Molecular cloning and expression analysis of the sucrose transporter gene family from Theobroma cacao L.

In this study, we performed cloning and expression analysis of six putative sucrose transporter genes, designated TcSUT1, TcSUT2, TcSUT3, TcSUT4, TcSUT5 and TcSUT6, from the cacao genotype ‘TAS-R8’. The combination of cDNA and genomic DNA sequences revealed that the cacao SUT genes contained exon numbers ranging from 1 to 14. The average molecular mass of all six deduced proteins was approximately 56 kDa (range 52 to 66 kDa). All six proteins were predicted to exhibit typical features of sucrose transporters with 12 trans-membrane spanning domains. Phylogenetic analysis revealed that TcSUT2 and TcSUT4 belonged to Group 2 SUT and Group 4 SUT, respectively, and the other TcSUT proteins were belonging to Group 1 SUT. Real-time PCR was conducted to investigate the expression pattern of each member of the SUT family in cacao. Our experiment showed that TcSUT1 was expressed dominantly in pods and that, TcSUT3 and TcSUT4 were highly expressed in both pods and in bark with phloem. Within pods, TcSUT1 and TcSUT4 were expressed more in the seed coat and seed from the pod enlargement stage to the ripening stage. TcSUT5 expression sharply increased to its highest expression level in the seed coat during the ripening stage. Expression pattern analysis indicated that TcSUT genes may be associated with photoassimilate transport into developing seeds and may, therefore, have an impact on seed production.     

蕨类植物问荆DEAD-box RNA解旋酶基因的克隆与分析

DEAD-box RNA解旋酶参与RNA多方面的代谢,在植物生长发育和逆境反应中起重要作用。本研究从蕨类植物问荆（Equisetum arvense）中克隆到一条DEAD-box RNA解旋酶c DNA全长序列,命名为EaRH1,并在Gen Bank注册登记（KJ734026）。序列分析显示：该c DNA全长3 230 bp,包含一个从487 bp到2 799 bp编码770个氨基酸的开放读码框,其对应的蛋白序列包含9个保守模块结构。EaRH1与其它物种DEAD-box RNA解旋酶蛋白序列比对结果显示：模块Ⅰa、Ⅱ和Ⅲ序列几乎完全相同,模块Q、Ⅰ和Ⅳ序列存在一些差异。EaRH1与江南卷柏（Selaginella moellendorffii）基因组一条假定序列相似度高达69%,其中相似度最高的区域集中在包含9个保守模块的结构域。系统进化树分析显示：EaRH1与拟南芥（Arabidopsis thaliana）DEAD-box RNA解旋酶At3g22320在氨基酸序列上有相对较高的同源性。序列结构比较和进化分析可推测出EaRH1可能参与植物体生长发育、miRNA生物合成、与RNA结合蛋白的相互作用和非生物胁迫应答。本文的研究为探索问荆DEAD-box RNA解旋酶的进一步功能提供参考。     

Nodes occupying central positions in human tissue specific PPI networks are enriched with many splice variants

The functional repertoire of genes in the eukaryotic organisms is enhanced by the phenomenon of alternative splicing. Hence, a node in a tissue specific protein–protein interaction (TS PPIN) network can be thought of as an ensemble of various spliced protein products of the corresponding gene expressed in that tissue. Here we demonstrate that the nodes that occupy topologically central positions characterized by high degree, betweenness, closeness, and eigenvector centrality values in TS PPINs of Homo sapiens are associated with high number of splice variants. We also show that the high “centrality” of these genes/nodes could in part be explained by the presence of a large number of promiscuous domains.     

One step forward: contrasting the effects of Toe clipping and PIT tagging on frog survival and recapture probability

Amphibians have been declining worldwide and the comprehension of the threats that they face could be improved by using mark–recapture models to estimate vital rates of natural populations. Recently, the consequences of marking amphibians have been under discussion and the effects of toe clipping on survival are debatable, although it is still the most common technique for individually identifying amphibians. The passive integrated transponder (PIT tag) is an alternative technique, but comparisons among marking techniques in free‐ranging populations are still lacking. We compared these two marking techniques using mark–recapture models to estimate apparent survival and recapture probability of a neotropical population of the blacksmith tree frog, Hypsiboas faber. We tested the effects of marking technique and number of toe pads removed while controlling for sex. Survival was similar among groups, although slightly decreased from individuals with one toe pad removed, to individuals with two and three toe pads removed, and finally to PIT‐tagged individuals. No sex differences were detected. Recapture probability slightly increased with the number of toe pads removed and was the lowest for PIT‐tagged individuals. Sex was an important predictor for recapture probability, with males being nearly five times more likely to be recaptured. Potential negative effects of both techniques may include reduced locomotion and high stress levels. We recommend the use of covariates in models to better understand the effects of marking techniques on frogs. Accounting for the effect of the technique on the results should be considered, because most techniques may reduce survival. Based on our results, but also on logistical and cost issues associated with PIT tagging, we suggest the use of toe clipping with anurans like the blacksmith tree frog.