Polychlorinated biphenyls (PCBs) in fish-eating sea birds—II. Molecular features of PCB isomers and congeners in adipose tissue of male and female puffins (Fratercula arctica), guillemots (Uria aalga), shags (Phalacrocorax aristotelis) and cormorants (Phalacrocorax carbo) of British and Irish coastal waters

1. The concentration of individual PCBs was measured in adipose tissue of male and female puffins, shags, guillemots and cormorants obtained from the Isle of May and the Saltees islands.2. The concentrations of total PCBs showed positive correlations with that ofp,p'-DDE in the tissues.3. Enrichment factors were calculated by comparing the concentration of an individual PCB in the tissue with its abundance in commercial mixtures of PCBs.4. Of the 47 individual PCBs identified five prominent PCBs had enrichment factors considerably > 1 and accounted for approximately 35% of the total concentration of PCBs present. They shared the common molecular feature of chlorine atoms at adjacent meta-para positions in at least one of the biphenyl rings.5. Many PCBs had enrichment factors of <1, which suggested that they had been subjected to metabolism and presumably excretion. They shared the common feature of the absence of chlorine atoms at the meta-para positions of the biphenyl rings.6. These results support strongly the structural “rules” suggested in the preceding paper (Borlakoglu et al., 1990a) for the tendency of individual PCBs to accumulate or to be subjected to metabolism.     

Polychlorinated biphenyls (pcbs) in fish-eating sea birds—III. Molecular features and metabolic interpretations of PCB isomers and congeners in adipose tissues

1. Enrichment factors have been calculated for several persistent PCB congeners in the adipose tissue for five species of fish-eating sea birds (female razorbills, puffins, guillemots, shags and cormorants) obtained from the same sites during 1978–1984 (see preceding papers).2. The enrichment factor of an individual PCB is expressed as its concentration in the tissue compared with its abundance in commerical mixtures of PCBs or compared with the concentration in the tissue of the abundant congener 2,2',4,4',5,5'-hexachlorobiphenyl (congener 153, IUPAC system of numbering).3. There were no significant differences between the five species in the enrichment factor of individual persistent PCBs compared with congener 153, indicating similar levels of diminished metabolism of this group of congeners.4. Of the 47 individual PCBs identified, ten congeners had enrichment factors of > 1 in all of the species and these accounted for up to 70% of the concentration of total PCBs present. Some of these persistent congeners had approximately coplanar configurations (i.e. non-ortho -substituted congeners). Five congeners, which accounted for about 35% of the total concentration of PCBs in the tissues, shared the molecular feature of chlorine substituents at adjacent meta-para carbon atoms.5. A number of congeners were identified with enrichment factors of <1 compared with their abundance in Aroclor 1260, and very striking differences were observed between the five species in the ratio of non-persistent congeners to the persistent congener 153. These non-persistent congeners share the molecular feature of at least one pair of adjacent unsubstituted meta-para carbon atoms in the rings. This agrees with our molecular “rule” (see preceding papers) that congeners with this structural feature are subjected to metabolism by the cytochrome P-450 component of hepatic microsomal monooxygenases.6. Evidence is presented that this molecular rule applies to the persistence or non-persistence of classes of PCBs in other biological systems and that the complete absence of H atoms at adjacent carbon atoms is an essential structural requirement for the accumulation of PCBs in tissues.7. The persistence or non-persistence of individual PCBs is compared with their ability to induce specific isoforms of the cytochrome P-450 components of hepatic microsomal monooxygenases, and the toxic effects of individual PCBs that accumulate is discussed in terms of the potential environmental hazard that they represent.     

British Isles coastal waters: The concentrations of selected heavy metals in sea water,suspended matter and biological indicators — A pilot survey

Data, from British Isles coastal waters, on the concentrations of selected metals in sea water and biological indicators, have been obtained by analytical techniques based on atomic absorption spectrophotometry. The results show that there are some areas where significant contamination exists, and the east Irish Sea appears to have the highest concentrations of most metals. However, data in most regions indicate that the concentrations of the metals examined are not significantly higher than those in the open Atlantic Ocean adjacent to the British Isles. The sampling of seaweeds strongly suggests that concentrations of most metals, including those in polluted areas, have changed little over the ten years up to 1970; the concentrations of cadmium may well, on average, have fallen over this period. In the Irish Sea, where the most detailed examination has been made, there is a rapid decrease in sea water concentrations from the shoreline to offshore, and, in general, the proportions of a metal associated with suspended matter remain fairly constant with respect to variations of total concentrations in either time or space.     

Fine-scale sociality reveals female–male affiliations and absence of male alliances in bottlenose dolphins (Tursiops truncatus) in the Shannon Estuary,Ireland

Knowledge of social behavior at an individual level is central to our understanding of complex mammalian societies. In this study, we analyzed the fine-scale sociality of wild bottlenose dolphins in the Shannon Estuary, Ireland, by examining associations between members of the whole population and between specific female and male dolphins. We carried out 51 boat-based individual focal follows on 18 identifiable bottlenose dolphins over 90.8 hr (39 days) between 2014 and 2016. Additionally, we conducted 353 boat-based surveys (with 607 sightings) between 2012 and 2015, and identified 121 distinct adult/juvenile dolphins. The mean group size of focal dolphin groups was 7.2 ± 4.1 (range = 1–20) and the mean fission-fusion rate was 3.06 ± 1.35 changes/hr. The most frequent composition of within-group affiliate pairs was female–male. Focal males spent more time with female nearest-neighbors than male nearest-neighbors (p = .013). Differences between female and male activity budgets were not strongly supported (p = .13). There was no evidence for male alliance formation in the Shannon Estuary population, and all of the known-sex top-ranked associates (7) of known males (n = 10) were females. This research reveals a distinct bottlenose dolphin society with female–male affiliations and an absence of male alliances.     

Alpha 1- and beta-adrenergic receptors in brown adipose tissue of lean (Fa/?) and obese (fa/fa) Zucker rats. Effects of cold-acclimation,sucrose feeding and adrenalectomy.

1. The populations of alpha 1- and beta-adrenergic receptors in brown adipose tissue (BAT) of genetically obese Zucker rats (fa/fa) were studied with [3H]prazosin and [3H]CGP-12177 respectively. 2. The density of alpha 1-adrenergic receptors in BAT was significantly lower in obese than in lean Zucker rats, both at 2-4 months of age and at 6 weeks of age. The density of beta-adrenergic receptors was identical in BAT of lean and obese 6-week-old Zucker rats. 3. Cold-acclimation increased the alpha 1-receptor density significantly in BAT of both lean and obese Zucker rats, and the number of beta-receptors was also somewhat increased. 4. Sucrose feeding did not affect the density of alpha 1-receptors in BAT of lean or obese Zucker rats, but it increased beta-receptor density. 5. Adrenalectomy restored the density of alpha 1-adrenergic receptors in BAT of obese Zucker rats to the value observed in lean rats. 6. It is concluded that there is a direct correlation between alpha 1-receptor density and tissue recruitment, and that alpha 1-receptor density is thus positively correlated with sympathetic activity. beta-Receptor density is apparently better correlated with feeding conditions.     

A new male-specific gene “<Emphasis Type="Italic">OTOKOGI</Emphasis>” in <Emphasis Type="Italic">Pleodorina starrii</Emphasis> (Volvocaceae,Chlorophyta) unveils the origin of male and female

Eukaryotic sex was initially isogametic and it is assumed that anisogamy/oogamy evolved independently in many lineages including animals, land plants and volvocine green algae. The exact evolutionary mechanisms that were responsible for the evolution of oogamy from isogamy were poorly understood until Nozaki et al. (2006) introduced the use of molecular-genetic data in elucidating the evolutionary origin of oogamy from isogamy in the colonial volvocacean Pleodorina starrii. In the close relative Chlamydomonas reinhardtii, sexual reproduction is isogametic with mating-types plus and minus. Mating type minus represents a “dominant sex” because the MID (“minus-dominance”) gene of C. reinhardtii is both necessary and sufficient to cause the cells to differentiate as isogametes of the minus mating type. No sex-specific genes had been identified in the volvocine green algae until Nozaki et al. (2006a) successfully cloned the MID gene of P. starrii. This “OTOKOGI” (PlestMID) gene is present only in the male genome, and encodes a protein localized abundantly in the nuclei of mature sperm. Thus, P. starrii maleness evolved from the dominant sex (mating type minus) of its isogamous ancestor. This breakthrough provides an opportunity to address various extremely interesting questions regarding the evolution of oogamy and the male-female dichotomy. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.