Immunochemical evidence for the transport of neurophysin in the hypothalamo-neurohypophysial system of the dog

Summary 1. An immunohistochemical study has been made of the hypothalamo-neurohypophyseal system of the dog, 20h after crushing the pituitary stalk.2. By use of a cross-species-reactive neurophysin antiserum it was shown that neurophysin is a component of the axons which originate in the supraoptic and paraventricular nuclei and terminate around blood vessels in the posterior pituitary.3. Neurophysin specific fluorescence accumulated in axons proximal to the constriction but was absent from the axons immediately distal to the site of injury.4. In dogs left for six days it was shown by radioimmunoassay that the amount of neurophysin in the hypothalamus and stalk proximal to the constriction increased twofold while that remaining in the posterior pituitary and stalk distal to the constriction decreased five-fold over the same period.5. The results are interpreted as evidence for a rapid axonal transport of neurophysin from its site of synthesis in the cell bodies of the hypothalamus to the posterior pituitary. Acknowledgements: This work was supported by a research grant to D. B. Hope from the Medical Research Council. L. O. Uttenthal was supported by a Medical Research Training Award and B. G. Livett by a Nuffield Dominions Trust Demonstratorship (Australia). We thank Mrs. Marion Martin for radioimmunoassay of neurophysin, Miss Wendy Jones for technical assistance and the U.C.L.A. Brain Information Service for help with the bibliography.     

Quinacrine fluorescence and Giemsa banding in trisomy 22

Summary Using quinacrine fluorescence and Giemsa banding techniques we have identified an extra chromosome 22 in three non-mongoloid children with similar phenotypes and 47 chromosomes. In one of the children, the long arm of the extra 22 was shorter than usual. This 22q—chrcmcscme was observed in 4 normal family members with 46 chromosomes. In a fourth child, with similar physical findings, the extra G chromosome was shown to be neither a normal 21 nor 22. It must have arisen from a rearrangement in a parental gamete since it was not present in either parent's karyotype.No constellation of clinical findings, in association with an extra G chromosome, is sufficient evidence for the diagnosis of trisomy 22. The positive identification of the extra chromosome must be made using fluorescence and banding.This paper is dedicated to Professor Marcus M. Rhoades on his 70th birthday in grateful recognition of his friendship, help and advice.Supported in part by U.S. Public Health Service Grants HD1313, RR-75 and TI-HD-66 from the National Institutes of Health. A portion of this paper was presented at the annual meeting of the Society for Pediatric Research, Atlantic City, N.J. May 1, 1971.     

Potential role for microbial ureolysis in the rapid formation of carbonate tufa mounds

Modern carbonate tufa towers in the alkaline (~pH 9.5) Big Soda Lake (BSL), Nevada, exhibit rapid precipitation rates (exceeding 3 cm/year) and host diverse microbial communities. Geochemical indicators reveal that carbonate precipitation is, in part, promoted by the mixing of calcium-rich groundwater and carbonate-rich lake water, such that a microbial role for carbonate precipitation is unknown. Here, we characterize the BSL microbial communities and evaluate their potential effects on carbonate precipitation that may influence fast carbonate precipitation rates of the active tufa mounds of BSL. Small subunit rRNA gene surveys indicate a diverse microbial community living endolithically, in interior voids, and on tufa surfaces. Metagenomic DNA sequencing shows that genes associated with metabolisms that are capable of increasing carbonate saturation (e.g., photosynthesis, ureolysis, and bicarbonate transport) are abundant. Enzyme activity assays revealed that urease and carbonic anhydrase, two microbial enzymes that promote carbonate precipitation, are active in situ in BSL tufa biofilms, and urease also increased calcium carbonate precipitation rates in laboratory incubation analyses. We propose that, although BSL tufas form partially as a result of water mixing, tufa-inhabiting microbiota promote rapid carbonate authigenesis via ureolysis, and potentially via bicarbonate dehydration and CO₂ outgassing by carbonic anhydrase. Microbially induced calcium carbonate precipitation in BSL tufas may generate signatures preserved in the carbonate microfabric, such as stromatolitic layers, which could serve as models for developing potential biosignatures on Earth and elsewhere.     

Revised Sequence and Annotation of the Rhodobacter sphaeroides 2.4.1 Genome

The DNA sequences of chromosomes I and II of Rhodobacter sphaeroides strain 2.4.1 have been revised, and the annotation of the entire genomic sequence, including both chromosomes and the five plasmids, has been updated. Errors in the originally published sequence have been corrected, and ∼11% of the coding regions in the original sequence have been affected by the revised annotation.     

Warming up for dinner: torpor and arousal in hibernating Natterer’s bats (Myotis nattereri) studied by radio telemetry

The frequency and function of arousals during hibernation in free-living mammals are little known. We used temperature-sensitive radio transmitters to measure patterns of torpor, arousal and activity in wild Natterer’s bats Myotis nattereri during hibernation. Duration of torpor bouts ranged from 0.06 to 20.4 days with individual means ranging from 0.9 to 8.9 days. Arousals from torpor occurred most commonly coincident with the time (relative to sunset) typical for bats emerging from summer roosts to forage. Bats with lower body condition indices had a shorter average duration of their torpor bouts. We found a non-linear relationship between duration of torpor bout and ambient temperature: the longest average torpor bouts were at temperatures between 2 and 4°C with shorter bouts at lower and higher ambient temperatures. One individual was radio-tracked for ten nights, remained active for an average of 297 min each night and was active for longer on warmer nights. Our results suggest that vespertilionid bats use relatively short torpor bouts during hibernation in a location with a maritime climate. We hypothesise that Natterer’s bats time arousals to maximise opportunities for potential foraging during winter although winter feeding is not the sole determinant of arousal as bats still arouse at times when foraging is unlikely.     

The environmental water of the middle Eocene Arctic: Evidence from δD, δ18O and δ13C within specific compounds

The extensive vertical exposure (> 150 m) of terrestrial sediments on Axel Heiberg Island, which contain thick fossiliferous lignites, presents an exceptional opportunity to follow the establishment and re-establishment of Arctic Metasequoia forests during the middle Eocene. We compared δD values in n-alkanes of chain length 23, 25, 27 and 29 with δ¹⁸O values in phenylglucosazone (P-G) derived from α-cellulose; we also analyzed %-abundance of ferns, gymnosperms and angiosperms using pollen and spores isolated from each lignite. Our results showed that forest composition was altered upon uplift, as gymnosperms became more abundant within the relatively well-drained upland sediments. This was also reflected in the small (1‰), but significant, increase in the δ¹³C value of TOM from lowland to upland environments. However, neither the δD values of n-alkanes nor the δ¹⁸O in P-G were statistically different in the upland sediments, as compared to the lowland sediments; from this we inferred that the oxygen isotope signature of environmental water available to the forests for plant growth was relatively uniform throughout the time of the fossil forests. The δD value of environmental water implied by both n-alkanes and P-G ranged from ? 168 to ? 131% and was considerably enriched compared to all environmental water samples available from the modern Arctic region (< ? 180%). In addition to indicating a warmer Eocene Arctic, subject to meteoric transport patterns different from today's, these results argue against the presence of an Eocene polar ice cap.     

Complete genome sequence of Desulfomicrobium baculatum type strain (X)

Desulfomicrobium baculatum is the type species of the genus Desulfomicrobium, which is the type genus of the family Desulfomicrobiaceae. It is of phylogenetic interest because of the isolated location of the family Desulfomicrobiaceae within the order Desulfovibrionales. D. baculatum strain X(T) is a Gram-negative, motile, sulfate-reducing bacterium isolated from water-saturated manganese carbonate ore. It is strictly anaerobic and does not require NaCl for growth, although NaCl concentrations up to 6% (w/v) are tolerated. The metabolism is respiratory or fermentative. In the presence of sulfate, pyruvate and lactate are incompletely oxidized to acetate and CO(2). Here we describe the features of this organism, together with the complete genome sequence and annotation. This is the first completed genome sequence of a member of the deltaproteobacterial family Desulfomicrobiaceae, and this 3,942,657 bp long single replicon genome with its 3494 protein-coding and 72 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.