应用Y染色体SNP对新疆三个隔离人群遗传多样性的研究

克里雅人、罗布人、刀郎人是生活在我国西部边疆沙漠腹地、人口稀少的隔离人群。基于对这三个隔离人群179人Y染色体全序列的测序和分型,得到每个个体Y染色体所有突变的SNP位点和隶属的单倍群,并对各单倍群类型和频率进行了分析。以探知三个隔离人群的Y染色体遗传结构和遗传多样性。通过研究结果表明:克里雅人群检出12个单倍群,高频单倍群有J2a1b1(25.64%),R1a1a1b2a(20.51%),R2a(17.95%),R1a1a1b2a2(15.38%);罗布人群检出16个单倍群,高频单倍群有J2a1(43.75%),J2a2(14.06%),R2(9.38%),L1c(7.81%);刀郎人群检出40个单倍群,高频单倍群有R1b1a1a1(9.21%),R1a1a1b2a1a(7.89%),R1a1a1b2a2b(6.58%),C3c1(6.58%).三个隔离人群与维吾尔族、蒙古族、撒拉族亲缘关系较近;在单倍群类型和频率上与维吾尔族最接近且无显著性差异(f=0.833,p=0.367)。此外,三个隔离人群单倍群类型和频率显示明显的亚欧混合现象,经过长期基因融合使其具有中亚人群的典型特征,适用于法医遗传学。     

Natural occurrence of free fatty aldehydes in bovine cardiac muscle

Free fatty acids, aldehydes, alcohols, and 1-O-alkyl and alk-1-enyl glycerols were identified and quantified in lipid extracts from bovine cardiac muscle. Although a number of components present in the free fatty aldehydes were also noted in the fatty chains in the 1-O-alk-1-enyl glycerols, a direct qualitative similarity did not exist as would be expected if the free fatty aldehydes were artifactual in origin. Also, a qualitative similarity did not exist between the fatty chains of the 1-O-alkyl and alk-1-enyl glycerols. This latter observation would suggest a mechanism other than biodehydrogenation of the alkyl ethers for the origin of the alk-1-enyl glycerols. Free fatty aldehydes were distributed evenly between the 105,000 g supernatant and particulate fractions of cardiac muscle, while the 1-O-alk-1-enyl glycerols were associated primarily with the particulate fraction. Free fatty alcohols were noted only in the supernatant fraction, while the 1-O-alkyl glycerols were present in both fractions.     

Isolation of two forms of activated C1s, a subcomponent of the first component of rabbit complement.

Two forms of activated C1s, a subcomponent of the first component of complement, were present in preparations of C1 specifically purified from rabbit serum by affinity chromatography on IgG-Sepharose 6B and were separated by DEAE-cellulose chromatography in the presence of EDTA. These two activated C1s, designated C1s(I) and C1s(II), were indistinguishable with regard to hemolytic activity as well as C1s esterase activity, though they had different molecular weights. C1s(I) had a molecular weight of 106,000, consisting of H and L chains connected by disulfide bonds; the molecular weights of the chains were 70,000 and 36,000, respectively. On the other hand, C1s(II), with a molecular weight of 72,000, consisted of two chains each with a molecular weight of about 37,000, which were also connected by disulfide bonds. These results suggest that, in the case of rabbit C1s, the primary product of activation with C1r, C1s(I), may be susceptible to further cleavage of its H chain without any loss of C1s activity, resulting in the formation of C1s(II), though the active principle responsible for this conversion remains to be elucidated.     

Cryoenzymic studies on actomyosin ATPase. Evidence that the degree of saturation of actin with myosin subfragment 1 affects the kinetics of the binding of ATP

The initial steps of actomyosin subfragment 1 (acto-S1) ATPase (dissociation and binding of ATP) were studied at -15 degrees C with 40% ethylene glycol as antifreeze. The dissociation kinetics were followed by light scattering in a stopped-flow apparatus, and the binding of ATP was followed by the ATP chase method in a rapid-flow quench apparatus. The data from the chase experiments were fitted to E + ATP in equilibrium (K1) E.ATP----(k2) E*ATP, where E is acto-S1 or S1. The kinetics of the binding of ATP to acto-S1 were sensitive to the degree of saturation of the actin with S1. There was a sharp transition with actin nearly saturated with S1: when the S1 to actin ratio was low, the kinetics were fast (K1 greater than 300 microM, k2 greater than 40 s-1); when it was high, they were slow (K1 = 14 microM, k2 = 2 s-1). With S1 alone K1 = 12 microM and k2 = 0.07 S-1. With acto heavy meromyosin (acto-HMM) the binding kinetics were the same as with saturated acto-S1, regardless of the HMM to actin ratio. The dissociation kinetics were independent of the S1 to actin ratio. Saturation kinetics were obtained with Kd = 460 microM and kd = 75 S-1. The data for the saturated acto-S1 could be fitted to a reaction scheme, but for lack of structural information the abrupt dependence of the ATP binding kinetics upon the S1 to actin ratio is difficult to explain.(ABSTRACT TRUNCATED AT 250 WORDS)     

47份外引小麦种质资源Waxy和HMW-GS分子检测与品质性状分析

为有效利用外引小麦种质资源,本研究对收集的47份外引小麦种质材料进行Waxy和HMW-GS等位基因的分子检测,并分析了其直链淀粉、支链淀粉、湿面筋等品质参数.结果 表明,在Wx-A1位点存在3种类型:Wx-A1a、Wx-A1g和Wx-A1b,39份材料(82.98％)为Wx-A1a类型;Wx-B1位点3种类型:Wx-B...     

Structures of the O-linked oligosaccharides of the major cell surface sialoglycoprotein of MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma

Structures of the principal O-glycosides from the major cell surface sialoglycoprotein (ASGP-1) of the MAT-B1 and MAT-C1 ascites sublines of the 13762 rat mammary adenocarcinoma have been determined. Oligosaccharitols were released by alkaline borohydride treatments of ASGP-1 and purified by gel filtration, DEAE-Sephadex ion exchange chromatography, and high performance liquid chromatography. On the basis of carbohydrate composition, methylation analysis, periodate oxidation, and exoglycosidase digestion, the five major oligosaccharides released by mild alkaline borohydride were assigned the following structures: Component II-3: (NeuAc alpha 2----3Gal beta 1----4GlcNAc beta 1----6)Ga 1 NAcOH(3----1 betaGa 1 3----2 alpha NeuAc) III-2a: (Ga 1 beta 1----4G1cNAc beta 1----6)Ga 1 NAcOH(3----1 beta Ga 1 3----2 alpha NeuAc) III-2c: (Ga 1 alpha 1----3Ga 1 beta 1----4G1cNAc beta 1----6) Ga 1 NAcOH(3----1 beta Ga 1 3----2 alpha NeuAc) IV-1a: (Ga 1 beta 1----4G 1 cNAc beta 1----6)Ga 1 NAcOH(3----1 beta Ga 1) IV-1c: (Ga 1 alpha 1----3Ga 1 beta 1----4G 1 cNAc beta 1----6) Ga 1 NAcOH(3----1 beta Ga 1) Fucosylated derivatives of III-2a, IV-1a, and IV-1c were found in smaller amounts with the fucose tentatively assigned to the 2-position of the lactosamine galactose. Components II-3, III-2a, and the fucosylated derivative of III-2A were found in both MAT-B1 and MAT-C1 sublines. The alpha-galactosides were found in detectable quantities only in subline MAT-B1. Oligosaccharides from MAT-C1 cells were enriched in sialic acid when compared to those from MAT-B1 cells. These results suggest that the 13762 ascites sublines, which bear different oligosaccharides, will provide models useful for the investigation of mechanisms regulating the expression of structures of the larger O-linked oligosaccharides.     

Antibody-independent activation of C1. II. Evidence for two classes of nonimmune activators of the classical pathway of complement

Nonimmune activation of the first component of complement (C1) by cardiolipin (CL) vesicles present specific features which were not demonstrated on immune complexes. CL vesicles which activate C1 in the presence of C1-inhibitor (C1-INH) were found to bind C1s in the absence of C1r, and to induce a specific C1r-independent cleavage of C1q-bound C1s. Therefore, several known natural nonimmune activators were analyzed by comparing their ability to activate C1 in the presence of C1-INH and to mediate a C1r-independent cleavage of C1s. Freshly isolated human heart mitochondria (HHM) activated C1 only in the absence of C1-INH. However, mitoplasts derived from HHM (HHMP) activated C1 regardless of the presence of C1-INH, and induced a specific cleavage of C1q-bound C1s. The same pattern was observed in the case of smooth E. coli and a semi-rough E. coli strain. DNA, known to activate C1 only in the absence of C1-INH, does not induce C1s cleavage in the absence of C1r. Thus, nonimmune activators can be classified into two distinct categories. "Strong" activators, such as CL vesicles, HHMP, or the semi-rough E. coli strain J5 can activate C1 in the presence of C1-INH. By using C1qs2 as a probe, they exhibit a specific, C1r-independent cleavage of C1s. C1s-binding to C1q is a critical factor for the activation process in this group. In the case of "weak" activators, such as E. coli smooth strains, DNA, or HHM, no C1s-binding to activator-bound C1q was detected, and C1r-independent C1s cleavage and C1 activation in the presence of C1-INH were not observed. As in the case of immune complexes, C1r activation appears to play a key role in the C1 activation by "weak" activators.     

Retardation of removal of radiation-induced apoptotic cells in developing neural tubes in macrophage galactose-type C-type lectin-1-deficient mouse embryos

MGL1/CD301a is a C-type lectin that recognizes galactose and N-acetylgalactosamine as monosaccharides and is expressed on limited populations of macrophages and dendritic cells at least in adult mice. In this study, pregnant mice with Mgl1+/- genotype were mated with Mgl1+/- or Mgl1-/- genotype males, and the embryos were used to assess a hypothesis that this molecule plays an important role in the clearance of apoptotic cells. After X-ray irradiation at 1 Gy of developing embryos at 10.5 days post coitus (d.p.c.), the number of Mgl1-/- pups was significantly reduced as compared with Mgl1+/+ pups. Distributions of MGL1-positive cells, MGL2-positive cells, and apoptotic cells were histologically examined in irradiated Mgl1+/+ embryos. MGL1-positive cells were detected in the neural tube in which many cells undergo apoptosis, whereas MGL2-positive cells were not observed. Biotinylated recombinant MGL1 bound a significant portion of the apoptotic cells. When Mgl1+/+ and Mgl1-/- embryos were examined for the presence of apoptotic cells, similar numbers of apoptotic cells gave rise, but the clearance of these cells was slower in Mgl1-/- embryos than in Mgl1+/+ embryos. These results strongly suggest that MGL1/CD301a is involved in the clearance of apoptotic cells. This process should be essential in the repair and normal development of X-ray-irradiated embryos.     

Kinetics of action of chymosin (rennin) on some peptide bonds of bovine beta-casein

The first steps of proteolysis of bovine beta-casein by chymosin were studied quantitatively by using reverse-phase high-performance liquid chromatography (RP-HPLC). Although chymosin has a broad specificity, it has been possible to selectively study the hydrolysis of two bonds (Ala-189-Phe-190 and Leu-192-Tyr-193) by choosing appropriate conditions. The disappearance of the substrate and the appearance of the reaction products as a function of time were followed at 220 nm by RP-HPLC. For concentrations where beta-casein was in a micellar form, the Michaelian parameters corresponding to the cleavage of bond 192-193 were determined by measuring initial rates of reaction at different substrate concentrations in a time period for which splitting of bond 189-190 was negligible. The following results were obtained; k1cat = 1.54 s-1, K1m = 0.075 mM, and k1cat/K1m = 20.6 mM-1 s-1. Under conditions where the protein was in a monomeric state, the following parameters were determined for the splitting of bond 192-193 by integrating the Michaelis equation: k2cat = 0.056 s-1, K2m = 0.007 mM, and k2cat/K2m = 79.7 mM-1 s-1. Under the latter conditions the four enzymic reactions involved in the cleavage of bonds 189-190 and 192-193 were first-order reactions. The four corresponding apparent rate constants were calculated by using a computer program. Excellent agreement was obtained between concentrations of four molecular species measured during the reaction period and those calculated by using the four apparent rate constants.     

Occurrence of Lewis a epitope in N-glycans of a glycoallergen, Jun a 1, from mountain cedar (Juniperus ashei) pollen

We have determined the structures of N-glycans linked to major allergens in the mountain cedar (Juniperus ashei) pollen, Jun a 1. First, two kinds of the pollen glycoallergen (Jun a 1-A and Jun a 1-B) were purified from partially purified Jun a 1 by cation exchange chromatography. The N-glycans were liberated by hydrazinolysis from the two glycoallergens and the resulting sugar chains were N-acetylated and then coupled with 2-aminopyridine. Three pyridylaminated sugar chains were purified by reversed-phase HPLC and size-fractionation HPLC from Jun a 1-A and Jun a 1-B respectively. The structures were determined by a combination of exo- and endo-glycosidase digestions, two dimensional sugar chain mapping, and electrospray ionization mass spectrometry (ESI-MS) analysis. Structural analysis indicated that Lewis a epitope (Galbeta1-3(Fucalpha1-4)GlcNAcbeta1-) occurs in the N-glycans of the pollen allergens.     

Effects of copper sulphate on in vitro encystment of the cercariae of Echinostoma caproni

The effects of various concentrations of copper sulphate were studied on in vitro encystment of Echinostoma caproni in a Locke's-artificial spring water (ASW) (1:1) medium. Cercariae were killed in 10,000 mg l(-1) CuSO4 in Locke's-ASW (1:1) within 24 h and extruded cystogenous material to produce an abnormal cyst wall. The 'emergency response' of encystment to high concentrations of copper reported for Parorchis acanthus cercariae did not occur in E. caproni. Concentrations of 1000 mg l(-1) and 100 mg l(-1) CuSO4 in Locke's-ASW (1:1) also killed the cercariae without encystment by 48 h. A concentration of 10 mg l(-1) CuSO4 in Locke's-ASW (1:1) allowed for normal in vitro encystment within 48 h and these cysts were capable of excystation in a trypsin-bile salts medium.     

Isolation and characterization of cDNA clones corresponding to the genes expressed preferentially in floral organs of Arabidopsis thaliana

Seventeen cDNA clones of genes corresponding to mRNAs expressed preferentially in floral organs of Arabidopsis thaliana were obtained by differential screening of a flower bud cDNA library, and classified into five groups (1A, 17A, 1B, 4B and 5B) by cross-hybridization and restriction analysis. Sequence analysis revealed that the 1A-1 and 17A-1 clones encode vegetative storage proteins (VSPs). The VSP mRNAs were detected in a small amount in leaves and increased to a limited level by wounding. Both 1B-1 and 5B-1 clones were homologous to transmembrane protein cDNAs. The protein encoded by 4B-1 clone contained a proline-rich region, but no homologous proteins were found in databases.     

Diurnal expressions of four subtypes of melatonin receptor genes in the optic tectum and retina of goldfish

Four subtypes of melatonin receptor genes (Mel(1a) 1.4, Mel(1a) 1.7, Mel(1b), and Mel(1c)) are considered to be expressed to mediate various physiological functions of melatonin in goldfish (Carassius auratus). To examine their tissue distribution and diurnal changes in expression levels, we cloned partial gene fragments for these melatonin receptor subtypes, and established specific RT-PCR and quantitative real-time PCR systems. Mel(1a) 1.4 and Mel(1b) were predominantly expressed in various neuronal and peripheral tissues, while Mel(1a) 1.7 and Mel(1c) were expressed in the restricted tissues. All subtype genes were expressed in the optic tectum, diencephalon, mesencephalon, vagal lobe, retina and spleen. The real-time PCR analyses showed that significant differences among time were observed for Mel(1a) 1.4 in the optic tectum and for Mel(1a) 1.7 and Mel(1b) in the retina. In the retina, the levels of Mel(1a) 1.7 and Mel(1b) mRNAs showed diurnal changes with one peak at ZT24. The present results show differential distribution of four subtypes of melatonin receptor mRNAs in the neuronal and peripheral tissues. However, the expressions of all subtype genes in the retinorecipient brain regions and retina reinforce the role of the melatonin receptor in processing visual information. Furthermore, the present study demonstrates diurnal expressions of the major subtype genes, i.e. Mel(1a) 1.4 in the optic tectum and Mel(1a) 1.7 in the retina.     

Generation of a conditional null allele of Lbx1

The homeobox gene Lbx1 not only plays critical roles in myogenesis and neurogenesis during embryonic development but is also expressed in activated satellite cells of adult mice. To address the potential postnatal functions of Lbx1, we generated conditional Lbx1-null mice using the Cre-loxP system. We generated a mouse in which Exon 2 of Lbx1 was floxed (Lbx1flox/flox), followed by cross-breeding between the Lbx1flox/flox mouse and either a transgenic mouse where a tamoxifen-inducible Cre-recombinase (Cre) was ubiquitously expressed, or a Myf5Cre mouse where Cre was inserted into the Myf5 locus. In both Lbx1-null mouse lines generated, Pax3-expressing limb muscle precursor cells were seriously reduced during embryonic development and eventually the limb extensor muscles were lost after birth. Since the conditional Lbx1-null mice generated were viable for a prolonged time, they will be useful in the investigation of Lbx1 function throughout the lifespan of the mouse.     

Transient kinetics of the interaction of actin with myosin subfragment-1 in the absence of nucleotide.

The kinetics of the association of actin with myosin subfragment-1 (S1) has been studied by using S1 labeled at the sulfhydryl group SH1 with 5-(iodoacetamido)fluorescein (S1-AF). Upon rapid mixing in a stopped-flow apparatus, the fluorescence intensity of the fluorescein moiety increased by 50%, followed by a slower increase that was well resolved. This slow phase of the fluorescence change could not be fitted to either a monoexponential or a biexponential function, but it could be fitted to a sum of three exponential terms yielding three observed first-order rate constants (lambda i). The dissociation of acto.-(S1-AF) was studied by displacement of S1-AF from the complex with native S1. The dissociation kinetics was characterized by a single rate constant (approximately 0.012 s-1 at 20 degrees C), and this constant was independent of S1 concentration. Together with previous equilibrium data that were obtained under identified conditions for formation of acto-subfragment-1 (Lin, S.-H., and H. C. Cheung. 1991. Biochemistry. 30:4317-4323), a six-state two-pathway model is proposed as a minimum kinetic scheme for formation of rigor acto.S1. In this model, unbound subfragment-1 exists in two conformational states (S1' and S1) which are in equilibrium with each other, one corresponding to the previously established low-temperature state and the other to the high-temperature state. Each subfragment-1 state can interact with actin to form a collision complex, followed by two isomerizations to form two acto-subfragment-1 states (A.S1' and A.S1). Both isomerizations were visible in stopped-flow experiments. Two special cases of the model were considered: 1) a rapid pre-equilibration of the initial collision complex with actin and S1, and 2) trace accumulation of the collision complex. The first case required that the three combinations of the three observed rate constants be independent of actin concentration. The data were incompatible with this approximation. The other special case required that the sum of the lambda i vary linearly with actin concentration and the other two combinations of lambda i vary with actin concentration in a quadratic fashion. The present data were in agreement with the second case. At 20 degrees C and in 60 mM KCl, 2 mM MgCl2, 30 mM 2-([-hydroxy-1,1-bis(hydroxymethyl)ethyl]amino)ethanesulfonic acid, and pH 7.5, the biomolecular association rate constants for the interaction of actin with S1' and S1 were 8.58 x 10(5) and 1.11 x 10(6) M-1 s-1, respectively.     

Effect of nephrectomy and of adrenergic receptor blockers on the cardiorenal actions of endothelin

The cardiorenal actions of endothelin-1 (ET-1) were evaluated in rats following nephrectomy, in rats during alpha-adrenergic blockade with phentolamine, and in rats during beta-adrenergic blockade with propranolol. Female rats were anesthetized with pentobarbital and, following surgery, were allowed 60 min to stabilize before 3 x 20 min-control clearances were collected. ET-1 was then infused at a rate of 100 ng kg-1 min-1 for 30 min, the infusion was stopped, and three additional clearances were collected. Four groups of rats were studied: in Group 1 (n = 10), ET-1 was infused; in Group 2 (n = 5), a bilateral nephrectomy was performed 120 min before infusing ET-1; in Group 3 (n = 5), ET-1 was infused into rats treated with phentolamine (0.015 mg kg-1 min-1); and in Group 4 (n = 5), ET-1 was infused into rats treated with propranolol (0.015 mg kg-1 min-1). At 30 min during infusion of ET-1 into Group 1 rats, mean arterial blood pressure had increased (P less than 0.01) by 27 +/- 2% (SE) and the glomerular filtration rate had decreased (P less than 0.01) by 71 +/- 6% of baseline values. Nephrectomy potentiated and prolonged the ET-1-induced systemic vasoconstriction. Phentolamine had no effect on the cardiorenal actions of ET-1 whereas propranolol enhanced ET-1-induced changes in mean arterial blood pressure; mean arterial blood pressure increased 38 +/- 2% at 30 min during ET-1 + propranolol infusion (P less than 0.01 versus value with ET-1 alone). These data indicate that the kidney affects ET-1-induced systemic vasoconstriction and that beta-adrenergic (but not alpha-adrenergic) receptors are activated during infusion of ET-1 with a resultant attenuation of ET-1-induced changes in systemic blood pressure.     

Characterization of Glycogen-Deficient Glc Mutants of Saccharomyces Cerevisiae

Forty-eight mutants of Saccharomyces cerevisiae with defects in glycogen metabolism were isolated. The mutations defined eight GLC genes, the functions of which were determined. Mutations in three of these genes activate the RAS/cAMP pathway either by impairment of a RAS GTPase-activating protein (GLC1/IRA1 and GLC4/IRA2) or by activating Ras2p (GLC5/RAS2). SNF1 protein kinase (GLC2) was found to be required for normal glycogen levels. Glycogen branching enzyme (GLC3) was found to be required for significant glycogen synthesis. GLC6 was shown to be allelic to CIF1 (and probably FDP1, BYP1 and GGS1), mutations in which were previously found to prevent growth on glucose; this gene is also the same as TPS1, which encodes a subunit of the trehalose-phosphate synthase. Mutations in GLC6 were capable of increasing or decreasing glycogen levels, at least in part via effects on the regulation of glycogen synthase. GLC7 encodes a type 1 protein phosphatase that contributes to the dephosphorylation (and hence activation) of glycogen synthase. GLC8 encodes a homologue of type 1 protein phosphatase inhibitor-2. The genetic map positions of GLC1/IRA1, GLC3, GLC4/IRA2, GLC6/CIF1/TPS1 (and the adjacent VAT2/VMA2), and GLC7 were clarified. From the data on GLC3, there may be a suppression of recombination near the chromosome V centromere, at least in some strains.     

Processing of Nonstructural Protein 1a of Human Astrovirus

Astrovirus contains three open reading frames (ORF) on its genomic RNA, ORF1a, ORF1b, and ORF2. ORF1a encodes a 920-amino-acid (aa) nonstructural protein, nsP1a, which displays a 3C-like serine protease motif. Little is known about the processing of nsP1a or whether the protease it contains is active and involved in autocatalytic processing. Here we address both of these matters. Intact and N-terminally deleted forms of ORF1a from human astrovirus serotype 1 were expressed in BHK cells, and nsP1a-derived processing products were immunoprecipitated with an nsP1a-specific antibody or an antibody specific for an N-terminally linked epitope tag. The mapping of the main processing products, p20 and p27, suggests cleavage sites near aa 170, 410, and 655 of nsP1a. Cleavages at around aa 410 and 655, but not aa 170, were abolished when a 9-aa substitution was introduced into the protease motif in nsP1a. The p27 processing product was also found in Caco-2 cells that had been infected with human astrovirus serotype 1, confirming the presence of the cleavage sites at approximately aa 410 and 655.     

Genetic profile of LIBP/1 inbred strain derived from the Kunming outbred stock of the mouse]

To make the genetic profile of the LIBP/1 inbred strain obtained from Kunming mice, the most widely used outbred stock in China, 26 loci were examined. The genotypes of four kinds of coat color genes were a/a, B/B, c/c and D/D. The results of testing 21 biochemical marker genes showed Akp-1b, Amy-1a, Car-2a, Ce-2a, Es-1b, Es-3a, Es-10a, Es-11a, Gpd-1a, Gpi-1a, Gus-1b, Hbbs, Idh-1a, Ldr-1a, Mod-1a, Mup-1b, Pep-3b, Pgm-a, Sep-1b, Tam-1c, and Trfb. The H-2 gene loci were Kb and Db.