Search results for "homology"
showing 10 items of 770 documents
Generalized Hodge classes on the moduli space of curves
2003
On the moduli space of curves we consider the cohomology classes which can be viewed as a generalization of the Hodge classes λi defined by Mumford in [6]. Following the methods used in this paper, we prove that these classes belong to the tautological ring of the moduli space.
The associated sheaf functor theorem in algebraic set theory
2008
We prove a version of the associated sheaf functor theorem in Algebraic Set Theory. The proof is established working within a Heyting pretopos equipped with a system of small maps satisfying the axioms originally introduced by Joyal and Moerdijk. This result improves oil the existing developments by avoiding the assumption of additional axioms for small maps and the use of collection sites.
Hochschild Cohomology Theories in White Noise Analysis
2008
We show that the continuous Hochschild cohomology and the differential Hochschild cohomology of the Hida test algebra endowed with the normalized Wick product are the same.
dfh is a Drosophila homolog of the Friedreich's ataxia disease gene
2000
Abstract A putative Drosophila homolog of the Friedreich's ataxia disease gene (FRDA) has been cloned and characterized; it has been named Drosophila frataxin homolog (dfh). It is located at 8C/D position on X chromosome and is spread over 1 kb, a much smaller genomic region than the human gene. Its genomic organization is simple, with a single intron dividing the coding region into two exons. The predicted encoded product has 190 amino acids, being considered a frataxin-like protein on the basis of the sequence and secondary structure conservation when compared with human frataxin and related proteins from other eukaryotes. The closest match between the Drosophila and the human proteins in…
Structure, organization and expression of two clustered cuticle protein genes during the metamorphosis of an insect, Tenebrio molitor.
1998
A 4-kb DNA segment of Tenebrio molitor (Insecta, Coleoptera) genomic DNA containing two larval-pupal cuticular genes has been cloned and sequenced. These genes, transcribed in opposite directions, are related in DNA sequence and the proteins encoded are very similar. Each of them contains a single intron located inside the sequence encoding the signal peptide, and a conserved sequence at -200 bp from the mRNA start position. These similarities in sequence suggest that these genes have evolved by duplication followed by diversification and that they are members of a family of genes with a common ancestry. They are the first example of clustered genes in Tenebrio molitor.
Molecular cloning and primary structure of a Rhesus (Rh)-like protein from the marine sponge Geodia cydonium
1997
In humans, the 30,000 M(r) Rhesus (Rh) polypeptide D (RhD) is a dominant antigen (Ag) of the Rh blood group system. To date, an Rh-like protein has been found in chimpanzees, gorillas, gibbons, and rhesus monkeys. Related to the 30,000 M(r) Rh Ag protein are two polypeptides of 50,000 M(r), the human 50,000 M(r) Rh Ag and the RhD-like protein from Caenorhabditis elegans. The function of all these proteins is not sufficiently known. Here we characterize a cDNA clone (GCRH) encoding a putative 57,000 M(r) polypeptide from the marine sponge Geodia cydonium, which shares sequence similarity both to the RhD Ag and the Rh50 glycoprotein. The sponge Rh-like protein comprises 523 aa residues; hydro…
Complete sequence, expression and evolution of two members of the hexamerin protein family during the larval development of the rice moth, Corcyra ce…
2002
Three distinct types of storage hexamerins are expressed in the "last-instar" larvae of the rice moth, Corcyra cephalonica. A cDNA expression library was constructed from fat body-RNA and screened with a polyclonal antibody raised against purified hexamerin (SP2) of Corcyra cephalonica. Two slightly different "full-length" hexamerin cDNA clones (Hex2a and Hex2b) were isolated and sequenced. Both include open reading frames of 2109 bp which are translated into polypeptides of 703 amino acids with 92.5% identity. Signal peptides of 19 amino acids are present at the N-termini. The 684 amino acids native proteins have a high content of aryl groups (17.6%). According to both the criteria for ami…
mp23, a Theileria parva transmembrane protein with homology to the protein disulfide isomerase family
2002
The protozoan parasite Theileria parva (Apicomplexa) causes the bovine disease East Coast Fever in endemic areas in Subsaharan Africa. The intralymphocytic schizont stage is largely responsible for the pathogenicity and induces a transformed phenotype in host cells [1]. Current evidence supports a model in which the schizont perturbs the immune response by inducing production of cytokines and stimulating the growth of parasitized cells [2]. We were interested to identify parasite proteins involved in parasite/host interaction and have described earlier a screening procedure for identification of schizont stage-exported proteins based on cell-free expression of cDNA and testing for transloca…
Diplopod hemocyanin sequence and the phylogenetic position of the Myriapoda
2001
Hemocyanins are copper-containing respiratory proteins of the Arthropoda that have so far been thoroughly investigated only in the Chelicerata and the Crustacea but have remained unstudied until now in the Myriapoda. Here we report the first sequence of a myriapod hemocyanin. The hemocyanin of Spirostreptus sp. (Diplopoda: Spirostreptidae) is composed of two distinct subunits that are arranged in a 6 x 6 native molecule. The cloned hemocyanin subunit cDNA codes of for a polypeptide of 653 amino acids (75.5 kDa) that includes a signal peptide of 18 amino acids. The sequence closely resembles that of the chelicerate hemocyanins. Molecular phylogenetic analyses reject with high statistical con…
The nucleotide and deduced amino acid structures of sheep and pig fetuin. Common structural features of the mammalian fetuin family
1992
This study was initiated to gain further insight into the structural features of the mammalian fetuin family. The cDNA structures of sheep and pig fetuin were determined. The cDNA insert encoding sheep (pig) fetuin comprised 1550 (1470) nucleotides, including 54 (46) nucleotides encoding a signal peptide of 18 (15) residues and 1038 (1041) nucleotides encoding the 346 (347) amino acids of the mature plasma protein. The predicted amino-terminal sequence of the mature pig fetuin was confirmed by the amino-terminal sequence of the purified protein. However, two alternative sheep amino-terminal sequences were found in fetuin purified from the plasma of a single sheep fetus; the minor product wa…