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PubMed1989

Composition and chromosomal localization of cetacean highly repetitive DNA with special reference to the blue whale, Balaenoptera musculus.

Three highly repetitive DNA components--the common cetacean component, the heavy (GC-rich) satellite and the light (AT-rich) satellite--were were studied in the blue whale. Consensus sequences of the common component and the heavy satellite were determined on the basis of three repeats of the common component and eight repeats of the heavy satellite. The tandemly organized common cetacean component, which comprises a large portion of all cetacean--both odontocete (toothed whale) and mysticete (whalebone whale)--genomes has a repeat length of 1,760 bp and the three clones analysed showed a high degree of conformity. The repeat contains a 72 bp sequence with dyad symmetry and striking intrastrand complementarity. The rest of the repeat comprises a unique sequence. The repeat unit of the heavy satellite of the blue whale is 422 bp. Also this component is tandemly organized. About half the length of the repeat constitutes a unique sequence and the other half is made up of subrepeats with TTAGGG as a frequent motif. The light satellite has not been sequenced and its basic repeat unit has not yet been identified. The chromosomal localization of the three components was determined by in situ hybridization using 3H-labelled cloned fragments as probes. The common cetacean component was located in most interstitial and terminal C-bands. The heavy satellite occurred primarily in terminal C-bands. When the two components hybridized to the same terminal C-bands, the localization of the heavy satellite was distal to that of the common cetacean component. Neither component shared localization with the light satellite which is located in centromeric C-bands in just a few chromosome pairs.

Animals↗

PubMed1993

Sequence organization and evolution, in all extant whalebone whales, of a DNA satellite with terminal chromosome localization.

A heavy (GC rich) DNA satellite with terminal chromosomal localization is characteristic for all mysticete (whalebone whale) genomes. Sequences of 58 repeats of the satellite were compared in all ten extant mysticete species. In three families comprising eight species, the typical repeat length was 422 (421) bp. In two species, the northern right whale and the bowhead, of family Balaenidae (right whales) the repeats were much longer, typically ca. 900 and ca. 1200 bp. In all species the repeats were composed of a unique portion of constant length (212/211 bp), and a subrepeat portion, the length of which was variable. The evolutionary rigidity of the unique portion of the repeat is contrasted by the pronounced length variability of the subrepeat portion. The subrepeat portion consists essentially of 6 bp motifs, such that length differences are usually in multiples of 6 bp. The motif TTAGGG constituted 35%-50% of the subrepeats. Comparison between the unique portion of the 58 sequenced repeats revealed that the repeats divided into two primary groups, one comprising the two balaenids, the other including the eight remaining species. The mean difference between the two groups averaged 8.4%. In this sequence comparison the repeats of the pygmy right whale constituted a group that was separated from repeats of the other species. In all other cases repeats were intermingled to some extent between species. Comparison of individual repeats suggests that the unique portion evolves in concert, at a slow rate. A neighbor-joining comparison between the consensuses of all species suggests that the unique portion of the repeats evolves at a somewhat different rate in different lineages.

Animals↗

PubMed1988

The separation of whale myoglobins with two-dimensional electrophoresis.

Five myoglobins (sperm whale, Sei whale, Hubbs' beaked whale, pilot whale, and Amazon River dolphin) were examined using two-dimensional electrophoresis. Previous reports indicated that none of these proteins could be separated by using denaturing (in the presence of 8-9 M urea) isoelectric focusing. This result is confirmed in the present study. However, all the proteins could be separated by using denaturing nonequilibrium pH-gradient electrophoresis in the first dimension. Additionally, all the myoglobins have characteristic mobilities in the second dimension (sodium dodecyl sulfate), but these mobilities do not correspond to the molecular weights of the proteins. We conclude that two-dimensional electrophoresis can be more sensitive to differences in primary protein structure than previous studies indicate and that the assessment seems to be incorrect that this technique can separate only proteins that have a unit charge difference.

Animals↗

PubMed1976

Variations in lipid composition and sound velocity in melon from the North Atlantic Pilot whale, globicephala melaena melaena.

Nonpolar lipids and sound velocity at different distances from the skin surface within a sample of pilot whale melon were studied. Thin layer chromatography, sensitive radioisotopic methods, and an ultrasonic echo scanner were used. Wax esters had a maximum concentration at 11-12 cm from the skin surface. Non- and monoisovalero triglycerides both exhibited a minimum at 8-10 cm, whereas the diisovalero species increased steadily from the skin surface towards the center of the pilot whale head. A minimum of sound velocity, ca. 1340 m/s, was found at 9-11 cm, thus coinciding with a region rich in isovaleric acid esterified in wax and diisovalero triglycerides. These findings are compatible with predictions based on the known correlations between lipid structure and sound velocity. Consequently, additional evidence for refraction of sound in pilot whale melon is presented. This is important in understanding the system of echolocation of toothed whales.

Animals↗

PubMed2002

Bioaccumulation of organochlorine contaminants in bowhead whales (Balaena mysticetus) from Barrow, Alaska.

Bowhead whale (Balaena mysticetus) blubber (n = 72) and liver (n = 23) samples were collected during seven consecutive subsistence harvests (1997-2000) at Barrow, Alaska, to investigate the bioaccumulation of organochlorine contaminants (OCs) by this long-lived mysticete. The rank order of OC group concentrations (geometric mean, wet weight) in bowhead blubber samples were toxaphene (TOX; 455 ng/g) > polychlorinated biphenyls (SigmaPCBs; 410 ng/g) > dichlorodiphenyltrichloroethane-related compounds (SigmaDDT; 331 ng/g) >or= hexachlorocyclohexane isomers (SigmaHCHs; 203 ng/g) >or= chlordanes and related isomers (SigmaCHLOR; 183 ng/g) > chlorobenzenes (SigmaCIBz; 106 ng/g). In liver, SigmaHCH (9.5 ng/g; wet weight) was the most abundant SigmaOC group, followed by SigmaPCBs (9.1 ng/g) >or= TOX (8.8 ng/g) > SigmaCHLOR (5.5 ng/g) > SigmaCIBz (4.2 ng/g) >or= SigmaDDT (3.7 ng/g). The dominant analyte in blubber and liver was p,p'-DDE and alpha-HCH, respectively. Total TOX, SigmaPCBs, SigmaDDT, and SigmaCHLOR concentrations in blubber generally increased with age of male whales (as interpreted by body length), but this relationship was not significant for adult female whales. Biomagnification factor (BMF) values (0.1-45.5) for OCs from zooplankton (Calanus sp.) to bowhead whale were consistent with findings for other mysticetes. Tissue-specific differences in OC patterns in blubber and liver may be attributed to variation of tissue composition and the relatively low capacity of this species to biotransform various OCs. Principal component analysis of contaminants levels in bowhead blubber samples suggest that proportions of OCs, such as beta-HCH, fluctuate with seasonal migration of this species between the Bering, Chukchi, and Beaufort Seas.

Adipose Tissue↗

PubMed2003

Renal toxicity in rats after oral administration of mercury-contaminated boiled whale livers marketed for human consumption.

Some people living in Japan have traditionally eaten the internal organs of small cetaceans (toothed whales and dolphins), and a mixed package of boiled liver, kidney, lung, and so on is still marketed for human consumption. Recently, we reported that these organs are highly contaminated with mercury. In this study, we investigated the absorption, distribution, excretion, and biochemical parameters in serum and urine after a single oral administration of boiled whale liver containing 1980 microg/g of total mercury and 23.5 microg/g of methyl mercury to rats (0.2 g boiled liver/100 g rat). The single administration of the boiled liver resulted in marked increases of the mercury concentration in the rat kidney, urinary volume, and the urinary excretion of N-acetyl-beta-D-glucosanidase, albumin, and sodium, suggesting the renal toxicity caused by inorganic mercury. Furthermore, the administration increased lactate dehydrogenase activity and creatinine, potassium, and phosphorus concentrations in serum. About 95% of total mercury dose was excreted in feces and less than 0.05% was excreted in the urine. Thus, the absorption rate of mercury from the boiled whale liver appears to be about 5% or slightly higher. These data indicate that the human consumption of boiled whale liver may cause acute intoxication by the contaminated inorganic mercury.

Administration, Oral↗

PubMed1999

Organochlorines in stranded pilot whales (Globicephala melaena) from the coast of Massachusetts.

Pilot whales strand periodically along the U.S. coast, and these strandings offer an opportunity for the collection of tissues for biomonitoring of contaminant exposure in cetaceans, as well as for specimen archiving. Concentrations of organochlorine (OC) contaminants (e.g., PCB congeners, pesticides, DDTs) were measured in tissue samples from pilot whales that stranded in 1986 and 1990 along the Massachusetts coast. Adult and fetal samples of blubber, liver, brain, and kidney were collected, as well as ovaries from mature female whales. Many of the OCs found in maternal tissues were detected in corresponding fetal tissues indicating maternal transfer of OCs to the fetus. The concentrations of individual OCs in tissues varied considerably among the animals. Statistically significant differences were found between females and males for the concentrations of certain analytes (e.g., SigmaPCBs, p,p'-DDE) and these differences may be partially due to contaminants being transferred by the female whales during gestation and lactation. The concentrations of OCs in different tissues were similar when based on total lipid weight, except for the brain, which contained the lowest lipid-normalized OC concentrations. The low concentrations in brain may be related to the disparate lipid compositions in this tissue as well as the presence of the blood-brain barrier. The availability of data on these archived and biomonitoring samples provides a baseline for future retrospective studies.

Animals↗

PubMed2004

Song copying by humpback whales: themes and variations.

Male humpback whales (Megaptera novaeangliae) produce long, structured sequences of sound underwater, commonly called "songs." Humpbacks progressively modify their songs over time in ways that suggest that individuals are copying song elements that they hear being used by other singers. Little is known about the factors that determine how whales learn from their auditory experiences. Song learning in birds is better understood and appears to be constrained by stable core attributes such as species-specific sound repertoires and song syntax. To clarify whether similar constraints exist for song learning by humpbacks, we analyzed changes over 14 years in the sounds used by humpback whales singing in Hawaiian waters. We found that although the properties of individual sounds within songs are quite variable over time, the overall distribution of certain acoustic features within the repertoire appears to be stable. In particular, our findings suggest that species-specific constraints on temporal features of song sounds determine song form, whereas spectral variability allows whales to flexibly adapt song elements.

Acoustics↗

PubMed1987

Trace elements intake in the Faroe Islands. I. Element levels in edible parts of pilot whales (Globicephalus meleanus).

We examined the distribution of copper, zinc, selenium, arsenic, cadmium and mercury (total and methyl mercury) in samples of muscle, liver, kidney and blubber from pilot whales (Globicephalus meleanus) caught off the Faroe Islands in 1977 and 1978. The very high total mercury level in the mature pilot whale exhibited differences among tissues and was highest in the liver. The total mercury concentration increased with body size. With increasing body size the ratio of methyl mercury to total mercury was relatively constant in muscle and kidney, but it decreased in liver. The concentrations of total mercury in the tissues of immature whales were much lower than those of mature whales. Selenium levels increased with body size. Significant correlation coefficients were found between the total mercury and selenium in liver and kidney. Selenium was present in the kidney in molar excess relative to mercury, whereas the opposite was the case in the muscle tissue. High cadmium contents were found in kidney and liver. In muscle and liver no significant correlations were found between cadmium and selenium, but a weak correlation between these elements was recorded in the kidney.

Adipose Tissue↗

PubMed1987

Trace elements intake in the Faroe Islands. II. Intake of mercury and other elements by consumption of pilot whales (Globicephalus meleanus).

The long-term intakes of total mercury, methyl mercury and cadmium from eating pilot whale (Globicephalus meleanus) in the Faroe Islands have been estimated. The long-term intakes of both total and methyl mercury far exceed the Provisional Tolerable Weekly Intakes (PTWI) recommended by WHO. For the general population The PTWI's are 300 and 200 micrograms mercury per person per week for total and methyl mercury, respectively. The calculated intake of methyl mercury in this study approaches the lower value (1200 micrograms/person/week) of the recognized critical level of methyl mercury intoxication in the general population. In the years 1980 and 1981 the cadmium intake from consuming pilot whale foods exceeded the PTWI by a factor of 2. The PTWI for cadmium is 400-500 micrograms/person/week. It is concluded that the general Faroe Island population should significantly restrict the consumption of pilot whale foods. Pregnant women probably should not eat pilot whale foods at all, as the critical levels for methyl mercury intoxication of pregnant women and fetuses are lower by a factor of 2-5 than for the general population.

Adipose Tissue↗

PubMed1994

Organochlorines and mercury in pilot whale blubber consumed by Faroe islanders.

Some 22,000 pilot whales (Globicephala melaena) were taken in the Faroe Islands between 1970 and 1992. It is known that tissues from these animals are widely consumed by the islanders. The position of these animals at the apex of a direct marine food chain renders them liable to accumulate toxic chemicals, such as metals and organochlorines. Although the consumption of contaminating metals in pilot whale tissues has been studied, the significance of blubber as a dietary source of organochlorine compounds has not been fully considered. This study reports levels of organochlorine and mercury contamination in the blubber of pilot whales taken in two Faroese kills. Published estimates of pilot whale tissue consumption are used to evaluate dietary organochlorine intake in relation to established national and international guidelines and clinical studies conducted in the North American Great Lakes.

Adipose Tissue↗

PubMed2005

On the difference in stability between horse and sperm whale myoglobins.

The work in the literature on apomyoglobin is almost equally divided between horse and sperm whale myoglobins. The two proteins share high homology, show similar folding behavior, and it is often assumed that all folding phenomena found with one protein will also be found with the other. We report data at equilibrium showing that horse myoglobin was 2.1 kcal/mol less stable than sperm whale myoglobin at pH 5.0, and aggregated at high concentrations as measured by gel filtration and analytical ultracentrifugation experiments. The higher stability of sperm whale myoglobin was identified for both apo and holo forms, and was independent of pH from 5 to 8 and of the presence of sodium chloride. We also show that the substitution of sperm whale myoglobin residues Ala15 and Ala74 to Gly, the residues found at positions 15 and 74 in horse myoglobin, decreased the stability by 1.0 kcal/mol, indicating that helix propensity is an important component of the explanation for the difference in stability between the two proteins.

Animals↗

PubMed2005

Neuron numbers in sensory cortices of five delphinids compared to a physeterid, the pygmy sperm whale.

With its large mass and enormous gyrification, the neocortex of whales and dolphins has always been a challenge to neurobiologists. Here we analyse the relationship between neuron number per cortical unit in three different sensory areas and brain mass in six different toothed whale species, five delphinids and one physeterid. Cortex samples, including primary cortical areas of the auditory, visual, and somatosensory systems were taken from both hemispheres of brains fixed in 10% buffered formalin. The samples were embedded in paraffin, sectioned at 25 microm thickness and stained with cresyl violet. Because cortical thickness varies among toothed whale species, cell counts were done in cortical units measuring 150mum in width, 25 microm in thickness, and extending from the pial surface to the white matter. By arranging the delphinid brains according to their total mass, 834-6052 g, we found decreasing neuron numbers in the investigated areas with increasing brain mass. The pigmy sperm whale (Kogia breviceps), a physeterid with an adult brain weight of 1000 g had a distinctly lower neuron number per cortical unit. As had been expected, an increase in adult brain weight in delphinid cetaceans (family Delphinidae) is not correlated with an increase in neuron number per cortical unit.

Animals↗

PubMed2006

Age-dependent accumulation of heavy metals in a pod of killer whales (Orcinus orca) stranded in the northern area of Japan.

Mercury (Hg), cadmium (Cd), iron (Fe) manganese (Mn), zinc (Zn) and copper (Cu) concentrations in the liver, kidney and muscle of nine killer whales (including three calves) that stranded together in the northern area of Japan were determined. The Hg and Cd concentrations were found at trace levels in the calf organs, and increased with age. The Fe concentration in the muscle was significantly lower in the calves than in the mature whales and also increased with age. In contrast, Mn and Cu concentrations in the muscle were significantly higher in the calves than in the mature whales, and changes in the Zn concentration relative to age were unclear. These results suggest minimal mother-to-calf transfer of the toxic metals Hg and Cd and accumulation of these metals in the organs with age, while the essential metals Mn and Cu were found at higher concentrations in the muscle of calves than in mature whales.

Age Factors↗

PubMedDate not supplied

Searching for novel CYP members using cDNA library from a minke whale liver.

The contaminant-induced cytochrome P450 (CYP) members in minke whale (Balaenoptera acutorostrata) can be potential biomarkers of the contaminant exposure and toxic effects. In this study, we constructed a cDNA library from the liver of minke whale from the North Pacific, and further screened a total of 6930 clones randomly selected in the library for the isolation of cDNA clones encoding novel members of CYP superfamily. The screening revealed the isolation of six novel CYP cDNA clones that are classified into CYP1A, CYP2C, CYP2E, CYP3A, CYP4, and CYP4A subfamilies. The BLAST homology search using the partial cDNA fragments of four CYP subfamilies (CYP1A, CYP2C, CYP2E and CYP4A) demonstrated that the minke whale CYPs were most closely related to pig CYPs (81-91%). Identification of multiple CYP genes in marine mammal species such as minke whale will provide new insights into the metabolic or toxicological functions of individual CYP members.

Amino Acid Sequence↗

PubMed2004

Molecular evidence of new variant Brucella in North Pacific common minke whales.

Brucella, a causative agent of brucellosis, has been isolated recently from a variety of marine mammals. The molecular analysis of marine mammalian Brucella strains, without manifest pathology of brucellosis in the eastern North Atlantic, showed that they are distinct from terrestrial Brucella species. Previously, we reported abnormal gonads in common minke whales (Balaenoptera acutorostrata) in the western North Pacific and suggested the presence of Brucella infection in the whales in pathology and serology studies. In the present study, using polymerase chain reaction (PCR), Brucella was detected in granular testes of the whales showing caseation or calcification. The insertion of an IS711 transposable element specific for marine mammal isolates as well as a seal isolate-specific DNA fragment were also found. Molecular characterization of Brucella based on sequence analysis of the PCR products amplified from the outer membrane protein (omp) 2 gene showed that the Brucella from North Pacific common minke whales was different from terrestrial and North Atlantic marine mammal Brucella strains. The North Pacific Brucella showed the highest similarity to North Atlantic seal strains among the known Brucella strains.

Animals↗

PubMed2004

Baleen as a biomonitor of mercury content and dietary history of North Atlantic minke whales (Balaenopetra acutorostrata): combining elemental and stable isotope approaches.

Baleen is an incrementally-growing tissue of balaenopteran whales which preserves relatively well over time in museums and some archeological sites, and, therefore might be useful for studies examining long-term changes of metal levels in whales. This study examined Hg and stable C and N isotopic composition of baleen plates of the North Atlantic minke whale (Balaenoptera acutorostrata), which continues to be a food source for people in Greenland and elsewhere. We compared the Hg levels and stable isotopes of major tissues (kidney, liver and muscle) with those of baleen plates to see whether baleen could be used as a biomonitor of variations of Hg intake and diet both between individuals and within individuals over time. Mercury was significantly correlated with concentrations in all tissues (kidney, liver and muscle). Stable C and N isotopes in baleen were generally similar to those of muscle, which reflects the recent (approximately one month) feeding of the whale, but in some individuals there were significant differences between baleen and muscle. Sectioning of baleen into 1 cm longitudinal increments showed that these differences were due to marked dietary shifts by some individuals over time that had been recorded in the baleen but were lost from the muscle record. Whole baleen C and N isotopes were better correlated with tissue Hg levels, suggesting that baleen may provide a more reliable indicator of long-term average diet, which in turn may be better related to Hg accumulation in tissues than the shorter-term diet record contained in muscle.

Animals↗

PubMed2006

Morbilliviral infection in a pygmy sperm whale (Kogia breviceps) from Taiwanese waters.

Morbilliviral infection was diagnosed in an adult male pygmy sperm whale (Kogia breviceps) from southwestern Taiwan on the basis of pathological findings, immunohistochemical staining, and reverse transcription-polymerase chain reaction. The whale was found alive stranded on the beach and died after 5 days of medical care. It was thin and had dozens of nematode in the first stomach. The lungs were dark red and heavy. Histopathological examination revealed diffuse, moderate bronchointerstitial pneumonia. Intranuclear and intracytoplasmic inclusions with occasional syncytial cell formation were noted in the lungs, lymph nodes, and spleen. The RNA extracted from lung tissue was subjected to morbilliviral gene amplification. After priming with specific oligonucleotides, the cDNA covering the phosphoprotein (P) gene was copied and then amplified by PCR. The gene fragment amplified from the lung tissue was sequenced. Phylogenetic analysis of partial P gene revealed 97.6% sequence identity to the dolphin morbillivirus and 90.2% similarity to the pilot whale morbillivirus. Morbilliviral antigens were detected in the lungs, lymph nodes, and spleen by immunohistochemistry using polyclonal antibody against rinderpest virus. This is the first report of morbilliviral infection with genetic evidence in a pygmy sperm whale from the Western Pacific Ocean around Taiwan.

Animals↗