Establishment of a canine lens epithelial cell line

Some immortalized lens epithelial cell lines have been established and are useful for molecular analysis. The establishment of additional cell lines must, however, enable a variety of in-vitro examinations. The objective of this study was to establish a new canine lens epithelial cell line by isolating CLC-1 cells from the lens tissue of a dog with cataracts. In CLC-1 cells, transforming growth factor beta (TGF-β) treatment significantly decreased gene expression of an epithelial marker and elevated that of mesenchymal markers; these characteristics are similar to those of a human lens epithelial cell line. Interestingly, CLC-1 cells exhibited lower expression of an epithelial marker and higher expression of mesenchymal markers than an anterior lens capsule. These results suggest that CLC-1 cells were derived from a cell population that was committed to epithelial-mesenchymal transition in cataract lens tissue. In conclusion, CLC-1 cells could be useful for analyzing molecular pathogenesis in canine cataracts.     

Pedigree analysis of genetic subdivision in a population of Japanese Black cattle

Twenty‐five subpopulations (i.e. populations of prefectures) of more than 2000 Japanese Black cows younger than or equal to 10 years of age were analyzed to evaluate the genetic relationships in the current population. The total number of cows analyzed was 392 346 and their pedigrees were traced back to 1944 or before. Using the pedigree records, the genetic relationships among the subpopulations were estimated by the two different measurements: (i) the average additive relationship coefficients and (ii) Nei's standard genetic distances. Principal component analysis (PCA) was performed to the matrix of the average additive relationship coefficients, and the factor loadings of subpopulations were plotted on the plane to visualize the genetic configuration of subpopulations. To understand the grouping process of the subpopulations, cluster analysis was applied to the matrix of the Nei's genetic distances, and a dendrogram was constructed. There was a high consistency between the results from PCA and cluster analysis. Eight subpopulations with relatively low migration rates showed their unique genetic compositions, and the other 17 subpopulations with high migration rates formed a single cluster. The major cause of the genetic similarity among the 17 subpopulations was inferred to be the strong genetic influence from one subpopulation (Hyogo prefecture) with prominent characteristics for meat quality.     

Complete cDNA sequence and mRNA expression of dog preproendothelin-3

The full-length cDNA of dog preproendothelin-3 (PPET3) was cloned from lung tissue using RT-PCR and rapid amplification of cDNA ends. Aside from the poly (A) tail, the full-length cDNA was 1976 bp. A polyadenylation signal sequence and one copy of a consensus sequence, ATTTA, which is related to mRNA turnover, was found in the 3' noncoding region. The cDNA had a 594-bp open reading frame encoding a 198-amino acid polypeptide. Regions corresponding to a bioactive mature ET3 peptide, an intermediate form known as big-ET3, and an ET3-like peptide were observed in dog PPET3. Expression of PPET3 mRNA was detected throughout the organs examined, which included heart, lung, liver, kidney, spleen, stomach, pancreas, duodenum, colon, uterus, ovary and testis.     

Susceptibility to N-methyl-N-nitrosourea-induced retinal degeneration in different rat strains

To evaluate the potential role of genetic background in the susceptibility to retinal degeneration induced by N-methyl-N-nitrosourea (MNU), female rats of the Sprague-Dawley (SD), Long-Evans (LE) and Copenhagen (CH) strains were administered 50 mg/kg MNU or saline at 7 weeks of age. Retina morphology and morphometric analysis of all rats was performed 7 days after MNU administration. Atrophy of both the peripheral and central outer retina occurred in all rat strains exposed to MNU. Decreased photoreceptor cell ratio and increased retinal damage ratio were observed. The severities of the retinal atrophy were similar among all three rat strains. In conclusion, MNU-induced photoreceptor degeneration developed consistently in all three strains regardless of the absence (SD rats) or presence (LE and CH rats) of melanin in the retina, suggesting that genetic and melanin factors did not affect photoreceptor cell death after MNU.