摘要:

AbstractTwo forms of phenobarbital‐induced cytochrome P‐450 were partially purified from the Rutgers diazinon‐resistant strain of house fly using cholate solubilization, polyethylene glycol 6000 precipitation, and chromatography on DEAE cellulose. The preparation of highest purity had an absorbance maximum of 452 nm, a specific content of 10.0 nmol/mg protein, and an apparent molecular weight of 60,000 when examined by sodium dodecyl sulfate polyacrylamide electrophoresis. The yield of the highly purified cytochrome P‐450 was 2–3%. This form contained proportionately less cytochrome P‐420 than the original cholate solubilized microsomes, and is thus apparently more stable. A second form of cytochrome P‐450 having a specific content of 0.50–0.89 nmol/mg protein was eluted from DEAE cellulose with a 0‐0.25 M salt gradient. This is consistent with a previously reported elution pattern for Emulgen 913‐solubilized house fly microsomes. Several methods of solubilizing house fly microsomes were examined. High salt, 2M KCI, in the absence of detergents effectively solubilized cytochrome P‐450 (50–70% recovery) with little or no conversio

ISSN:0739-4462    

DOI:10.1002/arch.940010202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe sterols of four species of Pentatomomorpha—Oncopeltus fasciatus (Dallas), Nezaraviridula(L.),Dysdercus cingulatus(F.), andPodisus maculiventris(Say)—and threé species of Cimicomorpha—Rhodnius prolixusStal,Arilus cristatus(L), andCimex lectularius(L.)—were isolated and examined in order to compare neutral sterol utilization and content with the known ecdysteroids of these species. In the phytophagous Pentatomomorpha,O. fasciatus, N. viridula, andD. cingulatus, the low content of cholesterol and the high content of C28and C29phytosterols (99% of the tissue sterols, respectively) indicated that these species are unable to dealkylate the C‐24 position of sterols. These insects appear to have adapted to the challenge of both insufficient dietary cholesterol and inability to dealkylate phytosterols by evolving the ability to produce a C28ecdysteroid (makisterone A). The secondarily predaciousP. maculiventrishas adequate cholesterol available for C27ecdysteroid production, but appears to have retained the ecdysteroid biosynthetic pathways of its phytophagous ancestors because it produces a C28ecdysteroid. Cholesterol was the major sterol of each of the three species of Cimicomorpha, and these insects are only able to produce C27ec

ISSN:0739-4462    

DOI:10.1002/arch.940010203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractMaternal treatment with 5 μg of the precocene analogue 7‐ethoxy‐6‐methoxy‐2,2‐dimethylchromene influenced offspring development in the pea aphid,Acyrthosiphon pisum. Under conditions favoring the production of apterous offspring, virginoparous aphids produced a significant proportion of alates and precocious adultoids; the precocious adultoids were sterile. The effect of precocene on offspring development was temporary. Some implications of precocene treatment for aphid control are

ISSN:0739-4462    

DOI:10.1002/arch.940010204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe direct hemolytic activities of the venoms from 21 species of stinging insects were determined. The activities spanned 3 1/2 orders of magnitude, ranging from a low of four to a high of 12,000 hemolytic units/mg dry venom, respectively, for the solitary wasp,Dasymutilla lepeletierii, and the social wasp,Polistes infuscatus. The latter activity is the highest reported for any insect venom and represents a level that is potentially harmful to humans stung by the wasp.The social wasps as a group generally possessed highly hemolytic venoms; the ants, poorly hemolytic venoms; and the solitary stinging species, venoms with extremely low activity. For the venoms, hemolytic activity correlated with neither lethal toxicity (LD50) nor algogenicity. This finding suggests that hemolysins alone do not determine venom toxicity, and that the hemolysins of stinging insect venoms serve a variety of poorly understood roles. The range of activity of hemolysins from different venoms indicates they probably have different chemical structures and functions.

ISSN:0739-4462    

DOI:10.1002/arch.940010205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractWe present the phospholipid fatty acid compositions, determined by GLC,* of four individual tissues (testes, mushroom glands, conglobate glands, and salivary glands) from adult male cockroaches,P. americana. The testes phospholipids contained higher proportions of palmitic acid than did the exocrine tissues (16% vs about 8%). This was also true for palmitoleic (2.3% vs 0.4–1.3%), oleic (49% vs 30–35%), and linolenic acids (7% vs 0.5–2.8%). Testicular extracts were lower in linoleic acid (16%) than were the exocrine gland extracts (at 40–45%). All four tissues also contained low proportions of several long‐chain polyunsaturated fatty acids of both omega‐3 and omega‐6 metabolic families, including C20:3n6, C20:4n6, and C20:5n3. The data suggest that the phospholipid fatty acid profiles of specific tissues differ from each other and from those obtained from whole‐insect extracts. The presence of several polyenoics from the n3 and n6 metabolic families is interpreted in the context of complex fatty acid requirements at t

ISSN:0739-4462    

DOI:10.1002/arch.940010206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe musculature of the oviduct consists of an outer, irregular layer of longitudinal muscle and an inner layer of circular muscle. The four basic modes of activity—compression, segmentation, peristalsis, and reverse peristalsis—were evident in the isolated oviduct. These spontaneous events often occurred in an organized sequence. In fact eggs could be transported down the lateral oviducts by this myogenic activity once the sphincter between the common oviduct and vagina was severed. Myographic recordings were made of only the contractions of the longitudinal muscles.L‐glutamate caused a distinct phasic contraction at 2.2 × 10−5M. The response became larger and more complex as the concentration of the amino acid was increased. Acetylcholine (1.6 × 10−5M) caused either a phasic or tonic response, or a combination thereof. By contrast, 5HT and tyramine simply increased the frequency of small phasic contractions, although in some preparations both monoamines caused an inhibition. The ecdysones, a juvenile hormone analogue (1 × 10−6M), and prostaglandin E2had no effect on oviduct activity.Initially high KCI solutions (162 mM) without Ca++induced a strong contraction but subsequent additions failed to do so. However, when a high KCI solution (158 mM) with 2 mM Ca++was added to the preparation the response was partially restored. Also the potent calcium antagonist Mn++(2mM) can suppress sponta

ISSN:0739-4462    

DOI:10.1002/arch.940010207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractThe oviducts of Locustamigratoriaare innervated by a pair of nerves which arise from, the seventh abdominal ganglion. A distinctive network of striated muscle fibres occurs in the oviducts. The lateral oviducts and common oviduct consist of an inner circular layer of muscle and an outer longitudinal layer of muscle. At the junction of the lateral and common oviduct an additional thin longitudinal layer is found adjacent to the basement epithelium.The oviducts contracted spontaneously when isolated from the central nervous system. These myogenic contractions took the form of peristaltic contractions in the lateral oviduct, and intermittent phasic‐like contractions of the posterior regions of the lateral oviduct and the common oviduct. These phasic‐like contractions were associated with individual complex potentials recorded extracellularly from the muscle fibres.In locusts that had been interrupted in the process of egg laying, there were large‐amplitude action potentials, firing in a bursting pattern, in the oviducal nerves. These large action potentials were absent in locusts that had not been egg‐laying. These action potentials were associated with both bioelectric potentials and mechanical events in the posterior region of the lateral oviduct and the common oviduct.Electrical stimulation of the oviducal nerve mimicked the effects of spontaneous action potentials, resulting in the appearance of monophasic potentials and contractions. The contractions were graded and dependent upon both frequency and duration of stimulation.It is concluded that the oviducts ofLocustaare both myogenic and neurogenic. The role of these contractions in oviposition is di

ISSN:0739-4462    

DOI:10.1002/arch.940010208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractPossible sites of heme synthesis in the fourth instar ofChironomus thummiwere investigated by means of autoradiography of specific isotope incorporation. “Body wall” preparations, which include subepidermal and visceral fat body, oenocytes, muscle, epidermis, and cuticle, were cultured for 1 h in a medium containing tritiated‐δ‐aminolevulinic acid, a specific precursor to heme biosynthesis. Light‐microscopic examination of autoradiographs of sections of the body walls indicates that the subepidermal fat body is the major site of incorporation of the precursor into heme. The visceral fat body shows few silver grains. Oenocytes, as well as muscle and epidermis, are characterized by absence of silver deposits. These findings indicate that the subepidermal fat body ofChironomusis the primary site of heme synthesis, and are discussed in relation to specific hemoglobin

ISSN:0739-4462    

DOI:10.1002/arch.940010209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

摘要:

AbstractInSpodoptera mauritiarepeated daily treatments of larvae with 40 μg of precocene II throughout the fifth and sixth instar larval period had no effect on the larval‐larval period but prolonged larval‐pupal ecdysis. The resulting pupae showed precocious adult differentiation of mouth parts, wings, eyes, legs, and fat

ISSN:0739-4462    

DOI:10.1002/arch.940010210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY

ISSN:0739-4462    

DOI:10.1002/arch.940010211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1983

数据来源: WILEY