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Computer-assisted species recognition facilitates the analysis of relevant biological information in continuous audio recordings. In the present study, we assess the suitability of this approach for determining distinct life-cycle phases of the Southern Lapwing Vanellus chilensis lampronotus based on adult vocal activity. For this purpose we use passive 14-min and 30-min soundscape recordings (n = 33 201) collected in 24/7 mode between November 2012 and October 2013 in Brazil’s Pantanal wetlands. Time-stamped detections of V. chilensis call events (n = 62 292) were obtained with a species-specific sound recognizer. We demonstrate that the breeding season fell in a three-month period from mid-May to early August 2013, between the end of the flood cycle and the height of the dry season. Several phases of the lapwing’s life history were identified with presumed error margins of a few days: pre-breeding, territory establishment and egg-laying, incubation, hatching, parental defense of chicks, and post-breeding. Diurnal time budgets confirm high acoustic activity levels during midday hours in June and July, indicative of adults defending young. By August, activity patterns had reverted to nonbreeding mode, with peaks around dawn and dusk and low call frequency during midday heat. We assess the current technological limitations of the V. chilensis recognizer through a comprehensive performance assessment and scrutinize the usefulness of automated acoustic recognizers in studies on the distribution pattern, ecology, life history, and conservation status of sound-producing animal species.

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The sequence of the tufA gene from the extreme thermophilic eubacterium Thermus aquaticus EP 00276 was determined. The GC content in third positions of codons is 89.5%, with an unusual predominance of guanosine (60.7%). The derived protein sequence differs from tufA‐ and tufB‐encoded sequences for elongation factor Tu (EF‐Tu) of Thermus thermophilus HB8, another member of the genus Thermus, in 10 of the 405 amino acid residues. Three exchanges are located in the additional loop of ten amino acids (182–191). The loop, probably involved in nucleotide binding, is absent in EF‐Tu of the mesophile Escherichia coli. Since EF‐Tu from E. coli is quite unstable, the protein is well‐suited for analyzing molecular changes that lead to thermostabilization. Comparison of the EF‐Tu domain I from E. coli and Thermus strains revealed clustered amino acid exchanges in the C‐terminal part of the first helix and in adjacent residues of the second loop inferred to interact with the ribosome. Most other exchanges in the guanine nucleotide binding domain are located in loops or nearest vicinity of loops suggesting their importance for thermostability. The T. aquaticus EF‐Tu was overproduced in E. coli using the tac expression system. Identity of the recombinant T. aquaticus EF‐Tu was verified by Western blot analysis, N‐terminal sequencing and GDP binding assays.

The gene region of Thermus aquaticus corresponding to the distal portion of the S10 operon and to the 5'-portion of the Escherichia coli spc operon was cloned, using the E. coli gene for the ribosomal protein L5 as hybridization probe. The gene arrangement was found to be identical to E. coli, i.e. S17, L14, L24, L5, S14, S8 and L6. Stop and start regions of contiguous cistrons overlap, except for the S 1 4 -S intergenic region, whose size (67 bases) even exceeds the corresponding spacer regions in E. coli and Bacillus subtilis. A G + C content of 94% in third positions of codons was found in the ribosomal protein genes of T. aquaticus analyzed here. The stop codon of gene S17 (the last gene of the S10 operon in E. coli) and the start codon of gene L14 (the first gene of the spc operon in E. coli) overlap in T. aquaticus, thus leaving no space to accomodate an intergenic promoter preceding spc-operon-encoded genes in T. aquaticus. A possible promoter, localized within the S17 coding region, yielded only weak resistance (20 pg/ml) to chloramphenicol in E. coli and therefore could be largely excluded as the main promoter for spc-operon-encoded genes. We failed to detect a structure resembling the protein S8 translational repressor site, located at the beginning of the L5 gene in E. coli, in the corresponding region or any other region in the cloned T. aquaticus spc DNA.Organization and regulation of the synthesis of ribosomal protein genes have been almost exclusively studied in Escherichia coli. Mechanisms that account for the balanced synthesis of ribosomal proteins were found to be operative on the transcriptional and post-transcriptional level in E. coli Transcription of spc-operon-encoded proteins in E. coli is initiated at a promoter located in the 163-bp spacer region between the last gene (S17) of the S10 ribosomal protein operon and the first gene (L14) of the spc operon [3, 10, 111. Nevertheless, a certain readthrough of S10 operon transcription into the spc operon has been observed [12]. The sequence of genes in the E. coli spc operon is L14, L24, L5, S14, S8, L6, L18, S 5 , L30, L15, secY and rpmJ [lo, 13, 141 [l-91.followed by 3'+ 5'-exonucleolytic degradation of spc mRNA thereby inhibiting also L14 and L24 (and L5) synthesis [3].So far, little is known about organization and expression of ribosomal protein genes in prokaryotes more distantly related to E. coli. Recently, the sequence of the 5'-portion of the spc operon from Bacillus subtilis was reported [12] which showed an identical arrangement of genes relative to E. coli.In this communication, we report the analysis of a chromosomal segment from T. aquaticus that corresponds to the 3'-portion of the S10 operon and to the 5'-part of the spc operon in E. coli. Since extreme thermophilic bacteria of the genus Thermus represent a relatively deep branch in the eubacterial line of descent [17, 181, our studies will contribute to a better assessment of how ubiquitous or unique organization and mechanisms of ribosomal protein expression found in E. coli ...

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