Marco Antonio Zago
Encyclopedia
Marco Antonio Zago is a Brazilian physician
and prominent medical scientist
, who is active in the fields of hereditary diseases of the blood
(hemoglobin
s, clotting, thrombosis
), molecular basis of cancer and human population genetics
. Since 2007 he is also the president of the Brazilian National Research Council (CNPq).
Dr. Zago graduated in Medicine
from the School of Medicine of Ribeirão Preto of the University of São Paulo
in 1970, where he received the M.Sc. degree in medicine
(1973) and the Ph.D.
degree (1975), under the supervision of Professor Cássio Bottura, one of the most outstanding Brazilian hematologist and cytogeneticist.
After his post-doctoral training at the Oxford University, in the laboratories of Professor Sir David J. Wetherall, whose group was at the time establishing the molecular bases of the thalassemia
s, he returned to Brazil and started a research
group with a major scientific interest in the genetic bases of hematological diseases.
This group soon attracted attention with the following achievements, among others:
As a medical academic, Dr. Zago has supervised ca. 20 PhD or MSc theses, and most of his former graduate students are now researchers in different universities. Apart from his research group in Ribeirão Preto, his students have founded two other prominent research nuclei of human population genetics (in Belem
, Pará
) and hematology (in Campinas
). He participates in two consortia coordinated by FAPESP, a science foundation in the State of S. Paulo, and the Ludwig Institute for Cancer Research (LICR): the sequencing of the Xylella fastidiosa
genome
, the first phytopathogen whose genome was completely sequenced, and the FAPESP/LICR Human Cancer Genome Project, that studied the gene expression
in human neoplastic
tissues, and generated one of the largest contributions of gene expression to public databases.
Dr. Zago is a member of the Brazilian Academy of Sciences
and holds a Commend of the Brazilian Order of Scientific Merit
presented by the Presidency of the Republic on August 2000.
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...
and prominent medical scientist
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
, who is active in the fields of hereditary diseases of the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
(hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
s, clotting, thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
), molecular basis of cancer and human population genetics
Population genetics
Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population...
. Since 2007 he is also the president of the Brazilian National Research Council (CNPq).
Dr. Zago graduated in Medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
from the School of Medicine of Ribeirão Preto of the University of São Paulo
University of São Paulo
Universidade de São Paulo is a public university in the Brazilian state of São Paulo. It is the largest Brazilian university and one of the country's most prestigious...
in 1970, where he received the M.Sc. degree in medicine
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
(1973) and the Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
degree (1975), under the supervision of Professor Cássio Bottura, one of the most outstanding Brazilian hematologist and cytogeneticist.
After his post-doctoral training at the Oxford University, in the laboratories of Professor Sir David J. Wetherall, whose group was at the time establishing the molecular bases of the thalassemia
Thalassemia
Thalassemia is an inherited autosomal recessive blood disease that originated in the Mediterranean region. In thalassemia the genetic defect, which could be either mutation or deletion, results in reduced rate of synthesis or no synthesis of one of the globin chains that make up hemoglobin...
s, he returned to Brazil and started a research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
group with a major scientific interest in the genetic bases of hematological diseases.
This group soon attracted attention with the following achievements, among others:
- Demonstrated that the residual amount of HbFHBFHBF may refer to:* The Human Betterment Foundation, a eugenics organization established in 1928 by E.S. Gosney.* HbF, the form of hemoglobin found in the fetus.* HBF Health Fund, a provider of private health insurance in Western Australia....
produced in adults is genetically determined. The molecular bases for this inheritance are complex, involving at least three loci, and are of importance for the treatment of hereditary anemiaAnemiaAnemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...
s. - Identified for the first time in the country and described the genetic, the biochemical and the clinical features of several structural defects of hemoglobins and thalassemia variants, including a point mutationPoint mutationA point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. Often the term point mutation also includes insertions or deletions of a single base pair...
in the promoter region of the gamma globin geneGeneA gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
responsible for the Brazilian form of HbF persistence. - Identified molecular defects in hemophilias
- Identified a mutation of the LDL-r gene that is responsible for most of the cases of familial hypercholesterolemiaHypercholesterolemiaHypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...
in Brazil. - Revealed an until then unsuspected heterogeneity of the blood group O gene (from the ABO blood group), showing that the group O variants have a heterogeneous ethnic distribution and identified the molecular basis of this diversity, describing at least seven new molecular variants of the blood group O gene.
- Studied the contribution of genetic factors to the origin of thrombosis, including the role of mutations of several genes, related or not to the blood coagulation system. One mutation of especial interest involves de coagulation factor XIII and protects against the occurrence of arterial thrombosis.
- Studied the population genetics and physical anthropologyPhysical anthropologyBiological anthropology is that branch of anthropology that studies the physical development of the human species. It plays an important part in paleoanthropology and in forensic anthropology...
of Brazilian populations, especially the Amerindians and the BlacksBlacksBlacks may refer to:* All Blacks, New Zealand rugby union team* Black people* Blacks Leisure Group, owner of Blacks and Millets in the United Kingdom* The Blacks , a play by Jean Genet* Zamora, California, formerly called Blacks...
. On the basis of DNA markers linked to the sickle cell anemia gene, he demonstrated that the Brazilian black population is predominantly of Bantu origin, with a lesser contribution from the BeninBeninBenin , officially the Republic of Benin, is a country in West Africa. It borders Togo to the west, Nigeria to the east and Burkina Faso and Niger to the north. Its small southern coastline on the Bight of Benin is where a majority of the population is located...
and very little contribution from the Senegambia. These data demonstrated that this Black population is significantly different from its U.S. or Caribbean counterparts, with implications for the medical genetic studies that compare these populations and for the understanding of the hereditary diseases. Furthermore, his studies on markers linked to the mitochondrial DNAMitochondrial DNAMitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
, the Y chromosomeY chromosomeThe Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...
, several nuclear genes and VNTRs have contributed to the understanding of the genetic diversityGenetic diversityGenetic diversity, the level of biodiversity, refers to the total number of genetic characteristics in the genetic makeup of a species. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary....
of the Amerindian populations, the relationship with the founder populations, and the black Brazilian populations. His laboratory and his collaborators have contributed the largest volume of data on DNA markers in the Brazilian populations thus far.
As a medical academic, Dr. Zago has supervised ca. 20 PhD or MSc theses, and most of his former graduate students are now researchers in different universities. Apart from his research group in Ribeirão Preto, his students have founded two other prominent research nuclei of human population genetics (in Belem
Belem
Belem or Belém may refer to:* Belém, capital city of the Brazilian state of Pará* Belem , a three-masted barque from France* Belém, Alagoas, a municipality located in the Brazilian state of Alagoas...
, Pará
Pará
Pará is a state in the north of Brazil. It borders the Brazilian states of Amapá, Maranhão, Tocantins, Mato Grosso, Amazonas and Roraima. To the northwest it also borders Guyana and Suriname, and to the northeast it borders the Atlantic Ocean. The capital is Belém.Pará is the most populous state...
) and hematology (in Campinas
Campinas
Campinas is a city and municipality located in the coastal interior of the state of São Paulo, Brazil. is the administrative center of the meso-region of the same name, with 3,783,597 inhabitants as of the 2010 Census, consisting of 49 cities....
). He participates in two consortia coordinated by FAPESP, a science foundation in the State of S. Paulo, and the Ludwig Institute for Cancer Research (LICR): the sequencing of the Xylella fastidiosa
Xylella fastidiosa
Xylella fastidiosa, a bacterium in the class Gammaproteobacteria, is an important plant pathogen that causes phoney peach disease in the southern United States, oleander leaf scorch, and Pierce's disease, and citrus variegated chlorosis disease in Brazil.-Pierce's disease:Pierce's disease was...
genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
, the first phytopathogen whose genome was completely sequenced, and the FAPESP/LICR Human Cancer Genome Project, that studied the gene expression
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
in human neoplastic
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
tissues, and generated one of the largest contributions of gene expression to public databases.
Dr. Zago is a member of the Brazilian Academy of Sciences
Brazilian Academy of Sciences
The Brazilian Academy of Sciences is the national academy of Brazil. It is headquartered in the city of Rio de Janeiro and was founded in 1916....
and holds a Commend of the Brazilian Order of Scientific Merit
Brazilian Order of Scientific Merit
The National Order of Scientific Merit is an honor bestowed upon Brazilian and foreign personalities recognized for their scientific and technical contributions to the cause and development of science in Brazil.-Biology:* Marcelo Hermes-Lima* Jorge Curi...
presented by the Presidency of the Republic on August 2000.
Source
- Adapted from the official biography at the Brazilian Academy of Sciences, by permission of the biographed.