If you or someone you know would like to enroll in an internet summer school that has a strong an... more If you or someone you know would like to enroll in an internet summer school that has a strong and trustworthy reputation, then that describes ours perfectly. We're an online American high educational institution that offers international accreditation.
Summer is supposed to be a time to kick back, relax, and have fun. Students who find themselves e... more Summer is supposed to be a time to kick back, relax, and have fun. Students who find themselves enrolled in summer school instead may struggle to find ways to stay on track. These techniques will help.
... Accepted 25 April 1997. Landscape ecology of algal symbionts creates variation in episodes of... more ... Accepted 25 April 1997. Landscape ecology of algal symbionts creates variation in episodes of coral bleaching. Rob Rowan 1, 2 , Nancy ...
The sequence of 1.6 kb of DNA surrounding the alcohol dehydrogenase (Adh) gene from five species ... more The sequence of 1.6 kb of DNA surrounding the alcohol dehydrogenase (Adh) gene from five species of the Planitibia subgroup of the Hawaiian picture-winged Drosophila, with estimated divergence times of 0.4-S. 1 Myr, has been determined. The gene trees which were found by using the sequence divergence from different regions of the sequences are generally in accord with the phylogeny
Proceedings of the National Academy of Sciences, 1992
Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine... more Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine invertebrates. The issue of zooxanthella diversity has been difficult to address. Most zooxanthellae have been placed in the dinoflagellate genus Symbiodinium as one or several species that are not easily distinguished. We compared Symbiodinium and nonsymbiotic dinoflageliates using small ribosomal subunit RNA sequences. Surprisingly, small ribosomal subunit RNA diversity within the genus Symbiodinium is comparable to that observed among different orders of nonsymbiotic dinoflagellates. These data reinforce the conclusion that Symbiodiniumlike zooxanthellae represent a collection of distinct species and provide a precedent for a molecular genetic taxonomy of the genus Symbiodinium.
Soritids are large calcareous foraminiferans abundant in Indo-Paci®c coral reefs. Soritids are kn... more Soritids are large calcareous foraminiferans abundant in Indo-Paci®c coral reefs. Soritids are known to host endosymbionts morphologically and genetically similar to Symbiodinium-like dino¯agellates commonly found in corals and other marine invertebrates. In order to examine the phylogenetic relationships between symbionts present in foraminiferal and coelenterate hosts, we used DNA sequencing and PCR-based RFLP methods to analyse 157 foraminiferal and 110 coral DNA samples from 12 localities in Guam (Micronesia) collected in July 1999 and December 1999. Ribosomal DNA sequences were obtained for 14 foraminiferal and 12 coral samples. Sequence analyses allowed identi®cation of six dierent Symbiodinium phylotypes among soritids and two phylotypes among examined coelenterates. A single phylotype, previously described as lineage C, was common in foraminiferans and corals. The PCR-based RFLP analysis of 157 foraminiferal and 110 coral samples shows that lineage C dominates coral symbiont communities, accounting for 78% in both sampling periods. On the other hand, our data show that lineages C and Fr6 dominated foraminiferal symbiont communities in July 1999 versus a clear predominance of lineages C and Fr3 in November 1999. The other three phylotypes present in soritids (Fr1, Fr4, Fr5) were uncommon and seem to occur seasonally. The phylogenetic analysis of the present data indicates relative speci®city of soritid symbionts compared to other Symbiodiniumlike dino¯agellates, but the causes of this speci®city are not yet understood. 1991). Soritids present, in some areas, a spectacular Marine
The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene from... more The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene from Drosophila ag~nidisjuncta, and the RNA sequences of the D. a~nidisjuncta Adh transcripts, are presented. These data support the eonclusion that two Adh promoters generate distinct, developmentally regulated Adh transcripts. Correlations between these sequences and the transcription map are discussed. Comparisons between these and equivalent data from D. melanogaster are also presented. We note the following observations: (I) Except at the extreme 3' end, the two genes are identically organized. (2) Drosophila Adh protein accumulates amino acid replacements at the rate of approximately 0.5 per million years. (3) Among the non-protein-coding DNA sequences, putative homologies occur in the two promoter regions.
Purpose Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ul... more Purpose Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ulnar-sided wrist pain; however, its efficacy in this setting still needs clarification. The purposes of this study were to investigate the prevalence of abnormal MRI findings in the triangular fibrocartilage complex (TFCC) in asymptomatic volunteers and to provide the clinician with comparative data when interpreting MRI results.
If you or someone you know would like to enroll in an internet summer school that has a strong an... more If you or someone you know would like to enroll in an internet summer school that has a strong and trustworthy reputation, then that describes ours perfectly. We're an online American high educational institution that offers international accreditation.
Summer is supposed to be a time to kick back, relax, and have fun. Students who find themselves e... more Summer is supposed to be a time to kick back, relax, and have fun. Students who find themselves enrolled in summer school instead may struggle to find ways to stay on track. These techniques will help.
... Accepted 25 April 1997. Landscape ecology of algal symbionts creates variation in episodes of... more ... Accepted 25 April 1997. Landscape ecology of algal symbionts creates variation in episodes of coral bleaching. Rob Rowan 1, 2 , Nancy ...
The sequence of 1.6 kb of DNA surrounding the alcohol dehydrogenase (Adh) gene from five species ... more The sequence of 1.6 kb of DNA surrounding the alcohol dehydrogenase (Adh) gene from five species of the Planitibia subgroup of the Hawaiian picture-winged Drosophila, with estimated divergence times of 0.4-S. 1 Myr, has been determined. The gene trees which were found by using the sequence divergence from different regions of the sequences are generally in accord with the phylogeny
Proceedings of the National Academy of Sciences, 1992
Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine... more Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine invertebrates. The issue of zooxanthella diversity has been difficult to address. Most zooxanthellae have been placed in the dinoflagellate genus Symbiodinium as one or several species that are not easily distinguished. We compared Symbiodinium and nonsymbiotic dinoflageliates using small ribosomal subunit RNA sequences. Surprisingly, small ribosomal subunit RNA diversity within the genus Symbiodinium is comparable to that observed among different orders of nonsymbiotic dinoflagellates. These data reinforce the conclusion that Symbiodiniumlike zooxanthellae represent a collection of distinct species and provide a precedent for a molecular genetic taxonomy of the genus Symbiodinium.
Soritids are large calcareous foraminiferans abundant in Indo-Paci®c coral reefs. Soritids are kn... more Soritids are large calcareous foraminiferans abundant in Indo-Paci®c coral reefs. Soritids are known to host endosymbionts morphologically and genetically similar to Symbiodinium-like dino¯agellates commonly found in corals and other marine invertebrates. In order to examine the phylogenetic relationships between symbionts present in foraminiferal and coelenterate hosts, we used DNA sequencing and PCR-based RFLP methods to analyse 157 foraminiferal and 110 coral DNA samples from 12 localities in Guam (Micronesia) collected in July 1999 and December 1999. Ribosomal DNA sequences were obtained for 14 foraminiferal and 12 coral samples. Sequence analyses allowed identi®cation of six dierent Symbiodinium phylotypes among soritids and two phylotypes among examined coelenterates. A single phylotype, previously described as lineage C, was common in foraminiferans and corals. The PCR-based RFLP analysis of 157 foraminiferal and 110 coral samples shows that lineage C dominates coral symbiont communities, accounting for 78% in both sampling periods. On the other hand, our data show that lineages C and Fr6 dominated foraminiferal symbiont communities in July 1999 versus a clear predominance of lineages C and Fr3 in November 1999. The other three phylotypes present in soritids (Fr1, Fr4, Fr5) were uncommon and seem to occur seasonally. The phylogenetic analysis of the present data indicates relative speci®city of soritid symbionts compared to other Symbiodiniumlike dino¯agellates, but the causes of this speci®city are not yet understood. 1991). Soritids present, in some areas, a spectacular Marine
The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene from... more The DNA sequence of a 3886-bp genomic region containing the alcohol dehydrogenase (Adh) gene from Drosophila ag~nidisjuncta, and the RNA sequences of the D. a~nidisjuncta Adh transcripts, are presented. These data support the eonclusion that two Adh promoters generate distinct, developmentally regulated Adh transcripts. Correlations between these sequences and the transcription map are discussed. Comparisons between these and equivalent data from D. melanogaster are also presented. We note the following observations: (I) Except at the extreme 3' end, the two genes are identically organized. (2) Drosophila Adh protein accumulates amino acid replacements at the rate of approximately 0.5 per million years. (3) Among the non-protein-coding DNA sequences, putative homologies occur in the two promoter regions.
Purpose Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ul... more Purpose Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ulnar-sided wrist pain; however, its efficacy in this setting still needs clarification. The purposes of this study were to investigate the prevalence of abnormal MRI findings in the triangular fibrocartilage complex (TFCC) in asymptomatic volunteers and to provide the clinician with comparative data when interpreting MRI results.
In Drosophila melanogaster X D. simulans hybrids, the alcohol dehydrogenase (ADH) electromorphs c... more In Drosophila melanogaster X D. simulans hybrids, the alcohol dehydrogenase (ADH) electromorphs characteristic of the two parents display tissue- and stage-specific differences in relative level of expression. This implies distinct cis-acting regulatory elements associated with the respective Adh alleles. These cis-acting elements account in part, but not completely, for markedly different overall patterns of ADH expression in the two species. The regulatory patterns seem to be adaptively significant since they correlate with species-specific patterns of ethanol tolerance. The activity differences are accounted for by different levels of enzyme protein, but the underlying mechanisms have not been fully analysed and may be complex. Independent evolution of various aspects of the ADH developmental programme may relate to use of different promoters for transcription of the Adh locus in different developmental contexts. This system illustrates the potential importance of regulatory genes in evolution and provides a model for investigating the molecular basis of evolved regulatory differences.
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