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1.
There are important genetic influences on the tendency to dizygotic (DZ) twinning and it is a plausible hypothesis that these reside in one or more of the genes coding for the major reproductive hormones. We used Southern analysis of DNA from 50 young (<32) mothers of DZ twins, who also had a family history of DZ twinning, and 50 controls, to examine allele frequencies of five restriction fragment length polymorphisms (RFLPs) in four hormone genes coding for follicle stimulating hormone (FSH), chorionic gonadotropin (CGB), inhibin B and gonadotropin releasing hormone (GnRH). Comparison of allele frequencies revealed no significant differences between DZ twin mothers and controls. However this does not rule out the role of these genes in the hereditary tendency of multiple ovulation in humans, since absence of linkage disequilibrium does not imply absence of linkage.  相似文献   

2.
Summary Homology maps between bacteriophages 81, 80 and were constructed on the basis of electron microscope observation of DNA heteroduplexes. In 81/80 heteroduplex, the left half and the right terminal region of 13% the total molecular length were highly homologous, while the remaining region covering the early gene cluster was entirely nonhomologous. In 81/ heteroduplex, high-degree homologies were detected at the left 14% terminal region covering the head gene cluster, the central 3.8% region covering the att-int-xis region and the 1.3% Q homology region. Low-degree homologies of shorter length were scattered at the tail gene cluster, b2 region, cIII region, PQ region and SR region. Comparing our results with the homology maps of other lambdoid phages reported by Simon et al. (1971) and Fiandt et al. (1971), a phylogenic relation of 81 to other lambdoid phages and the role of recombination in the course of divergence of lambdoid phages are discussed.  相似文献   

3.
Summary The crystallins are highly conserved structural proteins universally found in the eye lens of all vertebrate species. In mammals, three immunologically distinct classes are present, -, -, and -crystallins, and each class represents a multigene family. The -crystallin gene family consists of 1-crystallin (CRYA1) and 2-crystallin (CRYA2) genes (previously designated A-and B-crystallin, respectively), which show extensive sequence homology. We constructed a synthetic oligonucleotide probe of 25 bases corresponding to a specific region of the human 1-crystallin gene sequence. This 25-mer probe bears little sequence homology to human 2-crystallin gene and does not cross-hybridize to 2-crystallin sequences in Southern blot analysis. Using this unique synthetic probe, we have demonstrated the identity of the 1-crystallin gene in human genomic DNA. In addition, we have also confirmed its chromosomal location on human chromosome 21. Finally, we have regionally localized the gene to q22.3 by using both Southern blot analysis of a panel of cell hybrids containing different parts of human chromosome 21, and in situ hybridization to metaphase chromosomes. The use of synthetic oligonucleotide probes specific for individual genes should be useful in identifying and mapping members of multigene families.  相似文献   

4.
This study reports a novel splice variant form of the voltage-dependent calcium channel 2 subunit (2g). This variant is composed of the conserved amino-terminal sequences of the 2a subunit, but lacks the -subunit interaction domain (BID), which is thought essential for interactions with the 1 subunit. Gene structure analysis revealed that this gene was composed of 13 translated exons spread over 107 kb of the genome. The gene structure of the 2 subunit was similar in exon-intron organization to the murine 3 and human 4 subunits. Electrophysiological evaluation revealed that 2a and 2g affected channel properties in different ways. The 2a subunit increased the peak amplitude, but failed to increase channel inactivation, while 2g had no significant effects on either the peak current amplitude or channel inactivation. Other subunits, such as 3 and 4, significantly increased the peak current and accelerated current inactivation.  相似文献   

5.
Preincubation of lymphocytes with des-Tyr1--endorphin (DTE) inhibits the reaction between some HLA alloantisera and their corresponding antigens. One HLA-A2-specific antiserum was found which could detect a subtype of the HLA-A2 antigen on DTE-treated lymphocytes from some donors. Comparison with the HLA-A2 subtypes as defined by a combination of cytotoxic T lymphocyte typing and biochemistry showed a complete correlation with the previously described HLA-A2.3 subtype.  相似文献   

6.
In the present report, we used serological, cellular, and restriction fragment length polymorphism (RFLP) to investigate the DR1 haplotype in the Israeli population. We describe an Israeli homozygous typing cell (HTC), HLA-DwLVA, which defines a new lymphocyte-activating determinant associated with Bw65, DR1 and distinct from Dwl. The parents of this donor, non-Ashkenazi Algerian Jews, are first cousins and share HLA-Cw8, Bw65, BfS, DR1, DQw1, DPw4. No specificity could be assigned to HLA-DwLVA using the 91 Ninth Workshop HTCs. Two families and forty unrelated DR1 individuals were studied with DwLVA and a panel of DR1/Dw1 HTCs. HLA-DwLVA showed segregation as a single determinant within families. This new specificity was present in 24 out of 40 (60%) unrelated DR1 individuals, indicating that in the Israeli population DwLVA is the main lymphocyte-defined determinant associated with the serologically defined DRI specificity, in contrast to non-Jewish Caucasoids where DR1 is significantly associated with Dw1. The vast majority of DwLVA-positive carriers were also Bw65 carriers, indicating that Bw65, DR1, DwLVA may represent a typical allele combination in the Israeli population. The RFLP analysis established the correlation of certain RFLPs with Dw1 and DwLVA. In addition, we describe a cluster of RFLPs that may correspond to a new Dw subtype associated with DR1, for which no serological and cellular reagents have been described so far.  相似文献   

7.
In experiments on sexual competition in Drosophila melanogaster, the course of mating succes with time is represented by a sigmoid curve. By logarithmic transformation such curves are changed into straight lines that can be compared by covariance analysis. This method allows discrimination of the behaviour of the two types in competition, and allows us to follow it in the course of time. From a sexual competition experiment between the wild type Canton S and the mutant white-ebony we conclude that sexual activity of males and females of both types is generally frequency dependent, with evidence of rare-female advantage as well as rare-male advantage.  相似文献   

8.
Zur Brutbiologie des Seggenrohrs?ngers(Acrocephalus paludicola)   总被引:1,自引:1,他引:0  
Zusammenfassung In der vorliegenden Arbeit werden Beobachtungen ausgewertet, die in den letzten Jahren in einer Seggenrohrsängerpopulation der Mark Brandenburg gesammelt wurden. Brutbiotop ist eine Großseggenwiese. und haben getrennte Reviere, wobei sich -Reviere, -Reviere und auch - und -Reviere zum Teil sehr erheblich überlagern. Keinem konnte ein bestimmtes zugeordnet werden, sie leben also in Keinehe. versuchen, aus der Nestnähe zu vertreiben. Aggressive Handlungen zwischen benachbarten konnten nicht festgestellt werden. Ihre Singflüge unterscheiden sich von denen der Schilfrohrsänger. 28 Eier maßen im Durchschnitt 17,76×13,14 mm. Nur die brüten und Füttern. Die durchschnittliche Fütterungsfrequenz liegt bei 19,7 Fütterungen pro Stunde, die tägliche Aktivitätszeit der ist im Juli etwa 1 Stunde kürzer als im Juni. 13–14 Tage nach dem Schlüpfen verlassen die Jungen das Nest. In der Nestlingsnahrung ist bei Julibruten der hohe Heuschreckenanteil auffällig. Nachdem die Jungen selbständig sind, streunen sie im Brutbiotop umher. Zweitbruten sind sehr wahrscheinlich, konnten aber noch nicht nachgewiesen werden.
Summary Observations made during the last years on a population of the Aquatic Warbler (Acrocephalus paludicola) in Brandenburg, Germany, gave the following results:In a sedge meadow, withCarex elata the dominant species, males and females ofAcrocephalus paludicola held separate territories, those of males as well of females sometimes considerably overlapping territories held by other individuals of the same or the opposite sex. In no case a certain male could be considered as having formed a firm pair bond with a certain female: on the contrary, the relations between the sexes were very loose, and probably the birds are even promiscuous. Females try to chase away males from the neighbourhood of their nests. Aggressiveness between neighbouring males has not been observed. The display flights of the males are different from those of the Sedge Warbler(A. schoenobaenus). 28 eggs measure on the average 17,76×13,14 mm. Females alone incubate and feed the young, at an average rate of 19,7 times per hour. The young leave the nest 13–14 days after hatching. Young reared in July are fed a great amount of grasshoppers. Second broods probably occur, but could not be proved.
  相似文献   

9.
Summary The possible genetic linkage between HLA and neuraminidase deficiency was studied in a female patient with combined abnormalities of the infantile form of sialidosis type II and congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, and six members of her family. Her parents were consanguineous. The patient has the homozygous HLA haplotypes, TS-1, Cw3, DRw9. Four of the tested family members, including a distant male relative with congenital adrenal hyperplasia, were heterozygous of this HLA complex, and the neuraminidase activities in their skin fibroblasts and/or lymphocytes showed values between those of the patient and controls (25–48%), suggesting a carrier state of sialidosis. This indicates that the neuraminidase deficiency gene, similar to the 21-hydroxylase deficiency gene, is closely linked to the HLA genotype and is located on chromosome 6.  相似文献   

10.
Summary Short-term ACTH treatment provoked a decrease in volume of the lipid-droplet compartment in rat zona glomerulosa cells, and a rise in plasma and intracellular concentrations of corticosterone and aldosterone. It enhanced activities of 3-hydroxysteroid dehydrogenase (3HSD), 11-hydroxylase (11OH) and 18-hydroxylase (18OH). Long-term ACTH administration produced a hypertrophy of the zona glomerulosa and its parenchymal cells, a result of the increase in volume of the smooth endoplasmic reticulum and the mitochondrial compartment. The surface area per cell of mitochondrial inner membranes increased; the tubular cristae were transformed into a homogeneous population of vesicles. The plasma and intracellular concentrations of corticosterone further increased, whereas those of aldosterone fell below basal levels (the aldosterone-escape phenomenon). The activities of 3HSD and 11OH were enhanced, that of 180H decreased. Therefore, ACTH stimulates zona glomerulosa growth and transforms parenchymal elements into zona fasciculata celltypes. Cyanoketone nullified acute ACTH effects on plasma and intracellular concentrations of corticosterone and aldosterone, but did not affect the activities of 11OH and 18OH. Chronic ACTH treatment produced similar results, although 18OH activity was not suppressed. The mechanism underlying the aldosterone-escape phenomenon may thus involve a rise in the intracellular concentration of corticosterone, caused by the enhanced synthesis and activation of 3HSD and 11OH.  相似文献   

11.
Summary Recombinant cDNA plasmids possessing the coding sequences for the -type gliadins were isolated from a cDNA library prepared from wheat seed poly (A+) RNA. One of these plasmids, pGliB48, specifically hybridizes to poly (A+) RNA molecules 1 400–1 500 bases in length that direct the synthesis of polypeptides at 38 Kd and 46 Kd, the latter size characteristic of the -type gliadins. The cDNA sequence of pGliB48 was determined and encompasses the 3 untranslated region as well as 245 amino acids from the C-terminus of the -type gliadin polypeptide. The 5-end of the DNA coding sequence consists of a tandem repeat unit composed of eight amino acids. Localized regions of homology are observed for the /-type and -type gliadin cDNA sequences.  相似文献   

12.
Summary The Dwl specificity was highly correlated with the serologically determined HLA-DR1 antigen in the Eighth International Histocompatibility Workshop 1980. By testing a large number of HLA-Dwl, DR1 defined homozygous typing cells (HTC) in a checkerboard primary mixed lymphocyte reaction, on a panel of about 30 HLA-DR1 heterozygous individuals, and in family segregation, three Dwl subtypes could be defined in association with certain HLA-A, -B, and -C-antigens. HTC TA, FRI, and FRA carrying the HLA haplotypes A11, B35, Cw4 or A3, B35, Cw4 in the homozygous state gave positive typing results with most HLA-DR1 positive panel members and stimulated only four other Dw1 HTCs (SRR35%). In contrast to this operationally broad specificity, Dw1-HTC-HEN (HLA-A2, B44, C-, homozygous) was non-stimulatory to all HTCs except one, but gave high responses against these, leading to the definition of a narrow specificity included in the broad one. Another such narrow specificity was represented by HTC FEE (HLA-A2, B27, Cw2 homozygous). Typing patterns with FEE were mostly different from those defined with other HTC. In family studies a specific typing pattern for this HTC could be shown to segregate with HLA. However, within some of these responses a contribution of the HLA haplotype in the trans position must be assumed.Supported in part by DFG grant Ri 164/14  相似文献   

13.
Summary Gene localization studies revealed the presence of two structural -galactosidase (GAL) loci on the human chromosomes 3 and 22 (de Wit et al., 1979). To determine the function of these genes, proliferating hybrid cell lines were isolated following fusion of fibroblasts from two different patients with a GAL deficiency and Chinese hamster cells. The hybrids were analyzed electrophoretically and immunologically.Fibroblasts from a patient with an adult type of GAL deficiency associated with a neuraminidase deficiency were used for the first fusion. No evidence for a structural GAL mutation was found in these hybrids. The absence of a structural GAL mutation is consistent with a primary defect in neuraminidase in this adult patient.Fibroblasts from a patient with the infantile type 1 GM1-gangliosidosis were used for the second fusion. It is concluded that the human determinants present in the isolated hybrid lines occur in heteropolymeric man-Chinese hamster molecules. The heteropolymeric isoenzyme in (+3–22) hybrids is very labile and is sensitive to neuraminidase treatment. Therefore it is concluded that the infantile type 1 patient is mutated in the structural GAL gene on chromosome 3. Because this patient has a primary defect in GM1-GAL, the GAL gene on chromosome 3 is apparently a G M1-GAL gene. Interaction of the two GAL loci results in an additional band of GAL activity on electrophoresis. This suggests that the gene on chromosome 22 is also a structural G M1-GAL gene.  相似文献   

14.
Summary The distribution of the red cell acid phosphatase groups was studied on 1365 blood samples of Swiss individuals. The distribution is in agreement with the Hardy-Weinberg equilibrium. Gene frequencies similar to those observed in other Caucasian populations were obtained (PA=0.345, PB=0.607, PC=0.049). In 331 mother/child-combinations, we found no theoretically impossible combinations.  相似文献   

15.
The ability to produce extracellular O-glycosylhydrolases was studied in 14 strains of marine filamentous fungi sampled from the bottom sediments of the South China Sea. The following activities were detected in the culture liquids of the fungi: N-acetyl--D-glucosaminidase, -D-glucosidase, -D-galactosidase, -1,3-glucanase, amylase, and pustulanase. -1,3-Glucanases were isolated by ultrafiltration, hydrophobic interaction chromatography, and ion exchange chromatography, and their properties were studied. Data on products of enzymatic digestion of laminaran, absence of transglycosylation activity, and the pattern of action of natural inhibitors confirmed that -1,3-glucanase belonged to the exo type. Inhibitor analysis demonstrated the role of a thiol group and tryptophan and tyrosine residues in the catalytic activity.  相似文献   

16.
Summary A 2.3-kb-long probe derived from the 5 flanking region, the first exon and part of the first intron of the human muscle-specific phosphoglycerate mutase gene (PGAM-M) (EC 5.4.2.1) was used to map the gene by in situ chromosomal hybridization. The structural gene for PGAM-M was assigned to chromosome 7p12-7p13; a single hybridization peak indicated that there is a single gene for this isozyme of PGAM, and confirmed results obtained by Southern blot hybridization.  相似文献   

17.
Oligonucleotide primers specific for intron 5 sequences were used to amplify a unique 718 bp fragment in the human GST gene. Using DNA from a panel of somatic cell hybrids it was possible to confirm the assignment of the GST1 locus to chromosome 1p and to refine localisation to 1p13 using Southern blot analysis of DNA from three-generation CEPH families and a GST specific DNA probe.  相似文献   

18.
Summary The ultrastructure of a fir morphological mutant containing multinucleate cells is described in Schizophyllum commune. The germlings of basidiospores which arose from mating fir with wild-type mycelium were studied in culture by phase contrast microscopy to elucidate behavior of multinucleate cells. Nuclear division appeared synchronous from two nuclei yielding four progeny through six nuclei producing twelve products, beyond which loss of synchrony was indicated. Compensatory nuclear migration into an anucleate cell was presumed during synchronous division of nuclear aggregates in the adjacent cell of an individual germling. The migrant nucleus eventually returned to the cell of origin. However, the return route was not via the central pore of the septum but rather occurred at the juncture of the cross-wall with the germling-periphery. Ultrastructure of a partial septum in fir which could accommodate nuclear passage of this sort is described.  相似文献   

19.
The reaction of methanol dehydrogenase with cytochrome c L from Methylophaga marina and the reactions of the non-physiological substrates, Wurster's blue and ascorbic acid, with both proteins were studied as a function of temperature (4–32 °C), pressure (1–2000 bar) and ionic strength using the optical high pressure stopped-flow method. The thermodynamic parameters H, S and V were determined for all reactions where electron transfers are involved. These data allowed the determination of the Maxwell relationships which proved the internal thermodynamic consistency of the system under study. A conformational change on the cytochrome c L level was deduced from both breaks in the Arrhenius plots and the variation of the V with temperature.Abbreviations MOPS 4-morpholinepropanesulfonic acid - CHES 2-(cyclohexylamino)ethanesulfonic acid - MDH methanol dehydrogenase - EDTA ethylenedinitrilotetraacetic acid disodium salt - BTB bromothymol blue (3,3-dibromothymolsulfoneph-thalein) - PQQ 2,7,9-tricarboxy-lH-pyrrolo-[2,3f]quinoline-4,5-dione - cytochrome c HH mammalian horse heart cytochrome c  相似文献   

20.
A human HLA-DQ -chain cDNA was used as a probe to identify and isolate a rat major histocompatibility antigen -chain gene from a genomic library constructed in the vector Charon 28 using Wistar rat DNA (RT1 u). The isolated exon of the rat gene (RT1.B 2) encoding a -chain second domain was found to share 93% nucleotide homology with a mouse A 2 exon. Although the genomic organization of this gene is consistent with the hypothesis that it represents a pseudogene, the remarkable preservation of a specific sequence favors the view that this class II antigen -chain gene has retained its coding function.  相似文献   

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