Putting senescence genes on the map

Mapping a chromosome

 These pages represent a kind of crash course in genetics.  Obviously it isn’t possible to cover the whole of a deep and varied subject like genetics in a few sentences and images.  If you are inspired to get further into this, the discipline at the heart of biology, get hold of a good introductory textbook, such as this excellent volume by my good friend Neil Jones and colleagues.
 

Chromosomes
 

 <  Genes that regulate senescence, like all genes, are located on Chromosomes.
 

Mendel's laws
 

 <  Inheritance of traits (including senescence) specified by genes follows Mendel's laws, rules originally described by Gregor Mendel.
 

Linkage
 

 <  Genes on the same chromosome are generally inherited together, but during the formation of sex cells genes Linkage may be broken and the genes will recombine.
 

Mapping
 

 <  Mapping involves measuring the frequency of recombination to position genes on the genetic map.
 

QTL

 <  QTL analysis is a particular kind of linkage mapping that enables multiple genes contributing to complex traits to be located on the map.
 
 

Further information

The following papers will open the door to more information and the extensive literature on genetic mapping, senescence alleles and QTL:

R N Jones, H J Ougham, H Thomas (1997) Markers and mapping; we are all geneticists now. New Phytologist 137: 165-177

H Thomas, C J Howarth (2000) Five ways to stay green. Journal of Experimental Botany 51: 329-337

H Ougham, I Armstead, C Howarth, I Galyuon, I Donnison, H Thomas (2007) The genetic control of senescence revealed by mapping quantitative trait loci. Annual Plant Reviews 26: 171-201