Joseph Grafton Gall (born April 14, 1928) is an American
cell biologist
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...
who is noted for studies revealing the details of chromosome structure and function. Gall's studies were greatly facilitated by his knowledge of many different organisms because he could select the most favorable organism to study when approaching a specific question about nuclear structure. He was awarded the 2006
Albert Lasker Special Achievement Award
The Albert Lasker Special Achievement Award is one of the four Lasker Awards given by the Lasker Foundation for medical research in the United States. The first award was given in 1994; it is not awarded every year. In 2008, the award was renamed ...
. He was also a co-recipient (with
Elizabeth Blackburn
Elizabeth Helen Blackburn, (born 26 November 1948) is an Australian-American Nobel laureate who is the former president of the Salk Institute for Biological Studies. Previously she was a biological researcher at the University of California, S ...
and
Carol W. Greider
Carolyn Widney Greider (born April 15, 1961) is an American molecular biologist and Nobel laureate. She joined the University of California, Santa Cruz as a Distinguished Professor in the department of molecular, cell, and developmental biology ...
) of the 2007
Louisa Gross Horwitz Prize
The Louisa Gross Horwitz Prize for Biology or Biochemistry is an annual prize awarded by Columbia University to a researcher or group of researchers who have made an outstanding contribution in basic research in the fields of biology or biochemist ...
from
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...
. In 1983 he was honored with the highest recognition of the
American Academy of Arts and Sciences
The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and ...
in 1968, the
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
in 1972, and the
American Philosophical Society
The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...
in 1989.
Research career
Gall was called "the father of cell biology" in his citation for the Lasker award. Gall was a major contributor to the theory that a chromosome contained one DNA molecule running from one end to the other. In chromosomes after
DNA replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritanc ...
, each of the two daughter
chromatid
A chromatid (Greek ''khrōmat-'' 'color' + ''-id'') is one half of a duplicated chromosome. Before replication, one chromosome is composed of one DNA molecule. In replication, the DNA molecule is copied, and the two molecules are known as chro ...
s had one DNA molecule running its length. He revealed this structure by examining amphibian
lampbrush chromosome
Lampbrush chromosome are a special form of chromosome found in the growing oocytes (immature eggs) of most animals, except mammals. They were first described by Walther Flemming and Ruckert in 1882. Lampbrush chromosomes of tailed and tailless amp ...
s in the microscope after staining for DNA and for
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
and also after treatment with enzymes that break down DNA or RNA. Although the
Feulgen stain
Feulgen stain is a staining technique discovered by Robert Feulgen and used in histology to identify chromosomal material or DNA in cell specimens. It is darkly stained. It depends on acid hydrolysis of DNA, therefore fixating agents using strong ...
for DNA was not sensitive enough to stain the DNA in the loops of these chromosomes, but only stained the long axis of the structure, the loops were sensitive to
DNase Deoxyribonuclease (DNase, for short) refers to a group of glycoprotein endonucleases which are enzymes that catalyze the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. The role of the DNase enzyme in cells ...
so they must contain DNA that maintained their loop structure. Later, staining with
DAPI
DAPI (pronounced 'DAPPY', /ˈdæpiː/), or 4′,6-diamidino-2-phenylindole, is a fluorescent stain that binds strongly to adenine–thymine-rich regions in DNA. It is used extensively in fluorescence microscopy. As DAPI can pass through an inta ...
, a more sensitive dye, revealed the DNA running through each loop and then returning to the axis of the chromosome. He also unveiled the structure and location of the rDNA, the part of the genome that specifies the
ribosomal RNA
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA which is the primary component of ribosomes, essential to all cells. rRNA is a ribozyme which carries out protein synthesis in ribosomes. Ribosomal RNA is transcribed from ribosomal ...
and made many more important discoveries about nuclear structure.Anna Azvolinsky, (2017) “Captivated by Chromosomes,” https://www.the-scientist.com/profile/captivated-by-chromosomes-30181
Gall and then-graduate student
Mary-Lou Pardue
Mary-Lou Pardue is an American geneticist who is an emeritus professor in the Department of Biology at the Massachusetts Institute of Technology, which she originally joined in 1972. Her research focused on the role of telomeres in chromosome re ...
wanted to find out where in the chromosomes a distinctive highly repeated DNA sequence called
satellite DNA Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin.
The name "satellite DNA" refers to the p ...
occurred. To show the location of this special DNA, they developed the widely used laboratory technique known as ''
in situ hybridization
''In situ'' hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i.e., probe) to localize a specific DNA or RNA sequence in a portion or section of tissue (''in situ'') or ...
''. Using this method, they found that satellite DNA occurred at the ends or
telomeres
A telomere (; ) is a region of repetitive nucleotide sequences associated with specialized proteins at the ends of linear chromosomes. Although there are different architectures, telomeres, in a broad sense, are a widespread genetic feature mos ...
of the chromosomes.
When Elizabeth Blackburn, 2009 Nobel laureate in Medicine, worked with Gall they analyzed the ends of chromosomes and identified the major short repeated sequence that occurs in telomeres of most higher organisms. Blackburn and her student
Carol Greider
Carolyn Widney Greider (born April 15, 1961) is an American molecular biologist and Nobel laureate. She joined the University of California, Santa Cruz as a Distinguished Professor in the department of molecular, cell, and developmental biology ...
later discovered the enzyme
telomerase
Telomerase, also called terminal transferase, is a ribonucleoprotein that adds a species-dependent telomere repeat sequence to the 3' end of telomeres. A telomere is a region of repetitive sequences at each end of the chromosomes of most euka ...
that maintains the lengths of the protective telomeric sequences and identified its role in aging.
Joseph Gall currently heads the Gall Lab, a component of the Department of Embryology in the
Carnegie Institution for Science
The Carnegie Institution of Washington (the organization's legal name), known also for public purposes as the Carnegie Institution for Science (CIS), is an organization in the United States established to fund and perform scientific research. Th ...
, in Maryland.
Role as a mentor of women scientists.
Gall is credited with encouraging women biologists, a group sometimes called "Gall's Gals", in an era when this was relatively uncommon. A number of his former students have been elected to the
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
and won major research prizes including the
Nobel Prize
The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
. His students have included
Joan Argetsinger Steitz
Joan Elaine Argetsinger Steitz (born January 26, 1941) is Sterling Professor of Molecular Biophysics and Biochemistry at Yale University and Investigator at the Howard Hughes Medical Institute. She is known for her discoveries involving RNA, inclu ...
,
Mary-Lou Pardue
Mary-Lou Pardue is an American geneticist who is an emeritus professor in the Department of Biology at the Massachusetts Institute of Technology, which she originally joined in 1972. Her research focused on the role of telomeres in chromosome re ...
, and
Elizabeth Blackburn
Elizabeth Helen Blackburn, (born 26 November 1948) is an Australian-American Nobel laureate who is the former president of the Salk Institute for Biological Studies. Previously she was a biological researcher at the University of California, S ...
.
One of his students who went on to do important work in cytology is Susan Gerbi. She co—wrote an article about Gall's life and work in 2003. In her conversations with Gall, when asked to explain his encouragement of women in the sciences, he spoke about his mother. Gifted in math and science, she had been the first woman in her family to attend college, graduating in the 1920s. She became a homemaker, not a scientist. But she urged a young Joseph Gall to explore the natural world, encouraging him to catch bugs and bring them into the house so together they could identify the creatures using scientific reference books. "It never occurred to me that a woman's aptitude was different than a man's," Gall said. "My father -- a lawyer -- was afraid of animals and insects. So, if anything, maybe I thought it went the other way.".
Awards
* National Academy of Sciences, 1972
* EB Wilson Award, 1983
* Lasker Award, 2006
* Louisa Gross Horwitz Prize, 2007
Legacy
In 2005, Gall was featured in a series of interviews with well-known television personality,
Bill Nye
William Sanford Nye (born November 27, 1955), popularly known as Bill Nye the Science Guy, is an American mechanical engineer, science communicator, and television presenter. He is best known as the host of the science television show ''Bill ...
, for the
Science Channel
Science Channel (often simply branded as Science; abbreviated to SCI) is an American pay television channel owned by Warner Bros. Discovery. The channel features programming focusing on science related to wilderness survival, engineering, manu ...