Forestomach developmental failure in an 11-month-old Japanese Black steer with severely retarded growth and chronic ruminal tympany

This study reports findings from the pathological examination of the forestomach of an 11-month-old Japanese Black steer with severely retarded growth (41% of expected weight) and chronic ruminal tympany. The ruminal papillae were weakly formed (0.3–0.5 cm long) and unevenly distributed. The cellulae and cristae reticuli were underdeveloped; the cristae were 0.4–0.7 cm in height and milky white. The keratinized layer in the stratified squamous epithelium was thickened. Ruminal pH was 5.25, and ruminal volatile fatty acid concentration was 11.7 mM. The steer’s severely retarded growth was considered to be caused by malnutrition due to developmental and functional failure of the forestomach.     

Adipogenic potential of satellite cells from distinct skeletal muscle origins in the rat

The possible relationship between myofiber type composition and adipose tissue development in skeletal muscle in vivo has been suggested. Recent evidence indicated that satellite cells are multipotent cells that can undergo not only myogenic, but also adipogenic differentiation. In the present study, rat satellite cells were isolated from soleus, back, extensor digitorum longus, tibialis anterior and quadriceps muscles, and their adipogenic potentials were compared by culturing them under adipogenic conditions in vitro. Cells from soleus muscle exhibited the highest adipogenic potential as judged from Oil Red-staining and immunocytochemical C/EBPalpha-staining. The adipogenic potential of satellite cells was positively correlated with type I myofiber distribution in the corresponding muscle of origin. These results demonstrated that the adipogenic potential of satellite cells differs according to the muscle of origin and suggested that its possible correlation to type I myofiber distribution may account for preferential adipose tissue development in slow oxidative muscles.     

Application of marker‐assisted selection and genome‐wide association scanning to the development of winter food barley germplasm resources

Barley (Hordeum vulgare) is an important component of heart‐healthy whole grain diets because it contains β‐glucan. All current US barley varieties with high β‐glucan are spring habit and have waxy starch. Winter varieties have agronomic advantages but require low‐temperature tolerance (LTT). Vernalization sensitivity (VS) is associated with higher levels of LTT. To rapidly develop fall‐sown varieties with LTT and higher grain β‐glucan, we therefore used marker‐assisted selection (MAS) at the WX and VRN‐H2 loci. The MAS‐derived lines, together with unrelated non‐waxy germplasm developed via phenotypic selection (PS), were used for a genome‐wide association scan (GWAS). The panel was phenotyped for grain β‐glucan, LTT and VS. It was genotyped with 3072 single‐nucleotide polymorphisms (SNPs) and allele‐specific primers. Marker‐assisted selection fixed target alleles at both loci but only one of the target phenotypes (higher β‐glucan percentage) was achieved. Variation for VS and LTT is attributable to (i) incomplete information about VRN‐H1 at the outset of the project and (ii) unexpected allelic variation at VRN‐H3 with a large effect on VS and LTT.     

Idiopathic mesenteric and omental steatitis in a dog

A 2-year-old Miniature Dachshund was admitted to the hospital because of fever, frequent vomiting, and watery diarrhea. An intra-abdominal mass and a gastric ulcer were detected. At laparotomy, the omentum was yellow but not icteric, irregularly thickened, and fragile, and a large mass involving the root of the mesentery and the gastrosplenic ligament was found. The histopathologic diagnosis was steatitis, and the dog was treated with prednisolone and cyclosporine for 2.5 years. After 1.5 years, the abdominal mass was not detectable. The dog died suddenly from perforation of the small intestine caused by a foreign body. Necropsy revealed severe adhesions between portions of the small intestine, and cicatrization of the mesentery. Cause of the mesenteric and omental steatitis was not apparent.     

The combined effect of clothianidin and environmental stress on the behavioral and reproductive function in male mice

Neonicotinoids, some of the most widely used pesticides in the world, act as agonists to the nicotinic acetylcholine receptors (nAChRs) of insects, resulting in death from abnormal excitability. Neonicotinoids unexpectedly became a major topic as a compelling cause of honeybee colony collapse disorder, which is damaging crop production that requires pollination worldwide. Mammal nAChRs appear to have a certain affinity for neonicotinoids with lower levels than those of insects; there is thus rising concern about unpredictable adverse effects of neonicotinoids on vertebrates. We hypothesized that the effects of neonicotinoids would be enhanced under a chronic stressed condition, which is known to alter the expression of targets of neonicotinoids, i.e., neuronal nAChRs. We performed immunohistochemical and behavioral analyses in male mice actively administered a neonicotinoid, clothianidin (CTD; 0, 10, 50 and 250 mg/kg/day), for 4 weeks under an unpredictable chronic stress procedure. Vacuolated seminiferous epithelia and a decrease in the immunoreactivity of the antioxidant enzyme glutathione peroxidase 4 were observed in the testes of the CTD+stress mice. In an open field test, although the locomotor activities were not affected, the anxiety-like behaviors of the mice were elevated by both CTD and stress. The present study demonstrates that the behavioral and reproductive effects of CTD become more serious in combination with environmental stress, which may reflect our actual situation of multiple exposure.     

Ontogenic and morphological study of gonadal formation in genetically-modified sex reversal XYPOS mice

Mammalian sexual fate is determined by the presence or absence of sex determining region of the Y chromosome (Sry) in the “bipotential” gonads. Recent studies have demonstrated that both male and female sexual development are induced by distinct and active genetic pathways. Breeding the Y chromosome from Mus m. domesticus poschiavinus (POS) strains into C57BL/6J (B6J) mice (B6J-XY^POS) has been shown to induce sex reversal (75%: bilateral ovary, 25%: true hermaphrodites). However, our B6N-XY^POS mice, which were generated by backcrossing of B6J-XY^POS on an inbred B6N-XX, develop as males (36%: bilateral testis with fertility as well as bilateral ovary (34%), and the remainder develop as true hermaphrodites. Here, we investigated in detail the expressions of essential sex-related genes and histological features in B6N-XY^POS mice from the fetal period to adulthood. The onsets of both Sry and SRY-box 9 (Sox9) expressions as determined spatiotemporally by whole-mount immunohistochemistry in the B6N-XY^POS gonads occurred 2–3 tail somites later than those in B6N-XY^B6 gonads, but earlier than those in B6J-XY^POS, respectively. It is possible that such a small difference in timing of the Sry expression underlies testicular development in our B6N-XY^POS. Our study is the first to histologically show the expression and ectopic localization of a female-related gene in the XY^POS testes and a male-related gene in the XY^POS ovaries. The results from these and previous experiments indicate that the interplay between genome variants, epigenetics and developmental gene regulation is crucial for testis development.     

Imatinib mesylate treatment in a dog with gastrointestinal stromal tumors with a c-kit mutation

A 13-year-old spayed mixed-breed dog was diagnosed with a gastrointestinal stromal tumor (GIST) after histopathological examination of an abdominal mass. Five months after surgical resection of the tumor, we detected the recurrence of GIST with multiple disseminated abdominal lesions. A sequence analysis of cDNA obtained from a biopsy of the recurrent tumors revealed a mutation within exon 9 of the c-kit gene (1523A>T, Asn⁵⁰⁸Ile), which has been shown to cause ligand-independent phosphorylation of the KIT protein in GISTs and canine mast cell tumors (MCTs). Upon detection of the recurrent tumors, we initiated treatment with imatinib mesylate (10 mg/kg, q 24 hr). After 2 months, the dog achieved complete remission. Our findings indicate that canine GIST, and possibly MCT, may be responsive to molecular-targeted therapy.     

Temporal fluctuation in the abundance of alginate‐degrading bacteria in the gut of abalone Haliotis gigantea over 1 year

In this study, we identified and enumerated alginate‐degrading bacteria in the gut of abalone over 1‐year period. From a total of 360 colonies growing on agar medium enriched with alginate, 251 isolates (70%) had the ability to degrade alginate. In addition, a high number of viable alginate‐degrading bacteria were detected throughout the survey period. Alginate‐degrading bacteria were more abundant in the cold season relative to the summer season (10⁷ vs. 10⁴ CFU g^?1, respectively). Strong positive correlation was also observed between the number of alginate‐degrading bacteria and feed intake (R = 0.854; P < 0.01). The identified alginate‐degrading bacteria comprised of 35 species grouped into 11 genera including Algibacter, Formosa, Polarybacter, Tamlana, Tenacibaculum (CFB group), Roseobacter, Ruegeria, Silicibacter (α‐proteobacteria), Agarivorans, Shewanella and Vibrio (γ‐proteobacteria) respectively. More than 80% of the isolated alginate‐degrading bacteria belonged to the genus Vibrio, showing high homology to Vibrio cyclotorophicus, Vibrio splendidus, Vibrio halioticoli and Vibrio neonatus. Based on the results, it was suggested that algal‐polysaccharide (alginate) degrading bacteria (mainly Vibrio) commonly exist in the gut of abalone and may play an important role in the degradation and digestion of the host's feed.