Mapping QTL for fat area ratios and serum leptin concentrations in a Duroc purebred population

The reduction of extra subcutaneous, intermuscular and abdominal fat is important to increase the carcass lean percentage of pigs. Image analyses of fat area ratios were effective for estimation of separated fat in pig carcasses. Serum concentrations of leptin are useful as physiological predictors of fat accumulation in pigs. The objectives of the present study were to perform a quantitative trait locus (QTL) analysis for fat area ratios and serum leptin concentrations in a Duroc purebred population. Pigs (n = 226 to 538) were measured for fat area ratios of carcass cross‐sections at the fifth to sixth thoracic vertebrae, half body length and last thoracic vertebra using an image analysis system, and serum leptin concentration. In total, animals were genotyped for 129 markers and used for QTL analysis. For fat area ratios, four significant and 12 suggestive QTLs were detected on chromosomes 1, 6, 7, 8, 9, 12 and 13. Significant QTLs were detected on the same region of chromosome 6, which was located near a leptin receptor gene. For serum leptin concentrations, two significant and two suggestive QTLs were detected on chromosomes 6, 9, and 16, and the QTLs on chromosome 6 were also in the same region for fat area ratios.     

Evaluation of bovine uterine gland functions in 2D and 3D culture system

In ruminants, uterine glands play key roles in the establishment of pregnancy by secreting various factors into the uterine lumen. Although a three-dimensional (3D) culture system has been used for investigating cellular functions in vitro, the detailed functions of uterine gland have not been fully elucidated. In this study, we examined the benefits of 3D culture system to examine the innate functions of bovine uterine glands. Isolated bovine uterine glands were cultured on Matrigel (2D) or in Matrigel (3D), respectively, and the mRNA levels of secreted proteins (SERPINA14, MEP1B, APOA1, ARSA, CTGF, and SPP1) were measured in isolated and cultured uterine glands. The protein expression of estrogen receptor β (ERβ) and progesterone receptor (PR) and the establishment of apico-basal polarity were examined. In isolated uterine glands, the mRNA levels of secreted proteins changed during the estrous cycle. Although uterine glands cultured in both 2D and 3D expressed ERβ and PR, progesterone did not affect SERPINA14 mRNA expression. The expression of APOA1 mRNA in 2D cultured uterine glands did not respond to estrogen and progesterone. Additionally, the mRNA levels of secreted proteins in the 3D culture system were significantly higher than those in the 2D culture system, which might be attributed to the different cellular morphology between them. The locations of ZO-1 and β-catenin in 2D cultured uterine glands were disordered compared with 3D cultured uterine glands. These results showed that the hormonal responsiveness of secreted factor expression and cellular morphology were different between 2D and 3D cultured bovine uterine glands.     

Cloning of PRL and VIP cDNAs of the Java sparrow (Padda oryzivora)

Complementary DNA (cDNA) of prolactin (PRL) and vasoactive intestinal polypeptide (VIP) of the Java sparrow were cloned and sequenced. The proximal region of the PRL promoter was also identified. Java sparrow PRL was found to have 88.3, 88.3, and 89.1% sequence identity at the cDNA level to PRL of chicken, turkey, and duck, respectively. The predicted amino acid sequence had an overall similarity with a comparable region of chicken (91.4%), turkey (88.9%) and duck (92.0%) PRL. Based on the cDNA sequence and genomic structure of the chicken PRL gene, the proximal promoter was characterized. Sequence analysis of the proximal region of Java sparrow PRL promoter revealed a high degree of similarity to that of chicken, turkey and duck PRL promoters. Moreover, cDNA of prepro-VIP was also cloned and sequenced. Java sparrow prepro-VIP shows high similarity to chicken and turkey prepro-VIP. However, the region upstream of the 5' untranslated region of Java sparrow prepro-VIP did not show similarity to that of chicken. These results suggest that the mechanisms, which regulate expression of the VIP gene, may be different between precocial and altricial birds, but expression of the PRL gene may be widely conserved in avian species.     

Infection of Melissococcus plutonius clonal complex 12 strain in European honeybee larvae is essentially confined to the digestive tract

Melissococcus plutonius is an important pathogen that causesEuropean foulbrood (EFB) in honeybee larvae. Recently, we discovered a group of M.plutonius strains that are phenotypically and genetically distinct from otherstrains. These strains belong to clonal complex (CC) 12, as determined by multilocussequence typing analysis, and show atypical cultural and biochemical characteristicsin vitro compared with strains of other CCs tested. Although EFB isconsidered to be a purely intestinal infection according to early studies, it is unknownwhether the recently found CC12 strains cause EFB by the same pathomechanism. In thisstudy, to obtain a better understanding of EFB, we infected European honeybee(Apis mellifera) larvae per os with awell-characterized CC12 strain, DAT561, and analyzed the larvae histopathologically.Ingested DAT561 was mainly localized in the midgut lumen surrounded by the peritrophicmatrix (PM) in the larvae. In badly affected larvae, the PM and midgut epithelial cellsdegenerated, and some bacterial cells were detected outside of the midgut. However, theydid not proliferate in the deep tissues actively. By immunohistochemical analysis, the PMwas stained with anti-M. plutonius serum in most of the DAT561-infectedlarvae. In some larvae, luminal surfaces of the PM were more strongly stained than theinside. These results suggest that infection of CC12 strain in honeybee larvae isessentially confined to the intestine. Moreover, our results imply the presence ofM. plutonius-derived substances diffusing into the larval tissues inthe course of infection.     

Decrease in stearic acid proportions in adipose tissues and liver lipids in fatty liver of dairy cows

Samples of liver and perirenal, mesenteric and subcutaneous fat were collected from 16 sick necropsied dairy cows to evaluate the fatty acid profiles in the hepatic and adipose tissues associated with advanced fatty liver or hepatic lipidosis. Hepatic triglyceride and eight fatty acids were measured in the hepatic and adipose tissues. Six cows had more than 3% triglyceride on fresh weight in their livers and were classified as having fatty liver. Stearic and linoleic acid proportions in the liver decreased markedly with increased hepatic triglyceride levels, while the proportion of palmitic and oleic acids increased. The most striking fluctuations in hepatic lipidosis were manifested as decreased stearic acid in the adipose tissues including subcutaneous fat with the trend of decreasing stearic acid. Palmitic acid was elevated in hepatic and perirenal fat in fatty liver cows. In instances of advanced hepatic lipidosis, palmitoleic acid increased in only subcutaneous fat and not in perirenal or mesenteric fat. In addition to the proportions of hepatic fatty acids in fatty liver, this study also clarified the fluctuations observed in the profiles of fatty acids of the adipose tissues in cows with advanced hepatic lipidosis, particularly the decline in the proportions of stearic acid.     

VEGF promotes biliary epithelial cell viability and cystic dilation in rats with polycystic kidney

AIM:To explore the promoting effect of vascular endothelial growth factor (VEGF) on the viability of biliary epithelial cells and biliary cystic dilation in rats with polycystic kidney (PCK). METHODS:Immunohistoche-mical staining was used to detect the expression of VEGF (n=6) and CD31 (n=10) in the liver tissue of normal and PCK rats. RT-qPCR and ELISA were used to evaluate the expression levels of VEGF in rat biliary epithelial cells and culture supernatant. WST-1 assay was applied to measure the effect of VEGF on the viability of rat biliary epithelial cells, and the influence of cholangiocyte culture supernatant on the viability of rat vascular endothelial cells. The cell migration assay was employed to observe the effect of cholangiocyte culture supernatant on endothelial cell migration. Tube formation assay was used to assess the impact of cholangiocyte culture supernatant on the angiogenic ability of endothelial cells. RESULTS:The result of immunohistochemical staining manifested that VEGF was highly expressed in the cholangiocytes of the PCK rats (P<0.01). More newly formed blood vessels were observed in the hepatic portal area of PCK rats than that in normal rats (P<0.01). The results of RT-qPCR and ELISA suggested that the mRNA and protein expression levels of VEGF in the cholangiocytes of PCK rats were significantly higher than those in normal rats (P<0.01). VEGF enhanced the viability of cholangiocytes in PCK rats (P<0.01). The culture supernatant of cholangiocytes in PCK rats increased the endothelial cell viability (P<0.01). VEGF siRNA and VEGF receptor inhibitor reduced the viability of cholangiocytes (P<0.01). The results of cell migration assay and tube formation assay indicated that the abilities of endothelial cell migration and tube formation were improved by the culture supernatant of cholangiocytes in PCK rats (P<0.01). CONCLUSION:The bile duct cystic dilation of PCK rats was related to the excessive secretion of VEGF in bile duct epithelial cells.     

Sex differences in cervical spinal cord and spinal canal development in Thoroughbred horses

Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex differences in the development of cervical spinal cord and spinal canal in Thoroughbred horses. A total of 29 Thoroughbred horses underwent computed tomographic myelography. Thereafter, the volumes of cervical spinal cord and spinal canal were calculated. Accordingly, male horses had significantly lager cervical spinal cord volume and cervical spinal cord-to-spinal canal volume ratio than those of female horses (P<0.05). Sex differences in the cervical spinal cord-to-spinal canal volume ratio gradually decreased until around 1,400 days of age. Younger male horses have narrower interspace between the cervical spinal cord and spinal canal than younger female horses, suggesting that an imbalanced cervical spinal cord and spinal canal growth is one of the causes of CVSM.