scholarly journals Short photoperiod inhibition of growth in body mass and reproduction in ACI, BUF, and PVG inbred rats

Reproduction ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 857-862 ◽  
Author(s):  
Nicole R Francisco ◽  
Christen M Raymond ◽  
Paul D Heideman
Keyword(s):  
Body Mass ◽  
Food Restriction ◽  
Inbred Strains ◽  
Brown Norway ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Young Males ◽  
Laboratory Rats ◽  
Photoperiodic Responses ◽  
Inbred Rat

Laboratory rats have been generally considered non-photoresponsive, but strains of laboratory rats have been found to be variable for this trait. Young males of both the Fischer (F344) and Brown Norway strains (BN) suppress reproductive development, food intake and body mass in short winter photoperiod (short days (SD); 8 h light:16 h darkness), and food restriction interacts with SD to enhance the effect of SD alone. Conversely, young male Harlan Sprague Dawley outbred rats, along with other outbred laboratory rats tested, have little or no response to SD except when unmasked by food restriction or other treatments, and have generally been considered nonphotoperiodic. In order to assess how widespread this trait might be among rat strains, and to test for uncoupling of reproductive and nonreproductive responses, we tested 3 additional inbred strains, including ACI, PVG and BUF rats, for photoresponsiveness and for unmasking of photoperiodic responses by food restriction. Young males of all three inbred strains exhibited photoresponsiveness in testis mass (5–20% lower in SD), seminal vesicle mass (20–50% lower in SD), and body mass (5–10% lower in SD). Food restriction also suppressed reproduction, but there was little or no interaction with the effects of photoperiod. The results are consistent with the hypothesis that laboratory rats are genetically variable for photoperiodism, and that photoresponsiveness may be widespread among inbred rat strains, as all five inbred strains tested have shown photoperiodic responses. The results are particularly important because standard research protocols may unknowingly manipulate this pathway in rats, causing unsuspected variability among or within studies.

Genetic variation in photoperiodism among naturally photoperiodic rat strains

2001 ◽  
Vol 281 (6) ◽  
pp. R1817-R1824 ◽  
Author(s):  
Annaka M. Lorincz ◽  
M. Benjamin Shoemaker ◽  
Paul D. Heideman
Keyword(s):  
Somatic Growth ◽  
Brown Norway ◽  
Testis Size ◽  
Young Males ◽  
Laboratory Rats ◽  
Fischer 344 ◽  
Critical Photoperiod ◽  
Photoperiodic Responses ◽  
Different Strains ◽  
Long Photoperiod

Rattus norvegicus has been considered nonphotoperiodic, but Fischer 344 (F344) rats are inhibited in growth and reproductive development by short photoperiod (SD). We tested photoresponsiveness of the genetically divergent Brown Norway (BN) strain of rats. Peripubertal males were tested in long photoperiod or SD, with or without 30% food reduction. Young males were photoresponsive, with reductions in testis size, body mass, and food intake in SD and with enhanced responses to SD when food restricted. Photoperiods ≤11 h of light inhibited reproductive maturation and somatic growth, whereas photoperiods of 12 h or more produced little or no response. F344/BN hybrids differ from both parent strains in the timing, amplitude, and critical photoperiod of photoperiodic responses, indicating genetic differences in photoperiodism between these strains. This is consistent with the hypothesis that ancestors of laboratory rats were genetically variable for photoperiodism and that different combinations of alleles for photoperiodism have been fixed in different strains of rats.

scholarly journals Extended regions of suspected mis-assembly in the rat reference genome

2018 ◽  
Author(s):  
Shweta Ramdas ◽  
Ayse Bilge Ozel ◽  
Mary K. Treutelaar ◽  
Katie Holl ◽  
Myrna Mandel ◽  
...  
Keyword(s):  
Genome Sequencing ◽  
Reference Genome ◽  
Functional Results ◽  
Inbred Strains ◽  
Brown Norway ◽  
Whole Genome ◽  
Rat Strains ◽  
Inbred Rat Strains ◽  
Heterogeneous Stock ◽  
Inbred Rat

AbstractWe performed whole-genome sequencing for eight inbred rat strains commonly used in genetic mapping studies. They are the founders of the NIH heterogeneous stock (HS) outbred colony. We provide their sequences and variant calls to the rat genomics community. When analyzing the variant calls we identified regions with unusually high levels of heterozygosity. These regions are consistent across the eight inbred strains, including Brown Norway, which is the basis of the rat reference genome. These regions show higher read depths than other regions in the genome and contain higher rates of apparent tri-allelic variant sites. The evidence suggests that these regions may correspond to duplicated segments that were incorrectly overlaid as a single segment in the reference genome. We provide masks for these regions of suspected mis-assembly as a resource for the community to flag potentially false interpretations of mapping or functional results.

scholarly journals Chromosome-substituted rat strains provide insights into the genetics of placentation

2011 ◽  
Vol 43 (15) ◽  
pp. 930-941 ◽  
Author(s):  
Toshihiro Konno ◽  
Lea A. Rempel ◽  
M. A. Karim Rumi ◽  
Amanda R. Graham ◽  
Kazuo Asanoma ◽  
...  
Keyword(s):  
Quantitative Trait ◽  
Strain Differences ◽  
Transcript Level ◽  
Trophoblast Invasion ◽  
Brown Norway ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Junctional Zone ◽  
Transcript Levels ◽  
Inbred Rat

The rat possesses a hemochorial form of placentation. Pronounced intrauterine trophoblast cell invasion and vascular remodeling characterize this type of placentation. Strain-specific patterns of placentation are evident in the rat. Some rat strains exhibit deep intrauterine trophoblast invasion and an expanded junctional zone [Holtzman Sprague-Dawley (HSD), Dahl salt sensitive (DSS)], whereas placentation sites of other rat strains are characterized by shallow invasion and a restricted junctional zone [Brown Norway (BN)]. In this report, we identified a quantitative trait that was used to distinguish strain-specific features of rat placentation. Junctional zone prolactin family 5, subfamily a, member 1 ( Prl5a1) transcript levels were significantly greater in BN rats than in HSD or DSS rats. Prl5a1 transcript levels were used as a quantitative trait to screen placentation sites from chromosome-substituted rat strains (BN chromosomes introgressed into the DSS inbred strain; DSS-BN panel). Litter size, placental weights, and fetal weights were not significantly different among the chromosome-substituted strains. Regulation of the junctional zone Prl5a1 transcript-level quantitative trait was multifactoral. Chromosome-substituted strains possessing BN chromosomes 14 or 17 introgressed into the DSS inbred rat strain displayed Prl5a1 transcript levels that were significantly different from the DSS pattern and more closely resembled the BN pattern. The in situ placental distribution of Prl5a1 mRNA and the structure of the junctional zone of DSS-BN17 rats mimicked that observed for the BN rat. Prl5a1 gene expression was also assessed in BN vs. HSD trophoblast stem cells and following reciprocal BN and HSD embryo transfer. Strain differences intrinsic to trophoblast and maternal environment were identified. In summary, we have identified chromosomes 14 and 17 as possessing regulatory information controlling a quantitative trait associated with rat placentation.

scholarly journals Ventilation and metabolism among rat strains

1997 ◽  
Vol 82 (1) ◽  
pp. 317-323 ◽  
Author(s):  
Kingman P. Strohl ◽  
Agnes J. Thomas ◽  
Pamela St. Jean ◽  
Evelyn H. Schlenker ◽  
Richard J. Koletsky ◽  
...  
Keyword(s):  
Body Weight ◽  
Tidal Volume ◽  
Body Mass ◽  
Minute Ventilation ◽  
Independent Effect ◽  
Brown Norway ◽  
Hypoxic Exposure ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Strain Effects

Strohl, Kingman P., Agnes J. Thomas, Pamela St. Jean, Evelyn H. Schlenker, Richard J. Koletsky, and Nicholas J. Schork.Ventilation and metabolism among rat strains. J. Appl. Physiol. 82(1): 317–323, 1997.—We examined ventilation and metabolism in four rat strains with variation in traits for body weight and/or blood pressure regulation. Sprague-Dawley [SD; 8 males (M), 8 females (F)], Brown Norway (BN; 10 M, 11 F), and Zucker (Z; 11 M, 12 F) rats were compared with Koletsky (K; 11 M, 11 F) rats. With the use of noninvasive plethysmography, frequency, tidal volume, minute ventilation (V˙e), O2 consumption, and CO2 production were derived at rest during normoxia (room air) and during the 5th minute of exposure to each of the following: hyperoxia (100% O2), hypoxia (10% O2-balance N2), and hypercapnia (7% CO2-balance O2). Statistical methods probed for strain and sex effects, with covariant analysis by body weight, length, and body mass. During resting breathing, strain effects were found with respect to both frequency (BN, Z > K, SD) and tidal volume (SD > BN, Z) but not to V˙e. Sex influenced frequency (F > M) alone. Z rats had higher values for O2 consumption, CO2 production, and respiratory quotient than the other three strains, with no independent effect by sex. During hyperoxia, frequency was greater in BN and Z than in SD or K rats; SD rats had a larger tidal volume than BN or Z rats; Z rats had a greater V˙e than K rats; and M had a larger tidal volume than F. Strain differences persisted during hypercapnia, with Z rats exhibiting the highest frequency andV˙e values. During hypoxic exposure, strain effects were found to influenceV˙e (SD > K, Z), frequency (BN > K), and tidal volume (SD > BN, K, Z). Body mass was only a modest predictor of V˙e during normoxia, of both V˙e and tidal volume with hypoxia, hypercapnia, or hyperoxia, and of frequency during hypercapnia. We conclude that strain of rats, more than their body mass or sex, has major and different influences on metabolism, the pattern and level of ventilation during air breathing, and ventilation during acute exposure to hypercapnia or hypoxia.

Genetic strain differences in platelet aggregation and thrombus formation of laboratory rats

2007 ◽  
Vol 97 (04) ◽  
pp. 665-672 ◽  
Author(s):  
Hideki Ito ◽  
Hideki Hayashi ◽  
Yoshie Nagamura ◽  
Kazuyuki Toga ◽  
Yoshihisa Yamada ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Thrombus Formation ◽  
Strain Differences ◽  
Brown Norway ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Laboratory Rats ◽  
Thrombosis Model ◽  
Considerable Strain

SummaryRats are employed to investigate the role of platelets in thrombus formation under flow conditions in vivo and to evaluate the pre-clinical potential of antiplatelet drugs. While Wistar and Sprague-Dawley (SD) strains are commonly used in thrombosis models, a number of rat strains have been established. Each strain possesses genetically unique characteristics such as hypertension, hyperglycemia or hyperlipidemia. The appropriate selection of a strain might have advantages for physiological and pharmacological studies. Comparative investigation of platelet aggregation among laboratory strains of rats is useful for the development of thrombosis models. In the present study, platelet aggregation response in eight laboratory rat strains, ACI, Brown Norway (BN), Donryu, Fischer 344 (F344), LEW, SD, Wistar and WKAH, were compared. Considerable strain differences were observed in ADP-, collagen- and TRAP-induced platelet aggregation. SD and BN are high-platelet-aggregation strains, while F344 and ACI are low-response strains. In the arteriovenous shunt thrombosis model, SD formed larger thrombi than F344 andWistar rats. In the FeCl 3 -induced thrombosis model with the carotid artery, the time to occlusion of SD was significantly shorter than of F344 and ACI rats. F344 and ACI rats had significantly increased bleeding times compared with SD rat. The present study demonstrates that there are considerable strain differences in platelet aggregation among laboratory rats, which reflect thrombus formation.

scholarly journals THE Ah PHENOTYPE. SURVEY OF FORTY-EIGHT RAT STRAINS AND TWENTY INBRED MOUSE STRAINS

Genetics ◽  
1982 ◽  
Vol 100 (1) ◽  
pp. 79-87
Author(s):  
Daniel W Nebert ◽  
Nancy M Jensen ◽  
Hisashi Shinozuka ◽  
Heinz W Kunz ◽  
Thomas J Gill
Keyword(s):  
Specific Activity ◽  
Inbred Mouse ◽  
Inbred Mouse Strain ◽  
Mouse Strains ◽  
Ah Receptor ◽  
Inbred Mouse Strains ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Specific Activities ◽  
Inbred Rat

ABSTRACT Forty-four inbred and four randombred rat strains and 20 inbred mouse strains were examined for their Ah phenotype by determining the induction of liver microsomal aryl hydrocarbon (benzo[a]pyrene) hydroxylase activity (EC 1.14.14.1) by intraperitoneal treatment with either β-naphthoflavone or 3-methylcholanthrene. All 48 rat strains were found to be Ah-responsive. The maximally induced hydroxylase specific activities of the ALB/Pit, MNR/Pit, MR/Pit, SHR/Pit, and Sprague-Dawley strains were of the same order of magnitude as the basal hydroxylase specific activities of the ACI/Pit, F344/Pit, OKA/Pit, and MNR/N strains. Six of the 20 mouse strains were Ah-nonresponsive (i.e. lacking the normal induction response and presumably lacking detectable amounts of the Ah receptor). The basal hydroxylase specific activities of the BDL/N, NFS/N, STAR/N, and ST/JN mouse strains were more than twice as high as the maximally induced hydroxylase specific activity of the CBA/HT strain.——To date, 24 Ah-nonresponsive mouse strains have been identified, out of a total of 68 known to have been characterized. The reasons for not finding a single Ah-nonresponsive inbred rat strain—as compared with about one Ah-nonresponsive inbred mouse strain found for every three examined—remain unknown.

Comparison of upper and lower airway responses of two sensitized rat strains to inhaled antigen

1992 ◽  
Vol 73 (4) ◽  
pp. 1608-1613 ◽  
Author(s):  
L. J. Xu ◽  
S. Sapienza ◽  
T. Du ◽  
S. Waserman ◽  
J. G. Martin
Keyword(s):  
Upper Airway ◽  
Brown Norway ◽  
Lower Airway ◽  
Sprague Dawley ◽  
Pulmonary Resistance ◽  
Upper Airways ◽  
Tracheal Pressure ◽  
Airway Response ◽  
Airway Responses ◽  
Inbred Rat

The purpose of the study was to investigate the relationships between upper airways responses and pulmonary responses of two strains of highly inbred rats to inhaled antigen. To do this we measured the upper and lower airways resistance for 60 min after challenge of Brown-Norway rats (BN; n = 13) and an inbred rat strain (MF; n = 11), derived from Sprague-Dawley, with aerosolized ovalbumin (OA). Rats were actively sensitized with OA (1 mg sc) using Bordetella pertussis as an adjuvant. Two weeks later the animals were anesthetized and challenged. Tracheal pressure, esophageal pressure, and airflow were measured, from which total pulmonary resistance was partitioned into upper airway and lower pulmonary resistance (RL). The peak upper airway response to inhaled OA was similar in BN (1.89 +/- 0.66 cmH2O.ml-1.s; n = 7) and MF (2.85 +/- 0.68 cmH2O.ml-1.s; n = 6). The lower airway response to OA challenge was substantially greater in BN, and RL changed from 0.07 +/- 0.01 to 0.34 +/- 0.13 (n = 6; P < 0.05). The MF did not have any significant increase in RL after challenge; the baseline RL was 0.12 +/- 0.02 and only reached a peak value of 0.15 +/- 0.05 (n = 5; P = NS). Lower airway responsiveness of BN (n = 10) to serotonin, an important mediator early allergic airway responses, was similar to MF (n = 7).(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristics of the aortic elastic network and related phenotypes in seven inbred rat strains

2005 ◽  
Vol 288 (2) ◽  
pp. H769-H777 ◽  
Author(s):  
Jacques Behmoaras ◽  
Mary Osborne-Pellegrin ◽  
Dominique Gauguier ◽  
Marie-Paule Jacob
Keyword(s):  
Growth Factor ◽  
Vascular Function ◽  
Transforming Growth Factor ◽  
Brown Norway ◽  
Internal Elastic Lamina ◽  
Rat Strains ◽  
Inbred Rat Strains ◽  
Insulin Growth Factor ◽  
Igf I ◽  
Inbred Rat

Extracellular matrix (ECM) molecules such as elastin and collagen provide mechanical support to the vessel wall and are essential for vascular function. Evidence that genetic factors influence aortic ECM composition and organization was concluded from our previous studies showing that the inbred Brown Norway (BN) rat differs significantly from the outbred Long-Evans (LE) and the inbred LOU rat with respect to both thoracic aortic elastin content and internal elastic lamina (IEL) rupture in the abdominal aorta and iliac arteries. Here, we measured aortic elastin and collagen contents as well as factors that may modulate these parameters [insulin growth factor (IGF)-I, transforming growth factor (TGF)-β1, and matrix metalloproteinase (MMP)-2] in seven inbred rat strains, including BN and LOU. We also investigated whether IEL ruptures occur in strains other than BN. We showed that LOU, LE, BN, and Fischer 344 (F344) rats were significantly different for aortic elastin content and elastin-to-collagen ratio, whereas LE, Lewis, WAG, and Wistar-Furth (WF) were similar for these parameters. BN and F344 had the lowest values. BN was the only strain to present numerous IEL ruptures, whereas F344, LE, and WF presented a few and the other strains presented none. In addition, IGF-I and TGF-β1 levels in the plasma and aorta differed significantly between strains, suggesting genetic control of their production. Because inbred rat strains provide interesting models for quantitative trait locus analysis, our results concerning elastin, collagen, IEL ruptures, and cytokines may provide a basis for the search for candidate genes involved in the control of these phenotypes.

scholarly journals Ventilatory phenotypes among four strains of adult rats

2002 ◽  
Vol 93 (3) ◽  
pp. 974-983 ◽  
Author(s):  
Matthew R. Hodges ◽  
Hubert V. Forster ◽  
Paula E. Papanek ◽  
Melinda R. Dwinell ◽  
Genevieve E. Hogan
Keyword(s):  
Ventilatory Response ◽  
Strain Difference ◽  
Strain Differences ◽  
Inbred Strains ◽  
The Other ◽  
Brown Norway ◽  
Control Mechanisms ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Different Strains

Our purpose in this study was to identify different ventilatory phenotypes among four different strains of rats. We examined 114 rats from three in-house, inbred strains and one outbred strain: Brown Norway (BN; n = 26), Dahl salt-sensitive ( n = 24), Fawn-hooded Hypertensive (FHH: n = 27), and outbred Sprague-Dawley rats (SD; n = 37). We measured eupneic (room air) breathing and the ventilatory responses to hypoxia (12% O2-88% N2), hypercapnia (7% CO2), and two levels of submaximal exercise. Primary strain differences were between BN and the other strains. BN rats had a relatively attenuated ventilatory response to CO2 ( P < 0.001), an accentuated ventilatory response to exercise ( P < 0.05), and an accentuated ventilatory roll-off during hypoxia ( P < 0.05). Ventilation during hypoxia was lower than other strains, but hyperventilation during hypoxia was equal to the other strains ( P > 0.05), indicating that the metabolic rate during hypoxia decreased more in BN rats than in other strains. Another strain difference was in the frequency and timing components of augmented breaths, where FHH rats frequently differed from the other strains, and the BN rats had the longest expiratory time of the augmented breaths (probably secondary to the blunted CO2 sensitivity). These strain differences not only provide insight into physiological mechanisms but also indicate traits (such as CO2 sensitivity) that are genetically regulated. Finally, the data establish a foundation for physiological genomic studies aimed at elucidating the genetics of these ventilatory control mechanisms.

Functional polymorphisms in inbred rat strains and their allele frequencies in commercially available outbred stocks

2008 ◽  
Vol 33 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Takashi Kuramoto ◽  
Satoshi Nakanishi ◽  
Tadao Serikawa
Keyword(s):  
Coat Color ◽  
Cholesterol Biosynthesis ◽  
Inbred Strains ◽  
Rat Strains ◽  
Genetic Characteristics ◽  
Genetic Profiling ◽  
Prostate Tumorigenesis ◽  
Inbred Rat Strains ◽  
Functional Polymorphisms ◽  
Inbred Rat

Polymorphisms that have been proven to influence gene functions are called functional polymorphisms. It is significant to know the distribution of functional polymorphisms in the rat, widely used in animal models for human diseases. In this study, we assessed 16 functional polymorphisms consisting of 3 coat color and 13 disease-associated genes in 136 rat strains, as a part of the genetic profiling program of the National Bio Resource Project for the Rat (NBRP-Rat). Polymorphisms of Cdkn1a, Fcgr3, Grp10, Lss, and Fdft1, which were proven to function in prostate tumorigenesis, glomerulonephritis, hyperphagia, and cholesterol biosynthesis, were shared among various inbred strains. These findings indicated that most rat strains harbored the disease-associated alleles and suggested that many unidentified functional polymorphisms might exist in inbred rat strains. The functional polymorphisms shared in inbred strains were also observed within outbred stocks available commercially. Therefore, this implies that experimental plans based on either rat inbred strains or outbred stocks need to be carefully designed with a full understanding of the genetic characteristics of the animals. To select the most suitable strains for experiments, the NBRP-Rat will periodically improve and update the genetic profiles of rat strains.

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