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101.
Frank Slansky 《Journal of insect physiology》1980,26(2):79-84
Male/female pairs of adult milkweed bugs, Oncopeltus faciatus were offered reduced food rations (100 mg milkweed seeds/week, 50 mg seeds/week, and 25 mg seeds/week) at 232C, 14L : 10D photoperiod. The high rate of food consumption normally occurring during the teneral period (first 8 days posteclosion) and subsequent food consumption were reduced on both reduced rations. Initial fresh weight was lost by bugs on both reduced rations and their weekly fresh body weight tended to remain less than bugs on the 100 mg seeds/week ration.Normal onset of egg production (about 3 weeks posteclosion) was delayed 6 weeks and normal length of a female's life (13–14 weeks) was increased 7–8 weeks on the 25 mg seeds/week ration. Rate of egg production exhibited a linear decrease with decrease in food ration on both reduced rations due to an increased interclutch interval, while fresh egg weight, duration of egg stage, number of eggs/clutch and percentage of clutches containing fertile eggs were little affected.Gross egg production efficiency (efficiency of conversion of ingested food into eggs = dry mg egg production × 100/dry mg food ingested) was high on both the 100 and 50 mg seeds/week rations (27.9% and 21.1%, respectively) and low (7.7%) on the 25 mg seeds/week ration. These data are discussed in the context of the reciprocal interaction between nutrient intake and egg production. 相似文献
102.
The sensitivities of 26 starch gel electrophoretic enzyme assays have been compared using HeLa human cells and A9 mouse cells grown in vitro.This research was supported by National Institutes of Health Grant No. USPHS GM 09966. 相似文献
103.
Flavonoid compounds from 36 of the 38 known taxa of the genusArceuthobium (dwarf mistletoes) were examined. The flavonoid chemistry of the genus is rather uniform, all taxa producing 3-O-glycosides of the flavonols quercetin and myricetin. No infraspecific chemical variation was encountered, and in those instances where subspecific taxa are recognized, their chemistry was uniform. At the subgeneric level, members of subgenusArceuthobium synthesize primarily glucosides, whereas galactosides are more common in subgenusVaginata. In two of the four Old World species of subgenusArceuthobium (A. juniperi- procerae andA. oxycedri) only myricetin 3-O-glucoside was detected. There are no absolute flavonoid differences between subgenera, sections, or series. On the other hand, flavonoids are useful in several instances at the species level. In several cases, chemical data lend support to the recognition of species which in the past have been considered doubtfully distinct on the basis of morphology. 相似文献
104.
105.
106.
Davis J. A.; Frank M. H.; Whipp B. J.; Wasserman K. 《Journal of applied physiology》1979,46(6):1039-1046
107.
A simple, three-step conversion of 1,2-O-isopropylidene-α-d-glucofuranose into l-ascorbic acid, originally described by Bakke and Theander, was used to prepare l-[4-14C]ascorbic acid from milligram amounts of d-[3-14C]glucopyranose in 28% radioisotopic yield. In addition, l-[6-14C]- and l-[U-14C]-ascorbic acid were prepared from d-[1-14C]- and d-[U-14C]-glucopyranose, respectively. The procedure is useful for the synthesis of l-ascorbic acid bearing isotopic hydrogen, carbon, or oxygen atoms at specific positions, subject only to the availability of starting material. 相似文献
108.
Gene frequency variation at eight polymorphic allozyme loci in Drosophila melanogaster populations in North Carollina and the east coast of the United States were analyzed utilizing the variance component estimation procedures suggested by Cockerham (1969, 1973). These variance components were used to estimate correlations of genes within small geographic regions. The average (over loci) correlation between genes in the same individual within subpopulations was estimated to be 0.033. That between genes in the same subpopulation in different individuals was estimated to be very small, although significantly different from zero. The macrogeographic variation measured by the correlation of genes sampled from the same local region was large for some loci and smaller for others. this variation was also analyzed by correlation with latitude and longitude. Several previously recognized clines were identified as were several new clines.--These results were interpreted as indicating either some degree of nonrandom mating and local breeding unit isolation or a low frequency of null alleles. The geographic and temporal variation has no simple interpretation. 相似文献
109.
Linkage of the gene controlling the synthesis of the fourth component of complement to the major histocompatibility complex of the guinea pig 总被引:1,自引:1,他引:0
C4-deficient (C4D) guinea pigs are lacking in C4 synthesis, a condition that appears to be caused by a structural gene defect. This defect is inherited as a simple autosomal recessive trait. We have demonstrated linkage between C4D and the major histocompatibility complex of the guinea pig (GPLA). Inbred C4D and inbred strain 13 guinea pigs appear to have the same GPLA haplotype. The use of these two strains should provide an animal model for reconstitution studies of C4 synthesis and for studied exploring the possible role of C4 in cellular and humoral immune responses.Abbreviations used in this paper are C4D
deficiency of the fourth component of complement
- MHC
major histocompatibility complex
- GPLA
major histocompatibility complex of the guinea pig
- MLC
mixed lymphocyte culture 相似文献
110.
The wood lemming displays certain peculiar features: (1) The sex ratio shows a prevalence of females (FRANK, 1966; KALELA and OKSALA, 1966), and some females produce only female offspring (KALELA and OKSALA, 1966). (2) In a considerable proportion (in the present material, slightly less than half) of the females, an XY chromosome complement is found in the somatic tissues, but the Y is absent in the germ line of those studied (Fredga et al., 1976). Therefore, (3) a mechanism of double nondisjunction in early fetal life of XY females has to be postulated, which replaces the Y in the germ line by duplication of the X. It is assumed (4) that the X of XY females bears a sex-reversal factor that affects the male determining action of the Y (Fredga et al., 1977). There is (5) a strong presumption that in most cases the XY females are those that produce daughters only, but (6) a few exceptions may occur (FRANK, unpublished observations), suggesting that the regulation according to assumption 3 (perhaps also to 4) is incomplete in XY females. In the present report, four females are described with a 31,XO karyotype, two females with 33,XYY or 32,XY/33,XYY, respectively, two males with a 33,XXY, and one male with a 32,XX/33,XXY karyotype, as observed in a consecutive series of 502 wood lemmings. The incidence of sex-chromosome anomalies in liveborn and adult animals was 2.3%; the overall incidence, including embryos, was 1.79%. Neither the somatic XO constitution nor the existence of an extra Y in females precludes fertility. However, the XXY condition in the male results in sterility. There is certain evidence that an instability of the proposed mechanism for double mitotic nondisjunction of the sex chromosomes in oogonia accounts for the high rate of sex-chromosome aberrations in wood lemmings, at least when the mother is XY. 相似文献