Final

Front 1

Strategy of gene regulation in which a relatively small number of time- and tissue specific positive and negative regulatory elements are used in various combinations to regulate the expression of a much larger number of genes.

Back 1

combinatorial control

Front 2

Any of a group of genes that establish the basic anterior-posterior and dorsal-ventral axes of the early embryo.

Back 2

coordinate gene

Front 3

Any of a group of genes that control the development of contiguous segments or parasegments in Drosophila such that mutations result in gaps in the pattern of segmentation.

Back 3

gap gene

Front 4

A DNA sequence motif found in the coding region of many regulatory genes; the amino acid sequence corresponding to the homeobox has a helix-loop-helix structure.

Back 4

homeobox

Front 5

Any of a group of genes in which a mutation results in the replacement of one body structure for another body structure.

Back 5

homeotic (HOX) gene

Front 6

Structures present in the body of insect larvae from which the adult structures develop during pupation.

Back 6

imaginal disk

Front 7

A chart of cell lineages and their developmental fates.

Back 7

lineage diagram

Front 8

A mutation that eliminates gene function; also called a null mutation.

Back 8

loss-of-function mutation

Front 9

Any of a group of genes active early in Drosophila development that specifies the fates of alternating segments or parasegments. Mutations in these genes result in loss of even-numbered or odd-numbered segments or parasegments.

Back 9

pair-rule gene

Front 10

Developmental unit in Drosophila consisting of the posterior part of one segment and the anterior part of the next segment in line.

Back 10

parasegment

Front 11

Any characteristic of an organism that improves its chance of survival and reproduction in its environment; the evolutionary process by which a species undergoes progressive modification favoring its survival and reproduction in a given environment.

Back 11

adaptation

Front 12

Cumulative change in the genetic characteristics of a species through time.

Back 12

evolution

Front 13

A measure of the average ability of organisms with a given genotype to survive and reproduce.

Back 13

fitness

Front 14

A measure of the genetic effects of inbreeding in terms of the proportionate reduction in heterozygosity in an inbred organism compared with the heterozygosity expected with random mating.

Back 14

inbreeding coefficient (F)

Front 15

A group of statistical methods for estimating gene trees and often, by inference, the evolutionary relationships among the taxa of which the genes are representative.

Back 15

molecular phylogenetics

Front 16

In a phylogenetic tree, the most recent node that unites a particular subset of sequences, characters, or species.

Back 16

most recent common ancestor (MRCA)

Front 17

System of mating in which mating pairs are formed independently of genotype and phenotype

Back 17

random mating

Front 18

In evolution, condition that alters the ability of genotypes to survive and reproduce; in plant and animal breeding, the choosing of organisms with certain phenotypes to be parents of the next generation; in mutation studies, a procedure designed in such a way that only a desired type of cell can survive.

Back 18

selection

Front 19

The amount by which relative fitness is reduced or increased.

Back 19

selection coefficient

Front 20

A mutation that has no (or negligible) effects on fitness.

Back 20

selectively neutral mutation