Genetik 2_The genetic control of development

The set of genes responsible for the regulation of animal development, largely comprised of members of cell-cell signalling pathways and transcription factors.

A family of quite similar 180-bp DNA sequences that encode a polypetide sequence called homedomain, a sequence-specific DNA-binding sequence. Although the homeobox was first discovered in all homeotic genes, it is now known to encode a much more widespread DNA-binding motif.

A highly conserved family of sequences, 60 AS in length and found within a large number of transcription factors, that can form helix-turn-helix structures and bind DNA in a sequence-specific manner.

An informal term for a gene whose product is required in all cells and carries out a basic physiological function.

Members of this gene class are the clustered homeobox-containing, homeotic genes that govern the identity of body parts along the anterior-posterior axis of most bilateral animals

A gene that produces an effect only when present in the mother.

In Drosophila, a member of a class of zygotically expressed genes that act at an intermediary stage in the process of establishing the correct numbers of body segments. Pair-rule mutations have half the normal number of segment, owing to the loss of every other segment.

The process by which chemical cues that establish cell fate along geographic axis are established in a developing embryo or tissue primordium.

In Drosophila, a member of a class of genes that contribute to the final aspects of establishing the correct number of segments. Segment-polarity mutations cause a loss or change in a comparable part of each of the body segments.

Body parts that are members of repeated series, such as digits, ribs, teeth, limbs and segments.

A cell formed by the fusion of an egg and a sperm, the unique diploid cell that will divide mitotically to create a differentiated diploid organism.