Family values

Evolutionary Genetics (2nd edn) by J. Maynard Smith, Oxford University Press, 1998. £50.00 hbk, £19.95 pbk (368 pages) ISBN 0 19 850232 X/0 19 850231 1Selection in Natural Populations by J.B. Mitton, Oxford University Press, 1998. £50.00 hbk (252 pages) ISBN 0 19 506352 XProgress and Prospects in Evolutionary Biology edited by J.R. Powell, Oxford University Press, 1997. £49.50 hbk (576 pages) ISBN 0 19 507691 5Evolution on Islands edited by P.R. Grant, Oxford University Press, 1997. £24.99 pbk (348 pages) ISBN 0 19 850 1714     

A 20–24 H MICROCOLONY-IMMUNOBLOT TECHNIQUE to DIRECTLY DETECT and ENUMERATE LISTERIA MONOCYTOGENES INOCULATED INTO FOODS

A microcolony-immunoblot technique (MCIBI) was developed to directly enumerate, in less than 24 h, very low numbers of Listeria monocytogenes (8–12 colony forming units: CFU/g or mL) inoculated into foods. Four meat and poultry and two dairy products were artificially inoculated with L. monocytogenes V7 diluted and plated on Oxford agar medium. Each plate was overlaid with an Immobilon-P membrane and incubated for 18–20 h at 37C. Blot-transferred colonies on these membranes were probed with C11E9 monoclonal antibody (MAb) and developed using peroxidase conjugated goat antimo use Ig G and a water insoluble substrate (3,3-diaminobenzidin tetrahydmchloride; (DAB-HCI), Nickel chloride and H₂O₂). the MCIBT gave L. monocytogenes counts that were not significantly lower than direct colony counts on selective agars. This technique allowed the recovery of 94–100% of L. monocytogenes cells inoculated into foods containing natural background flora counts of 3 × 10⁴ to 8 × 10⁶ CFU/g or mL. Using a 2 h resuscitation period on nonselective agar before overlay with Oxford media, the MCIBT allowed detection of sublethally heat injured cells of strain V7.     

REVIEWS

Book reviewed in this article:
(1) The Elements of Experimental Embryology . By J. S. H uxley and G. R. D e B eer .
(2) Fentures in the Architecture of Physiologicad Function . By J. B ar - croft .
The Agricultural Register , 1933–4. Oxford: Agricultural Economic Research Institute. 1934.     

Brood division and transition to independence in Blackbirds Turdus merula

Blackbirds Turdus merula rearing young in the Botanic Garden, Oxford, were observed over three summers (1979–81). Between 0 and 10 days after fledging the young were divided between the parents so that each fed only certain fledglings and refused to feed others. This division was temporally stable. In broods where another nesting attempt followed, the male usually took responsibility for all the young, but in final broods they were divided fairly evenly. The probability of a fledgling surviving to independence declined as the number of young a parent fed increased; thus division should be favoured. However, if the female fed some young the inter-nest interval increased and the potential number of young that could be raised in that season was curtailed. This trade-off is examined by means of a model. After fledging the young improved in their ability to capture prey successfully and increased the size of the prey taken. At 15–24 days after fledging, self-feeding became more profitable than parental feeding and the young became fully independent. The timing of this transition is influenced by the parents, and it is suggested that by dividing the brood, parental feeding can be more carefully regulated so that finer control over the timing of independence is achieved.     

Duration of synchronous cleavage cycles and rate of development at different temperatures in the Baltic herring

The duration of one synchronous cleavage cycle (τ₀) in Clupea harengus membras at different temperatures ( T ) was given by: (logτ₀)= 2.4349–0–0684T for T= 0.9–13°C, and (logτ₀)= 1.61010–oooit for t= 13–18–7°C.     

Culture of meristem tips and micropropagation of 12 commercial clones of poplar in vitro

Twelve commercial clones of poplar were cultured in vitro from meristem lips (0.3–0.5 mm diameter), shoot tips (4–6 mm long) and nodal segments (5–10 mm long). Shoot-producing cultures were obtained from 4, 32 and 70% of meristem lips, shoot tips and nodal segments within 12, 6 and 4 weeks, respectively. The genotype of cultures had a greater influence on development of shoot-producing cultures than medium composition. Cultivars Max/Ber and Oxford had the highest rates of establishment in culture and subsequent shoot proliferation, while P. tacamahaca, P. trichocarpa and cv. Robusta exhibited very low rates of establishment and low vigor in vitro. Shoot tip development was best on agar-solidified medium whereas liquid medium resulted in vitrification. Higher rates of axillary shoot production from established cultures were obtained with benzyladeninc or zeutin than with 2-isopen-tenyladenine. deducting the benzyladenine concentration from 4,4 to 1.1 μ M , increased the production of elongated shoots suitable for rooting.     

Effects of Climate Change on Birds

2010, Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK

344 pages, hardcover or paperback, 75 black-and-white illustrations, and a four-page color plate section

ISBN 978-0-19-956974-8 (hardcover), 978-0-19-956975-5 (softcover). Price R575     

The fleas of a population of weasels in Wytham Woods, Oxford

Weasels were regularly livetrapped, anaesthetized and searched for fleas over two years, in Wytham Woods, near Oxford. Eleven species of fleas were identified among 262 collected. Seven normally occur on small rodents, one on rats, two on moles and one on birds. Fleas were collected on 103 of 338 occasions when an unconscious weasel was examined; on average males carried 0·6 fleas, females 1·5 fleas, but there was no significant difference between the proportion of males and females infested. The species distribution of the fleas on weasels in Wytham suggests that they acquire their fleas mainly from the nests and runways of their prey, which they have hunted through or taken over. Important prey, e.g. birds (22% of prey items identified) with uninviting nests contributed few fleas (2%); non-prey, e.g. moles (0–4% of items) with highly desirable nests, contributed disproportionately many, including 35 fleas (15%) of two species otherwise monoxenous on moles. A similar pattern is shown by the fleas carried by stoats in New Zealand.     

Oxygen uptake through gills and skin in relation to body weight of an air-breathing siluroid fish, Saccobranchus (=Heteropneustes) fossilis

Oxygen uptake through gills and skin has been measured in juvenile and adult Saccobranchus fossilis and its relationship represented by the equation Vo₂= aW^b. When air-breathing is allowed the O₂ uptake via the gills and skin together increases by powers of 1 -084, 0–986 and 1–328 in juvenile, adult and juvenile+adult respectively. When air-breathing is prevented the slope (b) for O₂ uptake via the gills appear to be less in juveniles (0–765) than in adults (0–784) and juveniles+adults together (0–814). Under the same experimental condition, the slope for O₂ uptake via the gills+skin is also less in juveniles (0–478) than in adults (0–799) and juveniles+adults (0–755). Further decrease in the exponent value is found for the oxygen uptake of skin in relation to body weight under surfacing-prevented conditions ( b = 0–542). Different exponent values for juvenile and adult fishes may be due to their different growth pattern and physiology.     

Molecular and genetic aspects of nitrate assimilation

Book Review

Molecular and genetic aspects of nitrate assimilationJ.L. Wray and J.R. Kinghorn (Eds.), Oxford, New York, Tokyo: Oxford Science Publications, 1989. xv + 410 pages. £45.00. ISBN 0-19-857696-X     

OBITUARIES

The following autobiographical sketch was written by the late R. E. Moreau at the invitation of Dr. David Lack and was deposited at the Edward Grey Institute, Oxford, in 1966. By printing it in full we dispense with the need for a formal obituary, and instead have invited four ornithologists who knew Reg Moreau especially well to contribute their personal appreciations. These follow on pp. 557–564. Ed.     

A medium density microsatellite map of BTA10: reassignment of INRA69

We have developed a genetic map of BTA10 based on 8952 informative meioses for 13 microsatellite markers and the erythrocyte antigen Z. With the exception of OarAE64 , the support for the order of all loci in the map exceeded a LOD > 3·0. The length of the BTA10 genetic map was 87·0 centimorgans (cM). The 14-marker, sex-average map in Kosambi cM was: CSSM38 –8·9- BM1237 –5·2- HH8A –2·6- INRA69 –10·6- TGLA378 –0·8- BM6305 –17·2- TGLA102 –17·9- INRA96 –0·3- CSRM60 –9·2- DIK20 –3·0- EAZ –6·7- CSSM46 –3·7- SRCRSP3 –1·0- OarAE64 with an average interval of 6·70 cM. The microsatellite INRA69 was recently assigned to the pseudoautosomal region of the bovine X chromosome by linkage analysis. However, we found that twopoint support for linkage between INRA69 and 15 X-linked bovine microsatellites was LOD < 0·50 in 529 reciprocal backcross and F₂ fullsib progeny. We performed twopoint analyses of INRA69 against 275 markers distributed throughout the bovine genome and found significant associations with a LOD > 3·0 only between INRA69 and eight BTA10 microsatellite loci. Consequently, we excluded INRA69 from the genetic map of the X chromosome and reassign this microsatellite to BTA10.     

Differentiation of Erwinia Species in the "Herbicola" Group by Class Analysis of Cellular Fatty Acids

Profiles of cellular fatty acids of Erwinia herbicola, E. ananas, E. stewartü and E. uredovora , comprising the Herbicola group in the genus Erwinia , contained 7 major components accounting for 90–95% of total fatty acids, and,30 minor components, each less than 1% of the total. The major components and their average percentage ranges in cells on King's medium B at 28°C for 1 days were: 12:0 (3.5–4.5%), 14:0 (3.6–4.3%), 16:0 (28.1–35.7%), 16:1 (17.5–24.2%), 18:1 (13.9–31.9%), 3-OH 14:0 (4.6–7.2%) and cyclopropane 17:0 (trace levels in E. stewartii , 5.0–6.7% in other species). Fatty acid composition changed as a function of physiological age of the cells. The regression coefficient ( b ) as a function of age for percentage of saturated even- and oddcarbon, straight-chain fatty acids (Classes A and B) was either negative or not significant for E. ananas and positive for the other species. A series of dichotomous steps was constructed based on fatty acid algorithms to differentiate all four species.     

Tumor-Promoting Phorbol Esters Promote Melanogenesis and Prevent Expression of the Adrenergic Phenotype in Quail Neural Crest Cells

Tumor-promoting phorbol esters were used to manipulate the in vitro development of neural crest cells. When plated at clonal density in secondary culture, quail neural crest cells from the trunk region gave rise to three types of colonies, pigmented, unpigmented, and mixed. Pigmented colonies consisted exclusively of melanocytes; up to 50% of the unpigmented and mixed colonies contained adrenergic nerve cells which could be identified by a catecholamine-specific histofluorescence method. Addition of potent tumor promoters to the culture medium shortened the doubling time of neural crest cells and altered their morphologic appearance. It also delayed the onset of pigmentation, prevented the expression of the adrenergic phenotype, reduced the number of unpigmented and mixed colonies, and increased the number of pigmented colonies, most likely by directing progenitor cells preferentially to the melanogenic pathway. There was a clear correlation between the ability of phorbol esters to promote skin tumors in mice and their ability to interfere with the in vitro development of quail neural crest cells. The potent promoters 12–0–tetradecanoyl phorbol 13–acetate (TPA) and phorbol 12,13–didecanoate (PDD) were most effective, phorbol 12,13–diacetate (PDA) was considerably less effective, the nonpromoting analogues 4–0–methyl 12–0–tetradecanoyl phorbol 13–acetate (4–0–Me-TPA) and 4α-phorbol 12,13–didecanoate (4α-PDD) and the parent alcohol phorbol (PHR) had little or no effect.     

Morphometries of the respiratory organs of the Indian green snake-headed fish, Channa punctata

Measurements of the dimensions of the different gills and the suprabranchial chambers have been made and the data analysed with respect to body weight using logarithmic transformations (Y = aW^b). The slope (b) for area of the total gill surface is 0–592 and for the supra-branchial chamber 0–696, and their combined respiratory surface: 0–623. The slope values for the surface areas of the 1st, 2nd, 3rd and the 4th gill arches were 0–595,0–578,0–614 and 0–572 respectively.
The slope for secondary lamellae/mm is –0138 and that for the bilateral surface area of an average-sized lamella 0–304.
These results indicate differences in growth patterns for the dimensions of the different gills. The growth-related decrease in the number of secondary lamellae/mm and size of an average secondary lamella together with evidence from "drowning" experiments and diffusing capacity calculation, suggest that this fish is better adapted for aquatic respiration than Anabas or Saccobranchus. The slopes for the total respiratory surface area and gill area seem to be comparatively low in this species.     

Characteristics of egg and larval production in captive bluespotted gobies

Spawning of the Hawaiian coral-reef goby Asterropteryx semipunctata was diurnal, occurring at various times throughout the day. Mean length of eggs deposited in nests was 0·76 mm (range 0·67–0·84); mean egg width was 0·47 mm (range 0·41–0·52). Clutch size varied from 296 to 1552 eggs (mean=886±309), and was independent of standard length, total body weight, and body condition. Mean relative clutch size was 1·59 eggs mg^-1 total body weight (range 0·84–2·43). Clutches hatched 4–5 nights after being deposited in a nest. Mean notochord length of newly-hatched larvae was 1·88 mm (range 1·60–2·04). The minimum period of time that elapsed between egg deposition and subsequent growth of a new batch of oocytes to spawning size was 5–6 days, providing a reasonable estimate of minimum spawning interval. Compared with other gobiids, tropical species tend to have shorter incubation periods, smaller eggs and smaller larvae at hatching.     

3D Bio-Plotted Composite Scaffold Made of Collagen Treated Hydroxyapatite-Tricalciumphosphate for Rabbit Tibia Bone Regeneration

Biphasic calcium phosphate scaffolds with 20/80 HA/TCP ratio were fabricated using the 3D-Bioplotting system to heal critical size defects in rabbit tibia bone. Four different architectures were printed in a layer by layer fashion with lay down patterns viz. (a) 0°– 90°, (b) 0°– 45°– 90°– 135°, (c) 0°–108°– 216° and (d) 0°– 60°– 120°. After high-temperature sintering scaffolds were coated with collagen and were further characterized by (FTIR) Fourier Transform Infrared Spectroscopy, (SEM) Scanning Electron Microscopy, (XRD) X-Ray diffraction, Porosity analysis and Mechanical testing. Scaffold samples were tested for its ability to induce cytotoxicity in Balb/c 3T3 cells at in vitro condition using elution method. Skin sensitization potential of scaffolds was evaluated in male guinea pigs using guinea pig maximization test (GPMT). Further, scaffolds were implanted in eight rabbit tibia bones and biocompatibility and histological evaluations were carried out after 4 and 8 weeks implantation periods. In-vitro results include bonding, surface morphology, phases, porosity, mechanical strength and Cytotoxicity. In-vivo results include sensitization, capsule formation, inflammation, presence of polymorphonuclear cells, giant cells, plasma cells, X-Rays and degradation of the material. It was concluded that HA/TCP/Collagen scaffold with 0°– 45°– 90°– 135° architecture exhibits the most excellent properties in healing critical size bone defects in rabbits.     

Growth of silver hake within the U.S. continental shelf ecosystem of the northwest Atlantic Ocean

Von Bertalanffy growth parameters were estimated for silver hake Merluccius bilinearis within four regions of the United States continental shelf ecosystem of the northwest Atlantic Ocean during 1975–1980, 1982–1987 and 1988–1992. Differences in silver hake growth were found between the Middle Atlantic and southern Georges Bank regions ( P <0–01) over all three time periods. Growth also differed between northern Georges Bank and the Gulf of Maine ( P <0–01) during 1975–1980 and 1982–1987, and significant differences between southern Georges Bank and northern Georges Bank were found only during 1982–1987. Silver hake in the Gulf of Maine exhibited larger asymptotic sizes, but attained their asymptotic size at slower rates (L₀₀= 47 cm and K =0–33) in comparison to silver hake in the Middle Atlantic ( L₀₀= 43 cm and K =0–51), while growth parameter estimates for silver hake on Georges Bank were intermediate between these. Although significant differences in growth of silver hake between the various regions are consistent with separate stocks in the U.S. continental shelf ecosystem, the growth characteristics from the different regions are inconsistent with the presently assigned stock boundaries. (c) 1996 The Fisheries Society of the British Isles     

Reproductive biology and growth of the goatfish, Parupeneus barberinus (Lacepede), in Aqaba, Jordan

Monthly changes in the gonadosomatic index indicate that the main spawning season of Parupeneus barberinus in Aqaba extends from May to August for females and from May to June for males. Males in the 4 years age-group (63–4%) and the 5 years age-group (65–1%) are predominant. The von Bertalanffy growth equation parameters calculated from mean total length data are: L_α= 32–8cm; K=0–225; (t_o=−0–73 for males and L_α= 32–7cm; K=0–206; t_o= −0.82 for females. The length-weight regression coefficients for males (2.85) and females (2.8) are not significantly different and they indicate a negative allometric growth. There is no significant change in condition factor with age.     

Potentially pathogenic vibrios associated with mussels from a tropical region on the Atlantic coast of Brazil

Mussels ( Perna perna ) harvested on the coast of Ubatuba, in three different stations in the State of São Paulo, Brazil, were examined for Vibrio spp. over a 1 year period. The ranges of most probable number (MPN 100 g^-1) were: Vibrio alginolyticus (<3–24000), V. parahaemolyticus (<3–24000), V. fluvialis (<3–1100), V. cholerae non-O1 (<3–23), V. furnissi (< 3–30), V. mimicus (< 3–9) and V. vulnificus (< 3–3). The highest incidence was observed for V. alginolyticus (92–100%), followed by V. parahaemolyticus (67–92%), V. fluvialis (34–67%), V. vulnificus (8–17%), V. furnissii (0–17%), V. mimicus (0–17%) and V. cholerae non-O1 (0–8%). Tests for virulence factors were positive in 34.1% of the vibrios in the rabbit ileal loop and 31.7% in the Dean test. Positive results in the Kanagawa test were obtained with 0.51% of V. parahaemolyticus strains. The mean values (MPN 100 g^-1) of faecal coliforms in mussels from the three regions varied from 1100 to 44000, and seawater collected at the same stations gave average values for faecal coliforms in the range 18–3300 MPN 100 ml^-1. These results highlight the potential risks of food poisoning associated with raw or undercooked seafood.