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Born:
February 22, 1933, Maarssen, The Netherlands.
Current:
1) Prof. Emeritus Biological Science
Florida State University
Tallahassee FL 32306
2) Research Director
Animal Genetics
Avian Biotech International
1336 Timberlane Road
Tallahassee, FL 32312
PH: 1-800-514-9672
e-mail: siwo@avianbiotech.com
Education:
Ph. D. in Biophysical Chemistry. University of Utrecht, The Netherlands,
1961.
Postdoctoral fellowship at the Rockefeller University, New York, NY 1961
- 1962. Isolation of messenger RNA from calf thymus.
Positions held:
1) Research Biochemist, N.V. Philips Gloeilampenfabrieken, 1963 - 1967
2) Associate Prof/Prof Biological Science, Florida State University 1967
- 1996.
3) Professor emeritus Florida State University 1996 - present.
4) Research director Avian Biotech Int. 1992 - present
Research Interests:
Avian molecular evolution and genome organization, Sex differentiation
and identification of birds, Avian diseases, Bird conservation.
RECENT PUBLICATIONS:
Dr. de Kloet
and Avian Biotech have studied and published in the following areas of
avian molecular biology and genetics.
Edwin
de Kloet, Siwo R. de Kloet Analysis of the Beak and Feather Disease
Viral Genome Indicates the Existence of Several Genotypes Which Have a
Complex Psittacine Host Specificity Archives of
Virology, In Press.
ABSTRACT: A study was made of the phylogenetic
relationships between fifteen complete nucleotide sequences as well as
43 nucleotide sequences of the putative coat protein gene of different
strains of Beak and Feather Disease virus obtained from 39 individuals
of 16 psittacine species. The species included among others, cockatoos
(Cacatuini), African grey parrots (Psittacus erithacus) and peach-faced
lovebirds (Agapornis roseicollis), which were infected at different geographical
locations, within and outside Australia, the native origin of the virus.
The derived amino acid sequences of the putative coat protein were highly
diverse, with differences between some strains amounting to 50 of the
250 amino acids. Phylogenetic analysis demonstrated that the putative
coat gene sequences form six clusters which show a varying degree of psittacine
species specificity. Most, but not all strains infecting African grey
parrots formed a single cluster as did the strains infecting the cockatoos.
Strains infecting the lovebirds clustered with those infecting such Australasian
species as Eclectus roratus, Psittacula kramerii and Psephotus haematogaster.
Although individual birds included in this study were, where studied,
often infected by closely related strains, infection by highly diverged
trains was also detected. The possible relationship between BFD viral
strains and clinical disease signs is discussed.
Rolf
S. de Kloet, Siwo R. de Kloet Independent cessation of recombination
of sex chromosomes at the spindlin locus in neognathous birds and tinamous,
a palaeognathous avian family. Genetica 199:
333-342, 2003.
ABSTRACT: Tinamous (Aves, Palaeognathae,
Tinamiformes) are primitive birds, generally considered to be the sister
group to the ratites. Tinamous possess a W sex-chromosome, intermediate
in heterochromatization between the largely euchromatic W chromosome of
the ratites and the highly condensed W chromosome of the neognathous birds.
Of the four genes which are known to have diverged copies on the neognathous
avian W and Z chromosome (ATP5A1, CHD1, PKC and SPIN) only the spindlin
gene has W- and Z-chromosomal forms in the tinamiformes. This paper describes
experiments which show that the sequences of these forms are more similar
to each other and to the homologous undifferentiated spindlin gene sequences
in the ratite genome than to the W or Z forms of the spindlin gene in
other, neognathous species. This suggests that cessation of recombination
at the spindlin locus of the ancestral W and Z chromosomes of the tinamiformes
and the neagnathous avian species were independent events.
de
Kloet, SR (2002) Molecular sex identification of tinamous with
PCR using primers erived from the spindlin gene. Molecular
Ecology Notes 2:465 - 466.
ABSTRACT: This paper describes results which
show that the spindlin gene has different forms on the tinamid W and Z
chromosome, providing a sensitive and accurate procedure for a molecular,
PCR-based, procedure for sex-identification of tinamous.
de
Kloet, SR. (2001c) A repetitive DNA sequence on the W chromosome
of owls (Strigiformes) with sequence similarity to the chicken W chromosomal
repeat. The Auk, submitted
de
Kloet, SR (2001b). Development of a CAPS (Cleaved Amplified Polymorphics
Sequence) assay for sex identification of the emu (Dromaius novaehollandiae).
Molecular Ecology Letters 1: 273 - 275.
ABSTRACT: Polymerase chain rection (PCR)
based procedures that have been used to identify the sex of most birds
cannot be used in ratites. This paper described the identification of
a female (W-chromosomal) specific randomly amplified polymorphic (RAPD)
1.3 kb DNA fragment (ESEXW) in the emu (Dromaius novaehollandiae). Southern
blot experiments and sequence analysis revealed that a related (96% similarity)
sequence exists of the emu Z-chromosome (ESEXZ). The sequences of ESEXW
and ESEXZ have been used for the development of a two-primer CAPS (cleaved
amplified polymorphic sequence) assay for reliable sex identification
of the emu.
de
Kloet, SR. (2001a) Loss of the gene of the alpha subunit of ATP
synthase (ATP5A1) from the W chromosome of the African grey parrot (Psittacus
erithacus). Journal of Molecular Evolution 53:
135 - 143.
ABSTRACT: This study describes the results
of an analysis using Southern blotting, the polymerase chain reaction,
and sequencing which shows that the African grey parrot (Psittacus erithacus)
lacks the W-chromosomal gene for the alpha subunit of mitochondrial ATP
synthase (ATP5A1W). Additional evidence shows that in other psittacines
a fragment of the ATP5A1W gene contains five times as many nonsynonymous
nucleotide replacements as the homologous fragment of the Z gene. Therefore,
whereas in these other psittacines the corresponding ATP5A1Z protein fragment
is highly conserved and varies by only a few, moderately conservative
amino acid substitutions, the homologous ATP5A1W fragments contain a considerable
number of, sometimes highly nonconservative, amino acid replacements.
In one of these species, the ringneck parakeet (Psittacula krameri), the
ATP5A1W gene is present in an inactive form because of the presence of
a nonsense codon. Other changes, possibly leading to an inactive ATP5A1W
gene product, involve the substitution of arginine residues by cysteine
in the ATP5A1W protein of the mitred conure (Aratinga mitrata) and the
blue and gold macaw (Ara ararauna). The data suggest also that although
the divergence of the psittacine ATP5A1W and ATP5A1Z genes preceded the
origin of the psittacidae, this divergence occurred independently of a
similar process in the myna (Gracula religiosa), the outgroup used in
this study.
Shi
L, Drummond P, de Kloet SR, Pimentel-Smith GE, Smith EJ (2000).
Comparative sequence analysis of genetic variation in the African grey
parrot (Psittacus erythacus). Genetica 110:
226 - 230.
ABSTRACT: Comparative genome analysis promises
to provide an insight into avian species that have been very little studied.
To test the feasibility of this approach, we investigated the use of heterologous
primers to generate single nucleotide polymorphisms (SNP) in the African
grey parrot, Psittacus erythacus, using primers specific for chicken and
turkey DNA fragments. Three of the primers were specific for three expressed
sequence tagged sites in the turkey and the fourth for a chicken proteoglycan
core protein-like DNA sequence. A total of about 2200 bp of the parrot
genome was evaluated for DNA sequence variation. Seven SNPs were identified
and confirmed by Mendelian segregation. The frequency distribution of
the most common nucleotide at each SNP locus in an unrelated group of
parrots ranged from 0.84 to 0.97. The percent similarity of each parrot
sequence to the reference sequence was inconsistent and ranged from zero
to 100%. The primers as well as the nucleotide variants described represent
valuable resources for genetic analysis in the parrot.
Madsen
CS, de Kloet E, de Kloet SR. (1994). Sequence conservation of an
avian centromeric repeated DNA component. Genome
35: 1037 - 1044.
ABSTRACT: The approximately 190-bp centromeric
repeat monomers of the spur-winged lapwing (Vanellus spinosus, Charadriidae),
the Chilean flamingo (Phoenicopterus chilensis, Phoenicopteridae), the
sarus crane (Grus antigone, Gruidae), parrots (Psittacidae), waterfowl
(Anatidae), and the merlin (Falco columbarius, Falconidae) contain elements
that are interspecifically highly variable, as well as elements (trinucleotides
and higher order oligonucleotides) that are highly conserved in sequence
and relative location within the repeat. Such conservation suggests that
the centromeric repeats of these avian species have evolved from a common
ancestral sequence that may date from very early stages of avian radiation.
Tuohy
JM, McHugh KP, deKloet SR. (1992). Systematic relationships among
some Anatini as derived from restriction endonuclease analysis of a repeated
DNA component. The Auk 109: 465 - 473.
Madsen CS, McHugh
KP, de Kloet SR. (1992). Characterization of a Major Tandemly Repeated
DNA Sequence (RBMII) Prevalent Among Many Species of Waterfowl (Anatidae).
Genome 35:1037 - 1044.
ABSTRACT: We have investigated the evolution
of a 190 base pair tandemly repeated DNA sequence (RBMII) in 27 different
species of waterfowl. In this paper we show that the RBMII sequence is
present in many species belonging to 7 of the 11 Anatid tribes. Inter-
and intra-tribal differences in repeat presence indicate that, although
the RBMII sequence has been maintained among widely divergent species,
it is rapidly evolving. Restriction enzyme analyses suggest very different
hierarchical repeat organizations among different species. DNA sequence
comparisons of 32 cloned monomer units from five different species revealed
what appears to be a nonrandom distribution of sequence divergence, as
well as large differences (up to 25-fold) in intraspecific sequence variation
between relatively closely related species.
PMID: 1473722 [PubMed - indexed for MEDLINE]
Madsen CS, de Kloet
DH, Brooks JE, de Kloet SR (1992). Highly repeated DNA sequences
in birds: the structure and evolution of abundant, tandemly repeated 190
bp DNA fragment in parrots. Genomics 14: 462
- 469.
ABSTRACT: Up to 6.8% of the parrot (Psittaciformes)
genome consists of a tandemly repeated, 190-bp sequence (P1) located in
the centromere of many if not all chromosomes. Monomer repeats from 10
different psittacine species representing four subfamilies were isolated
and cloned. The intraspecific sequence variation ranged from 1.5 to 7%.
The interspecific sequence variation ranged from less than 3% between
two species of cockatoos to approximately 45% between cockatoos and other
parrots. The monomer sequences of all 10 parrot species contained several
conserved (> 90%) sequence elements at identical locations within the
repeat. A comparison with tandemly repeated DNA sequences in other avian
species showed that several of these conserved elements were also present
at similar locations within the 184-bp repeat of the Chilean flamingo
(Phoenicopterus chilensis), suggesting a great antiquity of the repeat.
One of the elements was also found in the tandemly repeated sequences
of the crane (Gruidae) and falcon (Falconidae) families. The data were
used for the construction of a partial most parsimonious relationship
that supports a regional subdivision of the Psittaciformes.
de Kloet DH, de
Kloet SR (1992). Molecular Determination of the Sex of Parrots.
Focus (BRL) 14: 106 - 108.
McHugh KP, Madsen
CS, de Kloet SR. (1990). A highly repeated retropseudogene-like
sequence in DNA of the red-breasted merganser (Mergus serrator). Gene
87: 193 - 197.
ABSTRACT: We have investigated the evolution
of a 190 base pair tandemly repeated DNA sequence (RBMII) in 27 different
species of waterfowl. In this paper we show that the RBMII sequence is
present in many species belonging to 7 of the 11 Anatid tribes. Inter-
and intra-tribal differences in repeat presence indicate that, although
the RBMII sequence has been maintained among widely divergent species,
it is rapidly evolving. Restriction enzyme analyses suggest very different
hierarchical repeat organizations among different species. DNA sequence
comparisons of 32 cloned monomer units from five different species revealed
what appears to be a nonrandom distribution of sequence divergence, as
well as large differences (up to 25-fold) in intraspecific sequence variation
between relatively closely related species.
Madsen CS, McHugh
KP, de Kloet SR. (1988). A partial classification of waterfowl
(Anatidae) based on single copy DNA. The Auk
105: 452 - 459.
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