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91.
The Sry (sex determining region on Y chromosome) gene is a master gene for sex determination. We previously reported that the Sry gene has tissue-dependent and differentially methylated regions (T-DMRs) by analyzing the DNA methylation states at CpG sites in the promoter regions. In this study, we found unique non-CpG methylation at the internal cytosine in the 5'-CCTGG-3' pentanucleotide sequence in the Sry T-DMR. This non-CpG methylation was detected in four mouse strains (ICR, BALB/c, DBA2 and C3H), but not in two strains (C57BL/6 and 129S1), suggesting that the CCTGG methylation is tentative and unstable. Interestingly, this CCTGG methylation was associated with demethylation of the CpG sites in the Sry T-DMR in the developmental process. A methylation-mediated promoter assay showed that the CCTGG methylation promotes gene expression. Our finding shows that non-CpG methylation has unique characteristic and is still conserved in mammals.  相似文献   
92.
对海水灌溉下Salicornia bigelovii的不同种植密度及其个体间的养分积累及土壤盐分的影响进行了调查。结果表明:单位面积地上部的干质量随种植密度增加呈平缓增高,符合最终产量恒定法则;个体间竞争株质量随种植密度增加而降低;随S.bigelovii种植密度的上升,土壤的含盐量和电导率(EC)值明显降低,56株/m2处理区钠的吸收量达261.22 g,在336株/m2处理区钠的吸收量高达489.99 g;随种植密度的增加,个体间的无机盐含量略有下降,但没有显著差异,相反茎、叶中碳和氮含量呈上升趋势。  相似文献   
93.
Multiple forms of the gonadotropin-releasing hormone (GnRH) exist in teleost fish. A salmonid fish, masu salmon Oncorhynchus masou has salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II). sGnRH neurons were scattered from the olfactory nerve through the ventral telencephalon (VT) and the preoptic area (POA). sGnRH but not cGnRH-II was detected in the pituitary. sGnRH mRNA levels in the VT and the POA increased during gonadal maturation, suggesting that sGnRH neurons in these areas are involved in gonadal maturation. sGnRH neurons were first detected in a cluster near the olfactory epithelium 40 days after fertilization. sGnRH neurons were not detected in the brain by the olfactory epithelia lesion, suggesting that sGnRH neurons are derived from the olfactory epithelium. A pleuronectiform fish, barfin flounder Verasper moseri has sGnRH, cGnRH-II and seabream GnRH (sbGnRH). sGnRH and cGnRH-II-immunoreactive fibers were observed throughout the brain, but not in the pituitary. sbGnRH neurons were located in the POA and sent fibers to the pituitary, indicating that sbGnRH is involved in GTH secretion. Judging from the location of neuronal somata and their projections, it is indicated that three GnRH systems exist in the barfin flounder; the TN-, the MT- and the POA-GnRH system. However, in masu salmon, clear anatomical identification of the TN- and the POA-GnRH system is difficult, because the GnRH neurons located in the ventral forebrain are consecutive and the GnRH form produced in these neurons is the same (sGnRH). Thus, it is suggested in masu salmon that sGnRH neurons are derived from the olfactory epithelium, migrate into the brain and play different roles according to the location in the brain.  相似文献   
94.
It is costly and time‐consuming to carry out dairy cattle selection on a large experimental scale. For this reason, sire and cow evaluations are almost exclusively based on field data, which are highly affected by a large array of environmental factors. Therefore, it is crucial to adjust for those environmental effects in order to accurately estimate the genetic merits of sires and cows. Index selection is a simple extension of the ordinary least squares under the assumption that the fixed effects are assumed known without error. The mixed‐model equations (MME) of Henderson provide a simpler alternative to the generalized least squares procedure, which is computationally difficult to apply to large data sets. Solution to the MME yields the best linear unbiased estimator of the fixed effects and the best linear unbiased predictor (BLUP) of the random effects. In an animal breeding situation, the random effects such as sire or animal represent the animal's estimated breeding value, which provides a basis for selection decision. The BLUP procedure under sire model assumes random mating between sires and dams. The genetic evaluation procedure has progressed a long way from the dam‐daughter comparison method to animal model, from single trait to multiple trait analysis, and from lactational to test‐day model, to improve accuracy of evaluations. Multiple‐trait evaluation appears desirable because it takes into account the genetic and environmental variance‐covariance of all traits evaluated. For these reasons, multiple‐trait evaluation would reduce bias from selection and achieve a better accuracy of prediction as compared to single‐trait evaluation. The number of traits included in multiple‐trait evaluation should depend upon the breeding goal. Recent advances in molecular and reproductive technologies have created great potential for quantitative geneticists concerning genetic dissection of quantitative traits, and marker‐assisted genetic evaluation and selection.  相似文献   
95.
The sterol 14α-demethylation inhibitors 1-(4-substituted phenoxymethyl)-2, 2-dimethylpropyl imidazole-1-carboxylates and their corresponding thiocarboxylates were optimized for maximum in-vitro activity against Botrytis cinerea Pers. ex Fr. in terms of the lipophilic parameter π. The activity of both carboxylates and thiocarboxylates was strongly related with π and predicted to be maximum at π 1.38 and 0.72 respectively. However, the preventive efficacy of the carboxylates against B. cinerea on Solanum melongena L. grown in a greenhouse did not correlate with the parameter. Despite the unfavourable lower lipophilicity, compounds with p-alkoxy substituents were superior to those with any other substituent. Moreover, the p-methoxy-substituted thiocarboxylate 46 was much less effective in greenhouse tests than the corresponding carboxylate 15, despite their equivalent in-vitro activity. To clarify these discrepancies, hydrolytic and photolytic stabilities of several representative compounds including 15 and 46 were investigated. The carboxylates examined were much more labile to hydrolysis than the thiocarboxylate 46; however, the four thiocarboxylates studied were less stable to light than the carboxylates. Consequently, the above discrepancies were attributable mainly to the superior stability of the carboxylates to photolysis as compared to the thiocarboxylates.  相似文献   
96.
Among the many mycotoxins, T-2 toxin, citrinin (CTN), patulin (PAT), aflatoxin B1 (AFB1) and ochratoxin A (OTA) are known to have the potential to induce dermal toxicity and/or tumorigenesis in rodent models. T-2 toxin, CTN, PAT and OTA induce apoptosis in mouse or rat skin. PAT, AFB1 and OTA have tumor initiating properties, and OTA is also a tumor promoter in mouse skin. This paper reviews the molecular mechanisms of dermal toxicity and tumorigenesis induced in rodent models by these mycotoxins especially from the viewpoint of oxidative stress-mediated pathways.  相似文献   
97.
Variety in histochemical characteristics of the olfactory receptor cells (ORC) was examined by immunohistochemistry for protein gene product 9.5 (PGP9.5) and calretinin, and by lectin histochemistry with Phaseolus vulgaris leucoagglutinin (PHA-L) in the olfactory epithelium (OE) of the barfin flounder (Verasper moseri). PGP 9.5 immunoreactivity was observed in the ORC situated in the upper three fourths of the OE. Calretinin immunoreactivity was observed in the ORC which seemed to be immunonegative for PGP 9.5. These cells were located in the upper two thirds of the OE. PHA-L staining was observed in small subsets of the ORC. PGP 9.5 and calretinin immunoreactivities and PHA-L staining were also observed in the crypt cells unique to the fish OE. These findings suggest the different properties of olfactory perception among fish ORC.  相似文献   
98.
Morphogenesis of the olfactory pit (OP), olfactory lamella (OL) and olfactory epithelium (OE) was examined by scanning electron and light microscopy in the barfin flounder (Verasper moseri). At day 0 after hatch, the OP was already formed. At day 14, the cellular differentiation of the OE was prominent. At day 42, the OP became a cavity by the formation of its roof. At day 56, the first OL extended remarkably and was lined with the OE on both sides. The OL increased in number with development. These findings suggest that the OE is functionally active at day 14. The formation of the OL in the OP may be initiated by the stimulus when the barfin flounder touched at the bottom of the sea.  相似文献   
99.
Forelimb‐girdle muscular anomaly is a hereditary disorder of Japanese Black cattle characterized by tremors and astasia caused by hypoplasia of the forelimb‐girdle muscles. The locus responsible for this disorder has been mapped on a middle region of bovine chromosome 26. In this study, we applied marker‐assisted selection to identify the carriers of this disorder. Four microsatellite markers, DIK4440, BM4505, MOK2602 and IDVGA‐59, linked to the disorder locus were genotyped in 37 unaffected offspring of a carrier sire. Transmission of the mutant or wild‐type allele of the disorder locus of the sire to the 37 offspring was determined by examining the haplotypes of these markers. The results showed that nine and 18 of the 37 animals possessed the paternally transmitted mutant and wild‐type alleles, respectively, and therefore, the nine animals with the mutant allele were identified as carriers. We concluded that the marker‐assisted selection using these four markers can be applied for the identification of the carriers of forelimb‐girdle muscular anomaly of Japanese Black cattle.  相似文献   
100.
Applicability of gaseous treatment with allyl isothiocyanate (AIT) was evaluated for controlling the established microbial infestation of wood in the laboratory. Small sapwood specimens from five wood species measuring 20 mm (T)×20 mm (R)×10 mm (L) were first preincubated on 2% malt-agar medium with placing them on a fully grown monoculture of seven test fungi. After 7 weeks of preincubation they were transferred to fresh medium and exposed to AIT fumigant at concentrations of 2360 and 23600ppm AIT in the air of a petri dish to determine threshold values of exposure periods for each test fungus. The 2360 ppm concentration was not effective forPenicillium funiculosum, Gliocladium virens, orRhizopus stolonifer for any of the wood species-exposure period combinations. Those test fungi could grow even at 23600ppm after 48h exposure whenCryptomeria japonica andFagus crenata were used as wood substrate. Growth of other test fungi was inhibited at 2360ppm with a few exceptions in the case ofAspergillus niger. The required periods of exposure to suppress microbial regrowth were different with wood species-test fungi combinations. As two wood-decaying basidiomycetes,Trametes versicolor andFomitopsis palustris, were easily controlled at 2360ppm after 24h exposure regardless of wood species, AIT treatment proved applicable to the control of internal decay of utility poles and other relevant products in service.  相似文献   
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