Genetic variation of Japanese pink salmon populations inferred from nucleotide sequence analysis of the mitochondrial DNA control region

To estimate genetic variation and structure of pink salmon (Oncorhynchus gorbuscha) populations in Hokkaido, Japan, we analyzed the nucleotide sequence of about 500 bp in a variable portion of the 5′ end of the mitochondrial DNA control region for even- and odd-year broodlines. Sixty-seven haplotypes were detected in the examined individuals. Among these, 25 haplotypes were unique to the even-year broodline, while another 30 haplotypes were unique to the odd-year broodline. Five and three length-heteroplasmic haplotypes were detected in the even-year broodline and odd-year broodline, respectively. The distribution pattern of the 67 haplotypes was different among populations between both broodlines, while not different among populations within the same broodline. The haplotype and nucleotide diversity were higher for even-year broodline populations than for odd-year broodline populations, suggesting greater genetic variation within populations of the even-year broodline. Analysis of molecular variance and pairwise fixation index estimates also demonstrated strong genetic differentiation between even- and odd-year broodlines, although there was no genetic differentiation among populations within the same year broodline. The neutrality tests and mismatch distribution analysis indicate that the demographic history of pink salmon in Japan differs between even- and odd-year populations. Together, these results suggest strong reproductive isolation between the even- and odd-year broodlines of pink salmon, and high gene flow with broodlines due to straying.     

Portocaval shunt for hepatocyte package

In developing therapeutic alternatives to liver transplantation, we have used the strategy of applying a small intestinal segment as a scaffold for hepatocyte transplantation and also as a portocaval shunt (PCS) system to address both liver dysfunction and portal hypertension. The aim of this study was to investigate the feasibility of such an intestinal segment in animal models. Hepatocytes isolated from luciferase-transgenic Lewis rats were transplanted into jejunal segments of wild-type Lewis rats with mucosa removal without PCS application. Luciferase-derived luminescence from transplanted hepatocytes was stably detected for 30 days. Then, we performed autologous hepatocyte transplantation into the submucosal layer of an isolated and vascularized small intestinal segment in pigs. Transplanted hepatocytes were isolated from the resected left-lateral lobe of the liver. On day 7, hepatocyte clusters and bile duct-like structures were observed histologically. To create an intestinal PCS system in pigs, an auto-graft of the segmental ileum and interposing vessel graft were anastomosed to the portal vein trunk and inferior vena cava. However, thrombi were observed in vessels of the intestinal PCSs. We measured the correlation between infusion pressure and flow volume in whole intestines ex vivo in both species and found that the high pressure corresponding to portal hypertension was still insufficient to maintain the patency of the intestinal grafts. In conclusion, we demonstrated the feasibility of the small intestine as a scaffold for hepatocyte transplantation in rat and pig models, but PCS using an intestinal graft failed to maintain patency in a pig model.     

Predictive Factors for Reintubation following Noninvasive Ventilation in Patients with Respiratory Complications after Living Donor Liver Transplantation

Background

Postoperative respiratory complications are a major cause of mortality following liver transplantation (LT). Noninvasive ventilation (NIV) appears to be effective for respiratory complications in patients undergoing solid organ transplantation; however, mortality has been high in patients who experienced reintubation in spite of NIV therapy. The predictors of reintubation following NIV therapy after LT are not exactly known.

Methods

Of 511 adult patients who received living-donor LT, data on the 179 who were treated by NIV were retrospectively examined.

Results

Forty-three (24%) of the 179 patients who received NIV treatment required reintubation. Independent factors associated with reintubation by multivariate logistic regression analysis were controlled preoperative infections (odds ratio [OR] 8.88; 95% confidence interval (CI) 1.64 to 48.11; p = 0.01), ABO-incompatibility (OR 4.49; 95% CI, 1.50 to 13.38; p = 0.007), and presence of postoperative pneumonia at the time of starting NIV (OR 3.28; 95% CI, 1.02 to 11.01; p = 0.04). The reintubated patients had a significant higher rate of postoperative infectious complications and a significantly longer intensive care unit stay than those in whom NIV was successful (p<0.0001). Of the 43 reintubated patients, 22 (51.2%) died during hospitalization following LT vs. 8 (5.9%) of the 136 patients in whom NIV was successful (p<0.0001).

Conclusions

Because controlled preoperative infection, ABO-incompatibility or pneumonia prior to the start of NIV were independent risk factors for reintubation following NIV, caution should be used in applying NIV in patients with these conditions considering the high rate of mortality in patients requiring reintubation following NIV.     

Some Catalytic Properties of an Exo-l,6-α-glucosidase (Glucodextranase) from Arthrobacter globiformis I42

An exo-l,6-α-glucosidase (EC 3.2.1.70) (glucodextranase) produced extraceUularly by Arthrobacter globiformis I42 was found to invert the configuration of glucose released from dextran, and to require calcium for protection against warming. Among isomaltodextrins used as substrates for this enzyme, the rate of hydrolysis for isomaltose was the lowest and increased with the degree of polymerization (d. p.) of the saccharides up to d. p. 7. The minor activities accompanying purified glucodextranase preparations (release of glucose from starch, splitting of maltose, nigerose and kojibiose) were ascribed to the glucodextranase itself. Fourteen native dextrans and soluble potato starch were subjected to digestion by this glucodextranase and the rate, process and extent of hydrolysis of these substrates were studied relative to the composition of non-l,6-α-linkages of these polysaccharides.     

Genetic Stock Identification of Chum Salmon in the Bering Sea and North Pacific Ocean Using Mitochondrial DNA Microarray

A newly developed DNA microarray was applied to identify mitochondrial (mt) DNA haplotypes of more than 2200 chum salmon in the Bering Sea and North Pacific Ocean in September 2002 and also 2003, when the majority of maturing fish were migrating toward their natal river. The distribution of haplotypes occurring in Asian and North American fish in the surveyed area was similar in the 2 years. A conditional maximum likelihood method for estimation of stock compositions indicated that the Japanese stocks were distributed mainly in the north central Bering Sea, whereas the Russian stocks were mainly in the western Bering Sea. The North American stocks were abundant in the North Pacific Ocean around the Aleutian Islands. These results indicate that the Asian and North American stocks of chum salmon are nonrandomly distributed in the Bering Sea and the North Pacific Ocean, and further the oligonuleotide DNA microarray developed by us has a high potential for identification of stocks among mixed ocean aggregates of high-seas chum salmon.     

Mitochondrial DNA diversity and geographical distribution of sexual and asexual strains of the braconid parasitoid Meteorus pulchricornis

Asexuality is an important tool with regard to the use of parasitoid wasps as biocontrol agents. Asexual (apomictic thelytokous) strains of Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), a polyphagous endoparasitoid of lepidopteran larvae, are sympatric with sexual (arrhenotokous) strains in Japan. The results of phylogenetic analyses of mitochondrial cytochrome c oxidase subunit I (COI) sequences indicated two major haplotype groups on the Japanese islands. The northern group I predominantly contained sexual strains, whereas the southern group II contained both sexual and asexual strains. Most asexual strains were likely derived within group II. An asexual strain recently established in New Zealand has the identical haplotype to a strain in Japan and was proven to have originated from East Asia. Three hypotheses on the evolution of asexuality are discussed for this parasitoid wasp: recessive gene, hybridization, and cytoplasmic element.     

Genome-wide detection of non-additive quantitative trait loci for semen production traits in beef and dairy bulls

Semen production traits are important aspects of bull fertility, because semen quantity leads to direct profits for artificial insemination centres, and semen quality is associated with the probability of achieving a pregnancy. Most genome-wide association studies (GWASs) for semen production traits have assumed that each quantitative trait locus (QTL) has an additive effect. However, GWASs that account for non-additive effects are also important in fitness traits, such as bull fertility. Here, we performed a GWAS using models that accounted for additive and non-additive effects to evaluate the importance of non-additive effects on five semen production traits in beef and dairy bulls. A total of 65 463 records for 615 Japanese Black bulls (JB) and 50 734 records for 873 Holstein bulls (HOL), which were previously genotyped using the Illumina BovineSNP50 BeadChip, were used to estimate genetic parameters and perform GWAS. The heritability estimates were low (ranged from 0.11 to 0.23), and the repeatability estimates were low to moderate (ranged from 0.28 to 0.45) in both breeds. The estimated repeatability was approximately twice as high as the estimated heritability for all traits. In this study, only one significant region with an additive effect was detected in each breed, but multiple significant regions with non-additive effects were detected for each breed. In particular, the region at approximately 64 Mbp on Bos taurus autosome 17 had the highest significant non-additive effect on four semen production traits in HOL. The rs41843851 single nucleotide polymorphism (SNP) in the region had a much lower P-value for the non-additive effect (P-value = 1.1 × 10^?31) than for the additive effect (P-value = 1.1 × 10^?8) in sperm motility. The AA and AB genotypes on the SNP had a higher phenotype than the BB genotype in HOL, and there was no bull with the BB genotype in JB. Our results showed that non-additive QTLs affect semen production traits, and a novel QTL accounting for non-additive effects could be detected by GWAS. This study provides new insights into non-additive QTLs that affect fitness traits, such as semen production traits in beef and dairy bulls.     

Changes in Surgical Site Infections after Living Donor Liver Transplantation

Surgical site infections (SSIs) are a major threat for liver transplant recipients. We prospectively studied SSIs after living donor liver transplantation (LDLT) at Kyoto University Hospital from April 2001 to March 2002 (1^st period) and from January 2011 to June 2012 (2^nd period). We investigated the epidemiology of SSIs after LDLT and determined the differences between the two periods. A total of 129 adult recipients (66 during the 1^st period and 63 during the 2^nd period) and 72 pediatric recipients (39 and 33) were included in this study. The SSI rates for each period were 30.3% (1^st period) and 41.3% (2^nd period) among the adult recipients and 25.6% and 30.3% among the pediatric recipients. The overall rates of 30-day mortality among adult transplant recipients with SSIs were 10.0% (1^st period) and 3.9% (2^nd period). No pediatric recipient died from SSIs after LDLT in either period. The incidence of Enterococcus faecium increased from 5.0% to 26.9% in the adults and from 10.0% to 40.0% in the pediatric patients. Extended-spectrum β-lactamase-producing Enterobacteriaceae were emerging important isolates during the 2^nd period. For this period, a univariate analysis showed that ABO incompatibility (P = 0.02), total operation duration (P = 0.01), graft-to-recipient body weight ratio (GRWR [P = 0.04]), and Roux-en-Y biliary reconstruction (P<0.01) in the adults and age (P = 0.01) and NHSN risk index (P = 0.02) in the children were associated with SSI development. In a multivariate analysis, lower GRWR (P = 0.02) and Roux-en-Y biliary reconstruction (P<0.01) in the adults and older age (P = 0.01) in the children were independent risk factors for SSIs during the 2^nd period. In conclusion, SSIs caused by antibiotic resistant bacteria may become a major concern. Lower GRWR and Roux-en-Y biliary reconstruction among adult LDLT recipients and older age among pediatric LDLT recipients increased the risk of developing SSIs after LDLT.     

A novel effector,CsSp1, from Bipolaris sorokiniana,is essential for colonization in wheat and is also involved in triggering host immunity

The hemibiotrophic pathogen Bipolaris sorokiniana causes root rot, leaf blotching, and black embryos in wheat and barley worldwide, resulting in significant yield and quality reductions. However, the mechanism underlying the host–pathogen interactions between B. sorokiniana and wheat or barley remains unknown. The B. sorokiniana genome encodes a large number of uncharacterized putative effector proteins. In this study, we identified a putative secreted protein, CsSp1, with a classic N-terminal signal peptide, that is induced during early infection. A split-marker approach was used to knock out CsSP1 in the Lankao 9-3 strain. Compared with the wild type, the deletion mutant ∆Cssp1 displayed less radial growth on potato dextrose agar plates and produced fewer spores, and complementary transformation completely restored the phenotype of the deletion mutant to that of the wild type. The pathogenicity of the deletion mutant in wheat was attenuated even though appressoria still penetrated the host. Additionally, the infectious hyphae in the deletion mutant became swollen and exhibited reduced growth in plant cells. The signal peptide of CsSp1 was functionally verified through a yeast YTK12 secretion system. Transient expression of CsSp1 in Nicotiana benthamiana inhibited lesion formation caused by Phytophthora capsici. Moreover, CsSp1 localized in the nucleus and cytoplasm of plant cells. In B. sorokiniana-infected wheat leaves, the salicylic acid-regulated genes TaPAL, TaPR1, and TaPR2 were down-regulated in the ∆Cssp1 strain compared with the wild-type strain under the same conditions. Therefore, CsSp1 is a virulence effector and is involved in triggering host immunity.     

Granulated folliculo-stellate cells and growth hormone cells immunostained with anti-S 100 protein serum in the pituitary glands of the goat

Summary Goat pituitary glands were immunohistochemically studied with antisera for bovine S-100 protein, rat LH, FSH, TSH, prolactin, ovine GH, and porcine ACTH^1–39 by use of the superimposition technique on adjacent sections. Folliculo-stellate (F-S) cells were divided into two categories on the basis of ultrastructural properties: One consisted of a mass of agranular cells in which the pseudolumina were equipped with microvilli and cilia. Elongate gap junctions were often observed among these cells. The other was a group of granulated cells with or without pseudolumina. In this group the gap junctions were shown to be disintegrated. The dense granules 150–250 nm in diameter began to accumulate in the cells. However, neither type of these F-S cells was immunostained for S-100 protein. On the other hand, numerous polygonal, elongate, irregular or stellate cells containing S-100 protein were distributed throughout the gland. Most of them were immunohistochemically identical with the GH cells laden with the secretory granules 250–450 nm in diameter, but some of them were identical to TSH and prolactin cells which immunostained faintly for S-100 protein. This appears to be the first demonstration of GH cells intensely immunostained for S-100 protein.