Effects of in utero and lactational exposure to the no-observed-adverse-effect level (NOAEL) dose of the neonicotinoid clothianidin on the reproductive organs of female mice

Recently, developmental exposure to clothianidin (CLO) has been shown to cause reproductive toxicity in male mice, but the effects in female mice remain to be clarified. Pregnant C57BL/6N mice were given a no-observed-adverse-effect-level (NOAEL) dose of CLO until weaning. We then examined ovaries of 3- or 10-week-old female offspring. In the CLO-administered group, morphological changes, a decrease in the immunoreactivity of the antioxidant enzyme glutathione peroxidase 4 (GPx4), and activation of genes in the steroid hormone biosynthesis pathway were observed in 3-week-old mice, and decreases of GPx4 immunoreactivity, 17OH-progesterone and corticosterone levels were observed in 10-week-old mice, along with high rates of infanticide and severe neglect, providing new evidence that developmental exposure to CLO affects juvenile and adult mice differently.     

Monitoring of the genetic variability of the hatchery and recaptured fish in the stock enhancement program of the rare species barfin flounder <Emphasis Type="Italic">Verasper moseri</Emphasis>

ABSTRACT:   In relation to the stock enhancement program for barfin flounder, hatchery juveniles produced in 2001 were genotyped using microsatellite DNA markers (msDNA) and then released to natural waters. Subsequently, recaptured individuals, designated as 'tentative recaptured', were examined using msDNA. In order to evaluate the effectiveness of the stock enhancement program, pairwise F _ST and genic differentiation tests were used to estimate the genetic divergence between the wild samples, the hatchery broodstock, and the tentative recaptured samples. Analysis showed significant differentiation among these three groups. Pedigree determination by msDNA was used to establish the origin of the tentative recaptured individuals, in order to elucidate whether they were hatchery produced, 'real recaptured', or wild specimens. Wild individuals were not found. The effective population size of the real recaptured stock was very low ( N _e = 16.6). Equal family survivability was observed between the released and real recaptured stocks, indicating that the genetic variability of the released stock was maintained in the natural environment. Future broodstock management, breeding designs, and family contribution equalization of the offspring to be released will be required in this rare species to avoid unintended genetic differentiation between the wild population and the hatchery broodstock.     

Genetic diversity of wild mekong giant catfish Pangasianodon gigas collected from Thailand and Cambodia

The Mekong giant catfish Pangasianodon gigas is endemic to the Mekong River and is a critically endangered species. The genotypes of the microsatellite DNA (msDNA) and mitochondrial DNA (mtDNA) markers (right domain of the control region) were detected to evaluate the present status of genetic divergence of this species from the Mekong River in Thailand and Cambodia. The observed and expected heterozygosity values of Mekong giant catfish in Thailand and Cambodia were relatively low in comparison with those of other nonendangered freshwater fish species. These two populations from Thailand and Cambodia showed similar levels of genetic diversity, as evaluated by the 384 nucleotides of the mtDNA control region with 13 haplotypes. The pairwise F _ST value between the two populations based on the genotype frequencies of msDNA and mtDNA markers suggested a close genetic relationship between the populations in Thailand and Cambodia. The results of this study support the conclusion that the Mekong giant catfish is critically endangered. Care should be taken to sustain the genetic diversity of this species, as the level of genetic variability has already decreased in the wild population. This species is a target species for an ongoing stock enhancement program in the Mekong River in Thailand. It is proposed to apply these markers for proper broodstock management, such as for minimal kinship selective breeding in the hatchery.     

First report of Helleborus net necrosis virus isolated from hellebores with black death syndrome in Japan

Helleborus net necrosis virus (HeNNV) in hellebores (Helleborus spp.) has been detected for the first time in Japan. Infected plants had black streaks on fresh leaves and black spots on sepals, which resembled the symptoms of black death disease. The morphology of the virus particles isolated from infected plants was comparable to that of carlaviruses. RT-PCR analysis showed that the entire HeNNV genomic sequence isolated in Japan shared 99% identity with that of HeNNV previously reported in the United States.     

Detachable Coils for Occlusion of Patent Ductus Arteriosus in 2 Dogs

OBJECTIVE: To describe the use of a detachable coil for transcatheter closure (TCC) of patent ductus arteriosus (PDA) in 2 dogs. STUDY DESIGN: Clinical study. ANIMALS: Two female Pembroke Welsh Corgi dogs with PDA. METHODS: Using fluoroscopic guidance, an 8-mm-diameter coil stent with 5 loops (detachable coils for PDA closure) was inserted via catheterization of the femoral artery. The catheter was passed through the PDA into the pulmonary artery. The coil was withdrawn so that 1.5 loops remained on the pulmonary side of the orifice of the ductus. The rest of the loops were pushed out from the catheter into the ductus. After confirming the correct placement of the coil and the effectiveness of the occlusion, the delivery wire was detached from the coil. RESULTS: Insertion of the coil was easily performed, even without previous experience. Immediate and marked decrease of the cardiac murmur was auscultated. Only slight residual flow was detected by angiography conducted 3 months' postoperatively. The dogs experienced quick and uneventful recovery after coil placement and required minimal postoperative care. Follow-up evaluation of the dogs showed no functional clinical signs of PDA, and no cardiac abnormalities were detected on electrocardiographic, phonocardiographic, and echocardiographic examination. In dog 1, the residual flow had disappeared on the color-flow Doppler echocardiographic examination at 18 months' postoperatively. CONCLUSION: TCC using a detachable coil was easy, safe, and effective in 2 dogs with PDA. The minimal residual shunting observed only by echocardiography seemed hemodynamically insignificant. CLINICAL RELEVANCE: This method can be used as an alternative to traditional surgical methods.