The mouse homeobox gene, S8, is expressed during embryogenesis predominantly in mesenchyme.

The murine S8 gene, originally identified by Kongsuwan et al. [EMBO J. 7(1988)2131-2138] encodes a homeodomain which resembles those of the paired family. We studied the expression pattern during mid-gestation embryogenesis of S8 by in situ hybridization. Expression was detected locally in craniofacial mesenchyme, in the limb, the heart and the somites and sclerotomes all along the axis, and was absent from the central and peripheral nervous system, splanchnopleure, and endodermal derivatives. This pattern differs considerably from that of most previously described homeobox containing genes. By genetic analysis, the gene was located on chromosome 2, about 20 cM from the HOX-4 cluster.     

Genetic and sequence analysis of an 8.7-kilobase Pseudomonas denitrificans fragment carrying eight genes involved in transformation of precorrin-2 to cobyrinic acid.

A 8.7-kilobase DNA fragment carrying Pseudomonas denitrificans cob genes has been sequenced. The nucleotide sequence and the genetic analysis revealed that this fragment carries eight different cob genes (cobF to cobM). Six of these genes have the characteristics of translationally coupled genes. cobI has been identified as S-adenosyl-L-methionine (SAM):precorrin-2 methyltransferase structural gene because the encoded protein has the same NH2 terminus and molecular weight as those of the purified enzyme. From protein homology with CobA and CobI, two SAM-dependent methyltransferases of the cobalamin pathway, it is proposed that cobF, cobJ, cobL, and cobM code for other methyltransferases involved in the cobalamin pathway. In addition, purified CobF protein has affinity for SAM, as expected for a SAM-dependent methyltransferase. Accumulation of cobalamin precursors in Agrobacterium tumefaciens mutants complemented by any of these eight genes suggest that, apart from cobI, whose function is identified, the products of all these genes are implicated in the conversion of precorrin-3 into cobyrinic acid.     

Assay and purification of S-adenosyl-L-methionine:precorrin-2 methyltransferase from Pseudomonas denitrificans.

S-Adenosyl-L-methionine:precorrin-2 methyltransferase (SP2MT), which catalyzes the C-20 methylation of precorrin-2 to precorrin-3, was purified to homogeneity from extracts of a recombinant strain of Pseudomonas denitrificans derived from a cobalamin-overproducing strain. Ammonium sulfate fractionation followed by chromatography on DEAE-Trisacryl, hydroxyapatite, and Mono Q HR purified the enzyme about 110-fold, with a 28% yield. For enzyme purification and characterization, a coupled-enzyme assay was developed which generated in situ the highly oxygen-sensitive substrate, precorrin-2, from delta-aminolevulinic acid. Evidence is given that the chemically reduced form of sirohydrochlorin (dihydrosirohydrochlorin) is methylated at C-20 to precorrin-3 by pure SP2MT. No subsequent SP2MT-dependent methylation reaction of precorrin-3 was detected. The native enzyme has an apparent molecular weight of 53,000, as estimated by gel filtration, and consists of two identical subunits of Mr 26,000, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Stepwise Edman degradation provided the N-terminal sequence of the first 17 amino acids.     

Largest reported groups for the Indo‐Pacific bottlenose dolphin (Tursiops aduncus) found in Algoa Bay,South Africa: Trends and potential drivers

This study investigates how group size of Indo‐Pacific bottlenose dolphins (Tursiops aduncus) changes temporally, spatially, and/or with predominant behavior at two discreet sites along the Eastern Cape coastline of South Africa: Algoa Bay and the Wild Coast. The mean group size of bottlenose dolphins was large with an average of 52 animals. Significantly larger groups were observed in Algoa Bay ( = 60, range = 1–600) than off the Wild Coast ( = 32.9, range = 1–250). In Algoa Bay, the mean group size increased significantly over the study period, from an average 18 animals in 2008 to 76 animals in 2016. Additionally, the largest average and maximum group sizes ever reported both in South Africa and worldwide, were recorded in Algoa Bay (maximum group size = 600). Neither season nor behavior had a significant effect on mean group size at both sites. Similarly environmental variables such as the depth and substrate type also had no influence on group size. It remains unclear which ecological drivers, such as predation risk and food availability, are leading to the large groups observed in this area, and further research on abundance and distribution of both predators and prey is necessary.     

Small-scale experiments aimed at optimization of large-scale production of the microalga <Emphasis Type="Italic">Rhodomonas salina</Emphasis>

The cryptophyte Rhodomonas is an important feed item for live feed organisms in aquaculture and although large-scale cultivation of Rhodomonas in photobioreactors (PBRs) is feasible, the production needs to be optimized through further studies of specific factors. Through small-scale experiments, several factors relevant for an on-going large-scale production of Rhodomonas were studied and the results presented here provide a useful insight on factors that can help future large-scale production. The content of polyunsaturated fatty acids (PUFAs) and the temporal sedimentation was compared in five strains of Rhodomonas. Strain K-1487 (R. salina) was chosen as the most suitable for cultivation in PBRs due to a good biochemical content of PUFAs and low cell sedimentation. The f/2 growth medium used for cultivation was modified by excluding CoCl₂ which did not affect either growth rate or cell content of the PUFAs, DHA, EPA, and ARA. Furthermore, the growth medium was modified by adding the nitrogen source as ammonium (NH₄⁺), nitrate (NO₃^?), urea, or combinations of these, with NH₄⁺ yielding a significantly higher growth rate of 1.30?±?0.07 day^?1. The seawater used for cultivation was exposed to three types of treatments which gave no significant difference in the growth rate: (1) filtration (0.2 μm)?+?autoclaving, (2) filtration (0.2 μm)?+?UV-radiation, and (3) filtration (0.2 μm). Finally, the results for growth rates of inocula at initial densities ranging from 2000 to 200,000 cells mL^?1 showed that growth rate decreased with increasing density but a final density of 10⁶ cells mL^?1 was obtained fastest with the highest initial density. With the present findings, several barriers for effective cultivation of Rhodomonas are solved and future large-scale production has become a great step closer.     

mvmapper: Interactive spatial mapping of genetic structures

Characterizing genetic structure across geographic space is a fundamental challenge in population genetics. Multivariate statistical analyses are powerful tools for summarizing genetic variability, but geographic information and accompanying metadata are not always easily integrated into these methods in a user‐friendly fashion. Here, we present a deployable Python‐based web‐tool, mvmapper , for visualizing and exploring results of multivariate analyses in geographic space. This tool can be used to map results of virtually any multivariate analysis of georeferenced data, and routines for exporting results from a number of standard methods have been integrated in the R package adegenet , including principal components analysis (PCA), spatial PCA, discriminant analysis of principal components, principal coordinates analysis, nonmetric dimensional scaling and correspondence analysis. mvmapper 's greatest strength is facilitating dynamic and interactive exploration of the statistical and geographic frameworks side by side, a task that is difficult and time‐consuming with currently available tools. Source code and deployment instructions, as well as a link to a hosted instance of mvmapper , can be found at https://popphylotools.github.io/mvMapper/ .     

Evidence of a non-MHC susceptibility locus in type I diabetes linked to HLA on chromosome 6.

Linkage studies have led to the identification of several chromosome regions that may contain susceptibility loci to type I diabetes (IDDM), in addition to the HLA and INS loci. These include two on chromosome 6q, denoted IDDM5 and IDDM8, that are not linked to HLA. In a previous study, we noticed that the evidence for linkage to IDDM susceptibility around the HLA locus extended over a total distance of 100 cM, which suggested to us that another susceptibility locus could reside near HLA. We developed a statistical method to test this hypothesis in a panel of 523 multiplex families from France, the United States, and Denmark (a total of 667 affected sib pairs, 536 with both parents genotyped), and here present evidence (P = .00003) of a susceptibility locus for IDDM located 32 cM from HLA in males but not linked to HLA in females and distinct from IDDM5 and IDDM8. A new statistical method to test for the presence of a second susceptibility locus linked to a known first susceptibility locus (here HLA) is presented. In addition, we analyzed our current family panel with markers for IDDM5 and IDDM8 on chromosome 6 and found suggestions of linkage for both of these loci (P = .002 and .004, respectively, on the complete family panel). When cumulated with previously published results, with overlapping families removed, the affected-sib-pair tests had a significance of P = .0001 for IDDM5 and P = .00004 for IDDM8.     

Two forms of elongation factor 1 alpha (EF-1 alpha O and 42Sp50), present in oocytes, but absent in somatic cells of Xenopus laevis

We have purified and partially sequenced the EF-1 alpha protein from Xenopus laevis oocytes (EF-1 alpha O). We show that the two cDNA clones isolated by Coppared et al. (Coppard, N. J., K. Poulsen, H. O. Madsen, J. Frydenberg, and B. F. C. Clark. 1991. J. Cell Biol. 112:237-243) do not encode 42Sp50, as claimed by these authors, but two very similar forms of EF-1 alpha O (EF-1 alpha O and EF-1 alpha O1). 42Sp50 is the major protein component of a 42S nucleoprotein particle that is very abundant in previtellogenic oocytes of X. laevis, 42Sp50 differs from EF-1 alpha O not only by its amino acid sequence, but also by several properties already reported. In particular, 42Sp50 has a low EF-1 alpha activity. It is distributed uniformly in the cytoplasm of previtellogenic oocytes, in contrast to EF-1 alpha O which is concentrated in a small region of the cytoplasm, known as the mitochondrial mass or Balbiani body.