Advances in Genetics 

About: Advances in Genetics is an academic journal published by Elsevier BV. The journal publishes majorly in the area(s): Gene & Population. It has an ISSN identifier of 0065-2660. Over the lifetime, 731 publications have been published receiving 54357 citations.

Evolutionary Significance of Phenotypic Plasticity in Plants

Abstract: Publisher Summary This chapter focuses on evolutionary significance of phenotypic plasticity in plants. The expression of an individual genotype is modified by its environment. The amount by which it can be modified is termed its plasticity. This plasticity can be either morphological or physiological; these are interrelated. The plasticity of a character is related to the general pattern of its development, and apart from this, that plasticity is a general property of the whole genotype. Plasticity of a character appears to be specific for that character, specific in relation to particular environmental influences, specific in direction, under genetic control not necessarily related to heterozygosity, and able to be radically altered by selection. Because plants are static organisms, plasticity is of marked adaptive value in a great number of situations. Examples of all these situations in plant species are discussed. They indicate that adaptation by plasticity is a widespread and important phenomenon in plants and has evolved differently in different species. The mechanisms involved in plasticity are varied. At one extreme, the character shows a continuous range of modification dependent on the intensity of the environmental stimulus. At the other, the character shows only two discrete modifications. The stimulus causing these modifications may be direct or indirect. The mechanisms found can be related to the particular environmental situation involved.

The Genetics of Aspergillus nidulans

Abstract: Publisher Summary This discusses the lifecycle, the methods of culture, the isolation of mutants, the formal genetics, the identification of loci, and the diploids and mitotic recombination of Aspergillus nidulans (A. nidulans). It also presents various methods of genetic analysis, such as heterokaryosis, crossing, recombinant selection from random samples of ascosporesa, and perithecium analysis and relative heterothallism. As in most other filamentous fungi in which sexual reproduction occurs, A. nidulans (Eidam) Winter, an ascomycete shows a vegetative cycle side-by-side with a sexual cycle. On germination, an uninucleate haploid vegetative spore (conidium) produces colorless septate hyphae with multinucleate cells. The sexual cycle is concentrated in specialized organs, the fruiting bodies (cleistothecia or perithecia). The biochemical genetics of A. nidulans, though similar to that of Neurospora and Ophiostoma, has revealed interesting differences in detail: e.g., the inability of citrulline to replace ornithine for strains responding to ornithine or arginine; the inability of tryptophan to replace anthranilic acid for certain strains responding to anthranilic acid or nicotinic acid; the competitive inhibition by lysine of exogenous arginine or ornithine, and its sparing effect on exogenous proline; etc.

DNA methylation and cancer.

Abstract: DNA methylation is one of the most intensely studied epigenetic modifications in mammals. In normal cells, it assures the proper regulation of gene expression and stable gene silencing. DNA methylation is associated with histone modifications and the interplay of these epigenetic modifications is crucial to regulate the functioning of the genome by changing chromatin architecture. The covalent addition of a methyl group occurs generally in cytosine within CpG dinucleotides which are concentrated in large clusters called CpG islands. DNA methyltransferases are responsible for establishing and maintenance of methylation pattern. It is commonly known that inactivation of certain tumor-suppressor genes occurs as a consequence of hypermethylation within the promoter regions and a numerous studies have demonstrated a broad range of genes silenced by DNA methylation in different cancer types. On the other hand, global hypomethylation, inducing genomic instability, also contributes to cell transformation. Apart from DNA methylation alterations in promoter regions and repetitive DNA sequences, this phenomenon is associated also with regulation of expression of noncoding RNAs such as microRNAs that may play role in tumor suppression. DNA methylation seems to be promising in putative translational use in patients and hypermethylated promoters may serve as biomarkers. Moreover, unlike genetic alterations, DNA methylation is reversible what makes it extremely interesting for therapy approaches. The importance of DNA methylation alterations in tumorigenesis encourages us to decode the human epigenome. Different DNA methylome mapping techniques are indispensable to realize this project in the future.

The Complementary Genic Systems in Flax and Flax Rust

Abstract: Publisher Summary The type of pustule developed on a host variety following inoculation with a race of rust is the criterion both of the reaction of that variety to the race and of the pathogenicity of that race to the variety. Races of rust—genes for pathogenicity—are identified by the reaction of a series of varieties termed “rust differentials.” Genes for rust reaction are identified by the pathogenicity of races of rust. Rust resistance in flax is inherited as a dominant character although with some genes, dominance is not complete. Virulence in flax rust, melampsora lini, with one exception, is inherited as a recessive character. F 2 cultures of hybrids among races of flax rust segregated for pathogenicity on the differential varieties in accordance with the number of genes in the differential that conditioned resistance to the avirulent parent race.

Hereditary Anemias of the Mouse: A Review for Geneticists*

Abstract: Publisher Summary This chapter discusses the formal genetics of mouse anemias and their significance for an analysis of patterns of mammalian gene action. It also describes normal hemopoietic development, homeostasis, and hemoglobin polymorphism. Anemias are classified into five categories—(1) anemias of maturation arrest, (2) anemias involving defects in iron utilization, (3) anemias involving greatly reduced erythrocyte life-span, (4) hemoglobinopathies, and (5) anemias almost secondary to genetically induced defects. During the total life of a mouse, including prenatal development, hemopoiesis takes place in four different sites. Although hemopoiesis continues in the liver until birth and for a brief time thereafter, hemopoiesis (largely myelopoiesis) commences in the spleen on fetal day 15 or 16 and in the marrow around the time of birth. Hematologically normal adult mice from many different inbred strains regularly produce more than one kind of hemoglobin. There is a widespread genetic polymorphism at both the Hba locus, determining the α-globin structure and the Hbb locus, determining the β-globin structure, and both the loci involve considerable genetic complexity.