A mammalian sperm lectin related to rat hepatocyte lectin-2/3

In rat liver the asialoglycoprotein receptor is composed of three polypeptides, RHL-1, RHL-2 and RHL-3 [6]. In rat testis and spermatozoa a galactosyl receptor (RTG-r) which is immunologically related to RHL-2/3 has been described [7]. We now report that in addition to its presence in the rat, an antigenic species of 54 kDa related to RHL-2/3 is present on rabbit, human, pig and mouse spermatozoa. Purified rabbit testis galactosyl receptor (RbTG-r) consists of two major proteins of 54 and 49 kDa, while purified rabbit liver galactose lectin consists of two major proteins of 43 and 40 kDa. In an ELISA the purified rabbit testis galactosyl receptor was shown to bind biotinylated heat solubilized rabbit zonae, while the purified liver galactose lectin did not. We conclude that one of the mammalian sperm's zona binding proteins is a galactose lectin of 54 kDa related to rat liver RHL-2/3.     

Variability of NT-proBNP and its relationship with inflammatory status in patients with stable essential hypertension: a 2-year follow-up study

Background

The variability of NT-proBNP levels has been studied in heart failure, yet no data exist on these changes over time in hypertensive patients. Furthermore, studies on the relationship between natriuretic peptides and inflammatory status are limited.

Methodology/Principal Findings

220 clinically and functionally asymptomatic stable patients (age 59±13, 120 male) out of 252 patients with essential hypertension were followed up, and NT-proBNP was measured at baseline, 12 and 24 months. No differences in NT-proBNP were found with respect to the basal stage in the hypertrophic group, but significant changes were found in non-hypertrophic subjects. The reproducibility of NT-proBNP measurements was better in patients with hypertrophy than in the non-hypertrophic group for the three intervals (stage I-basal; stage II-stage I; stage II-basal) with a reference change value of 34%, 35% and 41%, respectively, in the hypertrophic group. A more elevated coefficient of correlation was obtained in the hypertrophic group than in patients without hypertrophy: basal versus stage I (r = 0.79, p<0.0001 and r = 0.59, p<0.0001) and stage I versus stage II (r = 0.86, p<0.0001 and r = 0.56, p<0.0001). Finally, levels of NT-proBNP significantly correlated with sTNF-R1 (p<0.0001) and IL-6 (p<0.01) during follow-up. A multivariate linear regression analysis showed that sTNF-R1 is an independent factor of NT-proBNP.

Conclusions/Significance

This work shows that there is good stability in NT-proBNP levels in a follow-up study of asymptomatic patients with stable hypertension and left ventricular hypertrophy. As a consequence, assessment of NT-proBNP concentrations may be a useful tool for monitoring the follow-up of hypertensive patients with hypertrophy. Measured variations in peptide levels, exceeding 35% in a 12-month follow-up and 41% in a 24-month follow-up, may indicate an increase in cardiovascular risk, and therefore implies adjustment in the medical treatment. In addition, this study shows a link between neurohormonal and inflammatory activation in these patients.     

Diversity of Listeria species in urban and natural environments

A total of 442 Listeria isolates, including 234 Listeria seeligeri, 80 L. monocytogenes, 74 L. welshimeri, 50 L. innocua, and 4 L. marthii isolates, were obtained from 1,805 soil, water, and other environmental samples collected over 2 years from four urban areas and four areas representing natural environments. Listeria spp. showed similar prevalences in samples from natural (23.4%) and urban (22.3%) environments. While L. seeligeri and L. welshimeri were significantly associated with natural environments (P ≤ 0.0001), L. innocua and L. monocytogenes were significantly associated with urban environments (P ≤ 0.0001). Sequencing of sigB for all isolates revealed 67 allelic types with a higher level of allelic diversity among isolates from urban environments. Some Listeria spp. and sigB allelic types showed significant associations with specific urban and natural areas. Nearest-neighbor analyses also showed that certain Listeria spp. and sigB allelic types were spatially clustered within both natural and urban environments, and there was evidence that these species and allelic types persisted over time in specific areas. Our data show that members of the genus Listeria not only are common in urban and natural environments but also show species- and subtype-specific associations with different environments and areas. This indicates that Listeria species and subtypes within these species may show distinct ecological preferences, which suggests (i) that molecular source-tracking approaches can be developed for Listeria and (ii) that detection of some Listeria species may not be a good indicator for L. monocytogenes.     

Deciphering the Transcriptional Regulation of Cholesterol Catabolic Pathway in Mycobacteria: IDENTIFICATION OF THE INDUCER OF KstR REPRESSOR*

Cholesterol degradation plays a prominent role in Mycobacterium tuberculosis infection; therefore, to develop new tools to combat this disease, we need to decipher the components comprising and regulating the corresponding pathway. A TetR-like repressor (KstR) regulates the upper part of this complex catabolic pathway, but the induction mechanism remains unknown. Using a biophysical approach, we have discovered that the inducer molecule of KstR in M. smegmatis mc²155 is not cholesterol but 3-oxo-4-cholestenoic acid, one of the first metabolic intermediates. Binding this compound induces dramatic conformational changes in KstR that promote the KstR-DNA interaction to be released from the operator, retaining its dimeric state. Our findings suggest a regulatory model common to all cholesterol degrading bacteria in which the first steps of the pathway are critical to its mineralization and explain the high redundancy of the enzymes involved in these initial steps.     

Rosaceae conserved orthologous set (RosCOS) markers as a tool to assess genome synteny between Malus and Fragaria

Intertribal comparisons of genome synteny between phylogenetically distant genera in Rosaceae, such as Malus (apple) and Fragaria (strawberry), have previously been hampered by a lack of transferable markers that can be used as anchor points between genetic maps. The availability of conserved orthologous set (COS) markers recently developed for this family, coupled with the release of the Malus?×?domestica and Fragaria vesca draft genome sequences, provide new tools for comprehensive pairwise comparisons. The genetic mapping of 56 Rosaceae COS (RosCOS) markers revealed 21 regions of genomic synteny between apple and strawberry. Information concerning the location of RosCOS markers on 15 of 17 apple linkage groups (LG) and all seven LG of strawberry was used to assess the ancestral relationships between the two genera. Four differences in orientation of ancestral chromosome fragments on extant LG were identified in comparison with previous studies, as well as two potential insertions, two potential translocations, and two potential inversions. The set of orthologous markers developed for use in genetic mapping in Rosaceae, in combination with high-throughput analysis, will allow the exploration of chromosome evolution and refinement of ancestral relationships within the family, orientation, and anchoring of genome sequences as they become available and provide resources to develop markers for nonsequenced genomes within the family.     

A Caenorhabditis elegans Wild Type Defies the Temperature–Size Rule Owing to a Single Nucleotide Polymorphism in tra-3

Ectotherms rely for their body heat on surrounding temperatures. A key question in biology is why most ectotherms mature at a larger size at lower temperatures, a phenomenon known as the temperature–size rule. Since temperature affects virtually all processes in a living organism, current theories to explain this phenomenon are diverse and complex and assert often from opposing assumptions. Although widely studied, the molecular genetic control of the temperature–size rule is unknown. We found that the Caenorhabditis elegans wild-type N2 complied with the temperature–size rule, whereas wild-type CB4856 defied it. Using a candidate gene approach based on an N2 × CB4856 recombinant inbred panel in combination with mutant analysis, complementation, and transgenic studies, we show that a single nucleotide polymorphism in tra-3 leads to mutation F96L in the encoded calpain-like protease. This mutation attenuates the ability of CB4856 to grow larger at low temperature. Homology modelling predicts that F96L reduces TRA-3 activity by destabilizing the DII-A domain. The data show that size adaptation of ectotherms to temperature changes may be less complex than previously thought because a subtle wild-type polymorphism modulates the temperature responsiveness of body size. These findings provide a novel step toward the molecular understanding of the temperature–size rule, which has puzzled biologists for decades.