Cellular events in protein-tolerant inbred rats. III. Antigen-reactive B cells in rats tolerant to human serum albumin.

Rats tolerant to human serum albumin (HSA) were injected with selected lymphocyte populations and challenged with HSA plus adjuvant to test for loss of tolerance. Thoracic duct lymphocytes (TDL) from normal or immune rats, either untreated or depleted of Ig-bearing cells or HSA-binding cells by affinity chromatography were all equally effective in restoring the HSA antibody response in previously tolerant recipients. In contrast, recirculating B cells (TDL from B rats) were not effective. The results indicated that unresponsiveness to HSA was a lesion of the T- but not the B-cell compartment. However, antibody affinity failed to mature to a high level in tolerant rats that were restored with T cells, and the response of transferred primed B cells into unresponsive recipients was inhibited, suggesting that the tolerant state was not merely due to a T-cell deletion.     

Possible noncalcareous algae in the upper part of the bell canyon formation (Permian), New Mexico

A new genus and species of alga called Sinoglypha nassichuki is identified and described from Guadalupian rocks of the Delaware Basin, New Mexico. It occurs in tilted to almost upright position in laminites generally accepted as being deposited in deep, anoxic water. The fossils are noncalcareous, having a wavy nature. They are not classed as trace fossils of animals. They are leafy, 2–5 cm long and may be preserved in original position.

If Sinoglypha is an alga it leads to the tentative, but not new, conclusion that perhaps the water was not deep but shallow enough for light penetration—30 meters for the upper part of the Bell Canyon Formation.     

A C-type lectin from the tunicate, Styela plicata, that modulates cellular activity

Previous studies have identified proteins from tunicates (invertebrate members of the Phylum Chordata) that have physicochemical and functional properties similar to those of the inflammatory cytokine, interleukin 1 (IL-1). Here we characterize one of those proteins from the tunicate, Styela plicata, that can stimulate tunicate and mammalian cell proliferation, activate phagocytosis, increase interleukin 2 (IL-2) secretion by mammalian peripheral blood mononuclear cells and enhance IL-2 receptor (IL-2R) expression by mammalian EL-4.IL-2 cells. Partial amino acid sequence data showed that the S. plicata protein resembles three C-type lectins (TC14, TC14-1 and TC14-2) from a closely related tunicate species, Polyandrocarpa misakiensis. Its similarity to carbohydrate recognition domains (CRDs) from P. misakiensis lectins suggests that the S. plicata protein modulates the activities of mammalian immunocompetent cells by interacting with carbohydrate moieties of glycosylated cell surface receptors.     

角倍蚜冬寄主侧枝匐灯藓的生长特性研究

角倍蚜［Ｓｃｈｌｅｃｈｔｅｎｄａｌｉａｃｈｉｎｅｎｓｉｓ（Ｂｅｌ）］是致瘿形成五倍子的主要蚜虫之一,由它寄生在盐肤木（ＲｈｕｓｃｈｉｎｅｎｓｉｓＭｉｌ．）复叶的叶翅上形成的虫瘿角倍,其产量占我国五倍子总产量的７５％以上。角倍蚜完成一个生活周期,必须经...     

角倍蚜优良冬寄主侧枝匐灯藓的繁育研究

侧枝匐灯藓是角倍蚜的优良冬寄主,其生长状况直接关系到角倍蚜越冬蚜的成活率,进而影响五倍子的产量,但目前关于侧枝匐灯藓培植方法的研究较少。本研究采用直接移栽、撕碎繁殖、切碎繁殖3种繁殖方式,结合垄床、塑料毡、泡沫箱3种不同载体进行试验处理,结果表明,采用1∶1比例直接移栽垄床植藓处理,藓的总鲜重、盖度、藓块厚度等指标值均最大,能够在较短的时间内提供释放秋迁蚜的冬寄主藓;采用比例为1∶1撕碎繁殖方式以垄床或泡沫箱载体植藓均能获得最大的藓新枝数和藓茎高度,可以作为角倍蚜种虫生产中冬寄主藓的主要繁殖方式;采用1∶4或1∶8比例进行切碎繁殖藓萌发的新枝最多,可以作为优良冬寄主藓的种藓繁殖的主要方式。通过主成分分析法进行分析,结果表明,3个主成分累积贡献率为86.573%,可以较好地反映出24个处理10个测试指标的综合信息。综合评价结果以A1B1C1、A1B1C2、A2B4C1、A2B5C1、A2B3C2、A2B5C2、A2B4C3处理的综合性状最佳。     

Difference in food selection between patas monkeys (Erythrocebus patas) and tantalus monkeys (<Emphasis Type="Italic">Cercopithecus aethiops tantalus</Emphasis>) in Kala Maloue National Park,Cameroon, in relation to nutrient content

Phytochemical or nutrient analyses of primate diets have revealed clues to their food selection in a single species. On the other hand, few interspecific comparisons of phytochemical or nutrient composition of primate diets have been made, although diets are considered to differ in phytochemical or nutrient content from primate species to species, since different species have different body weights and different morphological and physiological characteristics. I compared the nutrient content of diet between patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus) living sympatrically in Cameroon. Patas subsisted on a smaller number of food items, most of which were also tantalus food items. Then, I compared the protein–fiber ratio and the available energy content of the food items eaten by patas (patas foods) with those items eaten only by tantalus (tantalus foods). Both variables were higher in patas than tantalus foods, although there was no significant difference in available energy of plant foods. Next, when I performed discriminant analysis for patas foods and tantalus foods, employing the above two variables, a discriminant function with positive coefficients for both variables was obtained. The mean discriminant-function score of patas foods was higher than that of tantalus foods. Despite being somewhat larger in weight, patas selectively fed on a smaller number of foods of higher quality than did tantalus. I discuss why the results are inconsistent with a well known body weight–diet relationship (Jarman–Bell principle). Energy-efficient locomotion enables patas to exploit not only small dispersed food items of high quality but also areas where high-quality foods are distributed in clumps. Electronic Publication     

Beta-hexosaminidase,an enzyme from ripening bell capsicum (Capsicum annuum var variata)

beta-Hexosaminidase activity increased significantly during fruit development and ripening of bell capsicum (Capsicuum annuum var. variata). Three isoforms of beta-hexosaminidase from bell capsicum could be resolved upon ion exchange chromatography with step wise gradient (0.10, 0.15 and 0.20 M NaCl) having an abundance of 38, 47 and 15% for isoforms I, II and III respectively. Isoforms I and II were further purified on gel permeation chromatography. The pH optimum for these two isoforms was around 5. Isoform II exhibited higher thermal stability. Hg(2+) and Zn(2+) inhibited both, but isoform I showed a much higher inhibition by Cu(2+) also. The K(m) for isoforms I and II with pnp-beta-D-N-acetyl glucosamine pyranoside was 3.00 and 1.75 mM, respectively. Isoform II on SDS-PAGE was found to be a monomer with a relative molecular mass of 85 kD. This isoform (the most major) appeared to be electrophoretically homogeneous. beta-Hexosaminidase is novel in the context of fruit ripening. This enzyme has not been reported from fruits and studied hitherto.     

角倍蚜在冬夏寄主上的分布规律

角倍由角倍蚜Schlechtendaliachinensis（Bell）寄生在盐肤木RhuschinensisMill和滨盐肤木R.chinensisvar．raxburghii（DC）Rehd．叶上致瘿而形成,约占五倍子总产量的80％。藓圃上越冬若蚜和盐肤木林中角倍的分布均属聚集分布。影响越冬若蚜和角倍聚集度的主要生态因子分别为藓长势、湿度、光照和树与藓的距离、风向、风速。于母和雏倍分布在盐肤木和滨肤木的第5～11片叶上,其中7～9片叶上干母数和雏倍数超过50％。干母数与雏倍数存在着显著的线性关系。盐肤木上：y1=3.3394＋0.7662x1,r1=0．9994**滨盐肤木上：y2=3.6707＋0.7431x2,r2=0.9894**     

Postnatal ontogeny, population structure, and extinction of the giant moa Dinornis

Recent reinterpretation of the giant moa Dinornis as consisting of two sexually dimorphic allospecies permits thorough site-by-site investigation of the ontogeny and population biology of this genus. Analysis of subadult skeletal material from natural swamp sites in the North and South Islands of New Zealand forms the basis for recognition of growth series for each long bone element, characterized by sequential formation of fossulae in the femur and fusion of bones in the tibiotarsus and tarsometatarsus. Femora reached progressive developmental stages more rapidly than the other long bones, but all three elements reached maturity at about the same time. Patterns of bone fusion in Dinornis are more similar to those in Apteryx than in Struthio, and kiwi are recognized as a suitable developmental analog for interpreting moa ontogeny. Samples from Bell Hill Vineyard Swamp (South Island) and Makirikiri swamp (North Island) are interpreted as representing autochthonous moa populations; comparison with stages of kiwi long bone development suggests that Dinornis at these sites had high adult survivorship in strongly K-selected populations, with 72.5-87.3% of individuals having achieved adult body mass, and 55.9-78.2% being sexually mature. The pattern of low fecundity and probable high longevity in both Dinornis species suggests that populations were vulnerable to loss of adults, primarily through hunting, rather than as a result of habitat destruction.