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At least 19 recordsLinked to original sources
PubMed1991

Mapping of the gene for a major penicillin-binding protein to a genetically conserved region of the Bacillus subtilis chromosome and conservation of the protein among related species of Bacillus.

Penicillin-binding protein 5 is the most abundant penicillin-binding protein in the vegetative membranes of Bacillus subtilis and accounts for 95% of the D,D-carboxypeptidase activity of the cell. The structural gene for penicillin-binding protein 5 was mapped to a genetically conserved region near guaB at 0 degrees on the B. subtilis chromosome, and immunoassays revealed that there is conservation of this major penicillin-binding protein among related species.

Bacillus↗
PubMed1987

Male-enhanced expression and genetic conservation of a gene isolated with an anti-H-Y antibody.

The hypothesis of the serological H-Y antigen as the inducer molecule for mammalian male sex differentiation has been considered an important working model in developmental biology. However, because of the difficulties involved in its detection, supporting evidence in molecular terms is lacking for this hypothesis. The isolation of the gene for the serological H-Y antigen is essential to the acertainment of its proposed functions. Using recombinant DNA technology and specific anti-H-Y sera we have isolated a candidate gene, the MEA gene, for the serological H-Y antigen. Molecular characterization of the MEA gene shows male-enhanced expression and genetic conservation patterns similar to those attributed to the serological H-Y antigen. The isolation of this candidate gene for the serological H-Y antigen. The isolation of this candidate gene for the serological H-Y antigen would allow further investigations to identify the functions for this molecule in molecular terms.

Aging↗
PubMed1991

Purification, cloning, and primary structure of a new enantiomer-selective amidase from a Rhodococcus strain: structural evidence for a conserved genetic coupling with nitrile hydratase.

A new enantiomer-selective amidase active on several 2-aryl propionamides was identified and purified from a newly isolated Rhodococcus strain. The characterized amidase is an apparent homodimer, each molecule of which has an Mr of 48,554; it has a specific activity of 16.5 mumol of S(+)-2-phenylpropionic acid formed per min per mg of enzyme from the racemic amide under our conditions. An oligonucleotide probe was deduced from limited peptide information and was used to clone the corresponding gene, named amdA. As expected, significant homologies were found between the amino acid sequences of the enantiomer-selective amidase of Rhodococcus sp., the corresponding enzyme from Brevibacterium sp. strain R312, and several known amidases, thus confirming the existence of a structural class of amidase enzymes. Genes probably coding for the two subunits of a nitrile hydratase, albeit in an inverse order, were found 39 bp downstream of amdA, suggesting that such a genetic organization might be conserved in different microorganisms. Although we failed to express an active Rhodococcus amidase in Escherichia coli, even in conditions allowing the expression of an active R312 enzyme, the high-level expression of the active recombinant enzyme could be demonstrated in Brevibacterium lactofermentum by using a pSR1-derived shuttle vector.

Amides↗
PubMed2025

Genetic Conservation and Diversity of SARS-CoV-2 Envelope Gene Across Variants of Concern.

SARS-CoV-2 Envelope (E) protein is critical in viral assembly, release, and virulence. E gene was considered highly conserved and evolving slowly. Pan-sarbecoviruses-conserved regions in the E gene have been used as targets for various RT-PCR assays to detect SARS-CoV-2. It remains elusive whether SARS-CoV-2 variants of concern (VOCs) have accumulated significant E mutations that may affect protein stability and diagnostic RT-PCR assays. Herein we aimed to perform a comprehensive genetic analysis on the conservation and diversity of the E gene of SARS-CoV-2 and its VOCs in comparison with other human coronaviruses (HCoVs). In silico analysis of 20 326 HCoV E gene sequences retrieved from GenBank and GISAID suggests that SARS-CoV-2 E gene has multiple pan-HCoVs- and pan-SARS-CoV-2-conserved positions but accumulates significant mutations in VOC B.1.351 and Omicron strains. Mutations were often found in the 5' and 3' variable regions, whereas the central region is conserved. Nucleotide changes C109U and A114G may lead to potential failure of first-line SARS-CoV-2 diagnostic/screening assays. Nucleotide change C212U and its concomitant amino acid substitution Pro71Leu (i.e., C212U/Pro71Leu) is a hallmark mutation of B.1.351 variants, while C26U/Thr9Ile is characteristic of all Omicron variants. Later Omicron subvariants, such as XBB.1.5 and EG.5, additionally acquired the A31G/Thr11Ala mutation, as was confirmed by whole genome sequencing of SARS-CoV-2 in 118 pediatric cases. Wild-type E protein exhibits cytotoxicity to cells, but the mutations Thr9Ile, Thr11Ala, Thr9Ile + Thr11Ala, or Pro71Leu reduces its cytotoxicity. The Thr9Ile + Thr11Ala mutation stabilizes the E proteins of Omicron variants, while Pro71Leu alters the cellular distribution of the E protein, reducing its colocalization with the Golgi body. Altogether, this study not only sheds light on the conservation and diversity of the E gene in SARS-CoV-2 and its VOCs but also informs the improvement and development of SARS-CoV-2 or pan-HCoVs screening and diagnostic assays.

SARS-CoV-2↗
PubMed1992

Conservation genetics of whales and dolphins.

Whales and dolphins (cetaceans) are found in all the world's oceans and in some of the major rivers, yet little is known about the distribution and behaviour of many species. At the same time, cetaceans are under threat from a variety of pressures including direct and indirect takes, pollution, and competition for habitat and prey. To ensure their long-term survival it will be necessary to preserve genetic diversity through the identification and protection of differentiated populations, the assessment of variation within local populations, and through a better understanding of reproductive and dispersal behaviour. The application of molecular genetic techniques is helping to provide answers to some of these previously intractable questions. Early results suggest few consistent patterns. Obvious geographic boundaries correlate to genetic distance in some species, and not in others. Furthermore, morphological variation within species can be fairly extensive without correlating to genetic distance, or relatively minor between morphotypes that are as genetically distinct as some species. These examples emphasize the need for further study.

Animals↗
PubMed1987

Antigenic and genetic conservation of H3 influenza virus in wild ducks.

The hemagglutinins of H3 influenza viruses isolated from migratory ducks on the Pacific flyway in Japan during the period 1977 to 1985 were analyzed antigenically and genetically. Antigenic analysis using monoclonal antibodies to the hemagglutinins of A/Aichi/2/68 (H3N2) and A/duck/Hokkaido/8/80 (H3N8) viruses showed that antigenic drift occurred extensively in human strains, whereas the hemagglutinins of duck viruses were highly conserved. It was also found that the hemagglutinins of duck viruses were antigenically closely related to that of human 1968 H3 prototype strains. Nucleotide sequence analysis of seven duck H3 hemagglutinin genes showed a limited number of changes among the six duck isolates and between these duck isolates and Aichi/68. The deduced amino acid sequence revealed amino acid changes randomly distributed throughout the molecule and not confined to antigenic sites. These findings indicate that the duck virus hemagglutinin genes are conserved in nature and that viruses of different lineages cocirculate.

Amino Acid Sequence↗
PubMed1992

Evolution of influenza B/Victoria/2/87-like viruses: occurrence of a genetically conserved virus under conditions of low epidemic activity.

Nucleotide sequence analysis of the gene region coding for the HA1 domain of the influenza B virus haemagglutinin was performed on seven field strains isolated during the 1989 to 1990 season and two field strains isolated in 1985 and 1988 in Finland. All isolates were antigenically and genetically related to B/Victoria/2/87 virus and distinct from B/Yamagata/16/88 virus. The three strains isolated at the beginning of the 1989 1990 season in Turku were almost identical to an American variant (B/Texas/37/88-B/Ohio/10/88) of the previous season, whereas the four strains isolated later in the 1989 to 1990 season in Helsinki formed a new group of heterogeneous viruses. The phylogenetic tree compiled suggests that the two branches had evolved from a common origin, probably in 1987.

Amino Acid Sequence↗
PubMed1989

Lack of expression of HLA-B27 gene in transgenic mouse trophoblast. Conserved genetic pressures underlying extra-embryonic development.

The mechanisms that regulate developmental control of the expression of MHC class I genes during generation of extra-embryonic tissues are largely unknown. In the present study, we studied the levels of transcripts of the human HLA-B27 gene in extra-embryonic tissues of transgenic mice containing the HLA-B27 (heavy chain) gene by in situ hybridization with biotinylated single-stranded RNA probes. In contrast to extra-embryonic stromal cells and embryonic tissues which contain (varying levels of) messenger RNA coding for HLA-B27, specific transcripts were not detected in labyrintho-, or spongiotrophoblast, nor in trophoblastic giant cells. These cells are devoid of HLA A and B locus class I transcripts in man. Regulation of expression of human MHC class I genes in extra-embryonic trophoblast in transgenic animals is thus under conserved selective pressure that is retained across a species barrier. Thus, in extra-embryonic tissues, regulation of expression of MHC class I genes is distinct from the mechanisms operating in developing embryonic cells.

Animals↗
PubMed1991

Conservation genetics of the koala (Phascolarctos cinereus). II. Limited variability in minisatellite DNA sequences.

We have examined variability in TaqI and EcoRI restriction fragment sizes of DNA from the koala (Phascolarctos cinereus) using six HVR (hypervariable region) probes which reveal complex, individual-specific restriction patterns in humans and other species. Frequency of band-sharing among unrelated koalas was extremely high. This result is likely to be a consequence of the history of near-extinction and artificial recolonization of the populations we have studied, rather than a general marsupial or koala-wide phenomenon.

Animals↗
PubMed1991

Genetic conservation of cyclo-oxygenase.

Homology between sheep and mouse cyclo-oxygenase cDNA and a range of other species was investigated using "zoo blots". Both the sheep and mouse cDNAs showed a high degree of homology to other species. Human cyclooxygenase appears to have greater homology to sheep and other ruminants than to mouse. Both sheep and mouse cDNAs detected identically sized transcripts in human placental total RNA.

Animals↗
PubMedDate not supplied

The genetics of host-pathogen coevolution: implications for genetic resource conservation.

The results of long-term studies of coevolution in the Hordeum vulgare-Rhynchosporium secalis pathosystem are summarized. The genetic systems of barley (host) and R. secalis (pathogen) are complementary: Gene-for-gene interactions among loci affect many traits, leading to self-regulating adjustments over generations between host and pathogen populations. Different pathotypes differ widely in their ability to damage the host, and different host-resistance alleles differ widely in their ability to protect the host from the pathogen. Among 29 resistance loci in the specific host population studied, several played major roles in providing stable resistance, but many had net detrimental effects on the yield and reproductive ability of the host. Resistance alleles that protected against the most damaging pathotypes increased sharply in frequency in the host populations. It is concluded that the evolutionary processes that take place in genetically variable populations propagated under conditions of cultivation can be highly effective in increasing the frequency of desirable alleles and useful multilocus genotypes. This enhances the value of the evolving populations as sources of genetic variability in breeding for disease resistance and other characters that affect adaptedness.

Biological Evolution↗
PubMed1989

Trypanotolerance and the value of conserving livestock genetic resources.

Studies have been made in two main areas of genetic research on African trypanotolerant (N'Dama) cattle. The first is of the significance for performance and the heritability of trypanotolerance traits and the second is the search for markers of the breed type and the traits of interest. Results demonstrate significant effects of the ability of an animal to control parasitaemia and anaemia on its performance. Initial estimates suggested that parasitaemia measures had a very low heritability, but ability to maintain packed cell volume levels when detected as parasitaemic and to generate an immune response could form the basis of a practical selection approach. The search for markers has so far concentrated on the major histocompatibility complex and on a polymorphic system of common leukocyte antigens. Phenotypes that appeared more characteristic of the N'Dama in comparison with those of East African zebu cattle were examined for associations with trypanotolerance traits. One major histocompatibility complex encoded phenotype and two common leukocyte antigens gave indications of important associations. Planned research will further characterise the breed and define traits of importance to assist in increasing its productivity in Africa and thus in its conservation. The addition of a molecular genetics component to an integrated genetics research programme, principally through involvement in development of a linkage map of the bovine genome, will strengthen these efforts and make it possible to conserve specific N'Dama genes related to productivity.

Africa↗
PubMed1992

Analysis of nucleotide sequence of the rightmost 43 kbp of herpesvirus saimiri (HVS) L-DNA: general conservation of genetic organization between HVS and Epstein-Barr virus.

We present an analysis of 43,658 bp of contiguous nucleotide sequence comprising the right terminal region (conventional orientation) of the unique protein-coding component (L-DNA) of the herpesvirus saimiri (HVS) genome. Within this region lie the genes encoding the 160-kDa virion protein, which is homologous to the 140-kDa membrane antigen of Epstein-Barr virus (EBV), thymidylate synthase (TS), and the immediate-early (IE) 52-kDa protein which is homologous to the EBV BMLF1 product. The 160-kDa gene of HVS lies at the right terminus of HVS L-DNA, its homologue in EBV occurring at the left terminus of the EBV genome (conventional orientation). The TS gene of HVS occurs within a group of 5 genes that have no homologues in EBV. The translation product of one of these genes, ECRF3, shows amino acid sequence and hydrophobicity pattern similarities to the HCMV and cellular G-protein-coupled receptor family of proteins. Another, ECLF2, is homologous to the cyclin family of cellular proteins. The 5 nonconserved genes lie adjacent to the 160-kDa gene. In EBV, the region to the right of the 140-kDa gene (BNRF1) contains the latent replication origin (OriP) and the open reading frames BCRF1, BWRF1 (repeated 12 times), BYRF1, BHLF1, and BHRF1, counterparts of which are not present in this position in HVS. The subsequent 18 genes in EBV (BFLF2 to BLRF2, approximate positions 56,000-89,500) are represented in HVS, and the relative positions and orientations of these genes are directly comparable between the two viruses. There then occurs a nonhomologous gene in HVS, and genes BLLF2 to BZLF1 (positions 89,500 to 103,200) in EBV which are not present in this region of HVS, before collinearity resumes. Thus, the HVS sequence presented here shows general collinearity between conserved genes in the right terminal region of HVS and the left terminal region of EBV and reveals the presence of two sets of unique genes which occur in exactly analogous positions in HVS and EBV.

Amino Acid Sequence↗
PubMed2025

Genomic and phenotypic comparison of Saccharomyces cerevisiae and Saccharomyces boulardii.

Saccharomyces boulardii is a widely used probiotic yeast with clinical efficacy against certain gastrointestinal disorders. Although genomically related to S. cerevisiae, the extent to which S. boulardii harbors distinct probiotic-relevant traits remains incompletely defined, particularly across commercially distributed strains. Here, we performed comparative genomic, physiological, and functional analyses of five S. boulardii strains and three S. cerevisiae strains, including baker's and laboratory variants. S. boulardii strains shared conserved genetic features and exhibited a conserved chromosomal inversion on chromosome XVI, lower copy numbers of CAZyme genes, and lineage-specific amino acid substitutions in central and tryptophan catabolism pathways-potentially underlying elevated production of immunomodulatory metabolites. S. boulardii strains also exhibited enhanced acid tolerance, elevated acetate and succinate production, and robust immunomodulatory activity, including suppression of IL-8 secretion and NF-κB, and consistent activation of the aryl hydrocarbon receptor (AhR) compared to S. cerevisiae. In contrast, S. cerevisiae strains displayed greater bile salt tolerance and faster growth under aerobic and anaerobic conditions at both 30°C and 37°C but lacked consistent anti-inflammatory effects or AhR agonism. Metabolic and immunological phenotypes varied with oxygen availability and strain background. Despite high genomic similarity, S. cerevisiae and S. boulardii exhibit distinct functional capacities relevant to probiotic efficacy. These findings help define speciesand strain-specific features that inform the development and regulatory evaluation of next-generation yeast probiotics.

AhR activation↗
PubMed1992

An element regulating adrenal-specific steroid 21-hydroxylase expression is located within the slp gene.

In this report we demonstrate that a transcriptional regulatory element for one gene lies within a second, seemingly unrelated gene. Specifically, the 3' portion of the murine sex-limited protein (slp) gene, located within the class III region of the major histocompatibility complex, contains an element that regulates expression of the linked steroid 21-hydroxylase gene. A 4.2-kilobase (kb) major histocompatibility complex region, located between -2.2 and -6.4 kb upstream of 21OH-A, is required for expression of a chloramphenicol acetyltransferase reporter gene in transgenic mice. Two short regions of DNA, located between -5.3 and -6.0 kb, stimulate chloramphenicol acetyltransferase expression in Y1 adrenocortical tumor cells, and both of these active regions lie within the slp gene. A 21-base pair sequence, which is required for activity of the most 3' region, does not contain any of over 100 previously identified transcriptional regulatory elements. This juxtaposition of structural and regulatory elements of otherwise unrelated genes suggests a mechanism by which the evolutionarily conserved genetic linkage of 21OH-A and slp (or the homologous complement component C4) might provide a selective advantage. Analogous genetic arrangements may explain other examples of conserved linkage of disparate genes.

Adrenal Glands↗