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RNA was extracted from single or small groups of ovine ovarian follicles after treatment of ewes with FSH and/or LH. The content of mRNA for the alpha-inhibin and beta A-inhibin subunits was analyzed by hybridization with specific cDNA probes. All ewes were treated with progestin vaginal pessaries to suppress spontaneous preovulatory follicle maturation and ewes were given three intramuscular injections of gonadotropins at 8-hr intervals starting 24 hr prior to collection of ovaries. In experiment I, both Schering-FSH and NIDDK-oFSH-17 (oFSH) significantly increased alpha- and beta A-inhibin mRNA per ewe in 2-5 mm follicles and tended to increase alpha- and beta A-inhibin mRNA in large (greater than 5 mm) follicles. In experiment II, oFSH and NIDDK-oLH-25 (oLH) were administered in a 2X2 factorial arrangement. Separate administration of oFSH or oLH increased (P less than .05) the alpha-inhibin mRNA concentration in large follicles. alpha-inhibin mRNA concentration in 4-5 mm follicles was also increased by oFSH but was decreased by oLH. Concomitant treatment with oFSH and oLH did not change alpha-inhibin mRNA concentrations from those measured in oFSH treated ewes. In experiment II, beta A mRNA concentrations followed a pattern similar to that of alpha A mRNA, but the differences were not statistically significant. We conclude that, in the ewe, exogenous FSH increases the concentration of inhibin mRNA in the whole follicle. The ability of exogenous oLH to alter expression of the inhibin subunit genes may depend upon the stage of follicle maturation. 相似文献
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Bovine CAPN1 maps to a region of BTA29 containing a quantitative trait locus for meat tenderness 总被引：21，自引：0，他引：21
Micromolar calcium activated neural protease (CAPN1) was investigated as a potential candidate gene for a quantitative trait locus (QTL) on BTA29 affecting meat tenderness. A 2,948-bp bovine cDNA containing the entire coding region of the gene was obtained, showing 91% identity to human CAPN1. The 716 AA protein predicted from this sequence shows 97% similarity (95% identity) to the 714 AA human protein. Analysis of the gene structure revealed that CAPN1 mRNA is encoded by at least 19 exons, and 11,055 bp of the gene were sequenced, including 17 introns. Two single nucleotide polymorphisms (SNP) were detected in intron 12 and were used to map bovine CAPN1 to the telomeric end of the BTA29 linkage group. This approximately coincides with the position of the QTL, demonstrating that CAPN1 protease is a positional candidate gene potentially affecting variation in meat tenderness in a bovine resource mapping population. 相似文献
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I. Coulibaly S. A. Gahr J. Yao C. E. Rexroad III 《Fish physiology and biochemistry》2006,32(3):249-253
Uncoupling proteins are mitochondrial anions transporters that dissociate respiration from ATP synthesis through proton leaks. Uncoupling protein 2 reportedly plays a role in several physiological processes such as energy partitioning, nutrition, and fatty acid metabolism. The mRNA expression of rainbow trout UCP2 genes (UCP2A and UCP2B) was monitored during embryogenesis and early larval development. Both genes were recruited early and displayed similar steadily decreasing patterns from fertilization until hatching. The expression of UCP2A and UCP2B appeared significantly differentiated after hatching and during the yolk sac absorption, with UCP2A displaying higher expression. We suggest that UCP2 expression profiles in the rainbow trout embryo could be associated with the utilization of lipids as a source of energy during development. 相似文献
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文章通过对内蒙古大兴安岭林区培育大径材的目的、意义、必要性及方法等方面的分析,论述了大径级材培育是促进林区生态、经济和社会协调发展的有力措施。 相似文献
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We propose an isotopic fractionation mechanism, based on photolytic destruction, to explain the 15N/14N and 18O/16O fractionation of stratospheric nitrous oxide (N2O) and reconcile laboratory experiments with atmospheric observations. The theory predicts that (i) the isotopomers 15N14N16O and 14N15N16O have very different isotopic fractionations in the stratosphere, and (ii) laboratory photolysis experiments conducted at 205 nanometers should better simulate the observed isotopic fractionation of stratospheric N2O. Modeling results indicate that there is no compelling reason to invoke a significant chemical source of N2O in the middle atmosphere and that individual N2O isotopomers might be useful tracers of stratospheric air parcel motion. 相似文献
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Genetic engineering of mammalian embryos 总被引：2，自引：0，他引：2
R E Hammer V G Pursel C E Rexroad R J Wall D J Bolt R D Palmiter R L Brinster 《Journal of animal science》1986,63(1):269-278
A gene consisting of the mouse metallothionein I promoter/regulator (MT) fused to the human growth hormone (hGH) structural gene (MThGH) was microinjected into rabbit, sheep and pig eggs. Visualization of nuclear structures was accomplished by interference-contrast (I-C) microscopy for rabbit and sheep eggs and by centrifugation and I-C microscopy for pig eggs. The gene integrated into the chromosomes of each species with an efficiency of 13% in rabbits, 1% in sheep and 10% in pigs. Human GH mRNA was detected in the liver of transgenic rabbits as well as tail and ear samples of pigs. Immunoreactive hGH was present in the serum of a transgenic rabbit and plasma of most transgenic pigs. In several pigs hGH levels increased between birth and 90 d of age. The presence of substantial quantities of hGH in plasma of pigs did not increase postnatal somatic growth rates. Founder animals will be bred and their transgenic and control progeny used to assess the effects of hGH on feed efficiency and carcass composition. These experiments demonstrate the feasibility of introducing foreign genes into the genome of several animal species by microinjection of eggs. 相似文献
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C E Rexroad 《Journal of animal science》1984,58(5):1278-1284
Three studies were conducted to investigate concentrations of estrogen and progestin receptors in ewe myometrium during gestation. In the first two studies, concentrations were found to be similar in pregnant and nonpregnant ewes on d 5, 9, 12 and 14 postestrus. The receptor concentrations were relatively high on d 5 and were lowest on d 14. Apparently concentrations of myometrial steroid receptors during the luteal phase are commensurate with the successful establishment of pregnancy. The concentration of both types of receptors increased from d 14 to 35 in pregnant ewes. This change was associated with a concomitant increase in the amount of DNA and protein in cells. In Exp. 3, it was found that the concentrations of the estrogen receptor remained fairly constant after d 45 until late gestation, while the concentration of cytoplasmic progestin receptor increased after d 65. The ratio of RNA to DNA appeared to increase throughout pregnancy. Progestin receptor increases may be involved in the continued growth and quiescence of the uterine myometrium. 相似文献
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Co-culture of ovine ova with oviductal cells in medium 199 总被引：7，自引：0，他引：7
Three experiments were conducted to test the suitability of medium 199 supplemented with 10% fetal calf serum (M199FCS) as a medium for co-culture of one-cell sheep ova with sheep oviductal cells. In Exp. 1, ova were co-cultured for 5 d in 5 ml of M199FCS or in Ham's F10 medium supplemented with 10% fetal calf serum (F10FCS). Co-culture did not increase the number of cleavages at the end of 5 d of culture, but M199FCS supported more cleavages than did F10FCS (P = .016). In Exp. 2, ova were cultured for 1 to 3 d in M199FCS alone or on oviductal, uterine or kidney cell monolayers from ewes 2 d postestrus and transferred to recipients from which they were recovered at 8 d postestrus. Co-culture with oviductal cells improved (P less than .001) the cleavage index of recovered embryos compared with culture in medium alone or co-culture with other cell types. In Exp. 3, monolayers of oviductal cells from ewes 2 d postestrus and from luteal-phase ewes were cultured as in Exp. 2. No difference was observed between the two sources of oviductal cells for their ability to support in vitro development of one-cell sheep eggs for 1 or 2 d. These studies suggest that M199FCS may be a good medium to use in an oviductal cell co-culture system for one-cell sheep ova. Results further suggest that specific secretions of oviductal cells may be important for early embryo development in vivo. 相似文献