Wolffish antifreeze protein genes are primarily organized as tandem repeats that each contain two genes in inverted orientation

1988 ◽  
Vol 8 (9) ◽  
pp. 3670-3675
Author(s):  
G K Scott ◽  
P H Hayes ◽  
G L Fletcher ◽  
P L Davies
Keyword(s):  
Tandem Repeats ◽  
Sea Water ◽  
Transcription Termination ◽  
Antifreeze Protein ◽  
The Other ◽  
Direct Repeats ◽  
Inverted Orientation ◽  
Single Region ◽  
Flanking Sequences ◽  
Anarhichas Lupus

The antifreeze protein genes of the wolffish (Anarhichas lupus) constitute a large multigene family of 80 to 85 copies, which can be classified into two sets. One-third of the genes were linked but irregularly spaced. The other two-thirds were organized as 8-kilobase-pair (kbp) tandem direct repeats that each contained two genes in inverted orientation; DNA sequence analysis suggests that both genes are functional. Except for a single region specific to each gene, the genes and their immediate flanking sequences were 99.2% identical. This degree of identity ended soon after a putative transcription termination sequence; as the 3' ends of the genes were only 1.3 kbp apart, these sequences might confer mutual protection from interference by transcriptional runoff. A Southern blot of wolffish DNA restricted with enzymes that do not cut within the tandem repeats indicated that the repeats were clustered in groups of six or more. The organization of antifreeze protein genes in the wolffish was very similar to that in the unrelated winter flounder, which produces a completely different antifreeze. This similarity might reflect common dynamics by which their progenitors adapted to life in ice-laden sea water.

scholarly journals Wolffish antifreeze protein genes are primarily organized as tandem repeats that each contain two genes in inverted orientation.

1988 ◽  
Vol 8 (9) ◽  
pp. 3670-3675 ◽  
Author(s):  
G K Scott ◽  
P H Hayes ◽  
G L Fletcher ◽  
P L Davies
Keyword(s):  
Tandem Repeats ◽  
Sea Water ◽  
Transcription Termination ◽  
Antifreeze Protein ◽  
The Other ◽  
Direct Repeats ◽  
Inverted Orientation ◽  
Single Region ◽  
Flanking Sequences ◽  
Anarhichas Lupus

The antifreeze protein genes of the wolffish (Anarhichas lupus) constitute a large multigene family of 80 to 85 copies, which can be classified into two sets. One-third of the genes were linked but irregularly spaced. The other two-thirds were organized as 8-kilobase-pair (kbp) tandem direct repeats that each contained two genes in inverted orientation; DNA sequence analysis suggests that both genes are functional. Except for a single region specific to each gene, the genes and their immediate flanking sequences were 99.2% identical. This degree of identity ended soon after a putative transcription termination sequence; as the 3' ends of the genes were only 1.3 kbp apart, these sequences might confer mutual protection from interference by transcriptional runoff. A Southern blot of wolffish DNA restricted with enzymes that do not cut within the tandem repeats indicated that the repeats were clustered in groups of six or more. The organization of antifreeze protein genes in the wolffish was very similar to that in the unrelated winter flounder, which produces a completely different antifreeze. This similarity might reflect common dynamics by which their progenitors adapted to life in ice-laden sea water.

scholarly journals Recombination of Ty elements in yeast can be induced by a double-strand break.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 67-77 ◽  
Author(s):  
A Parket ◽  
O Inbar ◽  
M Kupiec
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Strand Break ◽  
Double Strand Break ◽  
The Other ◽  
Direct Repeats ◽  
Yeast Saccharomyces Cerevisiae ◽  
Low Frequencies ◽  
Ty Elements ◽  
Main Family

Abstract The Ty retrotransposons are the main family of dispersed repeated sequences in the yeast Saccharomyces cerevisiae. These elements are flanked by a pair of long terminal direct repeats (LTRs). Previous experiments have shown that Ty elements recombine at low frequencies, despite the fact that they are present in 30 copies per genome. This frequency is not highly increased by treatments that cause DNA damage, such as UV irradiation. In this study, we show that it is possible to increase the recombination level of a genetically marked Ty by creating a double-strand break in it. This break is repaired by two competing mechanisms: one of them leaves a single LTR in place of the Ty, and the other is a gene conversion event in which the marked Ty is replaced by an ectopically located one. In a strain in which the marked Ty has only one LTR, the double-strand break is repaired by conversion. We have also measured the efficiency of repair and monitored the progression of the cells through the cell-cycle. We found that in the presence of a double-strand break in the marked Ty, a proportion of the cells is unable to resume growth.

Part 2. The deeper structure of the Atlantic - Geological hypotheses and the earth's crust under the oceans

1954 ◽  
Vol 222 (1150) ◽  
pp. 341-348 ◽  
Keyword(s):  
Heat Flow ◽  
Recent Work ◽  
Sea Water ◽  
Volcanic Rocks ◽  
The Other ◽  
Ocean Floor ◽  
Peridotite Xenoliths ◽  
The Earth ◽  
Southern Rhodesia ◽  
Mohorovičić Discontinuity

Recent work has determined the depth of the Mohorovičić discontinuity at sea and has made it likely that peridotite xenoliths in basaltic volcanic rocks are samples of material from below the discontinuity. It is now possible to produce a hypothetical section showing the transition from a continent to an ocean. This section is consistent with both the seismic and gravity results. The possible reactions of the crust to changes in the total volume of sea water are dis­cussed. It seems possible that the oceans were shallower and the crust thinner in the Archean than they are now. If this were so, some features of the oldest rocks of Canada and Southern Rhodesia could be explained. Three processes are described that might lead to the formation of oceanic ridges; one of these involves tension, one compression and the other quiet tectonic conditions. It is likely that not all ridges are formed in the same way. It is possible that serpentization of olivine by water rising from the interior of the earth plays an important part in producing changes of level in the ocean floor and anomalies in heat flow. Finally, a method of reducing gravity observations at sea is discussed.

scholarly journals Slipped-Strand Mispairing at Noncontiguous Repeats in Poecilia reticulata: A Model for Minisatellite Birth

Genetics ◽  
2000 ◽  
Vol 155 (3) ◽  
pp. 1313-1320 ◽  
Author(s):  
John S Taylor ◽  
Felix Breden
Keyword(s):  
Tandem Repeat ◽  
Poecilia Reticulata ◽  
Tandem Repeats ◽  
Phylogenetic Reconstruction ◽  
Variable Number ◽  
Repeat Motif ◽  
Raw Material ◽  
Direct Repeats ◽  
Mt Dna ◽  
Variable Number Tandem Repeats

Abstract The standard slipped-strand mispairing (SSM) model for the formation of variable number tandem repeats (VNTRs) proposes that a few tandem repeats, produced by chance mutations, provide the “raw material” for VNTR expansion. However, this model is unlikely to explain the formation of VNTRs with long motifs (e.g., minisatellites), because the likelihood of a tandem repeat forming by chance decreases rapidly as the length of the repeat motif increases. Phylogenetic reconstruction of the birth of a mitochondrial (mt) DNA minisatellite in guppies suggests that VNTRs with long motifs can form as a consequence of SSM at noncontiguous repeats. VNTRs formed in this manner have motifs longer than the noncontiguous repeat originally formed by chance and are flanked by one unit of the original, noncontiguous repeat. SSM at noncontiguous repeats can therefore explain the birth of VNTRs with long motifs and the “imperfect” or “short direct” repeats frequently observed adjacent to both mtDNA and nuclear VNTRs.

The unreliability of mammalian glomerular markers in teleostean renal studies

1976 ◽  
Vol 64 (2) ◽  
pp. 369-378 ◽  
Author(s):  
K. W. Beyenbach ◽  
L. B. Kirschner
Keyword(s):  
Polyethylene Glycol ◽  
Urinary Bladder ◽  
Glomerular Filtration ◽  
Sea Water ◽  
The Other ◽  
Salmo Gairdneri ◽  
Renal Tubules ◽  
True Measure

1. The assumption that (3H) methoxy inulin, (14C) polyethylene glycol (PEG) and (125) iothalamate (glofil) are reliable volume and glomerular markers in teleosts was tested. 2. PEG occupied smaller volumes than inulin and glofil in sea-water-adapted Salmo gairdneri. Ureteral clearances of PEG were about 22% higher than those of inulin and glofil, and urine-to-plasma ratios were significantly greater for PEG than for the other two markers. 3. After introduction into the urinary bladder the three macro-molecules appeared in the plasma, PEG at the lowest rates. 4. These observations indicate that mammalian glomerular markers can penetrate the bladder and possibly the ureters and renal tubules. Therefore, their clearances may not give a true measure of glomerular filtration rates in teleosts.

scholarly journals The density and distribution of Pacific Oyster (Crassostrea gigas) in Krueng Cut, Aceh Besar

2021 ◽  
Vol 869 (1) ◽  
pp. 012056
Author(s):  
M Ramadhaniaty ◽  
C Octavina ◽  
FA Putri ◽  
S Karina ◽  
Ichsan
Keyword(s):  
Crassostrea Gigas ◽  
Aquatic Environment ◽  
Random Sampling ◽  
Pacific Oyster ◽  
Sea Water ◽  
The Other ◽  
High Abundance ◽  
Nutrient Input ◽  
Oyster Population

Abstract Crassostrea gigas is a Pacific oyster that has the largest size among the other oysters. This oyster is most often found because of its ability to adapt to a variety of environments. Krueng Cut is an estuary area that gets a lot of nutrient input from sea water because it is directly adjacent to the ocean. This condition makes this area has a high abundance of oysters with high fishing and antropogenic activities as well. The purpose of this study was to determine the density and distribution of the oyster population from 3 representative stations along the estuary area of Krueng Cut. The method used in this study is random sampling using a quadratic transect. The results show that the highest density is indicated by station 3 with 55.67 ind/m2 and the lowest density is indicated by station 1 is 40.33 ind/m2. These results indicate that the activities of residents, the entry of contaminants from antropogenic affect the density of oysters. The distribution of oysters from the three stations showed similarities, namely they tended to grouping. The aquatic environment at the three research stations still supports the growth of oysters. This study confirms that there has been a decline in the population, which is characterized by a decrease in the number of catches and a smaller size of oysters.

scholarly journals ARMC Subfamily: Structures, Functions, Evolutions, Interactions, and Diseases

2021 ◽  
Vol 8 ◽  
Author(s):  
Yutao Huang ◽  
Zijian Jiang ◽  
Xiangyu Gao ◽  
Peng Luo ◽  
Xiaofan Jiang
Keyword(s):  
Signal Transduction ◽  
Amino Acids ◽  
Cell Adhesion ◽  
Tandem Repeats ◽  
Critical Role ◽  
The Other ◽  
Biological Functions ◽  
Armadillo Repeat ◽  
The One ◽  
Similar Domain

Armadillo repeat-containing proteins (ARMCs) are widely distributed in eukaryotes and have important influences on cell adhesion, signal transduction, mitochondrial function regulation, tumorigenesis, and other processes. These proteins share a similar domain consisting of tandem repeats approximately 42 amino acids in length, and this domain constitutes a substantial platform for the binding between ARMCs and other proteins. An ARMC subfamily, including ARMC1∼10, ARMC12, and ARMCX1∼6, has received increasing attention. These proteins may have many terminal regions and play a critical role in various diseases. On the one hand, based on their similar central domain of tandem repeats, this ARMC subfamily may function similarly to other ARMCs. On the other hand, the unique domains on their terminals may cause these proteins to have different functions. Here, we focus on the ARMC subfamily (ARMC1∼10, ARMC12, and ARMCX1∼6), which is relatively conserved in vertebrates and highly conserved in mammals, particularly primates. We review the structures, biological functions, evolutions, interactions, and related diseases of the ARMC subfamily, which involve more than 30 diseases and 40 bypasses, including interactions and relationships between more than 100 proteins and signaling molecules. We look forward to obtaining a clearer understanding of the ARMC subfamily to facilitate further in-depth research and treatment of related diseases.

scholarly journals XX. Discovery of the metamorphosis in the second type of the cirripedes, viz. the lepades, completing the natural history of these singular animals, and confirming their affinity with the crustacea

1835 ◽  
Vol 125 ◽  
pp. 355-358 ◽  
Keyword(s):  
North America ◽  
Natural History ◽  
Sea Water ◽  
The Other ◽  
External Appearance ◽  
The Real ◽  
Real Nature ◽  
History Of ◽  
The Mediterranean ◽  
The Waves

The Fourth Memoir, published in my Zoological Researches and Illustrations, No. III. page 69, &c., having first made known the real nature of the Cirripedes , the key of which remained concealed in their metamorphosis, it might have been expected that some naturalist favourably situated to investigate the oceanic tribe of these animals, would have been the first to make the same discovery in regard to these, and thereby complete their natural history. It was scarcely to be expected that the honour of this discovery also should be reserved for the author, fixed to one spot, where none of them naturally exist, and are but casually thrown upon our shores by the waves of the Atlantic, attached to pieces of wreck, or brought into port fixed to the bottoms of ships returning from distant voyages. Fortunately, however, two ships of this description came into this harbour (Cork), one from the Mediterranean, the other from North America, which, not being sheathed with copper, had their bot­toms literally covered with Barnacles of the three genera of Lepas , Cineras , and Otion ; and having persons employed expressly for the purpose, numbers of these were brought alive in sea water, amongst which were many with the ova in various stages of their progress, and some ready to hatch, which they eventually did in prodigious numbers, so as to enable him to add the proof of their being, like the Balani, natatory Crusta­cea in their first stage , but of a totally different facies and structure; a circumstance which determines the propriety of the separation of the Cirripedes into two tribes, and evinces the sagacity of Mr. MacLeay in being the first to indicate that these two tribes, the Balani and Lepades , were not so closely related as generally supposed. The larvæ of the Balani , described in Memoir IV. under the external appearance of the bivalve Monoculi ( Astracoda ), have a pair of pedunculated eyes, more numerous and more completely developed members, approximating to those of Cyclops , and of the perfect Triton ; while, in the present type, or Lepades , the larva resembles some­what that of the Cyclops , which Müller, mistaking for a perfect animal, named Amymone , and which can be shown to he common to a great many of the Entomostraca ; or the resemblance is still more striking to that of the Argulus Armiger of Latreille, which, in fact, is but an Amymone furnished with a tricuspidate shield at the back.

On the use of ammonium for buoyancy in squids

1979 ◽  
Vol 59 (2) ◽  
pp. 259-276 ◽  
Author(s):  
M. R. Clarke ◽  
E. J. Denton ◽  
J. B. Gilpin-Brown
Keyword(s):  
Developmental Stage ◽  
Sea Water ◽  
The Body ◽  
The Other ◽  
Neutral Buoyancy ◽  
Rich Solution ◽  
Almost All ◽  
Neutrally Buoyant

Squids (teuthoids) fall into two distinct groups according to their density in sea water. Squids of one group are considerably denser than sea water and must swim to stop sinking; squids in the other group are nearly neutrally buoyant. Analyses show that in almost all the neutrally buoyant squids large amounts of ammonium are present. This ammonium is not uniformly distributed throughout the body but is mostly confined to special tissues where its concentration can approach half molar. The locations of such tissues differ according to the species and developmental stage of the squid. It is clear that the ammonium-rich solution are almost isosmotic with sea water but of lower density and they are present in sufficient volume to provide the main buoyancy mechanism of these squids. A variety of evidence is given which suggests that squids in no less than 12 of the 26 families achieve near-neutral buoyancy in this way and that 14 families contain squids appreciably denser than sea water [at least one family contains both types of squid]. Some of the ammonium-rich squids are extremely abundant in the oceans.

Some Experiments on Sea-urchin Eggs with Desoxynucleic Acids from Sea-urchin Sperms

Development ◽  
1953 ◽  
Vol 1 (3) ◽  
pp. 261-262
Author(s):  
Sven Hörstadius
Keyword(s):  
New York ◽  
Sea Urchin ◽  
Sea Water ◽  
Water Injection ◽  
Dark Field ◽  
The Other ◽  
Columbia University ◽  
Sea Urchin Eggs ◽  
King's College ◽  
Fertilization Membrane

Dr. I. Joan Lorch, of King's College, London, and I have made some experiments on sea-urchin eggs with desoxynucleic acids (DNA) prepared from sperms of several sea-urchin species by Professor Erwin Chargaff, of Columbia University, New York. Unfertilized eggs did not react when put into a solution of DNA in sea-water. Injection of a small amount of DNA dissolved in Callan's solution had the following consequences. If the DNA did not mix with the cytoplasm but remained as a distinct droplet, the egg could be fertilized. The droplet moved slowly towards the surface and ran out of the egg. This sometimes only occurred after several cleavages. Such eggs developed normally. If, on the other hand, the DNA mixed with the cytoplasm the egg became activated. A fertilization membrane was raised. The surface layer in dark field changed in colour from yellow to white as is the case upon fertilization.

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