云南兔Lepus comus G.Allen的分类订正——包括两个新亚种的描记

云南兔Lepus comus G.Allen是云贵高原和滇西山地目前发现的唯一的一种野兔,初由G.M.Allen（1927）根据采自云南西部腾冲的标本命名。其后,国内外学者（包括G.M.Allen本人在内）对云南兔究竟是一独立种或为高原兔Lepus oiostulus（Hodgson）的一个地理亚种意见纷纭（罗泽珣,1981;高耀亭等,1964;Allen,1938;Ellerman et al.,1951;Angermann,1967;Corbet,1978。我们曾对国内有关单位所收藏的这两个类群的100余号标本进行较详细的对比研究。发现云南兔在形态上与高原兔确有明显区别,在分布上又有同域现象,因而主张仍应将云南兔保持其原定种的种级地位;同时,又查对了采于各地的云南兔所有标本,发现云南北部（丽江）至中部（景东、景谷）标本以及云南东部、南部和贵州西部标本都有异于滇西地模标本,且占有不同的地理分布区。经研究,应属两个新的亚种。其中,云南东部,南部和贵州西部的新亚种,为纪念先师彭鸿绶先生毕生献身于云、贵、川的科学考察事业和他的指导与培养,特以彭先生之姓氏命名,以资纪念。     

Roles of the trkB and trkC gene products of Escherichia coli in K+ transport

Mutations at the trkB and trkC loci of Escherichia coli produce an abnormal efflux of K+. The mutations are partially dominant in diploids and revert frequently by what appears to be intragenic suppression to the null state. The mutations can be reverted by insertion of Tn10 into the mutated gene, and spontaneous revertants are fully recessive to the mutant allele in diploids. K+ efflux produced by NEM* and by DNP* persists in strains with presumed null mutations at either locus, indicating neither gene product is the primary target for the effect of these inhibitors on K+ efflux. The results are consistent with the view that trkB and trkC encode independent systems for K+ efflux. Mutations at these loci alter regulation of the process so that K+ efflux occurs inappropriately. A second mutation to the null state abolishes this abnormal K+ efflux. These genes may encode K+/H+ antiporters, an activity postulated to mediate K+ efflux and demonstrated to exist in E. coli and other bacteria.     

湖北菱科的数量分类研究[Ⅱ]

引言菱科(Trapaceae)植物为一年生水生浮叶草本,常见于湖泊,池塘及沟渠中。全世界约有70余种,主要分布于旧大陆的温带、亚热带地区,亦见于热带地区,如印度,东南亚及非洲,后来被引进美洲大陆和澳大利亚。中国有5至10种及其栽培种。菱科为一单属科。自林奈时期以来,菱科的分类学研究一直是一个富有探索性的问     

Production of auto-anti-idiotypic antibody during the normal immune response: IX. Characteristics of the auto-anti-idiotype antibody and its production

Using hapten-reversible inhibition of plaque formation as an assay for auto-anti-idiotype antibody (anti-Id) and as a means for following idiotype (Id) expression, we have obtained evidence that following immunization with trinitrophenyl (TNP) conjugates (a) there are differences in Id expression in the anti-TNP antibody response to different TNP conjugates although there is some overlap; (b) different strains, although showing some differences in Id expression, tend to produce cross-reactive Ids, thus no obvious allotype linked inheritance of Id expression is observed in this heterogeneous immune response; (c) the auto-anti-Id produced following immunization with TNP-Brucella abortus or TNP-Ficoll tends to be of the IgG_2a and IgG_2b isotypes.     

伊蚊(纷蚊亚属)一新种——功果伊蚊的记述

1979年7月至1980年3月,作者在云南云龙县的功果采集到蚊类标本一批,发现伊蚊属纷蚊亚属(Finlaya)一新种,特记述如下。 功果伊蚊Aedes (Finlaya) gonguoensis,新种 雌蚊 中型黑色蚊虫,翅长3.5—4.2毫米。 头部 头顶前部平覆深褐宽鳞,中央区和后部具白弯鳞;头顶后部和后头有黑色窄竖鳞,并杂有少数白竖鳞;有眶白鳞线;头侧大部平覆白色宽鳞,仅前部有一褐鳞区。触角梗节内侧有淡色鳞。唇基光裸;喙约为前股的1.1倍长,一致暗黑色;触须约为喙     

云南壮异蝽属及娇异蝽属新种记述(半翅目:异蝽科)

云南地区的壮异蝽属(Urochela Dallas)和娇异蝽属(Hrostylis Westwood)截止到目前共记录23种。本文记述了在该省西部地区发现的5新种,现描述如下。模式标本保存于天津南开大学生物系。 钩壮异蝽Urochela hamata,新种(图1,2) 体黄褐色,具黑褐色花斑及黑色刻点。触角第4节中部及第5节基半部为淡黄色;     

Factors affecting the oligomeric structure of yeast external invertase

It has been assumed that yeast external invertase is a dimer, with each subunit composed of a 60-kDa polypeptide chain. We now present evidence that at its optimal pH of 5.0, the predominant form of external invertase is an octamer with an average size of 8 X 10(5) Da. During ultracentrifugation the octamer dissociated to lower molecular weight forms, including a hexamer, tetramer, and dimer. All forms of the enzyme were shown to possess identical specific activities and to contain a similar carbohydrate to protein ratio. Although the monomer subunits (1 X 10(5) Da) were heterogenous in carbohydrate content, each subunit possessed nine oligosaccharide chains. When stained for protein and enzyme activity following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, only the oligomeric form of the enzyme appeared to be active. Thus, on partially inactivating invertase with 4 M guanidine hydrochloride both octamer and monomer were evident on the gels but only the former was active. Similarly, incubating at pH 2.5 in the presence of sodium dodecyl sulfate yielded only inactive monomer. The monomer, unlike the active oligomeric aggregate, was unable to hydrolyze sucrose after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Consistent with the in vitro studies, freshly prepared yeast lysate was shown to contain the octameric species of external invertase as the major active form of this enzyme. From these studies and others which employed deglycosylated invertase, it is concluded that the carbohydrate component of external invertase contributes not only to stabilizing enzyme activity, but also to maintaining its oligomeric structure.     

Comparison of the 13C-n.m.r. spectra of gangliosides GM1 with those of GM1-oligosaccharide and asialo-GM1

The ¹³C-n.m.r. spectra of asialo-G_M1 and G_M1-oligosaccharide are completely assigned and compared to those previously found for intact G_M1 and for the series G_M4, G_M3, G_M2, G_M1, G_D1a, G_D1b, and G_T1b. Removal of the ceramide residue from G_M1 liberated a free, reducing aldehyde group, which was reflected in a doubling of the ¹³C-n.m.r. signals assignable to the d-glucose residue because of α,β equilibrium. The spectrum of asialo-G_M1 lacks the resonances from the sialic acid residue, as expected; in addition, several resonances from the neutral gangliotetraglycosyl residue shifted to different field positions after removal of sialic acid from G_M1. These resonances include that of C-4 of the inner β-d-galactosyl residue, and C-1 of the 2-acetamido-2-deoxy-d-galactosyl residue that is near the site of attachment of the sialosyl residue. The differences between the chemical shifts of the carbon resonances of oligomeric and monomeric saccharides, termed linkage shifts, provide a quantitative assignment aid. They are ～ $\text{1}\text{3}$ of those for residues linked to sialic acid than those for residues linked to the neutral hexose chain. Correlations among linkage shifts for pairs of glycosidically-linked carbon atoms for asialo-G_M1 and G_M1-oligosaccharide were compared with those for the series of gangliosides G_M4 to G_T1b, and differences are noted for resonances for carbon atoms near the sialic acid residue. The spectrum of ganglioside G_M1b, a positional isomer of G_M1 whose ¹³C-n.m.r. spectrum has not yet been observed, is predicted.     

Ontogeny of B-lymphocyte function. XIV. Maturation of the capacity of B cells to re-express surface immunoglobulin after treatment with anti-immunoglobulin

The maturation of the ability of the B-cell population to re-express surface immunoglobulin (sIg) after its removal by treatment with rabbit anti-mouse immunoglobulin (RAMIg) was studied in LAF1, C57BL/6, and C57L mice. As demonstrated by previous workers, the B-cell population from immature mice failed to re-express sIg after treatment with RAMIg. We have shown that the age at which the B-cell population acquires the capacity to re-express sIg is different in different strains and that the order in which the B-cell population of the different strains acquires the capacity to re-express sIg is different from the order in which their B-cell populations acquire the capacity to produce high-affinity antibodies. This suggests that these represent distinct differentiation events in the development of the B-cell population. In all of the strains studied the maturation of the capacity to re-express sIg occurred in two steps. After the first maturation step the B-cell population was able to re-express sIg after treatment with RAMIg for 1 hr but did not re-express sIg after treatment with RAMIg for 24 hr. After the second maturation step the B-cell population could re-express sIg even after 24 hr treatment with RAMIg. It has been suggested by previous workers that the inability of the immature B-cell population to re-express sIg could represent one of the mechanisms responsible for the development of B-cell self-tolerance. It is suggested here that the existence of a period during which cells become tolerant only upon prolonged exposure to antigen could protect the developing B cells from becoming unresponsive to transiently experienced foreign antigens but still permit them to become tolerant to self antigens which are continuously present.     

Loss and resynthesis of a developmentally regulated membrane protein (gp80) during dedifferentiation and redifferentiation in Dictyostelium

When developing cultures of Dictyostelium discoideum are disaggregated and resuspended in nutrient medium, they lose the capacity to rapidly reaggregate after 90 min, in a rapid and synchronous step referred to as the "erasure event." They then proceed to lose remaining developmentally acquired functions in a program of dedifferentiation culuminating with the loss of EDTA-resistant cohesion roughly 5 hr later. Immediately following the erasure event, cells can be stimulated to reenter the developmental program even though they still possess a number of developmentally acquired functions. These cells therefore appear to undergo dedifferentiation and redifferentiation simultaneously (D. R. Soll and L. H. Mitchell, 1982, Dev. Biol. 91, 183-190). In this report, we have employed an antiserum made against a developmentally acquired membrane glycoprotein, gp80, to examine whether gp80 is lost during dedifferentiation and whether it is either reutilized or resynthesized during redifferentiation. Results are presented which demonstrate that (1) when 9-hr developing cells are disaggregated and resuspended in nutrient medium, gp80 continues to accumulate for several hours after the erasure event, then is lost at roughly the same time as EDTA-resistant cohesion; (2) when cells are stimulated to reenter the developmental program immediately after the erasure event, both gp80 and EDTA-resistant cohesion are still lost according to the program of dedifferentiation, but are then reacquired soon afterwards according to the program of redifferentiation; (3) during redifferentiation, cells do not reutilize gp80 which had been synthesized during initial development; rather they synthesize gp80 de novo; and (4) developing cells of a dedifferentiation-defective variant, HI4, when disaggregated and resuspended in nutrient medium, retain gp80, EDTA-resistant cohesion, and the capacity to rapidly reinitiate aggregation for at least 12 hr. This last result indicates that the loss of gp80 is regulated by the dedifferentiation process and is not an independent response to disaggregation or the reintroduction of nutrients. Together, these results reinforce the conclusion that dedifferentiation and redifferentiation can function independently and simultaneously in the same cells.