Project description:In order to establish a rat embryonic stem cell transcriptome, mRNA from rESC cell line DAc8, the first male germline competent rat ESC line to be described and the first to be used to generate a knockout rat model was characterized using RNA sequencing (RNA-seq) analysis.
Project description:von Frey (vF) monofilaments are used to quantify mechanical hypersensitivity and nociception in rodents; however, this method of testing has been criticized due to inconsistencies in testing methods, filament properties, and nonlinearity. This study compared withdrawal thresholds measured by using vF monofilaments with those of a novel mechanical threshold testing device currently in development (RatMet) in a carrageenan inflammatory model in 9- to 11-wk-old male Wistar rats. Rats were randomly assigned to assessment of mechanical hypersensitivity after intraplantar carrageenan injection by using either vF monofilaments (n = 10) or the RatMet device equipped with 3 sizes of probe tips (0.9 mm [RM0.9], n = 15; 0.5mm [RM0.5], n = 11; and 0.09 mm [RM0.09], n = 11). All RatMet probe sizes and vF monofilaments identified a reduction in withdrawal threshold after treatment. Systematic differences in threshold were identified between vF and both RM0.9 and RM0.5 groups; RM0.09 did not differ from vF. Withdrawal thresholds showed linear relationships with probe diameter, square root of probe diameter, and area of the RatMet probes. In contrast, exponential relationships were observed with the vF monofilaments. Furthermore, none of the RatMet probe results differed in accuracy when comparing a single test with the averages of 3 or 5 tests per time point. Overall, the RatMet device measurements have construct validity even when the number of testing replicates is low. These data indicate that the RatMet device produces data comparable with those from vF monofilaments, with the potential for a shortened testing period without a decrease in accuracy.
Project description:A series of two color gene expression profiles obtained using Agilent 44K expression microarrays was used to examine sex-dependent and growth hormone-dependent differences in gene expression in rat liver. This series is comprised of pools of RNA prepared from untreated male and female rat liver, hypophysectomized (‘Hypox’) male and female rat liver, and from livers of Hypox male rats treated with either a single injection of growth hormone and then killed 30, 60, or 90 min later, or from livers of Hypox male rats treated with two growth hormone injections spaced 3 or 4 hr apart and killed 30 min after the second injection. The pools were paired to generate the following 6 direct microarray comparisons: 1) untreated male liver vs. untreated female liver; 2) Hypox male liver vs. untreated male liver; 3) Hypox female liver vs. untreated female liver; 4) Hypox male liver vs. Hypox female liver; 5) Hypox male liver + 1 growth hormone injection vs. Hypox male liver; and 6) Hypox male liver + 2 growth hormone injections vs. Hypox male liver. A comparison of untreated male liver and untreated female liver liver gene expression profiles showed that of the genes that showed significant expression differences in at least one of the 6 data sets, 25% were sex-specific. Moreover, sex specificity was lost for 88% of the male-specific genes and 94% of the female-specific genes following hypophysectomy. 25-31% of the sex-specific genes whose expression is altered by hypophysectomy responded to short-term growth hormone treatment in hypox male liver. 18-19% of the sex-specific genes whose expression decreased following hypophysectomy were up-regulated after either one or two growth hormone injections. Finally, growth hormone suppressed 24-36% of the sex-specific genes whose expression was up-regulated following hypophysectomy, indicating that growth hormone acts via both positive and negative regulatory mechanisms to establish and maintain the sex specificity of liver gene expression. For full details, see V. Wauthier and D.J. Waxman, Molecular Endocrinology (2008)
Project description:Analysis of hormone effects on irradiated LBNF1 rat testes, which contain only somatic cells except for a few type A spermatgogonia. Rats were treated for 2 weeks with either sham treatment (group X), hormonal ablation (GnRH antagonist and the androgen receptor antagonist flutamide, group XAF), testosterone supplementation (GnRH antagonist and testosterone, group XAT), and FSH supplementation ((GnRH antagonist, androgen receptor antagonist, and FSH, group XAFF). Results provide insight into identifying genes in the somatic testis cells regulated by testosterone, LH, or FSH.