Achaete-Scute Complex Genome Region: A genomic region found in DROSOPHILA. The region contains genes encoding BASIC HELIX-LOOP-HELIX TRANSCRIPTION FACTORS that play a critical role in the regulation of pattern formation during EMBRYONIC DEVELOPMENT.t-Complex Genome Region: A 20 cM region of mouse chromosome 17 that is represented by a least two HAPLOTYPES. One of the haplotypes is referred to as the t-haplotype and contains an unusual array of mutations that affect embryonic development and male fertility. The t-haplotype is maintained in the gene pool by the presence of unusual features that prevent its recombination.Genome: The genetic complement of an organism, including all of its GENES, as represented in its DNA, or in some cases, its RNA.Sperm Tail: The posterior filiform portion of the spermatozoon (SPERMATOZOA) that provides sperm motility.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Genome, Plant: The genetic complement of a plant (PLANTS) as represented in its DNA.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Genes, Lethal: Genes whose loss of function or gain of function MUTATION leads to the death of the carrier prior to maturity. They may be essential genes (GENES, ESSENTIAL) required for viability, or genes which cause a block of function of an essential gene at a time when the essential gene function is required for viability.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Crosses, Genetic: Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Chromosomes, Artificial, Bacterial: DNA constructs that are composed of, at least, a REPLICATION ORIGIN, for successful replication, propagation to and maintenance as an extra chromosome in bacteria. In addition, they can carry large amounts (about 200 kilobases) of other sequence for a variety of bioengineering purposes.Genomics: The systematic study of the complete DNA sequences (GENOME) of organisms.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Chromosomes, Plant: Complex nucleoprotein structures which contain the genomic DNA and are part of the CELL NUCLEUS of PLANTS.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Contig Mapping: Overlapping of cloned or sequenced DNA to construct a continuous region of a gene, chromosome or genome.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Genes, Plant: The functional hereditary units of PLANTS.Herpesvirus 1, Gallid: The type species of the genus ILTOVIRUS found on every continent and affecting mainly chickens and occasionally pheasants.