild snails. Pedigrees were recorded. Weight and diameter revealed high heritabilities (>0.4), which is relevant for commercial selection since variability of both traits was important. The design also revealed a significant non-genetic maternal effect and also that offspring from pairs where only one animal laid were bigger than offspring from pairs where both animals laid. This surprising observation has to be confirmed and its mechanisms studied.     

Cystic fibrosis in the population of Reunion Island

The frequencies of the delta F 508 mutation and haplotypes linked to the cystic fibrosis (CF) gene and detected with DNA probes XV-2C and KM-19 have been studied in the population of Reunion Island, a French province located in the Indian Ocean. The deletion was present in 41.3% of CF chromosomes, whereas this proportion is about 70% in the French population. The delta F 508 mutation was associated with the haplotype B defined by the DNA markers XV-2C (allele 1) and KM-19 (allele 2) in 76.4% of CF chromosomes, while this proportion is over 90% in the French population. Founder effect, genetic drift and admixture can explain these differences.     

Wahrnehmungspsychologische Untersuchungen am EichelhÄher. II

Ohne Zusammenfassung     

Focus: Zoonotic Disease: Molecular Detection of Zoonotic Pathogens in the Blood and Tissues of Camels (Camelus dromedarius) in Central Desert of Iran

Dromedary camels (Camelus dromedarius) play a major economic role in many countries in Africa and Asia. Although they are resistant to harsh environmental conditions, they are susceptible to a wide range of zoonotic agents. This study aimed to provide an overview on the prevalence of selected zoonotic pathogens in blood and tissues of camels in central Iran. Blood, liver, portal lymph node, and brain were collected from 100 apparently healthy camels at a slaughterhouse in Qom city to assess the presence of DNA of Brucella spp., Trypanosoma spp., Coxiella burnetii, and Bartonella spp. PCR products were sequenced bidirectionally and phylogenetic analyses were performed. Eleven percent of camels tested positive for Brucella abortus (3%) and Trypanosoma evansi (8%). Coxiella burnetii and Bartonella spp. DNA was not detected. Our data demonstrate that camels from Iran contribute to the epidemiology of some zoonotic pathogens. Performing proper control strategies, such as vaccination of camels and humans in contact with them, test-and-slaughter policy, and education of the general population is necessary for minimizing the risk of zoonotic infection.     

Rab35: GEFs,GAPs and Effectors

Rabs are the largest family of small GTPases and are master regulators of membrane trafficking. Following activation by guanine‐nucleotide exchange factors (GEFs), each Rab binds a specific set of effector proteins that mediate the various downstream functions of that Rab. Then, with the help of GTPase‐activating proteins, the Rab converts GTP to GDP, terminating its function. There are over 60 Rabs in humans and only a subset has been analyzed in any detail. Recently, Rab35 has emerged as a key regulator of cargo recycling at endosomes, with an additional role in regulation of the actin cytoskeleton. Here, we will focus on the regulation of Rab35 activity by the connecdenn/DENND1 family of GEFs and the TBC1D10/EPI64 family of GTPase‐activating proteins. We will describe how analysis of these proteins, as well as a plethora of Rab35 effectors has provided insights into Rab35 function. Finally, we will describe how Rab35 provides a novel link between the Rab and Arf family of GTPases with implications for tumor formation and invasiveness .      

A Polyamine-Deficient Diet Prevents Oxaliplatin-Induced Acute Cold and Mechanical Hypersensitivity in Rats

Background

Oxaliplatin is an anticancer drug used for the treatment of advanced colorectal cancer, but it can also cause painful peripheral neuropathies. The pathophysiology of these neuropathies has not been yet fully elucidated, but may involve spinal N-methyl-D-aspartate (NMDA) receptors, particularly the NR2B subunit. As polyamines are positive modulators of NMDA-NR2B receptors and mainly originate from dietary intake, the modulation of polyamines intake could represent an interesting way to prevent/modulate neuropathic pain symptoms by opposing glutamate neurotransmission.

Methods

The effect of a polyamine deficient diet was investigated in an animal model of oxaliplatin-induced acute pain hypersensitivity using behavioral tests (mechanical and cold hypersensitivity). The involvement of spinal glutamate neurotransmission was monitored by using a proton nuclear magnetic resonance spectroscopy based metabolomic approach and by assessing the expression and phosphorylation of the NR2B subunit of the NMDA receptor.

Results

A 7-day polyamine deficient diet totally prevented oxaliplatin-induced acute cold hypersensitivity and mechanical allodynia. Oxaliplatin-induced pain hypersensitivity was not associated with an increase in NR2B subunit expression or phosphorylation, but with an increase of glutamate level in the spinal dorsal horn which was completely prevented by a polyamine deficient diet. As a validation that the oxaliplatin-induced hypersensitivity could be due to an increased activity of the spinal glutamate system, an intrathecal administration of the specific NR2B antagonist, ifenprodil, totally reversed oxaliplatin-induced mechanical and cold hypersensitivity.

Conclusion

A polyamine deficient diet could represent a promising and valuable nutritional therapy to prevent oxaliplatin-induced acute pain hypersensitivity.