Heavy metal tissue distributions in southwestern Alaskan waterfowl: total mercury assays from muscle, brain, and bone

Thesis (M.S.) University of Alaska Fairbanks, 2005Food containing mercury has been identified as a possible health risk. Total mercury (THg), which is inorganic (Hg²), and methylmercury (MeHg) species, has been found in the arctic food web. In Alaska, birds are an important seasonal component of the diet, but have not been studied extensively and characterized for the presence of mercury. Birds are good subjects for examination because they feed at different trophic levels, can be long-lived, and are both abundant and widely distributed. Not only can birds monitor local Alaskan food webs, but, if they are migratory, can be used to compare exposure in different regions. Mercury levels in muscle, brain, and bone tissue of 140 birds taken by subsistence hunters across southwestern Alaska were determined. I tested the null hypothesis of no interspecific differences in total mercury levels in the 18 species of Alaska birds surveyed. There were interspecific differences with the Lesser Scaup (Aythyra marila mariloides), and the Black Scoter (Melanita nigra Americana), having the highest levels of mercury. In general, mercury levels were higher in muscle than in brain or bone. The mean values for mercury in the species studied were lower than the levels known to cause adverse reproductive or behavioral effects

Using Molecular Marker Technology for Improvement in Sow Reproductive Longevity

The longevity or productive life of sows is one of the important components that contribute to the economic bottom line of swine production. Involuntary sow culling rates caused by locomotion failure, reproductive failure or death have been growing in recent years causing many females to be culled before they reach their most productive parities and before the investment costs of those females have been recovered. In addition to factors such as management, sow condition, health, nutrition, and facilities, there are likely to be genetic components controlling sow longevity that have yet to be fully identified. Research ongoing at Iowa State University, in conjunction with Sygen and PIC, has focused on identifying the genes associated with variation in sow longevity

Rapid Communication: Genetic Linkage Mapping of the Porcine Fibroblast Growth Factor 7 (FGF7) Gene

Source and Description of Primers. The forward primer was developed from a human fibroblast growth factor ( FGF7) cDNA sequence (GenBank accession no. L06243), and the reverse primer was a published primer (Kelley et al., 1992). These primers were used to amplify a 1.3-kb fragment from porcine genomic DNA. This fragment included regions corresponding to exon 2, exon 3, and the intron flanked by these two exons. Sequences were obtained from both ends of the PCR fragment and compared with a human sequence showing 95.9% identity at the amino acid level in a 73-amino acid overlap. Sequences produced in this experiment have been submitted to GenBank (accession no. AF052657)

Rapid Communication: Linkage Mapping of Porcine Interleukin 6 (IL6)

Source and Description of Primers. Dog primers designed from human sequence (Venta et al., 1996) were used to amplify a 774-bp fragment of the porcine IL6 gene. The 5¢ primer is located in exon 3, and the 3¢ primer is located in exon 4

Rapid communication: Linkage and physical mapping of the porcine melanocortin-4 receptor (MC4R) gene

Genus and Species. Sus scrofa. Locus. Pig Melanocortin-4 Receptor (MC4R) gene. Source and Description of Primers. Primers were designed from well-conserved sequence regions between the human and rat MC4R genes (Genbank accession no. S77415 and U67863, respectively). The primers were used to amplify approximately 760 bp of the porcine MC4R gene from genomic DNA. The sequence of the PCR product showed 92.2 and 97.6% identities at the nucleotide and amino acid levels, respectively, to the corresponding human sequence. The porcine MC4R sequence has been submitted to GenBank (accession no. AF087937). Using this sequence, pig-specific primers were designed

Two ~35 day clocks in Her X-1: evidence for neutron star free precession

We present evidence for the existence of two ~35 day clocks in the Her X-1/HZ Her binary system. ~35 day modulations are observed 1) in the Turn-On cycles with two on- and two off-states, and 2) in the changing shape of the pulse profiles which re-appears regularly. The two ways of counting the 35 day cycles are generally in synchronization. This synchronization did apparently break down temporarily during the long Anomalous Low (AL3) which Her X-1 experienced in 1999/2000, in the sense that there must have been one extra Turn-On cycle. Our working hypothesis is that there are two clocks in the system, both with a period of about ~35 days: precession of the accretion disk (the less stable "Turn-On clock") and free precession of the neutron star (the more stable "Pulse profile clock"). We suggest that free precession of the neutron star is the master clock, and that the precession of the accretion disk is basically synchronized to that of the neutron star through a feed-back mechanism in the binary system. However, the Turn-On clock can slip against its master when the accretion disk has a very low inclination, as is observed to be the case during AL3. We take the apparent correlation between the histories of the Turn-Ons, of the Anomalous Lows and of the pulse period evolution, with a 5 yr quasi-periodicity, as evidence for strong physical interaction and feed-back between the major components in the system. We speculate that the 5 yr (10 yr) period is either due to a corresponding activity cycle of HZ Her or a natural ringing period of the physical system of coupled components. The question whether free precession really exists in neutron stars is of great importance for the understanding of matter with supra-nuclear density.Comment: 6 pages, 5 figures, accepted for publication by A&

Rapid Communication: The Very-Long-Chain Acyl-CoA Dehydrogenase Gene Maps to Pig Chromosome 12

Source and Description of Primers. Primers for the very-long-chain acyl-CoA dehydrogenase (ACADVL) gene were designed from a bovine cDNA sequence (GenBank accession No. U30817) aligned with the human ACADVL gene (GenBank accession No. L46590). The forward primer was 5¢-TTT GGG GAG AAA ATT CAC AAC-3¢ and the reverse primer was 5¢-GCG GCC TCT ATC TGG AAG T-3¢. The amplification product was expected to span from exon 11 to exon 12 of the ACADVL gene. Exonic parts (103 bp) of the pig sequence were 91% identical at the nucleotide level with the human ACADVL sequence. The pig sequence produced here has been submitted to GenBank (accession no. AF022255)

Rapid Communication: A HincII Polymorphism in the Porcine Calpain, Large Polypeptide L3 (CAPN3) Gene

Source and Description of Primers. Primers were designed from a published, partial porcine cDNA sequence (Genbank accession no. U05678) in positions corresponding to exons 11 and 13 of the human CAPN3 gene (Genbank accession no. X85030). Sequences were obtained from the ends of the PCR fragment and compared with the porcine cDNA sequence showing 98.1% identity in a 108-bp overlap at the exon 11 end and 99.2% identity in a 124-bp overlap at the exon 13 end. Sequences produced in this study have been submitted to Genbank (accession no. AF025660-AF025661)

Mapping of Two High Mobility Group Protein Genes for Growth and Composition traits in Pig

Using information from the human genome two new candidate genes for growth and composition traits were studied. The porcine high mobility group isoforms protein [HMGI(Y) and HMGIC] genes were chosen based on their presumed role in fat cell growth and differentiation. The HMGI(Y) gene was assigned to pig chromosome 7 by both linkage and physical mapping methods. This assignment agrees with other comparative mapping studies as the human HMGI(Y) gene maps to human chromosome 6p21, which is known to share a homology with pig chromosome 7. Interestingly, the pig HMGIC gene was assigned to the pig chromosome 1 by both methods. The localization of these candidate genes in the pig genome could improve the power of analyses for quantitative traits associated with growth and meat quality traits