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1.
The hatching distributions of rainbow trout (Salmo gairdneri) with different genotypes at eight loci are compared in two experiments with the same strain. Embryos were incubated at temperatures colder (5 and 8°C) and warmer (12°C) than normally experienced by these fish (9.5°C). At hatching, embryos were separated into five hatching groups representing the chronological order of hatching. There is no significant correlation between multilocus heterozygosity and hatching time at any temperature in either experiment. Fish in the middle of the hatching distribution had the highest average heterozygosity. In both experiments, heterozygotes at the majority of loci examined tended to hatch relatively later within the hatching distribution at 12°C than at both 5 and 8°C. Fish with different genotypes atPgm2 andCk1 showed significant differences in hatching time that were consistent between experiments.Ck1 heterozygotes hatched sooner than homozygotes at 8°C but later at 12°C.Pgm2 heterozygotes hatched later than homozygotes at all temperatures and significantly later in four of five cases. At the other loci examined, however, the relative hatching distributions of fish with particular genotypes were not significantly different or repeatable between experiments.This research was supported by National Science Foundation Grant BSR-8300039 awarded to Dr. Fred W. Allendorf. Moira M. Ferguson was supported by a postgraduate scholarship from the Natural Sciences and Engineering Research Council of Canada. 相似文献
2.
Ann Curtis F. Millan Susan Holloway Moira Mennie Aileen Crosbie J. A. Raeburn D. J. H. Brock 《Human genetics》1989,81(2):188-190
Summary Presymptomatic testing for Huntington's disease (HD) is possible through the use of restriction fragment length polymorphisms (RFLPs) at the closely linked D4S10 locus. Recombination between the HD and D4S10 loci will occur in 4%–5% of meioses, and is a well-recognised complication of predictive testing. Recombination between RFLPs within the D4S10 locus is a rare event and can usually be ignored. We report a case where such an intra-locus recombination frustrated attempts to predict the chance of a high-risk individual inheriting the HD gene. 相似文献
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A. Weston G. O. Humphreys Moira G. M. Brown J. R. Saunders 《Molecular & general genetics : MGG》1979,172(1):113-118
Summary This paper describes experiments involving simultaneous transformation of Escherichia coli by DNA of two species of multicopy plasmid in order to study competence and DNA uptake in this organism. In transformation mixtures where separate species of plasmid DNA were present in equal amounts, selection for a single plasmid gave doseresponse curves with slopes of 1. These results indicate that uptake of a single molecule of plasmid DNA is sufficient to produce one transformant. Simultaneous selection for markers on both plamsids gave a dose-response curve with a slope of 2. The total numbers of transformants obtained in single or double transformation experiments at saturating DNA concentrations were the same, and represented the maximum number of transformable cells. However, the absolute frequency of double transformants was reduced 4–6 fold relative to frequencies obtained with single markers. Similar results were obtained using pairs of compatible or incompatible plasmids in rec
+ or recA strains. These findings may be explained either on the basis of interference between competing plasmid molecules for uptake or establishment or by assuming that competent cells of Escherichia coli vary in their ability to incorporate more than one plasmid DNA molecule. Our results are consistent with an interpretation where more than 80% of the transformable cells are only capable of establishing one plasmid moiecule. 相似文献
6.
Juvenile brook charr (Salvelinus fontinalis) are territorial and have high levels of agonistic behaviour. Juvenile lake charr (S. namaycush) rarely show any indication of territoriality and have very low levels of agonistic behaviour. The inheritance of behaviour in their reciprocal hybrids was investigated by multivariate stepwise discriminant analysis. Lateral display, charge, chase, and forage composed the first canonical axis (87.2% of total dispersion). Pooled hybrid means were closer to that of brook charr, suggesting either directional dominance or modification of the behaviour of hybrids in response to water flow. The mean values of reciprocal hybrids were skewed towards the maternal parent, suggesting a maternal effect in the phenotypic expression of behaviour in these fish. 相似文献
7.
Michael E. Joesten Moira E. Royston Marlene Jimenez Axel Wadewitz Diana Melian Richard A. Lockshin 《Journal of insect physiology》1982,28(7):589-599
Larvae of Manduca sexta, (Sphingidae) increase their weight approx. 50% just before pupation and then secrete this fluid during the formation of their burrows. Time-lapse cinematography indicates that the fluid is ejected into the walls of the final burrow. It may offer some mechanical support; it is not particularly repellent to ants or mice, and it contains only small amounts of the alkaloids ingested from its preferred food plants. Comparison to other species indicates that the gain and loss of water is associated with burrowing behaviour; the fluid appears to be used in providing hydraulic pressure for burrowing, in forming and cementing the pupal chamber, and in acting as a CO2 trap underground. The secretion is a hypertonic, highly alkaline solution containing KHCO3 and small amounts of Na+, Ca2+, Mg2+, PO4?3 and some proteins. Haemolymph levels of K+ decrease, and those of Ca2+ increase, during the secretory phase. When radioactive calcium is injected into mature larvae, it appears promptly in the secretion. If however, the injection is given more than 24 hr before the animal begins secreting, then the calcium is bound to haemolymph protein and does not appear in the secretion. 相似文献
8.
Terence E. Nicholas Rodger G. Johnson Moira A. Lugg Patricia A. Kim 《Life sciences》1978,22(17):1517-1524
Incubation of fetal lung tissue with 0.2 μM 14C-cortisone revealed a 12-fold increase in the rate of reduction of cortisone to cortisol between day 22 and day 30 of gestation in the rabbit. This increase correlated closely with the increase in the rate of incorporation of 14C-choline into total lung lipids during the same period. In light of these findings it would seem inadequate to attempt to relate the plasma cortisol concentration alone with the rate of lung maturation. In addition, one would need consider both the plasma concentration of cortisone and the activity of 11β-hydroxysteroid dehydrogenase (11β-HSD) in the lung. 相似文献
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Delphine Durette‐Morin Kimberley T. A. Davies Hansen D. Johnson Moira W. Brown Hilary Moors‐Murphy Bruce Martin Christopher T. Taggart 《Marine Mammal Science》2019,35(4):1280-1303
North Atlantic right whale monitoring in Roseway Basin, Canada, is primarily based on short‐term (<14 d) visual surveys conducted during August–September. Variability in survey effort has been the biggest limiting factor to studying changes in the population's occurrence and habitat use. Such efforts could be enhanced considerably using passive acoustic monitoring (PAM). We sought to determine if variation in whale presence, relative abundance, demography, and/or behavior (estimated through visual surveys) could be explained by variation in three right whale call types in this habitat. A generalized linear model was fit to 23 d of concurrent PAM and visual monitoring during four summers within the Roseway Basin Right Whale Critical Habitat boundaries. The model revealed significant positive relationships between relative abundance, call counts and presence of surface‐active group behavior. PAM can refine daily right whale presence estimates. While visual observations (n = 23 d) implied a 40% decline in right whale presence during 2014–2015 relative to 2004–2005, PAM data (n = 211 d) showed right whales were present between 71%–85% of survey days throughout all years analyzed. We demonstrate that PAM is a useful tool to extend periods of right whale monitoring, especially in areas where visual monitoring efforts may be limited. 相似文献