Courting strategies and conflicts in a monogamous,biparental termite

In species where parental investment is extensive for both sexes, both males and females are predicted to exhibit choosiness when seeking their lifetime partners. Evidence is presented that both courting males and females are choosy in the wood-dwelling, biparental termite Zootermopsis nevadensis. There are, however, sex differences both in the method of mate rejection and in the mate-choice criteria. In particular, females are more likely than males to invite an extra suitor into the nest, whereas males are more likely than females to leave their nest and partner and seek a replacement elsewhere. Correlational analyses of adults show that head width is a mate-choice criterion used by females, whereas body mass and fat mass are used by males. Among males and females that sought replacement mates, those that had been rejected previously were more likely to end up paired with an adult that also had been rejected, compared with adults that had not been rejected. Additional findings reveal a rich repertoire of courting behaviours characterized by extensive intra- and intersexual conflict, including mate rejection, intrasexual combat, and even intrapair aggression.     

Courting a cure for fragile X

Fragile X syndrome is the most common heritable cause of mental retardation. Previous work has suggested that overactive signaling by group I metabotropic glutamate receptors (mGluRs) may be a mechanism underlying many of the disease symptoms. As a test of this theory, McBride et al. show that in a Drosophila model for Fragile X syndrome, treatment with mGluR antagonists can rescue short-term memory, courtship, and mushroom body defects.     

Failure of therapy with thrombocyte concentrates as a sequela of anti-Kob (3b) antibodies in a patient

The report deals with a failure in transfusing thrombocyte concentrates in a patient affected with bone-marrow hypoplasia caused by thrombocyte antibodies with anti-Kob (3b) specificity. This is referred to as a rare occurrence since, in general, HLA cytotoxins are identified as underlying cause and polyspecific or anti-Zwa(P1A1) antibodies only in exceptional cases.     

Conditioning Mutations in DROSOPHILA MELANOGASTER Affect an Experience-Dependent Behavioral Modification in Courting Males

One aspect of courtship in male Drosophila melanogaster has been reported to be experience dependent. Males that have courted fertilized females are virtually unresponsive to virgin females for 2–3 hr. Here, this response was utilized as an assay for the effects of conditioning mutations on experience-dependent courtship. Seven strains expressing conditioning mutations (previously isolated and characterized for learning or memory defects in an electrical shock-odor association paradigm, independent of courtship) were all found to be mutant in expression of this experience-dependent change in courtship behavior. By comparison, three control strains that were unselected for conditioning defects all expressed normal experience-dependent courtship. Other results indicate that males of the conditioning-defective strains are able to elicit necessary cues from fertilized females, yet do not then modify their courtship with virgin females. Thus, it is suggested that experience-dependent modification of courtship and the previously reported associative olfactory conditioning with electric shock share common elements of processing. The possibility that experience-dependent courtship represents adaptive behavior is discussed.     

Cytochrome b558, a component of the phagocyte NADPH oxidase, is a flavoprotein.

Cytochrome b558 is the only membrane component of the phagocyte O2(-)-producing NADPH oxidase. The O2- production by the oxidase reconstituted in vitro with the crude membrane fraction is enhanced several-fold by addition of FAD, whereas that with the partially purified cytochrome is completely dependent on exogenous FAD, suggesting that FAD acts through the membrane component, cytochrome b558. The alignments of the amino acid sequence of the large subunit of the cytochrome (gp91-phox) with those of previously characterized flavoproteins reveal that the middle and C-terminal portions of gp91-phox are likely to be FAD- and NADPH-binding domains, respectively. Cytochrome b558, thus, appears to be a flavoprotein with an NADPH-binding site, of the NADPH oxidase.     

Failure of diagnosis as a factor in tuberculosis mortality.

In British Columbia between January 1970 and December 1974 active tuberculosis was diagnosed only after death in 69 cases; this was more frequent for miliary tuberculosis (31% of reported cases) than for advanced pulmonary tuberculosis (3% of cases). Although 28% of the patients were more than 75 years old, some were much younger, and 38% of the latter were alcoholics. More than 50% of the patients had been hospitalized before death, for a mean of 14.5 days; they were most frequently thought to have pneumonia or cancer at the time of death. Clearly, increased awareness of the continuing presence of tuberculosis in our society is needed.     

Sulfite binding to a flavodehydrogenase, cytochrome b2 from baker's yeast.

Baker's yeast L-lactate dehydrogenase (flavocytochrome b2) is a typical flavodehydrogenase, in that it accepts two electrons from the substrate but has a monoelectronic acceptor. Yet it forms a red semiquinone [Capeillère Blandin et al. Eur. J. Biochem. 54, 549--566 (1975)] and it is shown in this paper that it forms a reversible covalent complex with sulfite (Kd = 1.4 muM). This complex can be observed by difference spectroscopy and provides a convenient tool for visualizing the flavin chromophore, usually hidden behind the intense heme absorbance. A number of anions (D-lactate, oxalate and pyruvate) are inhibitors of the enzymatic reaction and induce spectral perturbations of the flavin spectrum. It is concluded that probably two positive charges exist at the active site: one which stabilizes the red semiquinone and one which attracts organic anions and sulfite. It is also concluded that the correlation between reactivity with sulfite and reactivity with oxygen among flavo-proteins may not be as general as previously proposed [Massey et al. J. Biol. Chem. 244, 3999--4006 (1969)].     

An auto-anti-b in an a1b person. Serological studies.

The serum of a patient (Mr. Lat) with the regular blood group A1 B contains an anti-B reacting with all cells having a B antigen except Bx and cis AB. The anti-B reacts at 4 degrees C and occasionally at room temperature as shown by agglutination, absorption-eluction and by thermo-dynamic assays. The antibody is regarded as an irregular autoantibody belonging to the group of the so called "suppressed" or "latent" antibodies.     

Single-channel parameters of gramicidin a,b, and c

The single-channel conductance Λ and the mean channel lifetime τ1 of natural and synthetic gramicidins A, B, and C has been studied. Significant differences in Λ were found between gramicidin A and B; both gramicidins differ only in one amino acid (tryptophan replaced by phenylalinine). The distribution of Λ is narrow in glycerylmonooleate membranes but considerably broader in dioleoyl phosphatidylcholine and dioleoyl phosphatidylethanolamine membranes. The ratio of the single-channel conductances in glycerylmonooleate and dioleoyl phosphatidylcholine membranes is only about two and is considerable smaller than the conductance ratio of nonactin-mediated cation transport. This finding suggests that dipolar potentials at the membrane/solution interface have little influence on the conductance of the gramicidin channel.     

TIP49b, a new RuvB-like DNA helicase, is included in a complex together with another RuvB-like DNA helicase, TIP49a.

We previously reported that TIP49a is a novel mammalian DNA helicase showing structural similarity with the bacterial recombination factor RuvB. In this study, we isolated a new TIP49a-related gene, termed TIP49b, from human and yeast cells. TIP49b also resembled RuvB, thus suggesting that TIP49a and TIP49b are included in a gene family. Like TIP49a, TIP49b was abundantly expressed in the testis and thymus. Enzyme assays revealed that TIP49b was an single-stranded DNA-stimulated ATPase and ATP-dependent DNA helicase. Most of the enzymatic properties of TIP49b were the same as those of TIP49a, whereas the polarity of TIP49b DNA helicase activity (5' to 3') was the opposite to that of TIP49a. TIP49b and TIP49a bound to each other and were included in the same complex of approximately 700 kDa in a cell. We found that TIP49b was an essential gene for the growth of Saccharomyces cerevisiae, as is the TIP49a gene, suggesting that TIP49b does not complement the TIP49a function and vice versa. From these observations, we suggest that TIP49b plays an essential role in the cellular processes involved in DNA metabolism.     

B群脑膜炎单抗原疫苗能否出现

<正>脑膜炎仍旧是一种健康问题,因为还没有抗B群脑膜炎球菌的疫苗,B群脑膜炎球菌是引起脑膜炎疾病最常见的细菌。感染了脑膜炎的个体常常遭受到脑损伤、弱智、听力丧失、肢残,甚至死亡。脑膜炎病是全球的重大公共卫生问题,特别是对于婴幼     

Genetic identification of Thunnus orientalis, T. thynnus, and T. maccoyii by a cytochrome b gene analysis

The three species of bluefin tunas, Thunnus orientalis, T. maccoyii, and T. thynnus, are morphologically similar, which can pose problems for fisheries management and marketing. We examined intraspecific genetic diversity and interspecific genetic boundaries among these three species by analyzing the cytochrome (Cyt) b gene. The full lengths of the nucleotide sequences were 1,141 bp in T. orientalis and T. thynnus and ranged 1,138?~?1,141 bp in T. maccoyii. Mean nucleotide diversities were 0.0019?±?0.0002 in T. thynnus (n?=?8), 0.0063?±?0.0005 in T. orientalis (n?=?22), and 0.0059?±?0.0007 in T. maccoyii (n?=?24). Average numbers of nucleotide differences and nucleotide substitutions per site among the three species were 18.748?±?2.879 and 0.017?±?0.003, respectively. The Neighbor-joining and minimum-evolution trees showed distinct clades with high bootstrapping value support, and the high Fst value indicated significant differentiation among the three species. T. thynnus, T. orientalis, and T. maccoyii could be individually distinguished from each other Thunnus tunas by the 132nd, 375th, and 1,023rd sites of the Cyt b sequences. In the mismatch analysis, Fu??s and Tajima??s tests of sequences from T. orientalis and T. maccoyii provided evidence of their population expansion dating to the middle Pleistocene.     

CD11b is a calcium-dependent epitope in human neutrophils.

Human neutrophils expressing complement receptor 3 (CR3) were treated with various concentrations (0.04-10 mM) of Ca2+/Mg(2+)-chelating agent EDTA and the expression of CD11b, the CR3 alpha chain antigenic epitope, was examined using monoclonal antibodies and flow cytometry. EDTA caused a dose-dependent decrease in the reactivity of two anti-CD11b monoclonal antibodies, Leu15 and IOM1. The reduced expression of CD11b in EDTA-treated cells was partly restored by the addition of Ca2+ ions whereas the addition of Mg2+ ions had no effect on CD11b level. The expression of the CR3 beta chain epitope, CD18, was markedly decreased only by 10 mM EDTA. These results suggest that the CD11b epitope may be associated with the Ca(2+)-binding domains of CR3 alpha chain and its recognition by antibodies depends on the presence of bound Ca2+.