Actin gene number in the sea star Pisaster ochraceus

1985 ◽  
Vol 63 (11) ◽  
pp. 1145-1151 ◽  
Author(s):  
Imre Kovesdi ◽  
Michael J. Smith
Keyword(s):  
Copy Number ◽  
Genomic Dna ◽  
Genomic Clone ◽  
Actin Gene ◽  
Sea Star ◽  
Noncoding Regions ◽  
Pisaster Ochraceus ◽  
Actin Genes ◽  
Untranslated Sequence ◽  
Least Squares Fit

The number of actin genes per haploid genome of three sea star species has been measured by reassociation of a single-strand actin-coding sequence probe with excess genomic DNA. Least-squares fit analyses of the reassociation curve indicate five actin genes for Pisaster ochraceus and Pisaster brevispinus and eight actin genes for Dermasterias imbricata. Using 3′ untranslated sequence probes from cDNAs or 3′ noncoding regions of a genomic clone, essentially all of the actin-containing Southern digest fragments can be assigned to the three actin gene classes described earlier for P. ochraceus. Through analyses of genomic digests and dot blots from P. ochraceus probed with both the actin sequence and 3′ sequence, the copy number of gene class members per genome has also been estimated.

Actin genes from the sea star Pisaster ochraceus

1984 ◽  
Vol 782 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Imre Kovesdi ◽  
Frank Preugschat ◽  
Margaret Stuerzl ◽  
Michael J. Smith
Keyword(s):  
Sea Star ◽  
Pisaster Ochraceus ◽  
Actin Genes

Isolation and characterization of six different chicken actin genes

1984 ◽  
Vol 4 (11) ◽  
pp. 2498-2508
Author(s):  
K S Chang ◽  
W E Zimmer ◽  
D J Bergsma ◽  
J B Dodgson ◽  
R J Schwartz
Keyword(s):  
Dna Sequences ◽  
Genomic Dna ◽  
Genomic Library ◽  
Smooth Muscle Actin ◽  
Actin Gene ◽  
Muscle Actin ◽  
Repeated Dna ◽  
Alpha Smooth Muscle Actin ◽  
Actin Genes ◽  
Actin Isoform

Genes representing six different actin isoforms were isolated from a chicken genomic library. Cloned actin cDNAs as well as tissue-specific mRNAs enriched in different actin species were used as hybridization probes to group individual actin genomic clones by their relative thermal stability. Restriction maps showed that these actin genes were derived from separate and nonoverlapping regions of genomic DNA. Of the six isolated genes, five included sequences from both the 5' and 3' ends of the actin-coding area. Amino acid sequence analysis from both the NH2- and COOH-terminal regions provided for the unequivocal identification of these genes. The striated isoforms were represented by the isolated alpha-skeletal, alpha-cardiac, and alpha-smooth muscle actin genes. The nonmuscle isoforms included the beta-cytoplasmic actin gene and an actin gene fragment which lacked the 5' coding and flanking sequence; presumably, this region of DNA was removed from this gene during construction of the genomic library. Unexpectedly, a third nonmuscle chicken actin gene was found which resembled the amphibian type 5 actin isoform (J. Vandekerckhove, W. W. Franke, and K. Weber, J. Mol. Biol., 152:413-426). This nonmuscle actin type has not been previously detected in warm-blooded vertebrates. We showed that interspersed, repeated DNA sequences closely flanked the alpha-skeletal, alpha-cardiac, beta-, and type 5-like actin genes. The repeated DNA sequences which surround the alpha-skeletal actin-coding regions were not related to repetitious DNA located on the other actin genes. Analysis of genomic DNA blots showed that the chicken actin multigene family was represented by 8 to 10 separate coding loci. The six isolated actin genes corresponded to 7 of 11 genomic EcoRI fragments. Only the alpha-smooth muscle actin gene was shown to be split by an EcoRI site. Thus, in the chicken genome each actin isoform appeared to be encoded by a single gene.

scholarly journals Organization and evolution of the actin gene family in sea urchins.

1983 ◽  
Vol 3 (10) ◽  
pp. 1824-1833 ◽  
Author(s):  
P J Johnson ◽  
D R Foran ◽  
G P Moore
Keyword(s):  
Sea Urchin ◽  
Sequence Homology ◽  
Copy Number ◽  
Sea Urchins ◽  
Intron Position ◽  
Actin Gene ◽  
Genomic Libraries ◽  
Lytechinus Pictus ◽  
Transcriptional Orientation ◽  
Actin Genes

Genomic libraries of the sea urchins Strongylocentrotus franciscanus and Lytechinus pictus were screened with an actin cDNA clone from Strongylocentrotus purpuratus. Four nonoverlapping clones were isolated and characterized from the S. franciscanus library; three were isolated and characterized from the L. pictus library. Linked genes having the same transcriptional orientation were found on all S. franciscanus clones. Three clones contained two actin genes each; the other clone contained three. In contrast, the L. pictus clones contained only one actin gene. Comparison of actin genomic clones from these three species indicated a difference in the genomic organization of sea urchin actin genes in that the genes appear to be more highly clustered in S. franciscanus than in S. purpuratus and L. pictus. Genomic dot blots and reassociation kinetics demonstrated that the copy number of actin genes in all three species is 15 to 20. Nucleotide sequence homology of actin genes within and among the species was measured by thermal elution. These experiments indicated that there is a high degree of interspecies actin gene sequence homology but that, within each species, actin gene sequences may differ by as much as 30%. Sequencing of two S. franciscanus actin genes revealed introns at the same amino acid positions, 121 and 204, reported for S. purpuratus actin genes. These data demonstrated that the genomic copy number, the transcriptional orientation of linked genes, and, to the extent studied, the intron position of actin genes have evolved similarly in these three species. In contrast, significant change has occurred in the chromosomal arrangement of sea urchin actin genes.

scholarly journals Isolation and characterization of six different chicken actin genes.

1984 ◽  
Vol 4 (11) ◽  
pp. 2498-2508 ◽  
Author(s):  
K S Chang ◽  
W E Zimmer ◽  
D J Bergsma ◽  
J B Dodgson ◽  
R J Schwartz
Keyword(s):  
Dna Sequences ◽  
Genomic Dna ◽  
Genomic Library ◽  
Smooth Muscle Actin ◽  
Actin Gene ◽  
Muscle Actin ◽  
Repeated Dna ◽  
Alpha Smooth Muscle Actin ◽  
Actin Genes ◽  
Actin Isoform

Genes representing six different actin isoforms were isolated from a chicken genomic library. Cloned actin cDNAs as well as tissue-specific mRNAs enriched in different actin species were used as hybridization probes to group individual actin genomic clones by their relative thermal stability. Restriction maps showed that these actin genes were derived from separate and nonoverlapping regions of genomic DNA. Of the six isolated genes, five included sequences from both the 5' and 3' ends of the actin-coding area. Amino acid sequence analysis from both the NH2- and COOH-terminal regions provided for the unequivocal identification of these genes. The striated isoforms were represented by the isolated alpha-skeletal, alpha-cardiac, and alpha-smooth muscle actin genes. The nonmuscle isoforms included the beta-cytoplasmic actin gene and an actin gene fragment which lacked the 5' coding and flanking sequence; presumably, this region of DNA was removed from this gene during construction of the genomic library. Unexpectedly, a third nonmuscle chicken actin gene was found which resembled the amphibian type 5 actin isoform (J. Vandekerckhove, W. W. Franke, and K. Weber, J. Mol. Biol., 152:413-426). This nonmuscle actin type has not been previously detected in warm-blooded vertebrates. We showed that interspersed, repeated DNA sequences closely flanked the alpha-skeletal, alpha-cardiac, beta-, and type 5-like actin genes. The repeated DNA sequences which surround the alpha-skeletal actin-coding regions were not related to repetitious DNA located on the other actin genes. Analysis of genomic DNA blots showed that the chicken actin multigene family was represented by 8 to 10 separate coding loci. The six isolated actin genes corresponded to 7 of 11 genomic EcoRI fragments. Only the alpha-smooth muscle actin gene was shown to be split by an EcoRI site. Thus, in the chicken genome each actin isoform appeared to be encoded by a single gene.

Organization and evolution of the actin gene family in sea urchins

1983 ◽  
Vol 3 (10) ◽  
pp. 1824-1833
Author(s):  
P J Johnson ◽  
D R Foran ◽  
G P Moore
Keyword(s):  
Sea Urchin ◽  
Sequence Homology ◽  
Copy Number ◽  
Sea Urchins ◽  
Intron Position ◽  
Actin Gene ◽  
Genomic Libraries ◽  
Lytechinus Pictus ◽  
Transcriptional Orientation ◽  
Actin Genes

Genomic libraries of the sea urchins Strongylocentrotus franciscanus and Lytechinus pictus were screened with an actin cDNA clone from Strongylocentrotus purpuratus. Four nonoverlapping clones were isolated and characterized from the S. franciscanus library; three were isolated and characterized from the L. pictus library. Linked genes having the same transcriptional orientation were found on all S. franciscanus clones. Three clones contained two actin genes each; the other clone contained three. In contrast, the L. pictus clones contained only one actin gene. Comparison of actin genomic clones from these three species indicated a difference in the genomic organization of sea urchin actin genes in that the genes appear to be more highly clustered in S. franciscanus than in S. purpuratus and L. pictus. Genomic dot blots and reassociation kinetics demonstrated that the copy number of actin genes in all three species is 15 to 20. Nucleotide sequence homology of actin genes within and among the species was measured by thermal elution. These experiments indicated that there is a high degree of interspecies actin gene sequence homology but that, within each species, actin gene sequences may differ by as much as 30%. Sequencing of two S. franciscanus actin genes revealed introns at the same amino acid positions, 121 and 204, reported for S. purpuratus actin genes. These data demonstrated that the genomic copy number, the transcriptional orientation of linked genes, and, to the extent studied, the intron position of actin genes have evolved similarly in these three species. In contrast, significant change has occurred in the chromosomal arrangement of sea urchin actin genes.

scholarly journals Microtubular origin of mitotic spindle form birefringence. Demonstration of the applicability of Wiener's equation.

1975 ◽  
Vol 67 (3) ◽  
pp. 501-517 ◽  
Author(s):  
H Sato ◽  
G W Ellis ◽  
S Inoué
Keyword(s):  
Electron Microscopy ◽  
Volume Fraction ◽  
Sea Star ◽  
Repeat Distance ◽  
Pisaster Ochraceus ◽  
Form Birefringence ◽  
Best Value ◽  
Least Squares Fit ◽  
Best Fit

Meiosis I metaphase spindles were isolated from oocytes of the sea-star Pisaster ochraceus by a method that produced no detectable net loss in spindle birefringence. Some of the spindles were fixed immediately and embedded and sectioned for electron microscopy. Others were laminated between gelatine pellicles in a perfusion chamber, then fixed and sequentially and reversibly imbibed with a series of media of increasing refractive indices. Electron microscopy showed little else besides microtubules in the isolates, and no other component present could account for the observed form birefringence. An Ambronn plot of the birefringent retardation measured during imbibition was a good least squares fit to a computer generated theoretical curve based on the Bragg-Pippard rederivation of the Wiener curve for form birefringence. The data were best fit by the curve for rodlet index (n1) = 1.512, rodlet volume fraction (f) = 0.0206, and coefficient of intrinsic birefringence = 4.7 X 10(-5). The value obtained for n1 is unequivocal and is virtually as good as the refractometer determinations of imbibing medium index on which it is based. The optically interactive volume of the microtubule subunit, calculated from our electron microscope determination of spindle microtubule distribution (106/mum2), 13 protofilaments per microtubules, an 8 nm repeat distance and our best value for f, is compatible with known subunit dimensions as determined by other means. We also report curves fitted to the results of Ambronn imbibition of Bouin's-fixed Lytechinus spindles and to the Noll and Weber muscle imbibition data.

Testing ecological release as a compensating mechanism for mass mortality in a keystone predator

2020 ◽  
Vol 637 ◽  
pp. 59-69 ◽  
Author(s):  
J Sullivan-Stack ◽  
BA Menge
Keyword(s):  
Community Dynamics ◽  
Limiting Factor ◽  
Sea Star ◽  
Top Predator ◽  
Oregon Coast ◽  
Ecological Release ◽  
Keystone Predator ◽  
Pisaster Ochraceus ◽  
Wasting Syndrome

Top predator decline has been ubiquitous across systems over the past decades and centuries, and predicting changes in resultant community dynamics is a major challenge for ecologists and managers. Ecological release predicts that loss of a limiting factor, such as a dominant competitor or predator, can release a species from control, thus allowing increases in its size, density, and/or distribution. The 2014 sea star wasting syndrome (SSWS) outbreak decimated populations of the keystone predator Pisaster ochraceus along the Oregon coast, USA. This event provided an opportunity to test the predictions of ecological release across a broad spatial scale and determine the role of competitive dynamics in top predator recovery. We hypothesized that after P. ochraceus loss, populations of the subordinate sea star Leptasterias sp. would grow larger, more abundant, and move downshore. We based these predictions on prior research in Washington State showing that Leptasterias sp. competed with P. ochraceus for food. Further, we predicted that ecological release of Leptasterias sp. could provide a bottleneck to P. ochraceus recovery. Using field surveys, we found no clear change in density or distribution in Leptasterias sp. populations post-SSWS, and decreases in body size. In a field experiment, we found no evidence of competition between similar-sized Leptasterias sp. and P. ochraceus. Thus, the mechanisms underlying our predictions were not in effect along the Oregon coast, which we attribute to differences in habitat overlap and food availability between the 2 regions. Our results suggest that response to the loss of a dominant competitor can be unpredictable even when based in theory and previous research.

scholarly journals Sequential activation of alpha-actin genes during avian cardiogenesis: vascular smooth muscle alpha-actin gene transcripts mark the onset of cardiomyocyte differentiation.

1988 ◽  
Vol 107 (6) ◽  
pp. 2575-2586 ◽  
Author(s):  
D L Ruzicka ◽  
R J Schwartz
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Cardiac Cells ◽  
Actin Gene ◽  
Heart Tube ◽  
Specific Expression ◽  
Actin Genes ◽  
Beta Actin ◽  
Smooth Muscle Alpha Actin ◽  
Alpha Actin

The expression of cytoplasmic beta-actin and cardiac, skeletal, and smooth muscle alpha-actins during early avian cardiogenesis was analyzed by in situ hybridization with mRNA-specific single-stranded DNA probes. The cytoplasmic beta-actin gene was ubiquitously expressed in the early chicken embryo. In contrast, the alpha-actin genes were sequentially activated in avian cardiac tissue during the early stages of heart tube formation. The accumulation of large quantities of smooth muscle alpha-actin transcripts in epimyocardial cells preceded the expression of the sarcomeric alpha-actin genes. The accumulation of skeletal alpha-actin mRNAs in the developing heart lagged behind that of cardiac alpha-actin by several embryonic stages. At Hamburger-Hamilton stage 12, the smooth muscle alpha-actin gene was selectively down-regulated in the heart such that only the conus, which subsequently participates in the formation of the vascular trunks, continued to express this gene. This modulation in smooth muscle alpha-actin gene expression correlated with the beginning of coexpression of sarcomeric alpha-actin transcripts in the epimyocardium and the onset of circulation in the embryo. The specific expression of the vascular smooth muscle alpha-actin gene marks the onset of differentiation of cardiac cells and represents the first demonstration of coexpression of both smooth muscle and striated alpha-actin genes within myogenic cells.

Nucleotide sequence of the carboxy-terminal portion of a lodgepole pine actin gene

1988 ◽  
Vol 18 (12) ◽  
pp. 1595-1602 ◽  
Author(s):  
J. R. Kenny ◽  
B. P. Dancik ◽  
L. Z. Florence ◽  
F. E. Nargang
Keyword(s):  
Amino Acid ◽  
Nucleotide Sequence ◽  
Intron Position ◽  
Amino Acid Sequences ◽  
Pairwise Comparisons ◽  
Actin Gene ◽  
Terminal Portion ◽  
The Third ◽  
Actin Genes ◽  
Carboxy Terminal

We have determined the nucleotide sequence of the carboxy-terminal portion of an actin gene (PAc1-A) isolated from Pinuscontorta var. latifolia (Engelm.). Pairwise comparisons of both nucleotide and deduced amino acid sequences were made among PAc1-A, the soybean actins SAc3 and SAc1, maize actin MAc1, chicken β-actin, and yeast β-actin. Of the other actins SAc3 was most similar to the PAc1-A amino acid sequence (91.3% identity) and yeast actin the least similar (78.3% identity). The intron in PAc1-A is present at the same location as the third intron found in MAc1, SAc1, and SAc3 actin genes. This conservation of intron position is unusual when compared with nonplant actin genes.

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