Population structure of nuclear and mitochondrial DNA variation among humpback whales in the North Pacific

The population structure of variation in a nuclear actin intron and the control region of mitochondrial DNA is described for humpback whales from eight regions in the North Pacific Ocean: central California, Baja Peninsula, nearshore Mexico (Bahia Banderas), offshore Mexico (Socorro Island), southeastern Alaska, central Alaska (Prince Williams Sound), Hawaii and Japan (Ogasawara Islands). Primary mtDNA haplotypes and intron alleles were identified using selected restriction fragment length polymorphisms of target sequences amplified by the polymerase chain reaction (PCR–RFLP). There was little evidence of heterogeneity in the frequencies of mtDNA haplotypes or actin intron alleles due to the year or sex composition of the sample. However, frequencies of four mtDNA haplotypes showed marked regional differences in their distributions (Φ_ST = 0.277; P < 0.001; n = 205 individuals) while the two alleles showed significant, but less marked, regional differences (Φ_ST = 0.033; P < 0.013; n = 400 chromosomes). An hierarchical analysis of variance in frequencies of haplotypes and alleles supported the grouping of six regions into a central and eastern stock with further partitioning of variance among regions within stocks for haplotypes but not for alleles. Based on available genetic and demographic evidence, the southeastern Alaska and central California feeding grounds were selected for additional analyses of nuclear differentiation using allelic variation at four microsatellite loci. All four loci showed significant differences in allele frequencies (overall F_ST = 0.043; P < 0.001; average n = 139 chromosomes per locus), indicating at least partial reproductive isolation between the two regions as well as the segregation of mtDNA lineages. Although the two feeding grounds were not panmictic for nuclear or mitochondrial loci, estimates of long-term migration rates suggested that male-mediated gene flow was several-fold greater than female gene flow. These results include and extend the range and sample size of previously published work, providing additional evidence for the significance of genetic management units within oceanic populations of humpback whales.     

Shallow-marine ostracode faunas around the Eocene/Oligocene boundary in the northwestern Kyushu, southwestern Japan

Middle Eocene–early Oligocene ostracode faunal changes in northwestern Kyushu of southwestern Japan are identified in this study. Ostracodes occur from shelf deposits of five formations: the middle Eocene Okinoshima, the upper Eocene Funazu, the uppermost Eocene–lowermost Oligocene Kishima, the lowermost Oligocene Itanoura, and the lower Oligocene Waita Formations. The middle Eocene–earliest Oligocene ostracodes were characterized by warm-water genera, indicating tropical, subtropical and Tethyan genera, whereas the late early Oligocene ostracodes do not include warm-water taxa, consisting of temperate realm genera. The middle Eocene–earliest Oligocene ostracodes do not include remarkable changes of species composition, in contract with equatorial Pacific radiolarians and West Coast USA molluscs. Ostracodes suggest that distinct climatic cooling did not occur in the southwestern Japan during the middle Eocene–earliest Oligocene.     

Satellite‐tracking of Northern Pintail Anas acuta during outbreaks of the H5N1 virus in Japan: implications for virus spread

We fitted Northern Pintail Anas acuta in Japan with satellite transmitters and monitored their spring migration movements relative to locations where the highly pathogenic H5N1 avian influenza virus was detected in Whooper Swans Cygnus cygnus in 2008. Pintails were assumed not to be infected with the H5N1 virus at the time they were marked because capture occurred between 2 and 5 months before reported outbreaks of the virus in Japan. We assessed spatial and temporal overlap between marked birds and occurrence of the virus and tracked Pintails after they departed outbreak locations. Eight of 66 (12.1%) Northern Pintails marked with satellite transmitters used wetlands in Japan where the H5N1 virus was detected in Whooper Swans. Apparent survival did not differ between Pintails that used H5N1 sites and those that did not. However, the proportion of Pintails that migrated from Japan was significantly lower among birds that used H5N1 sites compared with those that did not (0.50 vs. 0.79). Northern Pintails were present at the H5N1 sites from 1 to 88 days, with five birds present at the sites from 0 to 7 days prior to detection of the virus in Swans. The six Pintails observed to depart H5N1 sites did so within 2–77 days of the reported outbreaks and moved between 6 and 1200 km within 4 days of departure. Four Pintails migrated to eastern Russia. After their departure from outbreak sites, Northern Pintails made long‐distance migrations within the period when newly infected ducks would shed the H5N1 virus. This supports a hypothesized mechanism by which a highly pathogenic avian influenza virus could be spread by migratory birds.     

Stimulation of the Growth of Excised Cultured Roots of Soya Bean by Abscisic Acid

Excised root cultures of soya bean cultured at 30 °C inWhite's medium (1943) supplemented with 0•1 per cent yeastextract have been serially sub-cultured over 13 culture passagesof 7 days although a decline in the linear growth and lateralformation begins in the third passage and the roots are devoidof laterals from the 8th passage onwards. Applications of abscisicacid within the concentration range 0•01–0•001mg l^–1 and during the first two culture passages enhancedthe linear growth of the main axis, the number of emergent lateralsand the total length of laterals. This effect has been shownfor two cultivars, with roots derived from seed in both itsfirst and second year of storage and under different conditionsof culture and culture pH.