| Y linkage |
| The inheritance pattern of genes found on
the Y chromosome but not on the X (rare). |
| Y linked |
| Inheritance pattern of loci located on the
Y chromosome only. Also refers to the loci themselves. |
| y-junction |
| The point of active DNA replication where
the double helix opens up so that each strand can serve as a template.
|
| yeast artificial chromosome
(YAC) |
| Originating from a bacterial plasmid; a
YAC contains additionally a yeast centromeric region (CEN); a yeast
origin of DNA replication (ARS); and two telomere regions (TEL).
YACs are capable of cloning very large pieces of DNA. |
| Z DNA |
| A left-handed form of DNA found under physiological
conditions in short GC segments that are methylated. It may be important
in regulating gene expression in eukaryotes. |
| ZFY gene |
| Originally believed to be the human male
sex switch gene located on the short arm of the Y chromosome. ZFY
stands for zinc finger protein on the Y chromosome. |
| zinc finger |
| Configuration of a DNA-binding protein that
resembles a finger with a base, usually cysteines and histidines,
binding a zinc ion. Discovered in a transcription factor in Xenopus
but present in a large number of different proteins. |
| zygonema (zygotene stage)
|
| The stage of prophase I of meiosis in which
synapsis occurs. |
| zygote |
| The unique diploid cell formed by the fusion
of two haploid cells (often an egg and a sperm) that will divide
mitotically to create a differentiated diploid organism. |
| zygotic induction |
| When a prophage is passed into an F- cell
during conjugation it may begin vegetative growth. The sudden release
of a lysogenic phage from an Hfr chromosome when the prophage enters
the F-(minus) cell, and the subsequent lysis of the recipient cell.
|
zygotic selection
The forces acting to cause differential mortality of an organism
at any stage (other than gametes) in its life cycle. |
