Stamatis Alahiotis | University of Patras (original) (raw)
Papers by Stamatis Alahiotis
Figure 2. Neighbor-joining (Saitou and Nei 1987) cladogram, based on the net nucleotide divergence.
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1983
ABSTRACT 1.1. Salivary glands from third instar larvae of Ceratitis capitata synthesize a set of ... more ABSTRACT 1.1. Salivary glands from third instar larvae of Ceratitis capitata synthesize a set of at least 8 specific polypeptides in response to heat shock (37°C for 30 min), while the overall protein synthesis is reduced.2.2. The main heat shock protein (hsp) was found to have on SDS, an apparent molecular weight 69,000 (69 K) and may correspond to the respective 70 K protein of Drosophila melanogaster. The rest hsps have been named according to their molecular weight as follows: 87, 34, 20, 16, 14, 13 and 12 K.3.3. The description of the heat shock (HS) system in the insect under investigation has revealed similarities and differences in comparison to that of Drosophila or other taxa, in terms of the electrophoretic distribution on SDS gel of several hsps, the optimum response, the time course of the hsp synthesis etc.4.4. Heat pretreatment at a mild temperature, followed by a heat shock of late third instar larvae resulted in an enhancement of both the survival and the hsp synthesis. Increased hsp synthesis was also observed when salivary glands were exposed to preheating before the heat shock. These observations are discussed in terms of the function l significance of hsps.5.5. Based on our data in combination to the information in the literature the selective and evolutionary significance of the heat shock genes is emphasised.
Journal of Natural History, 2008
ABSTRACT The genetic differentiation of 11 Greek Atherina hepsetus populations have been investig... more ABSTRACT The genetic differentiation of 11 Greek Atherina hepsetus populations have been investigated at the mtDNA level. Restriction fragment length polymorphism analysis of three mtDNA regions (12S rRNA, 16S rRNA and D‐loop) amplified by PCR was used. Eighteen restriction endonucleases were found to have at least one recognition site at the three mtDNA regions studied. Fifteen different composite haplotypes were detected among the populations studied while 80.6% of the individuals were grouped in two common haplotypes. The estimated net nucleotide sequence divergence values between the populations ranged from 0.003 to 0.379%, while the Nst value of 0.092 indicates the existence of low interpopulation genetic differentiation. The findings clearly support the existence of a single panmictic population in the sampling area.
Heredity, 2002
The genetic differentiation and the phylogenetic relationships of eight Atherina boyeri Greek pop... more The genetic differentiation and the phylogenetic relationships of eight Atherina boyeri Greek populations have been investigated at the mtDNA level. The populations studied are from two different lakes, a lagoon, the interface zone between the lagoon and the sea, and four marine sites. RFLP analysis of three mtDNA segments (12s rRNA, 16s rRNA and D-loop) amplified by PCR was used. Six, seven and eight restriction enzymes were found to have at least one recognition site at 12s rRNA, 16s rRNA and D-loop respectively. Twenty-one different haplotypes were detected among the populations studied. Several restriction patterns were revealed. These patterns can be used for the discrimi
Hereditas, 2004
The functional characteristics of homogeneously purified LDH were studied in the eight D. melanog... more The functional characteristics of homogeneously purified LDH were studied in the eight D. melanogaster species subgroup at two different growing temperatures (14"C, 25°C). The V
Genome, 1989
In spite of previous consensus that no F1 fertile hybrids (of both sexes) could be produced betwe... more In spite of previous consensus that no F1 fertile hybrids (of both sexes) could be produced between any mating combination of Drosophila melanogaster, D. simulans, and D. mauritiana, the present data indicate that such hybrids were obtained. Thus, some crosses between D. mauritiana females and D. simulans or D. melanogaster males yield F1 fertile hybrids (of both sexes) which have been named Masi (or Masi-2 and Masi-3) and Mame, respectively. Electrophoretic studies, using the species-diagnostic genes for 6-phosphogluconate dehydrogenase, alcohol dehydrogenase, and aldehyde oxidase (6-Pgd, Adh, and Aldox, respectively), were used to investigate the hybrid status, taking into consideration (i) their reproductive relationships, (ii) the coexistence of electromorphs from different species in the same hybrid, within the same generation, and (iii) the expression of the above electromorphs in the hybrids as well as in progeny from backcrosses, where unexpected irregularities and abnormali...
Biochemical Genetics, 1982
The term "pseudopolymorphism" was used by Gruneberg (1980), who described the genetics ... more The term "pseudopolymorphism" was used by Gruneberg (1980), who described the genetics of the shell patterns of marine snails of the genus Umbonium. As used by this author, the term refers to a situation where "there is no simple correspondence between genotype and phenotype: a single genotype may be moulded into several phenotypes by influence of the environment and presumably by interaction with a polygenic background." Almost simultaneously, Onoufriou and Alahiotis (1981) (both papers were submitted for publication in May 1980) have used the same term to describe another case where there is no correspondence between genotype and phenotype. More precisely the Ldh locus in Drosophila melanogaster, while monomorphic, appears polymorphic on starch or acrylamide gels. Genetic analyses have shown that the observed Ldh electrophoretic variant was not a real one and could be attributed to the presence of ADH (the Adh locus is polymorphic) which oxidizes D(-)-lactate or L(+)-lactate with NAD. Although in both cases there is no correspondence between genotype and phenotype and the use of the term pseudopolymorphism in a broad sense could cover the above-described different situations, in order to avoid any confusion and according to the rule concerning priorities, we wish to substitute, in place of "pseudopolymorhism," the term "pseudoelectromorphism" to apply to the particular kind of situation we described (Onoufriou and Alahiotis, 1981).
Biochemical Genetics, 2005
Biochemical Genetics, 2007
Journal of Apicultural Research, 2005
Genetics, 1983
Non-Mendelian inheritance was revealed for the "heat-sensitivity" character of the poik... more Non-Mendelian inheritance was revealed for the "heat-sensitivity" character of the poikilothermic insect Drosophila melanogaster. Genetic analyses were performed on heat-sensitive (S, S 1) strains, derived through indirect selection, and on stocks constructed through extensive chromosomal and cytoplasmic substitutions between strains obtained from two replicate cage populations. The populations were kept for about 7 years under different temperatures (14°-25°) and exhibited different survival. We conclude that the character studied is quantitative, responds to selection pressure and is transmitted through the maternal cytoplasm, while nuclear genes modify its expression.
Genetica, 1987
Strong sexual isolation established between D. melanogaster long-term cage populations (originate... more Strong sexual isolation established between D. melanogaster long-term cage populations (originated from common parents and being under selection pressure since 1972) is maintained (with a tendency to increase) for twelve years after the origin of the populations. The sexual isolation is also maintained when the populations are kept in common conditions for about two years, while it dramatically decreases when the populations live on a food medium supplemented with strong chemical selective factors, such as various metals or ethanol. Seasonal or geographical studies of sexual isolation between natural and our cage populations did not reveal significant deviation from random matings. The genetic nature of sexual isolation is discussed.
Pedagogy, Culture & Society, 2006
and-conditions-of-access.pdf This article maybe used for research, teaching and private study pur... more and-conditions-of-access.pdf This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Journal of Molecular Evolution, 1980
obtained from several temperate and tropical Drosophila species was examined by comparing their c... more obtained from several temperate and tropical Drosophila species was examined by comparing their catalytic properties, which related to temperature (K mE a-Q 1 0-T h e r m o s t a b i l i t y). Mitochondrial 0tGPO or m-MDH obtained either from temperate or from tropical species was found to exhibit similar catalytic properties while for both cytosolic enzymes, the aGPDH and s-MDH, K m patterns were similar among species from the same thermal habitat and different between thermal habitats. In combination with other observations reported in the literature these facts support the view that the function, and probably the structure, of mitochondrial enzymes are better conserved in evolution than those of the corresponding enzymes found in the cytosol. It is proposed that the relative invariance of the mitochondrial enzymes structure is probably linked to a necessary relative invariance of molecular interactions inside the mitochondrion.
Hereditas, 2004
The copy number and the chromosome positions of the P and hobo insertions were determined by mean... more The copy number and the chromosome positions of the P and hobo insertions were determined by means of in situ hybridization to polytene chromosomes, in five long-term Drosophila melanogaster cage populations kept for 18 years under different culture conditions (temperature and relative humidity). The analysis revealed that the copy number of both P and hobo elements were similar between the populations kept under the same culture conditions and significantly different among the populations maintained under different culture conditions. A tendency for similar distribution of these elements along the major chromosome arms was also observed in the populations of the same environmental manipulation. The distribution of the insertions along the chromosomes was not random for both the P and hobo elements; sites with high insertion frequencies were found (hot spots of occupation). Some of them were common in all cage populations while others were characteristic of the populations kept under the same conditions. Finally, fixed sites of occupation were also observed in all populations and refer mostly to hobo distribution. The data are discussed on the basis of the possible involvement of the P and hobo elements, in some way, to the adaptation process and speciation.
Hereditas, 2004
A three-season comparative analysis of the chromosomal distribution of P and hobo mobile elements... more A three-season comparative analysis of the chromosomal distribution of P and hobo mobile elements in a natural population of Drosophila melanoguster.-Hereditas 120: 127-140. Lund, Sweden.
Hereditas, 2008
Genetic analysis of 23.5 MRF (hobo) and P-M hybrid dysgenesis determinants in a Greek natural pop... more Genetic analysis of 23.5 MRF (hobo) and P-M hybrid dysgenesis determinants in a Greek natural population in six collections over 24 months, showed the existence of hobo activity in the population at rates higher than P activity. Moreover, seasonal differentiation in hobo GD-sterility potential and hobo repressor abilities were observed. The P activity was low in the population but some tendency for seasonal differentiation of the cytotype was detected. The two systems operate independently in nature. Analysis of isofemale lines, established from inseminated wild-caught females, showed rapid differentiation of their hybrid dysgenesis determinants in the laboratory. This shows that results obtained from isofemale lines do not necessarily reflect the original population structure. The seasonal differentiation may be correlated with seasonal environmental factors, and may be attributed to differences in structure and function of the elements that consequently affect their regulation and transposition.
Genetica, 1986
Four Drosophila melanogaster strains, each homozygous for one of the two major ADH allozymes, Fas... more Four Drosophila melanogaster strains, each homozygous for one of the two major ADH allozymes, Fast and Slow (Adh FI, Adh $1, Adh F2 and Adh se) were used to study the interaction of the Adh locus with ethanol and temperature. The separate and especially the combined effects of these two parameters allow the conclusion that the Adh locus of D. melanogaster intervenes in the adaptation process through the heat shock protein system.
Figure 2. Neighbor-joining (Saitou and Nei 1987) cladogram, based on the net nucleotide divergence.
Comparative Biochemistry and Physiology Part B: Comparative Biochemistry, 1983
ABSTRACT 1.1. Salivary glands from third instar larvae of Ceratitis capitata synthesize a set of ... more ABSTRACT 1.1. Salivary glands from third instar larvae of Ceratitis capitata synthesize a set of at least 8 specific polypeptides in response to heat shock (37°C for 30 min), while the overall protein synthesis is reduced.2.2. The main heat shock protein (hsp) was found to have on SDS, an apparent molecular weight 69,000 (69 K) and may correspond to the respective 70 K protein of Drosophila melanogaster. The rest hsps have been named according to their molecular weight as follows: 87, 34, 20, 16, 14, 13 and 12 K.3.3. The description of the heat shock (HS) system in the insect under investigation has revealed similarities and differences in comparison to that of Drosophila or other taxa, in terms of the electrophoretic distribution on SDS gel of several hsps, the optimum response, the time course of the hsp synthesis etc.4.4. Heat pretreatment at a mild temperature, followed by a heat shock of late third instar larvae resulted in an enhancement of both the survival and the hsp synthesis. Increased hsp synthesis was also observed when salivary glands were exposed to preheating before the heat shock. These observations are discussed in terms of the function l significance of hsps.5.5. Based on our data in combination to the information in the literature the selective and evolutionary significance of the heat shock genes is emphasised.
Journal of Natural History, 2008
ABSTRACT The genetic differentiation of 11 Greek Atherina hepsetus populations have been investig... more ABSTRACT The genetic differentiation of 11 Greek Atherina hepsetus populations have been investigated at the mtDNA level. Restriction fragment length polymorphism analysis of three mtDNA regions (12S rRNA, 16S rRNA and D‐loop) amplified by PCR was used. Eighteen restriction endonucleases were found to have at least one recognition site at the three mtDNA regions studied. Fifteen different composite haplotypes were detected among the populations studied while 80.6% of the individuals were grouped in two common haplotypes. The estimated net nucleotide sequence divergence values between the populations ranged from 0.003 to 0.379%, while the Nst value of 0.092 indicates the existence of low interpopulation genetic differentiation. The findings clearly support the existence of a single panmictic population in the sampling area.
Heredity, 2002
The genetic differentiation and the phylogenetic relationships of eight Atherina boyeri Greek pop... more The genetic differentiation and the phylogenetic relationships of eight Atherina boyeri Greek populations have been investigated at the mtDNA level. The populations studied are from two different lakes, a lagoon, the interface zone between the lagoon and the sea, and four marine sites. RFLP analysis of three mtDNA segments (12s rRNA, 16s rRNA and D-loop) amplified by PCR was used. Six, seven and eight restriction enzymes were found to have at least one recognition site at 12s rRNA, 16s rRNA and D-loop respectively. Twenty-one different haplotypes were detected among the populations studied. Several restriction patterns were revealed. These patterns can be used for the discrimi
Hereditas, 2004
The functional characteristics of homogeneously purified LDH were studied in the eight D. melanog... more The functional characteristics of homogeneously purified LDH were studied in the eight D. melanogaster species subgroup at two different growing temperatures (14"C, 25°C). The V
Genome, 1989
In spite of previous consensus that no F1 fertile hybrids (of both sexes) could be produced betwe... more In spite of previous consensus that no F1 fertile hybrids (of both sexes) could be produced between any mating combination of Drosophila melanogaster, D. simulans, and D. mauritiana, the present data indicate that such hybrids were obtained. Thus, some crosses between D. mauritiana females and D. simulans or D. melanogaster males yield F1 fertile hybrids (of both sexes) which have been named Masi (or Masi-2 and Masi-3) and Mame, respectively. Electrophoretic studies, using the species-diagnostic genes for 6-phosphogluconate dehydrogenase, alcohol dehydrogenase, and aldehyde oxidase (6-Pgd, Adh, and Aldox, respectively), were used to investigate the hybrid status, taking into consideration (i) their reproductive relationships, (ii) the coexistence of electromorphs from different species in the same hybrid, within the same generation, and (iii) the expression of the above electromorphs in the hybrids as well as in progeny from backcrosses, where unexpected irregularities and abnormali...
Biochemical Genetics, 1982
The term "pseudopolymorphism" was used by Gruneberg (1980), who described the genetics ... more The term "pseudopolymorphism" was used by Gruneberg (1980), who described the genetics of the shell patterns of marine snails of the genus Umbonium. As used by this author, the term refers to a situation where "there is no simple correspondence between genotype and phenotype: a single genotype may be moulded into several phenotypes by influence of the environment and presumably by interaction with a polygenic background." Almost simultaneously, Onoufriou and Alahiotis (1981) (both papers were submitted for publication in May 1980) have used the same term to describe another case where there is no correspondence between genotype and phenotype. More precisely the Ldh locus in Drosophila melanogaster, while monomorphic, appears polymorphic on starch or acrylamide gels. Genetic analyses have shown that the observed Ldh electrophoretic variant was not a real one and could be attributed to the presence of ADH (the Adh locus is polymorphic) which oxidizes D(-)-lactate or L(+)-lactate with NAD. Although in both cases there is no correspondence between genotype and phenotype and the use of the term pseudopolymorphism in a broad sense could cover the above-described different situations, in order to avoid any confusion and according to the rule concerning priorities, we wish to substitute, in place of "pseudopolymorhism," the term "pseudoelectromorphism" to apply to the particular kind of situation we described (Onoufriou and Alahiotis, 1981).
Biochemical Genetics, 2005
Biochemical Genetics, 2007
Journal of Apicultural Research, 2005
Genetics, 1983
Non-Mendelian inheritance was revealed for the "heat-sensitivity" character of the poik... more Non-Mendelian inheritance was revealed for the "heat-sensitivity" character of the poikilothermic insect Drosophila melanogaster. Genetic analyses were performed on heat-sensitive (S, S 1) strains, derived through indirect selection, and on stocks constructed through extensive chromosomal and cytoplasmic substitutions between strains obtained from two replicate cage populations. The populations were kept for about 7 years under different temperatures (14°-25°) and exhibited different survival. We conclude that the character studied is quantitative, responds to selection pressure and is transmitted through the maternal cytoplasm, while nuclear genes modify its expression.
Genetica, 1987
Strong sexual isolation established between D. melanogaster long-term cage populations (originate... more Strong sexual isolation established between D. melanogaster long-term cage populations (originated from common parents and being under selection pressure since 1972) is maintained (with a tendency to increase) for twelve years after the origin of the populations. The sexual isolation is also maintained when the populations are kept in common conditions for about two years, while it dramatically decreases when the populations live on a food medium supplemented with strong chemical selective factors, such as various metals or ethanol. Seasonal or geographical studies of sexual isolation between natural and our cage populations did not reveal significant deviation from random matings. The genetic nature of sexual isolation is discussed.
Pedagogy, Culture & Society, 2006
and-conditions-of-access.pdf This article maybe used for research, teaching and private study pur... more and-conditions-of-access.pdf This article maybe used for research, teaching and private study purposes. Any substantial or systematic reproduction, redistribution , reselling , loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Journal of Molecular Evolution, 1980
obtained from several temperate and tropical Drosophila species was examined by comparing their c... more obtained from several temperate and tropical Drosophila species was examined by comparing their catalytic properties, which related to temperature (K mE a-Q 1 0-T h e r m o s t a b i l i t y). Mitochondrial 0tGPO or m-MDH obtained either from temperate or from tropical species was found to exhibit similar catalytic properties while for both cytosolic enzymes, the aGPDH and s-MDH, K m patterns were similar among species from the same thermal habitat and different between thermal habitats. In combination with other observations reported in the literature these facts support the view that the function, and probably the structure, of mitochondrial enzymes are better conserved in evolution than those of the corresponding enzymes found in the cytosol. It is proposed that the relative invariance of the mitochondrial enzymes structure is probably linked to a necessary relative invariance of molecular interactions inside the mitochondrion.
Hereditas, 2004
The copy number and the chromosome positions of the P and hobo insertions were determined by mean... more The copy number and the chromosome positions of the P and hobo insertions were determined by means of in situ hybridization to polytene chromosomes, in five long-term Drosophila melanogaster cage populations kept for 18 years under different culture conditions (temperature and relative humidity). The analysis revealed that the copy number of both P and hobo elements were similar between the populations kept under the same culture conditions and significantly different among the populations maintained under different culture conditions. A tendency for similar distribution of these elements along the major chromosome arms was also observed in the populations of the same environmental manipulation. The distribution of the insertions along the chromosomes was not random for both the P and hobo elements; sites with high insertion frequencies were found (hot spots of occupation). Some of them were common in all cage populations while others were characteristic of the populations kept under the same conditions. Finally, fixed sites of occupation were also observed in all populations and refer mostly to hobo distribution. The data are discussed on the basis of the possible involvement of the P and hobo elements, in some way, to the adaptation process and speciation.
Hereditas, 2004
A three-season comparative analysis of the chromosomal distribution of P and hobo mobile elements... more A three-season comparative analysis of the chromosomal distribution of P and hobo mobile elements in a natural population of Drosophila melanoguster.-Hereditas 120: 127-140. Lund, Sweden.
Hereditas, 2008
Genetic analysis of 23.5 MRF (hobo) and P-M hybrid dysgenesis determinants in a Greek natural pop... more Genetic analysis of 23.5 MRF (hobo) and P-M hybrid dysgenesis determinants in a Greek natural population in six collections over 24 months, showed the existence of hobo activity in the population at rates higher than P activity. Moreover, seasonal differentiation in hobo GD-sterility potential and hobo repressor abilities were observed. The P activity was low in the population but some tendency for seasonal differentiation of the cytotype was detected. The two systems operate independently in nature. Analysis of isofemale lines, established from inseminated wild-caught females, showed rapid differentiation of their hybrid dysgenesis determinants in the laboratory. This shows that results obtained from isofemale lines do not necessarily reflect the original population structure. The seasonal differentiation may be correlated with seasonal environmental factors, and may be attributed to differences in structure and function of the elements that consequently affect their regulation and transposition.
Genetica, 1986
Four Drosophila melanogaster strains, each homozygous for one of the two major ADH allozymes, Fas... more Four Drosophila melanogaster strains, each homozygous for one of the two major ADH allozymes, Fast and Slow (Adh FI, Adh $1, Adh F2 and Adh se) were used to study the interaction of the Adh locus with ethanol and temperature. The separate and especially the combined effects of these two parameters allow the conclusion that the Adh locus of D. melanogaster intervenes in the adaptation process through the heat shock protein system.