Page 10 - Breeding Edge ebook

Building on the global collaborative efforts to improve field crops in developing countries, the Ford
Foundation, World Bank and others began in 1970 to set up a network of agricultural research centers
under permanent direction. The result was the Consultative Group on International Agricultural
Research (CGIAR), which is also supported by the United Nations Food and Agriculture Organization
and others. CGIAR operates several research centers.

Breeders pry into the cell nucleus

The path toward breeders’ genome manipulation required access to and knowledge of the millions of
genes on chromosomes, which lie in the cell nucleus. That access began with British researchers like
Rosalind Franklin, who, with an assistant, began producing the first high-resolution photos of
deoxyribonucleic acid (DNA) fibers in 1951.

Using such imagery, in 1953
molecular biologists James Watson
and Francis Crick were able to
describe chromosomes’ double helix,
the twisted-ladder structure of DNA.
That discovery became the sort of
first-grade graduation into modern
molecular biology, which is focused
on how genes control the chemical
processes of an organism’s growth
and bodily functions.

Norman Borlaug was a U.S. agronomist known as the father of the Green Revolution Biochemist Frederick Sanger, another
British scientist, and colleagues
pioneered what became known as the

“Sanger Method” of mapping the base pairs of genes, which are the letters of an organism’s genetic
code. His method was the original one for sequencing DNA and, in 1977, he published the sequence of a
virus genome of over 5,000 base pairs.

The Sanger Method became the usual one for mapping an organism’s genome. In recent decades, with
the expanding knowledge of DNA and massive capacity of computers to store and communicate
such data, researchers have moved ahead, compiling entire genomes of plants and animals.
Sequencing of the 3 billion base pairs of the human genome, a 13-year international collaborative
project, was completed in 2003.

Since 1995, scientists have sequenced the genomes of dozens of plants, including the major commercial
crops. Sequencing the genomes of farm animals began with that for a chicken in 2004, and those for a
cow (in 2009), and pig (2012) have since been published. Sequencing allows scientists to find specific
genes on the chromosomes and learn how each gene works together with an organism’s other genes to
create its phenotype, which is its appearance and how it grows, functions, and responds to changes, and
other characteristics.

At the same time, genetic engineering techniques were evolving to allow for the introduction of new
traits as well as greater control over traits than previous methods such as selective breeding and mutation
breeding, which is the process of exposing seeds to chemicals or radiation to generate mutants with
desirable traits that can then be bred with other cultivars.

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