Comparison of the nucleotide sequence of cloned DNA coding for an apolipoprotein (apoVLDL-II) from avian blood and the amino acid sequence of an egg-yolk protein (apovitellenin I): equivalence of the two sequences

We have compared the amino acid sequences of two low-molecular-weight avian apoproteins: apoVLDL-II from very low-density lipoproteins of hen plasma and apovitellenin I from hen egg yolk. The sequence of White Leghorn apoVLDL-II was derived from the nucleotide sequence of cloned apoVLDL-II DNA (Chan et al., 1980). The sequenator was used to determine the amino acid sequence of apovitellinin I from two breeds of hen (White Leghorn and Australorp). The sequences from the two breeds were not only identical, but they also completely matched the predicted sequence derived from the apoVLDL-II DNA sequence. The identity reported here establishes that this protein is transported intact from the blood to the egg yolk.     

Construction of recombinant plasmids containing rat thyroglobulin mRNA sequences

Two plasmids containing rat thyroglobulin cDNA sequences have been constructed and characterized. A plasmid with a 500-bp insert (pRT6) was isolated and identified as thyroglobulin-specific on the basis of the tissue specificity of the inserted sequence and of its ability to retain thyroglobulin mRNA on a nitrocellulose filter. The cDNA insert in pRT6 was subsequently used to screen a rat thyroid cDNA library constructed with large cDNA. A plasmid was found containing a 1700-bp insert. The polarity and the fidelity of the insert is demonstrated by S1 mapping.     

Climate oscillations and species interactions: large‐scale congruence but regional differences in the phylogeographic structures of an alpine plant and its monophagous insect

Aim To predict the fate of alpine interactions involving specialized species, using a monophagous beetle and its host plant as a case study. Location The Alps. Methods We investigated genetic structuring of the herbivorous beetle Oreina gloriosa and its specific host‐plant Peucedanum ostruthium. We used genome fingerprinting (in the insect and the plant) and sequence data (in the insect) to compare the distribution of the main gene pools in the two associated species and to estimate divergence time in the insect, a proxy for the temporal origin of the interaction. We quantified the similarity in spatial genetic structures by performing a Procrustes analysis, a tool from shape theory. Finally, we simulated recolonization of an empty space analogous to the deglaciated Alps just after ice retreat by two lineages from two species showing unbalanced dependence, to examine how timing of the recolonization process, as well as dispersal capacities of associated species, could explain the observed pattern. Results Contrasting with expectations based on their asymmetrical dependence, patterns in the beetle and plant were congruent at a large scale. Exceptions occurred at a regional scale in areas of admixture, matching known suture zones in Alpine plants. Simulations using a lattice‐based model suggested these empirical patterns arose during or soon after recolonization, long after the estimated origin of the interaction c. 0.5 million years ago. Main conclusions Species‐specific interactions are scarce in alpine habitats because glacial cycles have limited the opportunities for co‐evolution. Their fate, however, remains uncertain under climate change. Here we show that whereas most dispersal routes are paralleled at a large scale, regional incongruence implies that the destinies of the species might differ under changing climate. This may be a consequence of the host dependence of the beetle, which locally limits the establishment of dispersing insects.     

Isolation and cDNA cloning of an Em-like protein from mung bean (Vigna radiata) axes

Until now no 'early-methionine-labelled' (Em) proteins have been reported in the Fabaceae. To check whether a previously isolated low-molecular mass albumin from dry mung bean embryonic axes possibly corresponded to an Em-like protein, the protein was purified, sequenced and its cDNA clone isolated and characterized. N-terminal sequencing of cyanogen bromide cleavage products of the protein revealed homology with previously described Em-like proteins from other species. Analysis of cDNA clones encoding the mung bean Em protein revealed the presence of two classes of Em proteins and confirmed their homology to the previously characterized Em-like proteins. In vivo labelling and northern blot analysis further demonstrated that the mung bean protein is synthesized during early germination of the axes and that abscisic acid (ABA) extends its synthesis. It appears, therefore, that legumes also contain maturation-specific, ABA-responsive Em-like proteins.     

Cloning and Characterization of One Member of the Chalcone Synthase Gene Family from Solanum tuberosum L.

We have isolated a chalcone synthase gene 2 (ST-CHS2) from potato by rapid amplification of cDNA ends by PCR. CHS2 cDNA had high homology to tomato LET-CHS2 (98%), petunia PHCHSJ (94%), potato ST-CHS1B (92%), petunia PHCHSA (92%), and LET-CHS1 (90%) at the overall 389-amino acid level. Genomic hybridization analysis indicated that CHS genes of potato comprise a family of at least six individual members.     

生物素肼化学标记和DIG标记cDNA探针检测柑桔裂皮病类病毒

分别用生物素肼化学标记和ＤＩＧ标记我国柑桔裂皮病类病毒（ＣＥＶｄ）全长克隆ｃＤＮＡ,用以上探讨对不同来源的的核酸样品进行斑点杂交。两种探针可检出病柑桔总核酸的最低含量久为４００ｎｇ／斑点和８０ｎｇ／斑点;生物素肼标记ＣＥＶｄ－ＤＮＡ探讨针,可检出ＣＥＶｄ－ｃＤＮＡ的最低含量约为１０ｐｇ／斑点,研制的ＣＥＶｄ检测试剂盒能检测出发病和隐性带毒苗木中的ＣＥＶｄ,灵敏、特异、简便、快速。试剂盒已使用于检测